tinyfilemanager.php

<?php
//Default Configuration
$CONFIG = '{"lang":"sk","error_reporting":false,"show_hidden":false,"hide_Cols":false,"theme":"light"}';

/**
 * DREMONT ~ správca súborov 
 * @author CCP Programmers & PIAR team
  * @github https://github.com/prasathmani/tinyfilemanager
 * @link https://tinyfilemanager.github.io
 */

// TFM version
$tfmVersion = '2.11.04';
$releaseVersionPath = __DIR__ . '/RELEASE_VERSION';
if (@is_file($releaseVersionPath) && @is_readable($releaseVersionPath)) {
    $releaseVersion = trim((string) @file_get_contents($releaseVersionPath));
    if ($releaseVersion !== '' && preg_match('/^[0-9]+\.[0-9]+\.[0-9]+$/', $releaseVersion)) {
        $tfmVersion = $releaseVersion;
    }
}
define('VERSION', $tfmVersion);

//Application Title
define('APP_TITLE', 'Správca súborov');
define('LOGIN_COMPANY_NAME', 'Dremont s.r.o. PIAR & team');
define('LOGIN_COMPANY_URL', 'https://dremont.in');
define('LOGIN_LOGO_PATH', 'KatalogMD.webp');

// --- EDIT BELOW CONFIGURATION CAREFULLY ---

// Auth with login/password
// set true/false to enable/disable it
// Is independent from IP white- and blacklisting
$use_auth = true;

// Machine/API login by URL token.
// Set token in local config.php to allow automated login as a managed Joyee user.
// Keep empty to disable.
$machine_login_token = '';

// Target username for machine/API login. Must exist in $auth_users.
$machine_login_user = 'joyee';

// Login user name and password
// Users: array('Username' => 'Password', 'Username2' => 'Password2', ...)
// Generate secure password hash - https://tinyfilemanager.github.io/docs/pwd.html
// NOTE: All users, roles and directories are managed in config.php.
//       These defaults are only used if config.php is missing.
$auth_users = array();

// Readonly users (download/view only – no write access at all)
$readonly_users = array();

// Upload-only users (upload + download, cannot delete/rename/move/copy/edit)
$upload_only_users = array();

// Manager users (full access except delete)
$manager_users = array();

// Users for whom the bulk action bar should be hidden.
// Default behavior: enabled for all authenticated users.
$bulk_actions_disabled_users = array();

// Per-user welcome message template shown automatically on first login (non-admin only).
// Supported placeholders: {username}, {{username}}, %username%, :username
$user_welcome_messages = array();

// Users who have already received their first-login welcome message.
$welcome_message_shown_users = array();

// Global readonly, including when auth is not being used
$global_readonly = false;

// User-specific directories (leave empty – managed in config.php)
// array('Username' => 'Directory path', 'Username2' => array('Dir1', 'Dir2'), ...)
$directories_users = array();

// Ownership map for user administration and chat scoping.
// Format: array('username' => 'manager_username|admin')
$user_manager_owners = array();

// Shared home root for regular users (relative to $root_path or absolute path).
// This is the UI/Navigation "Home" boundary for non-admin users.
$user_home_root = '';

// Enable highlight.js (https://highlightjs.org/) on view's page
$use_highlightjs = true;

// highlight.js style
// for dark theme use 'ir-black'
$highlightjs_style = 'vs';

// Enable ace.js (https://ace.c9.io/) on view's page
$edit_files = true;

// Default timezone for date() and time()
// Doc - http://php.net/manual/en/timezones.php
$default_timezone = 'Etc/UTC'; // UTC

// Root path for file manager
// use absolute path of directory i.e: '/var/www/folder' or $_SERVER['DOCUMENT_ROOT'].'/folder'
//make sure update $root_url in next section
$root_path = $_SERVER['DOCUMENT_ROOT'];

// Root url for links in file manager.Relative to $http_host. Variants: '', 'path/to/subfolder'
// Will not working if $root_path will be outside of server document root
$root_url = '';

// Server hostname. Can set manually if wrong
// $_SERVER['HTTP_HOST'].'/folder'
$http_host = $_SERVER['HTTP_HOST'];

// input encoding for iconv
$iconv_input_encoding = 'UTF-8';

// date() format for file modification date
// Doc - https://www.php.net/manual/en/function.date.php
$datetime_format = 'm/d/Y g:i A';

// Path display mode when viewing file information
// 'full' => show full path
// 'relative' => show path relative to root_path
// 'host' => show path on the host
$path_display_mode = 'full';

// Allowed file extensions for create and rename files
// e.g. 'txt,html,css,js'
$allowed_file_extensions = '';

// Allowed file extensions for upload files
// e.g. 'gif,png,jpg,html,txt'
$allowed_upload_extensions = '';

// Favicon path. This can be either a full url to an .PNG image, or a path based on the document root.
// full path, e.g http://example.com/favicon.png
// local path, e.g images/icons/favicon.png
$favicon_path = 'https://dremont.sk/wp-content/uploads/2022/09/logo-MA-DREMONTnew.png';

// Files and folders to excluded from listing
// e.g. array('myfile.html', 'personal-folder', '*.php', '/path/to/folder', ...)
$exclude_items = array();

// Online office Docs Viewer
// Available rules are 'google', 'microsoft' or false
// Google => View documents using Google Docs Viewer
// Microsoft => View documents using Microsoft Web Apps Viewer
// false => disable online doc viewer
$online_viewer = 'google';

// DOCX preview mode for built-in viewer.
// auto      => use Microsoft viewer (most reliable default)
// local     => force local docx-preview only
// microsoft => force Microsoft viewer iframe
$docx_preview_mode = 'auto';

// Sticky Nav bar
// true => enable sticky header
// false => disable sticky header
$sticky_navbar = true;

// Maximum file upload size
// Increase the following values in php.ini to work properly
// memory_limit, upload_max_filesize, post_max_size
$max_upload_size_bytes = 5000000000; // size 5,000,000,000 bytes (~5GB)

// chunk size used for upload
// eg. decrease to 1MB if nginx reports problem 413 entity too large
$upload_chunk_size_bytes = 2000000; // chunk size 2,000,000 bytes (~2MB)

// Possible rules are 'OFF', 'AND' or 'OR'
// OFF => Don't check connection IP, defaults to OFF
// AND => Connection must be on the whitelist, and not on the blacklist
// OR => Connection must be on the whitelist, or not on the blacklist
$ip_ruleset = 'OFF';

// Should users be notified of their block?
$ip_silent = true;

// IP-addresses, both ipv4 and ipv6
$ip_whitelist = array(
    '127.0.0.1',    // local ipv4
    '::1'           // local ipv6
);

// IP-addresses, both ipv4 and ipv6
$ip_blacklist = array(
    '0.0.0.0',      // non-routable meta ipv4
    '::'            // non-routable meta ipv6
);

// if User has the external config file, try to use it to override the default config above [config.php]
// sample config - https://tinyfilemanager.github.io/config-sample.txt
$config_file = __DIR__ . '/config.php';
if (is_readable($config_file)) {
    @include($config_file);
}

// Load security layer
$security_file = __DIR__ . '/src/security.php';
if (is_readable($security_file)) {
    @include($security_file);
} else {
    // Fallback: create minimal security functions if security.php missing
    function fm_validate_magic_bytes($f, $e) { return true; }
    function fm_validate_mime_type($f, $t=[]) { return true; }
    function fm_validate_filepath($p, $r) { return true; }
    function fm_validate_input($i, $t='filename') { return $i; }
}

// Modular handlers (incremental extraction from monolith)
require_once __DIR__ . '/src/ArchiveHelpers.php';
require_once __DIR__ . '/src/BootstrapHelpers.php';
require_once __DIR__ . '/src/FM_Config.php';
require_once __DIR__ . '/src/ConfigStore.php';
require_once __DIR__ . '/src/PathHelpers.php';
require_once __DIR__ . '/src/RuntimeErrorHelpers.php';
require_once __DIR__ . '/src/TemplateHelpers.php';
require_once __DIR__ . '/src/TranslationHelpers.php';
require_once __DIR__ . '/src/handlers/ArchiveActionHandler.php';
require_once __DIR__ . '/src/handlers/AjaxActionHandler.php';
require_once __DIR__ . '/src/handlers/CopyActionHandler.php';
require_once __DIR__ . '/src/handlers/DownloadPreviewHandler.php';
require_once __DIR__ . '/src/handlers/FileActionHandler.php';
require_once __DIR__ . '/src/handlers/LegacyUploadHandler.php';
require_once __DIR__ . '/src/services/DirectoryListingService.php';
require_once __DIR__ . '/src/services/ChmodPageContextService.php';
require_once __DIR__ . '/src/services/FileEditorContextService.php';
require_once __DIR__ . '/src/services/FileViewContextService.php';
require_once __DIR__ . '/src/services/FileViewInfoService.php';

if (function_exists('fm_config_store_apply_scope_to_globals')) {
    fm_config_store_apply_scope_to_globals('runtime_config', 'global', fm_config_store_runtime_keys());
}

// External CDN resources that can be used in the HTML (replace for GDPR compliance)
$external = array(
    'css-bootstrap' => '<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YctnYmDr5pNlyT2bRjXh0JMhjY6hW+ALEwIH" crossorigin="anonymous">',
    'css-dropzone' => '<link href="https://cdnjs.cloudflare.com/ajax/libs/dropzone/5.9.3/min/dropzone.min.css" rel="stylesheet">',
    'css-font-awesome' => '<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" crossorigin="anonymous">',
    'css-highlightjs' => '<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/' . $highlightjs_style . '.min.css">',
    'js-ace' => '<script src="https://cdnjs.cloudflare.com/ajax/libs/ace/1.32.2/ace.js"></script>',
    'js-bootstrap' => '<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-YvpcrYf0tY3lHB60NNkmXc5s9fDVZLESaAA55NDzOxhy9GkcIdslK1eN7N6jIeHz" crossorigin="anonymous"></script>',
    'js-dropzone' => '<script src="https://cdnjs.cloudflare.com/ajax/libs/dropzone/5.9.3/min/dropzone.min.js"></script>',
    'js-jquery' => '<script src="https://code.jquery.com/jquery-3.6.1.min.js" integrity="sha256-o88AwQnZB+VDvE9tvIXrMQaPlFFSUTR+nldQm1LuPXQ=" crossorigin="anonymous"></script>',
    'js-jquery-datatables' => '<script src="https://cdn.datatables.net/1.13.1/js/jquery.dataTables.min.js" crossorigin="anonymous" defer></script>',
    'js-highlightjs' => '<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js"></script>',
    'pre-jsdelivr' => '<link rel="preconnect" href="https://cdn.jsdelivr.net" crossorigin/><link rel="dns-prefetch" href="https://cdn.jsdelivr.net"/>',
    'pre-cloudflare' => '<link rel="preconnect" href="https://cdnjs.cloudflare.com" crossorigin/><link rel="dns-prefetch" href="https://cdnjs.cloudflare.com"/>'
);

// --- EDIT BELOW CAREFULLY OR DO NOT EDIT AT ALL ---

// max upload file size
define('MAX_UPLOAD_SIZE', $max_upload_size_bytes);

// upload chunk size
define('UPLOAD_CHUNK_SIZE', $upload_chunk_size_bytes);

// private key and session name to store to the session
if (!defined('FM_SESSION_ID')) {
    define('FM_SESSION_ID', 'filemanager');
}

// Start session early so FM_Config can read the logged-in user and load per-user settings.
if (!defined('FM_EMBED')) {
    @set_time_limit(600);
    date_default_timezone_set($default_timezone);
    ini_set('default_charset', 'UTF-8');
    if (version_compare(PHP_VERSION, '5.6.0', '<') && function_exists('mb_internal_encoding')) {
        mb_internal_encoding('UTF-8');
    }
    if (function_exists('mb_regex_encoding')) {
        mb_regex_encoding('UTF-8');
    }
    session_cache_limiter('nocache');
    session_name(FM_SESSION_ID);
    set_error_handler('session_error_handling_function');
    session_start();
    restore_error_handler();
}

// Configuration – loads global defaults, then overrides with per-user settings if logged in.
$cfg = new FM_Config();

// Default language
$lang = isset($cfg->data['lang']) ? $cfg->data['lang'] : 'en';

// Show or hide files and folders that starts with a dot
$show_hidden_files = isset($cfg->data['show_hidden']) ? $cfg->data['show_hidden'] : true;

// PHP error reporting - false = Turns off Errors, true = Turns on Errors
$report_errors = isset($cfg->data['error_reporting']) ? $cfg->data['error_reporting'] : true;

// Hide Permissions and Owner cols in file-listing
$hide_Cols = isset($cfg->data['hide_Cols']) ? $cfg->data['hide_Cols'] : true;

// Theme
$theme = isset($cfg->data['theme']) ? $cfg->data['theme'] : 'light';

// List density mode for file table rows.
$list_density = isset($cfg->data['list_density']) ? strtolower((string) $cfg->data['list_density']) : 'compact';
if ($list_density !== 'normal' && $list_density !== 'compact') {
    $list_density = 'compact';
}

define('FM_THEME', $theme);

//available languages
$lang_list = array(
    'en' => 'English',
    'sk' => 'Slovensky'
);

if ($report_errors == true) {
    @ini_set('error_reporting', E_ALL);
    @ini_set('display_errors', 1);
} else {
    @ini_set('error_reporting', E_ALL);
    @ini_set('display_errors', 0);
}

// if fm included
if (defined('FM_EMBED')) {
    $use_auth = false;
    $sticky_navbar = false;
}

//Generating CSRF Token
if (empty($_SESSION['token'])) {
    if (function_exists('random_bytes')) {
        $_SESSION['token'] = bin2hex(random_bytes(32));
    } else {
        $_SESSION['token'] = bin2hex(openssl_random_pseudo_bytes(32));
    }
}

if (empty($auth_users)) {
    $use_auth = false;
}

// Optional machine/API login via URL token.
// Creates the same PHP session as regular login and then redirects without token in URL.
if ($use_auth && isset($_GET['machine_token'])) {
    $provided_machine_token = trim((string) $_GET['machine_token']);
    $machine_login_valid = false;

    if ($provided_machine_token !== '' && $machine_login_token !== '' && isset($auth_users[$machine_login_user])) {
        if (function_exists('hash_equals')) {
            $machine_login_valid = hash_equals((string) $machine_login_token, $provided_machine_token);
        } else {
            $machine_login_valid = ((string) $machine_login_token === $provided_machine_token);
        }
    }

    if ($machine_login_valid) {
        if (isset($_SESSION[FM_SESSION_ID]['logged']) && $_SESSION[FM_SESSION_ID]['logged'] !== $machine_login_user) {
            fm_online_remove_user($_SESSION[FM_SESSION_ID]['logged']);
        }
        $_SESSION[FM_SESSION_ID]['logged'] = $machine_login_user;
        fm_online_touch_user($machine_login_user);

        if (class_exists('AuditLogger')) {
            $audit = new AuditLogger();
            $audit->log('user_login_machine_token', $machine_login_user, 'Machine/API token login');
        }

        $target_path = isset($_GET['p']) ? fm_clean_path((string) $_GET['p']) : '';
        fm_set_msg(lng('You are logged in'));
        fm_redirect('?p=' . urlencode($target_path));
    }

    if (class_exists('AuditLogger')) {
        $audit = new AuditLogger();
        $audit->log('login_failed_machine_token', $machine_login_user, 'Invalid machine/API login token');
    }

    fm_set_msg('Machine login failed.', 'error');
    fm_redirect('?p=' . urlencode(isset($_GET['p']) ? fm_clean_path((string) $_GET['p']) : ''));
}

$forwarded_proto = '';
if (!empty($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
    $forwarded_proto_parts = explode(',', (string) $_SERVER['HTTP_X_FORWARDED_PROTO']);
    $forwarded_proto = strtolower(trim($forwarded_proto_parts[0]));
}

$forwarded_ssl_on = !empty($_SERVER['HTTP_X_FORWARDED_SSL']) && strtolower((string) $_SERVER['HTTP_X_FORWARDED_SSL']) === 'on';
$front_end_https_on = !empty($_SERVER['HTTP_FRONT_END_HTTPS']) && strtolower((string) $_SERVER['HTTP_FRONT_END_HTTPS']) !== 'off';
$request_scheme_https = !empty($_SERVER['REQUEST_SCHEME']) && strtolower((string) $_SERVER['REQUEST_SCHEME']) === 'https';

$is_https = (isset($_SERVER['HTTPS']) && (strtolower((string) $_SERVER['HTTPS']) === 'on' || (string) $_SERVER['HTTPS'] === '1'))
    || $forwarded_proto === 'https'
    || $forwarded_ssl_on
    || $front_end_https_on
    || $request_scheme_https;

if (!empty($_SERVER['HTTP_X_FORWARDED_HOST'])) {
    $forwarded_host_parts = explode(',', (string) $_SERVER['HTTP_X_FORWARDED_HOST']);
    $http_host = trim($forwarded_host_parts[0]);
} elseif (!empty($_SERVER['HTTP_HOST'])) {
    $http_host = (string) $_SERVER['HTTP_HOST'];
}

$fm_user_allowed_dirs = array();

// If root_url is empty and root_path is inside web document root, derive it automatically.
if ((string) $root_url === '' && !empty($_SERVER['DOCUMENT_ROOT']) && !empty($root_path)) {
    $doc_root_norm = rtrim(str_replace('\\', '/', (string) $_SERVER['DOCUMENT_ROOT']), '/');
    $root_path_norm = rtrim(str_replace('\\', '/', (string) $root_path), '/');
    if ($doc_root_norm !== '' && strpos($root_path_norm . '/', $doc_root_norm . '/') === 0) {
        $derived_root_url = ltrim(substr($root_path_norm, strlen($doc_root_norm)), '/');
        if ($derived_root_url !== '') {
            $root_url = $derived_root_url;
        }
    }
}

// clean $root_url
$root_url = fm_clean_path($root_url);

// abs path for site
defined('FM_ROOT_URL') || define('FM_ROOT_URL', ($is_https ? 'https' : 'http') . '://' . $http_host . (!empty($root_url) ? '/' . $root_url : ''));
$fm_self_path = isset($_SERVER['SCRIPT_NAME']) ? (string) $_SERVER['SCRIPT_NAME'] : '';
if ($fm_self_path === '') {
    $fm_self_path = isset($_SERVER['PHP_SELF']) ? (string) $_SERVER['PHP_SELF'] : '';
}
// Some servers include PATH_INFO in PHP_SELF; keep only script path ending with .php.
if (preg_match('#^(.+?\.php)(?:/.*)?$#i', $fm_self_path, $fm_self_match)) {
    $fm_self_path = $fm_self_match[1];
}
if ($fm_self_path === '') {
    $fm_self_path = '/tinyfilemanager.php';
}

defined('FM_SELF_PATH') || define('FM_SELF_PATH', $fm_self_path);
defined('FM_SELF_URL') || define('FM_SELF_URL', ($is_https ? 'https' : 'http') . '://' . $http_host . FM_SELF_PATH);
$fm_self_dir = dirname(FM_SELF_PATH);
if ($fm_self_dir === '\\' || $fm_self_dir === '.' || $fm_self_dir === '') {
    $fm_self_dir = '/';
}
$fm_self_dir = rtrim(str_replace('\\', '/', $fm_self_dir), '/');
if ($fm_self_dir === '') {
    $fm_self_dir = '/';
}
defined('FM_SELF_DIR') || define('FM_SELF_DIR', $fm_self_dir);
defined('FM_SELF_DIR_URL') || define(
    'FM_SELF_DIR_URL',
    ($is_https ? 'https' : 'http') . '://' . $http_host . (FM_SELF_DIR === '/' ? '/' : FM_SELF_DIR . '/')
);

if (isset($_GET['sw'])) {
    $cache_name = 'tfm-shell-v' . preg_replace('/[^a-zA-Z0-9_.-]/', '-', (string) VERSION);
    $shell_urls = array(
        FM_SELF_URL . '?p=',
        FM_SELF_URL . '?manifest=1',
    );

    $icon_source = LOGIN_LOGO_PATH ? LOGIN_LOGO_PATH : $favicon_path;
    if (!empty($icon_source) && !preg_match('#^https?://#i', (string) $icon_source)) {
        $shell_urls[] = FM_ROOT_URL . '/' . ltrim((string) $icon_source, '/');
    }

    $shell_urls = array_values(array_unique($shell_urls));

    header('Content-Type: application/javascript; charset=utf-8');
    header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
    echo "'use strict';\n";
    echo 'const FM_CACHE_NAME = ' . json_encode($cache_name, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . ";\n";
    echo 'const FM_SHELL_URLS = ' . json_encode($shell_urls, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . ";\n";
    echo "self.addEventListener('install', (event) => {\n";
    echo "  event.waitUntil(caches.open(FM_CACHE_NAME).then((cache) => cache.addAll(FM_SHELL_URLS)).then(() => self.skipWaiting()));\n";
    echo "});\n";
    echo "self.addEventListener('activate', (event) => {\n";
    echo "  event.waitUntil(caches.keys().then((keys) => Promise.all(keys.filter((key) => key !== FM_CACHE_NAME).map((key) => caches.delete(key)))).then(() => self.clients.claim()));\n";
    echo "});\n";
    echo "self.addEventListener('fetch', (event) => {\n";
    echo "  if (event.request.method !== 'GET') {\n";
    echo "    return;\n";
    echo "  }\n";
    echo "  const requestUrl = new URL(event.request.url);\n";
    echo "  if (requestUrl.origin !== self.location.origin) {\n";
    echo "    return;\n";
    echo "  }\n";
    echo "  if (event.request.mode === 'navigate') {\n";
    echo "    event.respondWith(fetch(event.request).catch(() => caches.match(FM_SHELL_URLS[0])));\n";
    echo "    return;\n";
    echo "  }\n";
    echo "  if (FM_SHELL_URLS.includes(requestUrl.href)) {\n";
    echo "    event.respondWith(caches.match(event.request).then((cached) => cached || fetch(event.request)));\n";
    echo "  }\n";
    echo "});\n";
    exit;
}

// Lightweight PWA manifest endpoint
if (isset($_GET['manifest'])) {
    $icon_source = LOGIN_LOGO_PATH ? LOGIN_LOGO_PATH : $favicon_path;
    $icon_url = '';
    if (!empty($icon_source)) {
        if (preg_match('#^https?://#i', $icon_source)) {
            $icon_url = $icon_source;
        } else {
            $icon_url = FM_ROOT_URL . '/' . ltrim($icon_source, '/');
        }
    }

    $icon_type = 'image/png';
    $icon_ext = strtolower(pathinfo($icon_source, PATHINFO_EXTENSION));
    if ($icon_ext === 'webp') {
        $icon_type = 'image/webp';
    } elseif ($icon_ext === 'svg') {
        $icon_type = 'image/svg+xml';
    } elseif ($icon_ext === 'jpg' || $icon_ext === 'jpeg') {
        $icon_type = 'image/jpeg';
    } elseif ($icon_ext === 'avif') {
        $icon_type = 'image/avif';
    }

    $manifest = array(
        'name' => APP_TITLE,
        'short_name' => 'TFM',
        'start_url' => FM_SELF_URL . '?p=',
        'scope' => FM_SELF_DIR_URL,
        'display' => 'standalone',
        'orientation' => 'portrait',
        'background_color' => '#f7f7f7',
        'theme_color' => '#1f6feb',
        'icons' => array(),
    );

    if (!empty($icon_url)) {
        $manifest['icons'][] = array(
            'src' => $icon_url,
            'sizes' => '192x192',
            'type' => $icon_type,
            'purpose' => 'any'
        );
        $manifest['icons'][] = array(
            'src' => $icon_url,
            'sizes' => '512x512',
            'type' => $icon_type,
            'purpose' => 'any'
        );
    }

    header('Content-Type: application/manifest+json; charset=utf-8');
    echo json_encode($manifest, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
    exit;
}

// On unexpected runtime failures, fallback to login page instead of exposing errors.
if (!defined('FM_EMBED')) {
    set_exception_handler('fm_unexpected_exception_handler');
    register_shutdown_function('fm_unexpected_shutdown_handler');
}

// logout
if (isset($_GET['logout'])) {
    if ($use_auth && isset($_SESSION[FM_SESSION_ID]['logged'])) {
        fm_online_remove_user($_SESSION[FM_SESSION_ID]['logged']);
        // Audit log logout
        if (class_exists('AuditLogger')) {
            $audit = new AuditLogger();
            $audit->log('user_logout', $_SESSION[FM_SESSION_ID]['logged']);
        }
    }
    // Unset all session variables
    $_SESSION = array();
    // Delete the session cookie to prevent the browser from reusing the session ID
    if (ini_get('session.use_cookies')) {
        $p = session_get_cookie_params();
        setcookie(session_name(), '', time() - 42000,
            $p['path'], $p['domain'],
            $p['secure'], $p['httponly']
        );
    }
    // Destroy the session on the server side
    session_destroy();
    // Prevent browser from serving cached authenticated pages via Back button
    header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
    header('Pragma: no-cache');
    header('Expires: Sat, 26 Jul 1997 05:00:00 GMT');
    fm_redirect(FM_SELF_URL);
}

// Validate connection IP
if ($ip_ruleset != 'OFF') {
    $clientIp = getClientIP();
    $proceed = false;
    $whitelisted = in_array($clientIp, $ip_whitelist);
    $blacklisted = in_array($clientIp, $ip_blacklist);

    if ($ip_ruleset == 'AND') {
        if ($whitelisted == true && $blacklisted == false) {
            $proceed = true;
        }
    } else
    if ($ip_ruleset == 'OR') {
        if ($whitelisted == true || $blacklisted == false) {
            $proceed = true;
        }
    }

    if ($proceed == false) {
        trigger_error('User connection denied from: ' . $clientIp, E_USER_WARNING);

        if ($ip_silent == false) {
            fm_set_msg(lng('Access denied. IP restriction applicable'), 'error');
            fm_show_header_login();
            fm_show_message();
        }
        exit();
    }
}

// Checking if the user is logged in or not. If not, it will show the login form.
$fm_signed_preview_request = isset($_GET['preview'])
    && fm_has_valid_preview_signature(
        $_GET['p'] ?? '',
        $_GET['preview'] ?? '',
        $_GET['exp'] ?? '',
        $_GET['sig'] ?? ''
    );

if ($use_auth) {
    if (isset($_SESSION[FM_SESSION_ID]['logged'], $auth_users[$_SESSION[FM_SESSION_ID]['logged']]) || $fm_signed_preview_request) {
        // Logged. Prevent rendering or processing login form again.
        if (isset($_POST['fm_usr']) || isset($_POST['fm_pwd']) || (isset($_GET['login']) && $_GET['login'] == '1')) {
            fm_redirect(FM_SELF_URL . '?p=' . urlencode(''));
        }
    } elseif (isset($_POST['fm_usr'], $_POST['fm_pwd'], $_POST['token'])) {
        // Logging In - with rate limiting
        $username = isset($_POST['fm_usr']) ? fm_validate_input($_POST['fm_usr'], 'username') : '';
        $password = isset($_POST['fm_pwd']) ? $_POST['fm_pwd'] : '';
        $token = isset($_POST['token']) ? $_POST['token'] : '';
        
        // Rate limiting
        $rate_limiter = null;
        if (class_exists('RateLimiter')) {
            $rate_limiter = new RateLimiter();
            if (!$rate_limiter->check_limit('login')) {
                $audit = new AuditLogger();
                $audit->log('login_blocked_rate_limit', $username, 'Too many attempts');
                fm_set_msg(lng('Too many login attempts. Please try again later.'), 'error');
                fm_redirect(FM_SELF_URL);
            }
        }
        
        sleep(1); // Anti-brute force delay
        
        if (function_exists('password_verify')) {
            if ($username && isset($auth_users[$username]) && password_verify($password, $auth_users[$username]) && verifyToken($token)) {
                // Successful login
                if (isset($_SESSION[FM_SESSION_ID]['logged']) && $_SESSION[FM_SESSION_ID]['logged'] !== $username) {
                    fm_online_remove_user($_SESSION[FM_SESSION_ID]['logged']);
                }
                $_SESSION[FM_SESSION_ID]['logged'] = $username;
                fm_online_touch_user($username);

                $first_login_welcome = fm_maybe_issue_first_login_welcome($username);
                
                // Audit log
                if (class_exists('AuditLogger')) {
                    $audit = new AuditLogger();
                    $audit->log('user_login', $username, 'Successful login');
                }
                
                // Reset rate limiter
                if ($rate_limiter) {
                    $rate_limiter->reset('login');
                }

                // Force one-time redirect to the assigned default user root path.
                $_SESSION[FM_SESSION_ID]['post_login_redirect'] = true;
                
                fm_set_msg($first_login_welcome !== '' ? $first_login_welcome : lng('You are logged in'));
                fm_redirect(FM_SELF_URL);
            } else {
                // Failed login attempt
                $audit = new AuditLogger();
                $audit->log('login_failed', $username ?? 'unknown', 'Invalid username or password');
                
                // Record rate limit attempt
                if ($rate_limiter) {
                    $rate_limiter->record_attempt('login');
                }
                
                if (isset($_SESSION[FM_SESSION_ID]['logged'])) {
                    fm_online_remove_user($_SESSION[FM_SESSION_ID]['logged']);
                }
                unset($_SESSION[FM_SESSION_ID]['logged']);
                fm_set_msg(lng('Login failed. Invalid username or password'), 'error');
                fm_redirect(FM_SELF_URL);
            }
        } else {
            fm_set_msg(lng('password_hash not supported, Upgrade PHP version'), 'error');;
        }
    } else {
        // Form
        if (isset($_SESSION[FM_SESSION_ID]['logged'])) {
            fm_online_remove_user($_SESSION[FM_SESSION_ID]['logged']);
        }
        unset($_SESSION[FM_SESSION_ID]['logged']);
        fm_show_header_login();
?>
        <section class="h-100">
            <div class="container h-100">
                <div class="row justify-content-md-center align-content-center h-100vh">
                    <div class="card-wrapper">
                        <div class="card fat" data-bs-theme="<?php echo FM_THEME; ?>">
                            <div class="card-body">
                                <form class="form-signin" action="" method="post" autocomplete="off">
                                    <div class="mb-3">
                                        <div class="brand">
                                            <img src="<?php echo fm_enc(LOGIN_LOGO_PATH); ?>" alt="<?php echo fm_enc(LOGIN_COMPANY_NAME); ?>">
                                        </div>
                                        <div class="text-center">
                                            <h1 class="card-title"><?php echo APP_TITLE; ?></h1>
                                            <div class="company-subtitle">
                                                <?php echo LOGIN_COMPANY_NAME; ?>
                                            </div>
                                        </div>
                                    </div>
                                    <hr />
                                    <div class="mb-3">
                                        <label for="fm_usr" class="pb-2"><?php echo lng('Username'); ?></label>
                                        <input type="text" class="form-control" id="fm_usr" name="fm_usr" required autofocus>
                                    </div>

                                    <div class="mb-3">
                                        <label for="fm_pwd" class="pb-2"><?php echo lng('Password'); ?></label>
                                        <div class="input-group">
                                            <input type="password" class="form-control" id="fm_pwd" name="fm_pwd" required>
                                            <button type="button" class="btn btn-outline-secondary" id="fm_pwd_toggle" aria-label="<?php echo lng('Show password'); ?>"><?php echo lng('Show'); ?></button>
                                        </div>
                                    </div>

                                    <div class="mb-3">
                                        <?php fm_show_message(); ?>
                                    </div>
                                    <input type="hidden" name="token" value="<?php echo htmlentities($_SESSION['token']); ?>" />
                                    <div class="mb-3">
                                        <button type="submit" class="btn btn-success btn-block w-100 mt-4" role="button">
                                            <?php echo lng('Login'); ?>
                                        </button>
                                        <button type="button" id="fm_install_app_btn" class="btn btn-outline-primary w-100 fm-install-btn hidden" aria-hidden="true">
                                            Pridať aplikáciu do mobilu
                                        </button>
                                        <p id="fm_install_app_help" class="fm-install-help hidden" aria-live="polite"></p>
                                    </div>
                                </form>
                                <script>
                                (function () {
                                    var input = document.getElementById('fm_pwd');
                                    var button = document.getElementById('fm_pwd_toggle');
                                    var installButton = document.getElementById('fm_install_app_btn');
                                    var installHelp = document.getElementById('fm_install_app_help');
                                    var deferredInstallPrompt = null;

                                    function setInstallHelp(message) {
                                        if (!installHelp) {
                                            return;
                                        }

                                        if (message) {
                                            installHelp.textContent = message;
                                            installHelp.classList.remove('hidden');
                                        } else {
                                            installHelp.textContent = '';
                                            installHelp.classList.add('hidden');
                                        }
                                    }

                                    function showInstallButton() {
                                        if (!installButton) {
                                            return;
                                        }

                                        installButton.classList.remove('hidden');
                                        installButton.removeAttribute('aria-hidden');
                                    }

                                    function hideInstallButton() {
                                        if (!installButton) {
                                            return;
                                        }

                                        installButton.classList.add('hidden');
                                        installButton.setAttribute('aria-hidden', 'true');
                                    }

                                    function isIOSDevice() {
                                        return /iphone|ipad|ipod/i.test(window.navigator.userAgent || '');
                                    }

                                    function isSafariBrowser() {
                                        var ua = String(window.navigator.userAgent || '').toLowerCase();
                                        return ua.indexOf('safari') !== -1
                                            && ua.indexOf('chrome') === -1
                                            && ua.indexOf('android') === -1
                                            && ua.indexOf('crios') === -1
                                            && ua.indexOf('fxios') === -1
                                            && ua.indexOf('edgios') === -1;
                                    }

                                    function isStandaloneMode() {
                                        var byDisplayMode = window.matchMedia && window.matchMedia('(display-mode: standalone)').matches;
                                        var byNavigator = typeof window.navigator.standalone === 'boolean' && window.navigator.standalone;
                                        return !!(byDisplayMode || byNavigator);
                                    }

                                    if (!input || !button) {
                                        return;
                                    }

                                    button.addEventListener('click', function () {
                                        var isHidden = input.getAttribute('type') === 'password';
                                        input.setAttribute('type', isHidden ? 'text' : 'password');
                                        button.textContent = isHidden ? '<?php echo addslashes(lng('Hide')); ?>' : '<?php echo addslashes(lng('Show')); ?>';
                                        button.setAttribute('aria-label', isHidden ? '<?php echo addslashes(lng('Hide password')); ?>' : '<?php echo addslashes(lng('Show password')); ?>');
                                        input.focus();
                                    });

                                    window.addEventListener('beforeinstallprompt', function (event) {
                                        event.preventDefault();
                                        deferredInstallPrompt = event;
                                        setInstallHelp('');
                                        showInstallButton();
                                    });

                                    if (installButton) {
                                        installButton.addEventListener('click', function () {
                                            if (deferredInstallPrompt) {
                                                deferredInstallPrompt.prompt();
                                                deferredInstallPrompt.userChoice.then(function () {
                                                    deferredInstallPrompt = null;
                                                }).catch(function () {
                                                    deferredInstallPrompt = null;
                                                });
                                                return;
                                            }

                                            if (isIOSDevice() && isSafariBrowser() && !isStandaloneMode()) {
                                                setInstallHelp('iPhone: v Safari klikni Zdieľať a potom Pridať na plochu.');
                                                showInstallButton();
                                                return;
                                            }

                                            setInstallHelp('Ak sa dialóg nezobrazil, použi menu prehliadača a voľbu Pridať na plochu.');
                                            showInstallButton();
                                        });
                                    }

                                    window.addEventListener('appinstalled', function () {
                                        setInstallHelp('Aplikácia bola pridaná na plochu.');
                                        hideInstallButton();
                                    });

                                    if (isIOSDevice() && isSafariBrowser() && !isStandaloneMode()) {
                                        showInstallButton();
                                    }
                                })();
                                </script>
                            </div>
                        </div>
                        <div class="footer text-center">
                            &mdash;&mdash; &copy;
                            <a href="<?php echo LOGIN_COMPANY_URL; ?>" target="_blank" class="text-decoration-none text-muted" data-version="<?php echo VERSION; ?>"><?php echo LOGIN_COMPANY_NAME; ?></a> &mdash;&mdash;
                            <div class="login-version">
                                <?php echo lng('Version'); ?>: <?php echo htmlspecialchars(fm_get_release_version(), ENT_QUOTES, 'UTF-8'); ?>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        </section>

    <?php
        fm_show_footer_login();
        exit;
    }
}

if ($use_auth && isset($_SESSION[FM_SESSION_ID]['logged'])) {
    fm_online_touch_user($_SESSION[FM_SESSION_ID]['logged']);
}

fm_search_index_register_shutdown_sync();

// clean and check $root_path
$root_path = rtrim($root_path, '\\/');
$root_path = str_replace('\\', '/', $root_path);
if (!@is_dir($root_path)) {
    echo "<h1>" . lng('Root path') . " \"{$root_path}\" " . lng('not found!') . " </h1>";
    exit;
}

$fm_user_home_root = '';
if (isset($user_home_root) && is_string($user_home_root) && trim($user_home_root) !== '') {
    $home_candidate = str_replace('\\', '/', trim($user_home_root));
    $home_is_absolute = preg_match('/^(?:[a-zA-Z]:\/|\/)/', $home_candidate) === 1;
    $home_absolute = $home_is_absolute ? $home_candidate : ($root_path . '/' . ltrim($home_candidate, '/'));
    $home_absolute = rtrim(str_replace('\\', '/', $home_absolute), '/');

    if (fm_is_path_inside($home_absolute, $root_path)) {
        $fm_user_home_root = fm_clean_path(ltrim(substr($home_absolute, strlen($root_path)), '/'));
    }
}

// build per-user allowed directory list (optional restrictions)
if ($use_auth && isset($_SESSION[FM_SESSION_ID]['logged'], $directories_users[$_SESSION[FM_SESSION_ID]['logged']])) {
    $user_dirs = $directories_users[$_SESSION[FM_SESSION_ID]['logged']];
    if (!is_array($user_dirs)) {
        $user_dirs = array($user_dirs);
    }

    foreach ($user_dirs as $dir) {
        if (!is_string($dir) || trim($dir) === '') {
            continue;
        }

        $dir = str_replace('\\', '/', trim($dir));
        $is_absolute = preg_match('/^(?:[a-zA-Z]:\\/|\/)/', $dir) === 1;
        $candidate = $is_absolute ? $dir : ($root_path . '/' . ltrim($dir, '/'));
        $candidate = rtrim(str_replace('\\', '/', $candidate), '/');

        if (!fm_is_path_inside($candidate, $root_path)) {
            continue;
        }

        if (@is_dir($candidate)) {
            $fm_user_allowed_dirs[] = $candidate;
        }
    }

    $fm_user_allowed_dirs = array_values(array_unique($fm_user_allowed_dirs));

    if (empty($fm_user_allowed_dirs)) {
        // No valid personal directory found – fall back to the shared 'free' folder.
        $free_dir = rtrim(str_replace('\\', '/', $root_path), '/') . '/free';
        if (!@is_dir($free_dir)) {
            @mkdir($free_dir, 0755, true);
        }
        if (@is_dir($free_dir)) {
            $fm_user_allowed_dirs = array($free_dir);
        } else {
            fm_set_msg('Access denied. No valid project directories assigned to your account.', 'error');
            fm_show_header_login();
            fm_show_message();
            fm_show_footer_login();
            exit;
        }
    }
}

defined('FM_SHOW_HIDDEN') || define('FM_SHOW_HIDDEN', $show_hidden_files);
defined('FM_ROOT_PATH') || define('FM_ROOT_PATH', $root_path);
defined('FM_USER_HOME_ROOT') || define('FM_USER_HOME_ROOT', $fm_user_home_root);
if ($use_auth && isset($_SESSION[FM_SESSION_ID]['logged'])) {
    fm_search_index_auto_bootstrap(true, 'authenticated_request');
} elseif (!$use_auth) {
    fm_search_index_auto_bootstrap(true, 'unauthenticated_instance_request');
}
defined('FM_LANG') || define('FM_LANG', $lang);
defined('FM_FILE_EXTENSION') || define('FM_FILE_EXTENSION', $allowed_file_extensions);
defined('FM_UPLOAD_EXTENSION') || define('FM_UPLOAD_EXTENSION', $allowed_upload_extensions);
defined('FM_EXCLUDE_ITEMS') || define('FM_EXCLUDE_ITEMS', (version_compare(PHP_VERSION, '7.0.0', '<') ? serialize($exclude_items) : $exclude_items));
defined('FM_DOC_VIEWER') || define('FM_DOC_VIEWER', $online_viewer);
$docx_preview_mode = strtolower(trim((string) $docx_preview_mode));
if (!in_array($docx_preview_mode, array('auto', 'local', 'microsoft'), true)) {
    $docx_preview_mode = 'auto';
}
defined('FM_DOCX_PREVIEW_MODE') || define('FM_DOCX_PREVIEW_MODE', $docx_preview_mode);
$fm_logged_user = isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : '';
$fm_is_super_admin = ($fm_logged_user === 'admin');
define('FM_IS_ADMIN', $fm_is_super_admin);
define('FM_READONLY', $global_readonly || (!$fm_is_super_admin && $use_auth && !empty($readonly_users) && in_array($fm_logged_user, $readonly_users, true)));
define('FM_UPLOAD_ONLY', !$fm_is_super_admin && $use_auth && !empty($upload_only_users) && in_array($fm_logged_user, $upload_only_users, true));
define('FM_MANAGER', !$fm_is_super_admin && $use_auth && !empty($manager_users) && in_array($fm_logged_user, $manager_users, true));
define('FM_CAN_MANAGE_USERS', FM_IS_ADMIN || FM_MANAGER);
define('FM_IS_WIN', DIRECTORY_SEPARATOR == '\\');

$bulk_actions_disabled_users = isset($bulk_actions_disabled_users) && is_array($bulk_actions_disabled_users)
    ? array_values(array_unique(array_map('strval', $bulk_actions_disabled_users)))
    : array();
$user_welcome_messages = isset($user_welcome_messages) && is_array($user_welcome_messages)
    ? $user_welcome_messages
    : array();
$welcome_message_shown_users = isset($welcome_message_shown_users) && is_array($welcome_message_shown_users)
    ? array_values(array_unique(array_map('strval', $welcome_message_shown_users)))
    : array();
$user_manager_owners = isset($user_manager_owners) && is_array($user_manager_owners)
    ? $user_manager_owners
    : array();
$fm_bulk_actions_enabled = false;
if (!$use_auth) {
    $fm_bulk_actions_enabled = !FM_READONLY && !FM_UPLOAD_ONLY;
} elseif ($fm_logged_user !== '') {
    $fm_bulk_actions_enabled = !in_array($fm_logged_user, $bulk_actions_disabled_users, true);
}
define('FM_BULK_ACTIONS_ENABLED', $fm_bulk_actions_enabled);

$fm_is_ajax_request = (
    (isset($_POST['ajax']) && (string) $_POST['ajax'] !== '')
    || (isset($_REQUEST['ajax']) && (string) $_REQUEST['ajax'] !== '')
    || (isset($_SERVER['HTTP_X_REQUESTED_WITH'])
        && strtolower((string) $_SERVER['HTTP_X_REQUESTED_WITH']) === 'xmlhttprequest')
);

// always use ?p=
if (!$fm_is_ajax_request && !isset($_GET['p']) && !isset($_GET['help_doc']) && empty($_FILES)) {
    $default_path = '';
    if ($use_auth && !empty($_SESSION[FM_SESSION_ID]['logged'])) {
        $candidate_default_path = fm_get_navigation_home_root();
        if ($candidate_default_path !== '') {
            $candidate_absolute_path = rtrim(FM_ROOT_PATH, '/\\') . '/' . ltrim($candidate_default_path, '/');
            if (fm_user_can_access_path($candidate_absolute_path, true)) {
                $default_path = fm_clean_path($candidate_default_path);
            }
        }
        unset($_SESSION[FM_SESSION_ID]['post_login_redirect']);
    }

    fm_redirect(FM_SELF_URL . '?p=' . urlencode($default_path));
}

// Explicit empty path (?p=) should open assigned user root when available.
if (!$fm_is_ajax_request && isset($_GET['p']) && count($_GET) === 1 && !isset($_GET['help_doc']) && empty($_FILES) && fm_clean_path((string) $_GET['p']) === '') {
    $default_path = '';
    if ($use_auth && !empty($_SESSION[FM_SESSION_ID]['logged'])) {
        $candidate_default_path = fm_get_navigation_home_root();
        if ($candidate_default_path !== '') {
            $candidate_absolute_path = rtrim(FM_ROOT_PATH, '/\\') . '/' . ltrim($candidate_default_path, '/');
            if (fm_user_can_access_path($candidate_absolute_path, true)) {
                $default_path = fm_clean_path($candidate_default_path);
            }
        }
    }

    if ($default_path !== '') {
        fm_redirect(FM_SELF_URL . '?p=' . urlencode($default_path));
    }
}

// get path
$p = isset($_GET['p']) ? $_GET['p'] : (isset($_POST['p']) ? $_POST['p'] : '');

// clean path
$p = fm_clean_path($p);

// for ajax request - save
$input = file_get_contents('php://input');
$_POST = (strpos($input, 'ajax') != FALSE && strpos($input, 'save') != FALSE) ? json_decode($input, true) : $_POST;

// instead globals vars
define('FM_PATH', $p);

// --- ADMIN USERS OWNER MAP (admin only, AJAX GET/POST) ---
if (isset($_GET['admin_users_owner_map'])) {
    header('Content-Type: application/json; charset=utf-8');

    if (!FM_IS_ADMIN) {
        http_response_code(403);
        echo json_encode(array('ok' => false, 'error' => 'Forbidden'));
        exit;
    }

    $method = isset($_SERVER['REQUEST_METHOD']) ? strtoupper((string) $_SERVER['REQUEST_METHOD']) : 'GET';
    $rebuild = isset($_REQUEST['rebuild']) && (string) $_REQUEST['rebuild'] === '1';
    $action = ($method === 'POST') ? 'apply' : 'preview';

    if ($action === 'apply') {
        $token = isset($_POST['token']) ? (string) $_POST['token'] : '';
        if (!verifyToken($token)) {
            http_response_code(401);
            echo json_encode(array('ok' => false, 'error' => 'Invalid token'));
            exit;
        }
    }

    $config_file = __DIR__ . '/config.php';
    $config_data = fm_admin_load_user_config_arrays($config_file);
    if (empty($config_data['ok'])) {
        http_response_code(500);
        echo json_encode(array('ok' => false, 'error' => isset($config_data['error']) ? (string) $config_data['error'] : 'Failed to load config.'));
        exit;
    }

    $auth_users_local = isset($config_data['auth_users']) && is_array($config_data['auth_users']) ? $config_data['auth_users'] : array();
    $readonly_users_local = isset($config_data['readonly_users']) && is_array($config_data['readonly_users']) ? $config_data['readonly_users'] : array();
    $upload_only_users_local = isset($config_data['upload_only_users']) && is_array($config_data['upload_only_users']) ? $config_data['upload_only_users'] : array();
    $manager_users_local = isset($config_data['manager_users']) && is_array($config_data['manager_users']) ? $config_data['manager_users'] : array();
    $directories_users_local = isset($config_data['directories_users']) && is_array($config_data['directories_users']) ? $config_data['directories_users'] : array();
    $user_manager_owners_local = isset($config_data['user_manager_owners']) && is_array($config_data['user_manager_owners']) ? $config_data['user_manager_owners'] : array();
    $user_notes_local = isset($config_data['user_notes']) && is_array($config_data['user_notes']) ? $config_data['user_notes'] : array();
    $bulk_actions_disabled_users_local = isset($config_data['bulk_actions_disabled_users']) && is_array($config_data['bulk_actions_disabled_users']) ? $config_data['bulk_actions_disabled_users'] : array();
    $user_welcome_messages_local = isset($config_data['user_welcome_messages']) && is_array($config_data['user_welcome_messages']) ? $config_data['user_welcome_messages'] : array();
    $welcome_message_shown_users_local = isset($config_data['welcome_message_shown_users']) && is_array($config_data['welcome_message_shown_users']) ? $config_data['welcome_message_shown_users'] : array();

    $plan = fm_admin_build_owner_map_plan(
        $auth_users_local,
        $manager_users_local,
        $directories_users_local,
        $user_manager_owners_local,
        FM_ROOT_PATH,
        $rebuild
    );

    $submitted_owner_map = null;
    if ($action === 'apply' && isset($_POST['owners_json'])) {
        $owner_map_result = fm_admin_parse_owner_map_submission(
            (string) $_POST['owners_json'],
            $auth_users_local,
            $manager_users_local
        );
        if (empty($owner_map_result['ok'])) {
            http_response_code(400);
            echo json_encode(array('ok' => false, 'error' => isset($owner_map_result['error']) ? (string) $owner_map_result['error'] : 'Invalid owner map submission.'));
            exit;
        }
        $submitted_owner_map = isset($owner_map_result['owners']) && is_array($owner_map_result['owners']) ? $owner_map_result['owners'] : null;
    }

    if ($action === 'apply') {
        if (is_array($submitted_owner_map)) {
            $normalized_existing_local = fm_admin_normalize_user_manager_owners($user_manager_owners_local, $manager_users_local, $auth_users_local);
            $manager_set_local = array_fill_keys(array_values(array_unique(array_map('strval', $manager_users_local))), true);
            $merged_owner_map = array();
            foreach (array_keys($auth_users_local) as $known_username) {
                $known_username = (string) $known_username;
                if ($known_username === 'admin' || isset($manager_set_local[$known_username])) {
                    $merged_owner_map[$known_username] = 'admin';
                    continue;
                }

                if (isset($submitted_owner_map[$known_username])) {
                    $merged_owner_map[$known_username] = (string) $submitted_owner_map[$known_username];
                    continue;
                }

                if (isset($normalized_existing_local[$known_username])) {
                    $merged_owner_map[$known_username] = (string) $normalized_existing_local[$known_username];
                } else {
                    $merged_owner_map[$known_username] = 'admin';
                }
            }
            ksort($merged_owner_map);
            $plan['owners'] = $merged_owner_map;
            $plan['rows'] = array_map(static function ($row) use ($merged_owner_map) {
                $username = isset($row['username']) ? (string) $row['username'] : '';
                $new_owner = isset($merged_owner_map[$username]) ? (string) $merged_owner_map[$username] : (isset($row['new_owner']) ? (string) $row['new_owner'] : 'admin');
                $current_owner = isset($row['current_owner']) ? (string) $row['current_owner'] : '-';
                return array(
                    'username' => $username,
                    'current_owner' => $current_owner,
                    'new_owner' => $new_owner,
                    'reason' => 'submitted_from_ui',
                    'changed' => $current_owner !== $new_owner,
                );
            }, isset($plan['rows']) && is_array($plan['rows']) ? $plan['rows'] : array());
            $plan['summary']['changed'] = 0;
            foreach ($plan['rows'] as $row) {
                if (!empty($row['changed'])) {
                    $plan['summary']['changed']++;
                }
            }
        }

        $persist_result = fm_admin_persist_user_config_arrays(
            $config_file,
            $auth_users_local,
            $readonly_users_local,
            $upload_only_users_local,
            $manager_users_local,
            $directories_users_local,
            $user_notes_local,
            $bulk_actions_disabled_users_local,
            $user_welcome_messages_local,
            $welcome_message_shown_users_local,
            isset($plan['owners']) && is_array($plan['owners']) ? $plan['owners'] : array()
        );

        if (empty($persist_result['ok'])) {
            http_response_code(500);
            echo json_encode(array('ok' => false, 'error' => isset($persist_result['error']) ? (string) $persist_result['error'] : 'Failed to persist owner map.'));
            exit;
        }

        $actor = isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : 'admin';
        fm_admin_write_audit_event('owner_map_apply', $actor, 'user_manager_owners', array(
            'rebuild' => $rebuild,
            'users_total' => isset($plan['summary']['users_total']) ? (int) $plan['summary']['users_total'] : 0,
            'changed' => isset($plan['summary']['changed']) ? (int) $plan['summary']['changed'] : 0,
        ));
    }

    echo json_encode(array(
        'ok' => true,
        'data' => array(
            'action' => $action,
            'rebuild' => $rebuild,
            'rows' => isset($plan['rows']) && is_array($plan['rows']) ? $plan['rows'] : array(),
            'summary' => isset($plan['summary']) && is_array($plan['summary']) ? $plan['summary'] : array(),
        ),
    ));
    exit;
}

// --- ADMIN CONFIG SNAPSHOTS (admin only, AJAX GET/POST) ---
if (isset($_GET['admin_config_snapshots'])) {
    header('Content-Type: application/json; charset=utf-8');

    if (!FM_IS_ADMIN) {
        http_response_code(403);
        echo json_encode(array('ok' => false, 'error' => 'Forbidden'));
        exit;
    }

    $method = isset($_SERVER['REQUEST_METHOD']) ? strtoupper((string) $_SERVER['REQUEST_METHOD']) : 'GET';
    if ($method === 'POST') {
        $token = isset($_POST['token']) ? (string) $_POST['token'] : '';
        if (!verifyToken($token)) {
            http_response_code(401);
            echo json_encode(array('ok' => false, 'error' => 'Invalid token'));
            exit;
        }

        $snapshot_id = isset($_POST['snapshot_id']) ? (int) $_POST['snapshot_id'] : 0;
        if ($snapshot_id < 1) {
            http_response_code(400);
            echo json_encode(array('ok' => false, 'error' => 'Missing snapshot id.'));
            exit;
        }

        $restore_result = fm_config_store_restore_snapshot($snapshot_id, array(
            'created_by' => isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : 'admin',
            'updated_by' => isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : 'admin',
        ));

        if (empty($restore_result['ok'])) {
            http_response_code(500);
            echo json_encode(array('ok' => false, 'error' => isset($restore_result['error']) ? (string) $restore_result['error'] : 'Restore failed.'));
            exit;
        }

        echo json_encode(array('ok' => true, 'data' => $restore_result));
        exit;
    }

    $runtimeSnapshots = function_exists('fm_config_store_list_snapshots') ? fm_config_store_list_snapshots('runtime_config', 'global', 10) : array();
    $uiSnapshots = function_exists('fm_config_store_list_snapshots') ? fm_config_store_list_snapshots('ui_preferences', 'global', 10) : array();

    echo json_encode(array(
        'ok' => true,
        'data' => array(
            'runtime_config' => $runtimeSnapshots,
            'ui_preferences' => $uiSnapshots,
        ),
    ));
    exit;
}

// --- ADMIN USERS SAVE (admin/manager, AJAX POST) ---
if (isset($_GET['admin_users_save'])) {
    $is_ajax_request = isset($_SERVER['HTTP_X_REQUESTED_WITH'])
        && strtolower((string) $_SERVER['HTTP_X_REQUESTED_WITH']) === 'xmlhttprequest';

    if ($is_ajax_request) {
        header('Content-Type: application/json; charset=utf-8');
    }

    $admin_users_respond_error = function ($status_code, $message) use ($is_ajax_request) {
        http_response_code($status_code);
        if ($is_ajax_request) {
            echo json_encode(array('ok' => false, 'error' => $message));
        } else {
            fm_set_msg($message, 'error');
            fm_redirect(FM_SELF_URL . '?p=' . urlencode(FM_PATH) . '&admin_users=1');
        }
        exit;
    };

    $admin_users_respond_success = function () use ($is_ajax_request) {
        if ($is_ajax_request) {
            echo json_encode(array('ok' => true));
        } else {
            fm_set_msg('User saved successfully.', 'success');
            fm_redirect(FM_SELF_URL . '?p=' . urlencode(FM_PATH) . '&admin_users=1');
        }
        exit;
    };

    if (!FM_CAN_MANAGE_USERS) {
        $admin_users_respond_error(403, 'Forbidden');
    }

    if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
        $admin_users_respond_error(405, 'Method not allowed');
    }

    $token = isset($_POST['token']) ? (string) $_POST['token'] : '';
    if (!verifyToken($token)) {
        $admin_users_respond_error(401, 'Invalid token');
    }

    $mode = isset($_POST['mode']) && $_POST['mode'] === 'edit' ? 'edit' : 'new';
    $actor = isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : '';
    $username = isset($_POST['username']) ? trim((string) $_POST['username']) : '';
    $password = isset($_POST['password']) ? (string) $_POST['password'] : '';
    $password2 = isset($_POST['password2']) ? (string) $_POST['password2'] : '';
    $access_type = isset($_POST['access_type']) ? trim((string) $_POST['access_type']) : 'standard';
    $directories_raw = isset($_POST['directories']) ? (string) $_POST['directories'] : '';
    $manager_owner = isset($_POST['manager_owner']) ? trim((string) $_POST['manager_owner']) : '';
    $note = isset($_POST['note']) ? trim((string) $_POST['note']) : '';
    $welcome_message = isset($_POST['welcome_message']) ? trim((string) $_POST['welcome_message']) : '';
    $bulk_actions_enabled = isset($_POST['bulk_actions_enabled']) && (string) $_POST['bulk_actions_enabled'] === '1';
    $change_date = isset($_POST['date']) ? trim((string) $_POST['date']) : '';

    if ($username === '' || !preg_match('/^[A-Za-z0-9._-]{2,64}$/', $username)) {
        $admin_users_respond_error(400, 'Invalid username format. Use 2-64 chars: letters, digits, dot, underscore, hyphen.');
    }

    $allowed_access_types = array('standard', 'read only', 'upload only', 'manager');
    if (!in_array($access_type, $allowed_access_types, true)) {
        $admin_users_respond_error(400, 'Invalid access type');
    }

    $config_file = __DIR__ . '/config.php';
    $config_data = fm_admin_load_user_config_arrays($config_file);
    if (!$config_data['ok']) {
        $admin_users_respond_error(500, $config_data['error']);
    }

    $auth_users_local = $config_data['auth_users'];
    $readonly_users_local = $config_data['readonly_users'];
    $upload_only_users_local = $config_data['upload_only_users'];
    $manager_users_local = $config_data['manager_users'];
    $directories_users_local = $config_data['directories_users'];
    $user_manager_owners_local = isset($config_data['user_manager_owners']) && is_array($config_data['user_manager_owners'])
        ? $config_data['user_manager_owners']
        : array();
    $user_notes_local = $config_data['user_notes'];
    $user_welcome_messages_local = isset($config_data['user_welcome_messages']) && is_array($config_data['user_welcome_messages'])
        ? $config_data['user_welcome_messages']
        : array();
    $welcome_message_shown_users_local = isset($config_data['welcome_message_shown_users']) && is_array($config_data['welcome_message_shown_users'])
        ? array_values(array_unique(array_map('strval', $config_data['welcome_message_shown_users'])))
        : array();
    $bulk_actions_disabled_users_local = isset($config_data['bulk_actions_disabled_users']) && is_array($config_data['bulk_actions_disabled_users'])
        ? array_values(array_unique(array_map('strval', $config_data['bulk_actions_disabled_users'])))
        : array();
    $user_manager_owners_local = fm_admin_normalize_user_manager_owners($user_manager_owners_local, $manager_users_local, $auth_users_local);

    $exists = array_key_exists($username, $auth_users_local)
        || in_array($username, $readonly_users_local, true)
        || in_array($username, $upload_only_users_local, true)
        || in_array($username, $manager_users_local, true)
        || array_key_exists($username, $directories_users_local);

    if ($mode === 'new' && $exists) {
        $admin_users_respond_error(400, 'User already exists');
    }

    if ($mode === 'edit' && !$exists) {
        $admin_users_respond_error(404, 'User not found');
    }

    if ($mode === 'new' && trim($password) === '') {
        $admin_users_respond_error(400, 'Password is required for new user');
    }

    if (FM_MANAGER && !FM_IS_ADMIN) {
        if ($access_type === 'manager') {
            $admin_users_respond_error(403, 'Manager cannot create or assign manager role.');
        }

        if ($mode === 'edit' && !fm_admin_manager_can_manage_user($actor, $username, $manager_users_local, $user_manager_owners_local)) {
            $admin_users_respond_error(403, 'Manager can only edit users assigned to them.');
        }

        if ($mode === 'new' && ($username === 'admin' || in_array($username, $manager_users_local, true) || $username === $actor)) {
            $admin_users_respond_error(403, 'Manager cannot create this account.');
        }
    }

    $old_access_type = 'standard';
    if (in_array($username, $manager_users_local, true)) {
        $old_access_type = 'manager';
    } elseif (in_array($username, $upload_only_users_local, true)) {
        $old_access_type = 'upload only';
    } elseif (in_array($username, $readonly_users_local, true)) {
        $old_access_type = 'read only';
    }
    $old_dirs_count = 0;
    if (array_key_exists($username, $directories_users_local)) {
        $old_dirs_count = is_array($directories_users_local[$username]) ? count($directories_users_local[$username]) : 1;
    }
    $old_bulk_actions_enabled = !in_array($username, $bulk_actions_disabled_users_local, true);

    $password_changed = false;
    if ($password !== '' || $password2 !== '') {
        if ($password !== $password2) {
            $admin_users_respond_error(400, 'Passwords do not match');
        }
        if (function_exists('mb_strlen')) {
            if (mb_strlen($password, 'UTF-8') < 6) {
                $admin_users_respond_error(400, 'Password must be at least 6 characters long');
            }
        } elseif (strlen($password) < 6) {
            $admin_users_respond_error(400, 'Password must be at least 6 characters long');
        }
        $auth_users_local[$username] = password_hash($password, PASSWORD_DEFAULT);
        $password_changed = true;
    } elseif ($mode === 'new') {
        $admin_users_respond_error(400, 'Password is required for new user');
    }

    $readonly_users_local = array_values(array_diff($readonly_users_local, array($username)));
    $upload_only_users_local = array_values(array_diff($upload_only_users_local, array($username)));
    $manager_users_local = array_values(array_diff($manager_users_local, array($username)));

    if ($access_type === 'read only') {
        $readonly_users_local[] = $username;
    } elseif ($access_type === 'upload only') {
        $upload_only_users_local[] = $username;
    } elseif ($access_type === 'manager') {
        $manager_users_local[] = $username;
    }

    $readonly_users_local = array_values(array_unique($readonly_users_local));
    $upload_only_users_local = array_values(array_unique($upload_only_users_local));
    $manager_users_local = array_values(array_unique($manager_users_local));

    $parsed_dirs = fm_admin_parse_directories_input($directories_raw);
    $default_assigned_dir = fm_admin_resolve_default_user_directory($directories_users_local, FM_ROOT_PATH);
    if (count($parsed_dirs) === 0 && $default_assigned_dir !== '') {
        $parsed_dirs = array($default_assigned_dir);
    }
    $new_dirs_count = count($parsed_dirs);
    if (count($parsed_dirs) === 0) {
        $admin_users_respond_error(400, lng('At least one directory must be assigned.'));
    } elseif (count($parsed_dirs) === 1) {
        $directories_users_local[$username] = $parsed_dirs[0];
    } else {
        $directories_users_local[$username] = $parsed_dirs;
    }

    if ($note === '') {
        unset($user_notes_local[$username]);
    } else {
        $user_notes_local[$username] = $note;
    }

    if ($access_type === 'manager' || $username === 'admin') {
        $user_manager_owners_local[$username] = 'admin';
    } else {
        if (FM_MANAGER && !FM_IS_ADMIN) {
            $user_manager_owners_local[$username] = $actor;
        } else {
            if ($manager_owner === '' || $manager_owner === 'admin') {
                $user_manager_owners_local[$username] = 'admin';
            } elseif (in_array($manager_owner, $manager_users_local, true)) {
                $user_manager_owners_local[$username] = $manager_owner;
            } else {
                $admin_users_respond_error(400, 'Invalid manager owner selection.');
            }
        }
    }

    if ($welcome_message === '') {
        unset($user_welcome_messages_local[$username]);
    } else {
        $user_welcome_messages_local[$username] = $welcome_message;
    }

    if ($mode === 'new') {
        $welcome_message_shown_users_local = array_values(array_diff($welcome_message_shown_users_local, array($username)));
    }

    if ($bulk_actions_enabled) {
        $bulk_actions_disabled_users_local = array_values(array_diff($bulk_actions_disabled_users_local, array($username)));
    } else {
        $bulk_actions_disabled_users_local[] = $username;
        $bulk_actions_disabled_users_local = array_values(array_unique($bulk_actions_disabled_users_local));
    }

    $write_ok = fm_admin_persist_user_config_arrays(
        $config_file,
        $auth_users_local,
        $readonly_users_local,
        $upload_only_users_local,
        $manager_users_local,
        $directories_users_local,
        $user_notes_local,
        $bulk_actions_disabled_users_local,
        $user_welcome_messages_local,
        $welcome_message_shown_users_local,
        $user_manager_owners_local
    );

    if (!$write_ok['ok']) {
        $admin_users_respond_error(500, $write_ok['error']);
    }

    $audit_meta = array(
        'mode' => $mode,
        'access_type_old' => $old_access_type,
        'access_type_new' => $access_type,
        'directories_old_count' => $old_dirs_count,
        'directories_new_count' => $new_dirs_count,
        'password_changed' => $password_changed,
        'bulk_actions_enabled_old' => $old_bulk_actions_enabled,
        'bulk_actions_enabled_new' => $bulk_actions_enabled,
        'manager_owner' => isset($user_manager_owners_local[$username]) ? (string) $user_manager_owners_local[$username] : 'admin',
    );
    if ($note !== '') {
        $audit_meta['note'] = $note;
    }
    if ($welcome_message !== '') {
        $audit_meta['welcome_message'] = $welcome_message;
    }
    if ($change_date !== '') {
        $audit_meta['change_date'] = $change_date;
    }

    fm_admin_write_audit_event('user_save', $actor, $username, array(
        'mode' => $audit_meta['mode'],
        'access_type_old' => $audit_meta['access_type_old'],
        'access_type_new' => $audit_meta['access_type_new'],
        'directories_old_count' => $audit_meta['directories_old_count'],
        'directories_new_count' => $audit_meta['directories_new_count'],
        'password_changed' => $audit_meta['password_changed'],
        'bulk_actions_enabled_old' => isset($audit_meta['bulk_actions_enabled_old']) ? $audit_meta['bulk_actions_enabled_old'] : '',
        'bulk_actions_enabled_new' => isset($audit_meta['bulk_actions_enabled_new']) ? $audit_meta['bulk_actions_enabled_new'] : '',
        'manager_owner' => isset($audit_meta['manager_owner']) ? $audit_meta['manager_owner'] : '',
        'note' => isset($audit_meta['note']) ? $audit_meta['note'] : '',
        'welcome_message' => isset($audit_meta['welcome_message']) ? $audit_meta['welcome_message'] : '',
        'change_date' => isset($audit_meta['change_date']) ? $audit_meta['change_date'] : '',
    ));

    $admin_users_respond_success();
}

// --- ADMIN USERS DELETE (admin/manager, AJAX POST) ---
if (isset($_GET['admin_users_delete'])) {
    header('Content-Type: application/json; charset=utf-8');

    if (!FM_CAN_MANAGE_USERS) {
        http_response_code(403);
        echo json_encode(array('ok' => false, 'error' => 'Forbidden'));
        exit;
    }

    if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
        http_response_code(405);
        echo json_encode(array('ok' => false, 'error' => 'Method not allowed'));
        exit;
    }

    $token = isset($_POST['token']) ? (string) $_POST['token'] : '';
    if (!verifyToken($token)) {
        http_response_code(401);
        echo json_encode(array('ok' => false, 'error' => 'Invalid token'));
        exit;
    }

    $actor = isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : '';
    $username = isset($_POST['username']) ? trim((string) $_POST['username']) : '';
    if ($username === '') {
        http_response_code(400);
        echo json_encode(array('ok' => false, 'error' => 'Username is required'));
        exit;
    }

    if (isset($_SESSION[FM_SESSION_ID]['logged']) && $_SESSION[FM_SESSION_ID]['logged'] === $username) {
        http_response_code(400);
        echo json_encode(array('ok' => false, 'error' => 'Cannot delete currently logged-in user'));
        exit;
    }

    $config_file = __DIR__ . '/config.php';
    $config_data = fm_admin_load_user_config_arrays($config_file);
    if (!$config_data['ok']) {
        http_response_code(500);
        echo json_encode(array('ok' => false, 'error' => $config_data['error']));
        exit;
    }

    $auth_users_local = $config_data['auth_users'];
    $readonly_users_local = $config_data['readonly_users'];
    $upload_only_users_local = $config_data['upload_only_users'];
    $manager_users_local = $config_data['manager_users'];
    $directories_users_local = $config_data['directories_users'];
    $user_manager_owners_local = isset($config_data['user_manager_owners']) && is_array($config_data['user_manager_owners'])
        ? $config_data['user_manager_owners']
        : array();
    $user_notes_local = $config_data['user_notes'];
    $user_welcome_messages_local = isset($config_data['user_welcome_messages']) && is_array($config_data['user_welcome_messages'])
        ? $config_data['user_welcome_messages']
        : array();
    $welcome_message_shown_users_local = isset($config_data['welcome_message_shown_users']) && is_array($config_data['welcome_message_shown_users'])
        ? array_values(array_unique(array_map('strval', $config_data['welcome_message_shown_users'])))
        : array();
    $bulk_actions_disabled_users_local = isset($config_data['bulk_actions_disabled_users']) && is_array($config_data['bulk_actions_disabled_users'])
        ? array_values(array_unique(array_map('strval', $config_data['bulk_actions_disabled_users'])))
        : array();
    $user_manager_owners_local = fm_admin_normalize_user_manager_owners($user_manager_owners_local, $manager_users_local, $auth_users_local);

    $exists = array_key_exists($username, $auth_users_local)
        || in_array($username, $readonly_users_local, true)
        || in_array($username, $upload_only_users_local, true)
        || in_array($username, $manager_users_local, true)
        || array_key_exists($username, $directories_users_local);

    if (!$exists) {
        http_response_code(404);
        echo json_encode(array('ok' => false, 'error' => 'User not found'));
        exit;
    }

    if (FM_MANAGER && !FM_IS_ADMIN) {
        if (!fm_admin_manager_can_manage_user($actor, $username, $manager_users_local, $user_manager_owners_local)) {
            http_response_code(403);
            echo json_encode(array('ok' => false, 'error' => 'Manager can only delete users assigned to them.'));
            exit;
        }
    }

    $deleted_access_type = 'standard';
    if (in_array($username, $manager_users_local, true)) {
        $deleted_access_type = 'manager';
    } elseif (in_array($username, $upload_only_users_local, true)) {
        $deleted_access_type = 'upload only';
    } elseif (in_array($username, $readonly_users_local, true)) {
        $deleted_access_type = 'read only';
    }
    $deleted_had_dirs = array_key_exists($username, $directories_users_local);
    $deleted_manager_owner = isset($user_manager_owners_local[$username]) ? (string) $user_manager_owners_local[$username] : 'admin';

    unset($auth_users_local[$username]);
    unset($directories_users_local[$username]);
    unset($user_manager_owners_local[$username]);
    unset($user_notes_local[$username]);
    unset($user_welcome_messages_local[$username]);
    $welcome_message_shown_users_local = array_values(array_diff($welcome_message_shown_users_local, array($username)));
    $bulk_actions_disabled_users_local = array_values(array_diff($bulk_actions_disabled_users_local, array($username)));
    $readonly_users_local = array_values(array_diff($readonly_users_local, array($username)));
    $upload_only_users_local = array_values(array_diff($upload_only_users_local, array($username)));
    $manager_users_local = array_values(array_diff($manager_users_local, array($username)));

    if ($deleted_access_type === 'manager') {
        foreach ($user_manager_owners_local as $owned_user => $owner) {
            if ((string) $owner === $username) {
                $user_manager_owners_local[$owned_user] = 'admin';
            }
        }
    }

    $write_ok = fm_admin_persist_user_config_arrays(
        $config_file,
        $auth_users_local,
        $readonly_users_local,
        $upload_only_users_local,
        $manager_users_local,
        $directories_users_local,
        $user_notes_local,
        $bulk_actions_disabled_users_local,
        $user_welcome_messages_local,
        $welcome_message_shown_users_local,
        $user_manager_owners_local
    );

    if (!$write_ok['ok']) {
        http_response_code(500);
        echo json_encode(array('ok' => false, 'error' => $write_ok['error']));
        exit;
    }

    fm_admin_write_audit_event('user_delete', $actor, $username, array(
        'access_type' => $deleted_access_type,
        'had_directories' => $deleted_had_dirs,
        'manager_owner' => $deleted_manager_owner,
    ));

    echo json_encode(array('ok' => true));
    exit;
}

// --- ADMIN USERS MODAL (admin/manager, AJAX load) ---
if (isset($_GET['admin_users_modal'])) {
    if (!FM_CAN_MANAGE_USERS) {
        http_response_code(403);
        header('Content-Type: text/plain; charset=utf-8');
        echo 'Forbidden';
        exit;
    }
    header('Content-Type: text/html; charset=utf-8');
    $modal_mode = ($_GET['admin_users_modal'] === 'edit') ? 'edit' : 'new';
    $modal_username = isset($_GET['user']) ? $_GET['user'] : '';
    $modal_token = isset($_SESSION['token']) ? $_SESSION['token'] : '';
    $modal_access_type = 'standard';
    $modal_directories = '';
    $modal_default_directory = '';
    $modal_note = '';
    $modal_welcome_message = '';
    $modal_bulk_actions_enabled = true;

    $modal_config_file = __DIR__ . '/config.php';
    $modal_config = fm_admin_load_user_config_arrays($modal_config_file);
    $modal_readonly_users = $modal_config['ok'] ? $modal_config['readonly_users'] : (isset($readonly_users) && is_array($readonly_users) ? $readonly_users : array());
    $modal_upload_only_users = $modal_config['ok'] ? $modal_config['upload_only_users'] : (isset($upload_only_users) && is_array($upload_only_users) ? $upload_only_users : array());
    $modal_manager_users = $modal_config['ok'] ? $modal_config['manager_users'] : (isset($manager_users) && is_array($manager_users) ? $manager_users : array());
    $modal_directories_users = $modal_config['ok'] ? $modal_config['directories_users'] : (isset($directories_users) && is_array($directories_users) ? $directories_users : array());
    $modal_user_manager_owners = $modal_config['ok'] && isset($modal_config['user_manager_owners']) && is_array($modal_config['user_manager_owners'])
        ? $modal_config['user_manager_owners']
        : (isset($user_manager_owners) && is_array($user_manager_owners) ? $user_manager_owners : array());
    $modal_user_notes = $modal_config['ok'] ? $modal_config['user_notes'] : (isset($user_notes) && is_array($user_notes) ? $user_notes : array());
    $modal_user_welcome_messages = $modal_config['ok'] && isset($modal_config['user_welcome_messages']) && is_array($modal_config['user_welcome_messages'])
        ? $modal_config['user_welcome_messages']
        : (isset($user_welcome_messages) && is_array($user_welcome_messages) ? $user_welcome_messages : array());
    $modal_bulk_actions_disabled_users = $modal_config['ok'] && isset($modal_config['bulk_actions_disabled_users']) && is_array($modal_config['bulk_actions_disabled_users'])
        ? array_values(array_unique(array_map('strval', $modal_config['bulk_actions_disabled_users'])))
        : (isset($bulk_actions_disabled_users) && is_array($bulk_actions_disabled_users) ? array_values(array_unique(array_map('strval', $bulk_actions_disabled_users))) : array());
    $modal_default_directory = fm_admin_resolve_default_user_directory($modal_directories_users, FM_ROOT_PATH);
    $modal_user_manager_owners = fm_admin_normalize_user_manager_owners($modal_user_manager_owners, $modal_manager_users, isset($auth_users) && is_array($auth_users) ? $auth_users : array());
    $modal_is_manager_actor = FM_MANAGER && !FM_IS_ADMIN;
    $modal_logged_user = isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : '';
    $modal_manager_owner = $modal_mode === 'new'
        ? ($modal_is_manager_actor ? $modal_logged_user : 'admin')
        : fm_admin_get_user_manager_owner($modal_username, $modal_user_manager_owners, $modal_manager_users);

    if ($modal_is_manager_actor && $modal_mode === 'edit') {
        if (!fm_admin_manager_can_manage_user($modal_logged_user, $modal_username, $modal_manager_users, $modal_user_manager_owners)) {
            http_response_code(403);
            header('Content-Type: text/plain; charset=utf-8');
            echo 'Forbidden';
            exit;
        }
    }

    if ($modal_mode === 'edit' && $modal_username !== '') {
        if (!empty($modal_manager_users) && in_array($modal_username, $modal_manager_users, true)) {
            $modal_access_type = 'manager';
        } elseif (!empty($modal_upload_only_users) && in_array($modal_username, $modal_upload_only_users, true)) {
            $modal_access_type = 'upload only';
        } elseif (!empty($modal_readonly_users) && in_array($modal_username, $modal_readonly_users, true)) {
            $modal_access_type = 'read only';
        }

        if (!empty($modal_directories_users) && array_key_exists($modal_username, $modal_directories_users)) {
            $dirs = $modal_directories_users[$modal_username];
            if (is_array($dirs)) {
                $modal_directories = implode("\n", array_map('strval', $dirs));
            } else {
                $modal_directories = (string) $dirs;
            }
        }

        if (!empty($modal_user_notes) && array_key_exists($modal_username, $modal_user_notes)) {
            $modal_note = (string) $modal_user_notes[$modal_username];
        }

        if (!empty($modal_user_welcome_messages) && array_key_exists($modal_username, $modal_user_welcome_messages)) {
            $modal_welcome_message = (string) $modal_user_welcome_messages[$modal_username];
        }

        $modal_bulk_actions_enabled = !in_array($modal_username, $modal_bulk_actions_disabled_users, true);
    }
    require __DIR__ . '/src/renderers/admin-user-modal.php';
    exit;
}
define('FM_USE_AUTH', $use_auth);
define('FM_EDIT_FILE', $edit_files);
defined('FM_ICONV_INPUT_ENC') || define('FM_ICONV_INPUT_ENC', $iconv_input_encoding);
defined('FM_USE_HIGHLIGHTJS') || define('FM_USE_HIGHLIGHTJS', $use_highlightjs);
defined('FM_HIGHLIGHTJS_STYLE') || define('FM_HIGHLIGHTJS_STYLE', $highlightjs_style);
defined('FM_DATETIME_FORMAT') || define('FM_DATETIME_FORMAT', $datetime_format);

$fm_current_abs_path = FM_ROOT_PATH . (FM_PATH != '' ? '/' . FM_PATH : '');
if (!FM_IS_ADMIN && !fm_is_within_navigation_home($fm_current_abs_path)) {
    $fm_home_relative = fm_clean_path((string) fm_get_navigation_home_root());
    $fm_candidate_path = '';

    if ($fm_home_relative !== '' && FM_PATH !== '' && strpos(FM_PATH . '/', $fm_home_relative . '/') !== 0) {
        $fm_candidate_path = fm_clean_path($fm_home_relative . '/' . FM_PATH);
        $fm_candidate_abs_path = FM_ROOT_PATH . ($fm_candidate_path !== '' ? '/' . $fm_candidate_path : '');

        if (fm_is_within_navigation_home($fm_candidate_abs_path)
            && fm_user_can_access_path($fm_candidate_abs_path, true)
            && @is_dir($fm_candidate_abs_path)
        ) {
            fm_redirect(FM_SELF_URL . '?p=' . urlencode($fm_candidate_path));
        }
    }

    $fm_fallback_path = fm_get_navigation_home_root();
    fm_set_msg('Access denied. Home root boundary applicable.', 'error');
    fm_redirect(FM_SELF_URL . '?p=' . urlencode($fm_fallback_path));
}
if (!fm_user_can_access_path($fm_current_abs_path, true)) {
    $fm_fallback_path = fm_get_navigation_home_root();
    fm_set_msg('Access denied. Path restriction applicable.', 'error');
    fm_redirect(FM_SELF_URL . '?p=' . urlencode($fm_fallback_path));
}
define('FM_CAN_WRITE_IN_PATH', fm_user_can_access_path($fm_current_abs_path, false));

unset($p, $use_auth, $iconv_input_encoding, $use_highlightjs, $highlightjs_style);

/*************************** ACTIONS ***************************/

// Lightweight user-to-user chat API for online badge popups.
if (isset($_GET['chat_action']) && FM_USE_AUTH && !empty($_SESSION[FM_SESSION_ID]['logged'])) {
    header('Content-Type: application/json; charset=utf-8');

    $chat_action = isset($_GET['chat_action']) ? (string) $_GET['chat_action'] : '';
    $chat_current_user = (string) $_SESSION[FM_SESSION_ID]['logged'];
    $chat_allowed_peers = fm_chat_get_visible_peers(
        $chat_current_user,
        isset($auth_users) && is_array($auth_users) ? $auth_users : array(),
        isset($directories_users) && is_array($directories_users) ? $directories_users : array(),
        FM_ROOT_PATH,
        FM_USER_HOME_ROOT,
        isset($manager_users) && is_array($manager_users) ? $manager_users : array(),
        isset($user_manager_owners) && is_array($user_manager_owners) ? $user_manager_owners : array()
    );

    if ($chat_action === 'inbox') {
        $inbox = fm_chat_get_inbox($chat_current_user, 50);
        if (!empty($inbox)) {
            $inbox = array_values(array_filter($inbox, static function ($item) use ($chat_allowed_peers) {
                $sender = isset($item['sender']) ? (string) $item['sender'] : '';
                return $sender !== '' && in_array($sender, $chat_allowed_peers, true);
            }));
        }
        echo json_encode(array('ok' => true, 'data' => array('inbox' => $inbox)));
        exit;
    }

    $chat_peer = isset($_REQUEST['with']) ? trim((string) $_REQUEST['with']) : '';
    if ($chat_peer === '' && isset($_REQUEST['to'])) {
        $chat_peer = trim((string) $_REQUEST['to']);
    }

    if ($chat_peer === '' || !isset($auth_users[$chat_peer])) {
        http_response_code(400);
        echo json_encode(array('ok' => false, 'error' => 'Invalid chat user.'));
        exit;
    }

    if (!in_array($chat_peer, $chat_allowed_peers, true)) {
        http_response_code(403);
        echo json_encode(array('ok' => false, 'error' => 'Access denied for this chat peer.'));
        exit;
    }

    if ($chat_peer === $chat_current_user) {
        http_response_code(400);
        echo json_encode(array('ok' => false, 'error' => 'Cannot chat with yourself.'));
        exit;
    }

    if ($chat_action === 'fetch') {
        $messages = fm_chat_get_conversation($chat_current_user, $chat_peer, 150);
        $max_incoming_id = 0;
        foreach ($messages as $msg) {
            $msg_sender = isset($msg['sender']) ? (string) $msg['sender'] : '';
            $msg_recipient = isset($msg['recipient']) ? (string) $msg['recipient'] : '';
            $msg_id = isset($msg['id']) ? (int) $msg['id'] : 0;
            if ($msg_sender === $chat_peer && $msg_recipient === $chat_current_user && $msg_id > $max_incoming_id) {
                $max_incoming_id = $msg_id;
            }
        }

        if ($max_incoming_id > 0) {
            fm_chat_mark_read($chat_current_user, $chat_peer, $max_incoming_id);
        }

        echo json_encode(array('ok' => true, 'data' => array('messages' => $messages, 'read_upto' => $max_incoming_id)));
        exit;
    }

    if ($chat_action === 'mark_read') {
        if (!verifyToken(isset($_POST['token']) ? $_POST['token'] : '')) {
            http_response_code(401);
            echo json_encode(array('ok' => false, 'error' => 'Invalid token.'));
            exit;
        }

        $last_id = isset($_POST['last_id']) ? (int) $_POST['last_id'] : 0;
        if (!fm_chat_mark_read($chat_current_user, $chat_peer, $last_id)) {
            http_response_code(500);
            echo json_encode(array('ok' => false, 'error' => 'Failed to mark messages as read.'));
            exit;
        }

        echo json_encode(array(
            'ok' => true,
            'data' => array(
                'peer' => $chat_peer,
                'last_read_id' => fm_chat_get_last_read_id($chat_current_user, $chat_peer),
            ),
        ));
        exit;
    }

    if ($chat_action === 'send') {
        if (!verifyToken(isset($_POST['token']) ? $_POST['token'] : '')) {
            http_response_code(401);
            echo json_encode(array('ok' => false, 'error' => 'Invalid token.'));
            exit;
        }

        $message = isset($_POST['message']) ? trim((string) $_POST['message']) : '';
        if ($message === '') {
            http_response_code(400);
            echo json_encode(array('ok' => false, 'error' => 'Message cannot be empty.'));
            exit;
        }

        $message_length = function_exists('mb_strlen') ? mb_strlen($message, 'UTF-8') : strlen($message);
        if ($message_length > 2000) {
            http_response_code(400);
            echo json_encode(array('ok' => false, 'error' => 'Message is too long.'));
            exit;
        }

        if (!fm_chat_save_message($chat_current_user, $chat_peer, $message)) {
            http_response_code(500);
            echo json_encode(array('ok' => false, 'error' => 'Failed to save message.'));
            exit;
        }

        $messages = fm_chat_get_conversation($chat_current_user, $chat_peer, 150);
        echo json_encode(array('ok' => true, 'data' => array('messages' => $messages)));
        exit;
    }

    http_response_code(400);
    echo json_encode(array('ok' => false, 'error' => 'Unknown chat action.'));
    exit;
}

// Handle all AJAX Request
if ((((FM_USE_AUTH && !empty($_SESSION[FM_SESSION_ID]['logged'])) || !FM_USE_AUTH)) && isset($_POST['ajax'], $_POST['token'])) {
    $ajax_action_handler = new TFM_AjaxActionHandler(FM_ROOT_PATH, FM_PATH, __DIR__);
    $ajax_action_handler->handle($_POST, $_GET, $_REQUEST, $auth_users);
}

// Delete file / folder
if (isset($_GET['del'], $_POST['token']) && !FM_READONLY && !FM_UPLOAD_ONLY && !FM_MANAGER && FM_CAN_WRITE_IN_PATH) {
    $file_action_handler = new TFM_FileActionHandler(FM_ROOT_PATH, FM_PATH);
    $file_action_handler->handleDelete($_GET, $_POST);
    exit;
}

// Create a new file/folder
if (isset($_POST['newfilename'], $_POST['newfile'], $_POST['token']) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $file_action_handler = new TFM_FileActionHandler(FM_ROOT_PATH, FM_PATH);
    $file_action_handler->handleCreate($_POST);
    exit;
}

// Copy folder / file
if (isset($_GET['copy'], $_GET['finish']) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $copy_action_handler = new TFM_CopyActionHandler(FM_ROOT_PATH, FM_PATH);
    $copy_action_handler->handleCopy($_GET);
    exit;
}

// Mass copy files/ folders
if (isset($_POST['file'], $_POST['copy_to'], $_POST['finish'], $_POST['token']) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $copy_action_handler = new TFM_CopyActionHandler(FM_ROOT_PATH, FM_PATH);
    $copy_action_handler->handleMassCopy($_POST);
    exit;
}

// Rename
if (isset($_POST['rename_from'], $_POST['rename_to'], $_POST['token']) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $file_action_handler = new TFM_FileActionHandler(FM_ROOT_PATH, FM_PATH);
    $file_action_handler->handleRename($_POST);
    exit;
}

// Download
if (class_exists('TFM_DownloadPreviewHandler')) {
    $download_preview_handler = new TFM_DownloadPreviewHandler(FM_ROOT_PATH, FM_PATH);
    if ($download_preview_handler->handleDownload($_GET, $_POST)) {
        exit;
    }

    // Inline preview (images/audio/videos/pdf/office) for authenticated UI cards and file view embeds
    if ($download_preview_handler->handlePreview($_GET)) {
        exit;
    }
}

// Upload
if (!empty($_FILES) && (!FM_READONLY || FM_UPLOAD_ONLY) && FM_CAN_WRITE_IN_PATH) {
    $legacy_upload_handler = new TFM_LegacyUploadHandler(FM_ROOT_PATH, FM_PATH);
    $legacy_upload_handler->handle($_FILES, $_POST, $_REQUEST);
}

// Bulk download selected items as temporary ZIP (works for read-only users too)
if (isset($_POST['group'], $_POST['download_selected'], $_POST['token']) && FM_BULK_ACTIONS_ENABLED) {
    if (!verifyToken($_POST['token'])) {
        fm_set_msg(lng('Invalid Token.'), 'error');
        die('Invalid Token.');
    }

    if (!class_exists('ZipArchive')) {
        fm_set_msg(lng('Operations with archives are not available'), 'error');
        fm_redirect(FM_SELF_URL . '?p=' . urlencode(FM_PATH));
    }

    $selected_files = isset($_POST['file']) && is_array($_POST['file']) ? $_POST['file'] : array();
    $selected_files = array_values(array_unique(array_filter(array_map('fm_clean_path', $selected_files), 'strlen')));
    if (empty($selected_files)) {
        fm_set_msg(lng('Nothing selected'), 'alert');
        fm_redirect(FM_SELF_URL . '?p=' . urlencode(FM_PATH));
    }

    $base_dir = rtrim(FM_ROOT_PATH . (FM_PATH !== '' ? '/' . FM_PATH : ''), '/\\');
    if ($base_dir === '') {
        $base_dir = FM_ROOT_PATH;
    }

    $base_real = realpath($base_dir);
    if ($base_real === false || !is_dir($base_real)) {
        fm_set_msg(lng('Folder not found'), 'error');
        fm_redirect(FM_SELF_URL . '?p=' . urlencode(FM_PATH));
    }

    $tmp_zip_seed = tempnam(sys_get_temp_dir(), 'tfm_bulk_');
    if ($tmp_zip_seed === false) {
        fm_set_msg(lng('Archive not created'), 'error');
        fm_redirect(FM_SELF_URL . '?p=' . urlencode(FM_PATH));
    }

    $tmp_zip_path = $tmp_zip_seed . '.zip';
    @unlink($tmp_zip_seed);

    $zip = new ZipArchive();
    if ($zip->open($tmp_zip_path, ZipArchive::CREATE | ZipArchive::OVERWRITE) !== true) {
        @unlink($tmp_zip_path);
        fm_set_msg(lng('Archive not created'), 'error');
        fm_redirect(FM_SELF_URL . '?p=' . urlencode(FM_PATH));
    }

    $added_count = 0;
    foreach ($selected_files as $selected_rel) {
        $selected_name = ltrim(str_replace('\\', '/', $selected_rel), '/');
        if ($selected_name === '' || strpos($selected_name, '../') !== false) {
            continue;
        }

        $selected_abs = $base_real . DIRECTORY_SEPARATOR . str_replace('/', DIRECTORY_SEPARATOR, $selected_name);
        $selected_real = realpath($selected_abs);
        if ($selected_real === false) {
            continue;
        }

        $selected_real_norm = str_replace('\\', '/', $selected_real);
        $base_real_norm = rtrim(str_replace('\\', '/', $base_real), '/');
        if ($selected_real_norm !== $base_real_norm && strpos($selected_real_norm . '/', $base_real_norm . '/') !== 0) {
            continue;
        }

        if (is_dir($selected_real)) {
            $zip->addEmptyDir($selected_name);
            $added_count++;

            $iterator = new RecursiveIteratorIterator(
                new RecursiveDirectoryIterator($selected_real, FilesystemIterator::SKIP_DOTS),
                RecursiveIteratorIterator::SELF_FIRST
            );

            foreach ($iterator as $item) {
                $item_path = (string) $item->getPathname();
                $relative = ltrim(str_replace('\\', '/', substr($item_path, strlen($selected_real))), '/');
                $archive_path = trim($selected_name . '/' . $relative, '/');
                if ($archive_path === '') {
                    continue;
                }

                if ($item->isDir()) {
                    $zip->addEmptyDir($archive_path);
                    $added_count++;
                } elseif ($item->isFile()) {
                    $zip->addFile($item_path, $archive_path);
                    $added_count++;
                }
            }
            continue;
        }

        if (is_file($selected_real)) {
            $zip->addFile($selected_real, $selected_name);
            $added_count++;
        }
    }

    $zip->close();

    if ($added_count < 1 || !is_file($tmp_zip_path)) {
        @unlink($tmp_zip_path);
        fm_set_msg(lng('Archive not created'), 'error');
        fm_redirect(FM_SELF_URL . '?p=' . urlencode(FM_PATH));
    }

    $download_name = 'selected_' . date('Ymd_His') . '.zip';
    while (ob_get_level()) {
        ob_end_clean();
    }

    header('Content-Description: File Transfer');
    header('Content-Type: application/zip');
    header('Content-Disposition: attachment; filename="' . $download_name . '"');
    header('Content-Transfer-Encoding: binary');
    header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
    header('Pragma: no-cache');
    header('Expires: 0');
    header('Content-Length: ' . filesize($tmp_zip_path));

    readfile($tmp_zip_path);
    @unlink($tmp_zip_path);
    exit;
}

// Mass deleting
if (isset($_POST['group'], $_POST['delete'], $_POST['token']) && !FM_READONLY && !FM_UPLOAD_ONLY && !FM_MANAGER && FM_CAN_WRITE_IN_PATH) {
    $file_action_handler = new TFM_FileActionHandler(FM_ROOT_PATH, FM_PATH);
    $file_action_handler->handleMassDelete($_POST);
    exit;
}

// Pack files zip, tar
if (isset($_POST['group'], $_POST['token']) && (isset($_POST['zip']) || isset($_POST['tar'])) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $archive_action_handler = new TFM_ArchiveActionHandler(FM_ROOT_PATH, FM_PATH);
    $archive_action_handler->handlePack($_POST);
    exit;
}

// Unpack zip, tar
if (isset($_POST['unzip'], $_POST['token']) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $archive_action_handler = new TFM_ArchiveActionHandler(FM_ROOT_PATH, FM_PATH);
    $archive_action_handler->handleUnpack($_POST);
    exit;
}

// Change Perms (not for Windows)
if (isset($_POST['chmod'], $_POST['token']) && !FM_READONLY && !FM_UPLOAD_ONLY && !FM_IS_WIN && FM_CAN_WRITE_IN_PATH) {
    $file_action_handler = new TFM_FileActionHandler(FM_ROOT_PATH, FM_PATH);
    $file_action_handler->handleChmod($_POST);
    exit;
}

/*************************** ACTIONS ***************************/

$directory_listing_service = new TFM_DirectoryListingService(FM_ROOT_PATH, FM_PATH);
$listing_context = $directory_listing_service->buildContext();

$path = $listing_context['path'];
$parent = $listing_context['parent'];
$objects = $listing_context['objects'];
$folders = $listing_context['folders'];
$files = $listing_context['files'];
$current_path = $listing_context['current_path'];

if (isset($_GET['assistant_browser'])) {
    fm_show_header();
    fm_show_nav_path(FM_PATH);

    $assistant_config_file = __DIR__ . '/api.config.php';
    $assistant_api_token = '';
    $assistant_api_tokens = array();
    $assistant_workspace_root = __DIR__ . '/Joyee';
    if (is_readable($assistant_config_file)) {
        require $assistant_config_file;
        if (isset($api_tokens) && is_array($api_tokens)) {
            $assistant_api_tokens = $api_tokens;
        }
        if (isset($assistant_root_path) && trim((string) $assistant_root_path) !== '') {
            $assistant_workspace_root = (string) $assistant_root_path;
        }
    }

    foreach ($assistant_api_tokens as $configured_token => $configured_token_config) {
        if (is_string($configured_token) && trim($configured_token) !== '') {
            $assistant_api_token = trim($configured_token);
            break;
        }
    }

    $assistant_workspace_error = '';
    if (!is_dir($assistant_workspace_root)) {
        if (!@mkdir($assistant_workspace_root, 0775, true)) {
            $assistant_workspace_error = 'AI workspace sa nepodarilo vytvoriť.';
        }
    }

    $assistant_workspace_real_root = realpath($assistant_workspace_root);
    if ($assistant_workspace_real_root === false || !is_dir($assistant_workspace_real_root)) {
        $assistant_workspace_error = $assistant_workspace_error !== '' ? $assistant_workspace_error : 'AI workspace root neexistuje.';
    }

    $assistant_requested_path = isset($_GET['ajp']) ? (string) $_GET['ajp'] : '';
    if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['assistant_path'])) {
        $assistant_requested_path = (string) $_POST['assistant_path'];
    }
    $assistant_requested_path = str_replace('\\', '/', trim($assistant_requested_path));
    $assistant_requested_path = ltrim($assistant_requested_path, '/');

    $assistant_path_parts = array();
    if ($assistant_requested_path !== '') {
        foreach (explode('/', $assistant_requested_path) as $assistant_part) {
            $assistant_part = trim($assistant_part);
            if ($assistant_part === '' || $assistant_part === '.') {
                continue;
            }
            if ($assistant_part === '..' || strpos($assistant_part, "\0") !== false) {
                $assistant_workspace_error = 'Neplatná cesta v AI browseri.';
                $assistant_path_parts = array();
                break;
            }
            $assistant_path_parts[] = $assistant_part;
        }
    }

    $assistant_current_rel_path = implode('/', $assistant_path_parts);
    $assistant_current_abs_path = $assistant_workspace_real_root !== false
        ? rtrim($assistant_workspace_real_root, DIRECTORY_SEPARATOR) . ($assistant_current_rel_path === '' ? '' : DIRECTORY_SEPARATOR . str_replace('/', DIRECTORY_SEPARATOR, $assistant_current_rel_path))
        : '';

    if ($assistant_workspace_error === '' && ($assistant_workspace_real_root === false || !is_dir($assistant_current_abs_path))) {
        $assistant_workspace_error = 'Požadovaný AI priečinok neexistuje.';
        $assistant_current_rel_path = '';
        $assistant_current_abs_path = $assistant_workspace_real_root !== false ? $assistant_workspace_real_root : '';
    }

    $assistant_folder_items = array();
    $assistant_file_items = array();
    if ($assistant_workspace_error === '' && $assistant_current_abs_path !== '') {
        $assistant_scan_items = @scandir($assistant_current_abs_path);
        if ($assistant_scan_items === false) {
            $assistant_workspace_error = 'Nepodarilo sa načítať AI priečinok.';
        } else {
            foreach ($assistant_scan_items as $assistant_item) {
                if ($assistant_item === '.' || $assistant_item === '..') {
                    continue;
                }
                $assistant_item_abs = $assistant_current_abs_path . DIRECTORY_SEPARATOR . $assistant_item;
                if (is_dir($assistant_item_abs)) {
                    $assistant_folder_items[] = $assistant_item;
                } elseif (is_file($assistant_item_abs)) {
                    $assistant_file_items[] = $assistant_item;
                }
            }
            natcasesort($assistant_folder_items);
            natcasesort($assistant_file_items);
            $assistant_folder_items = array_values($assistant_folder_items);
            $assistant_file_items = array_values($assistant_file_items);
        }
    }

    $assistant_parent_rel_path = false;
    if ($assistant_current_rel_path !== '') {
        $assistant_parent_rel_path = trim(dirname($assistant_current_rel_path), '.');
        if ($assistant_parent_rel_path === DIRECTORY_SEPARATOR || $assistant_parent_rel_path === '.') {
            $assistant_parent_rel_path = '';
        }
    }

    $assistant_message = isset($_POST['assistant_message']) ? trim((string) $_POST['assistant_message']) : '';
    $assistant_error = '';
    $assistant_reply = '';
    $assistant_apply_ok = '';
    $assistant_session_auto_apply = !empty($_SESSION[FM_SESSION_ID]['assistant_auto_apply']);
    $assistant_require_confirmation = isset($_POST['assistant_require_confirmation'])
        ? ((string) $_POST['assistant_require_confirmation'] === '1')
        : !$assistant_session_auto_apply;
    $assistant_plan_json = isset($_POST['assistant_plan_json']) ? trim((string) $_POST['assistant_plan_json']) : '';
    $assistant_plan_summary = '';
    $assistant_plan_operations = array();
    $assistant_confirmed_operations = isset($_POST['assistant_confirmed']) && is_array($_POST['assistant_confirmed'])
        ? array_values(array_map('intval', $_POST['assistant_confirmed']))
        : array();
    $assistant_selected_files = isset($_POST['assistant_files']) && is_array($_POST['assistant_files']) ? array_values(array_filter(array_map('trim', $_POST['assistant_files']), 'strlen')) : array();
    $assistant_selected_files = array_values(array_filter($assistant_selected_files, static function ($value) {
        return strpos($value, "\0") === false;
    }));

    $assistant_normalize_plan = static function ($assistant_plan_data) {
        if (!is_array($assistant_plan_data)) {
            return array('summary' => '', 'operations' => array());
        }

        $assistant_summary = isset($assistant_plan_data['summary']) ? (string) $assistant_plan_data['summary'] : '';
        $assistant_operations = array();

        if (isset($assistant_plan_data['operations']) && is_array($assistant_plan_data['operations'])) {
            foreach ($assistant_plan_data['operations'] as $assistant_operation) {
                if (!is_array($assistant_operation)) {
                    continue;
                }
                $assistant_operation['action'] = isset($assistant_operation['action'])
                    ? strtolower(trim((string) $assistant_operation['action']))
                    : 'write';
                if ($assistant_operation['action'] === '') {
                    $assistant_operation['action'] = 'write';
                }
                $assistant_operations[] = $assistant_operation;
            }
        } elseif (isset($assistant_plan_data['edits']) && is_array($assistant_plan_data['edits'])) {
            foreach ($assistant_plan_data['edits'] as $assistant_edit) {
                if (!is_array($assistant_edit) || !isset($assistant_edit['path'])) {
                    continue;
                }
                $assistant_operations[] = array(
                    'action' => 'write',
                    'path' => (string) $assistant_edit['path'],
                    'content' => isset($assistant_edit['content']) ? (string) $assistant_edit['content'] : '',
                );
            }
        }

        return array(
            'summary' => $assistant_summary,
            'operations' => $assistant_operations,
        );
    };

    if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['assistant_session_allow'])) {
        $_SESSION[FM_SESSION_ID]['assistant_auto_apply'] = true;
        $assistant_session_auto_apply = true;
        $assistant_require_confirmation = false;
        $assistant_apply_ok = 'Session režim: potvrdenie je vypnuté do odhlásenia alebo resetu.';
    }

    if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['assistant_session_reset'])) {
        $_SESSION[FM_SESSION_ID]['assistant_auto_apply'] = false;
        $assistant_session_auto_apply = false;
        $assistant_require_confirmation = true;
        $assistant_apply_ok = 'Session režim bol zrušený. Potvrdenie je opäť zapnuté.';
    }

    if ($assistant_plan_json !== '') {
        $assistant_normalized_plan = $assistant_normalize_plan(json_decode($assistant_plan_json, true));
        $assistant_plan_summary = $assistant_normalized_plan['summary'];
        $assistant_plan_operations = $assistant_normalized_plan['operations'];
    }

    if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['assistant_run'])) {
        if ($assistant_message === '') {
            $assistant_error = 'Zadaj otázku pre asistenta.';
        } elseif ($assistant_api_token === '') {
            $assistant_error = 'API token pre interný request nie je nakonfigurovaný.';
        } elseif ($assistant_workspace_error !== '') {
            $assistant_error = $assistant_workspace_error;
        } elseif (empty($assistant_selected_files)) {
            $assistant_error = 'Vyber aspoň jeden súbor.';
        } else {
            $assistant_instruction = "Vytvor plan operacii pre vybrane subory. Odpovedz STRICTNE ako JSON objekt bez markdownu a bez dalsieho textu v tvare: {\"summary\":\"kratke zhrnutie\",\"operations\":[{\"action\":\"write|mkdir|delete|move|copy\",\"path\":\"relative/path\",\"content\":\"full file content\",\"from\":\"relative/from\",\"to\":\"relative/to\"}]}. Pouzi iba potrebne polia podla action. Ak nema byt ziadna zmena, vrat operations ako prazdne pole.";
            $assistant_payload = json_encode(array(
                'message' => $assistant_instruction . "\n\nUloha:\n" . $assistant_message,
                'files' => $assistant_selected_files,
            ), JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

            if ($assistant_payload === false) {
                $assistant_error = 'Nepodarilo sa pripraviť požiadavku pre asistenta.';
            } else {
                $assistant_base_path = rtrim(str_replace('\\', '/', dirname(isset($_SERVER['SCRIPT_NAME']) ? $_SERVER['SCRIPT_NAME'] : '')), '/');
                if ($assistant_base_path === '.' || $assistant_base_path === '/') {
                    $assistant_base_path = '';
                }
                $assistant_api_url = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https://' : 'http://') . $_SERVER['HTTP_HOST'] . $assistant_base_path . '/api.php?action=assistant';

                if (function_exists('curl_init')) {
                    $assistant_curl = curl_init($assistant_api_url);
                    curl_setopt_array($assistant_curl, array(
                        CURLOPT_RETURNTRANSFER => true,
                        CURLOPT_POST => true,
                        CURLOPT_POSTFIELDS => $assistant_payload,
                        CURLOPT_HTTPHEADER => array(
                            'Content-Type: application/json',
                            'Accept: application/json',
                            'Authorization: Bearer ' . $assistant_api_token,
                        ),
                        CURLOPT_CONNECTTIMEOUT => 20,
                        CURLOPT_TIMEOUT => 120,
                    ));
                    $assistant_raw_response = curl_exec($assistant_curl);
                    if ($assistant_raw_response === false) {
                        $assistant_error = 'Assistant request failed: ' . curl_error($assistant_curl);
                    } else {
                        $assistant_response_status = (int) curl_getinfo($assistant_curl, CURLINFO_HTTP_CODE);
                        $assistant_response_data = json_decode($assistant_raw_response, true);
                        if ($assistant_response_status < 200 || $assistant_response_status >= 300) {
                            $assistant_error = is_array($assistant_response_data) && isset($assistant_response_data['data']['error'])
                                ? (string) $assistant_response_data['data']['error']
                                : 'Assistant request failed.';
                        } elseif (is_array($assistant_response_data) && isset($assistant_response_data['data']['reply'])) {
                            $assistant_reply = (string) $assistant_response_data['data']['reply'];

                            $assistant_candidate = trim($assistant_reply);
                            if (preg_match('/```(?:json)?\s*(\{[\s\S]*\})\s*```/i', $assistant_candidate, $assistant_match)) {
                                $assistant_candidate = trim($assistant_match[1]);
                            }
                            $assistant_plan_data = json_decode($assistant_candidate, true);
                            $assistant_normalized_plan = $assistant_normalize_plan($assistant_plan_data);
                            if (!is_array($assistant_plan_data) || !array_key_exists('operations', $assistant_plan_data) && !array_key_exists('edits', $assistant_plan_data)) {
                                $assistant_error = 'Model nevratil validny plan zmien (JSON). Skus preformulovat poziadavku.';
                            } else {
                                $assistant_plan_payload = array(
                                    'summary' => $assistant_normalized_plan['summary'],
                                    'operations' => $assistant_normalized_plan['operations'],
                                );
                                $assistant_plan_json = json_encode($assistant_plan_payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT);
                                $assistant_plan_summary = $assistant_normalized_plan['summary'];
                                $assistant_plan_operations = $assistant_normalized_plan['operations'];
                            }
                        } else {
                            $assistant_error = 'Assistant response is invalid.';
                        }
                    }
                    curl_close($assistant_curl);
                } else {
                    $assistant_context = stream_context_create(array(
                        'http' => array(
                            'method' => 'POST',
                            'header' => implode("\r\n", array(
                                'Content-Type: application/json',
                                'Accept: application/json',
                                'Authorization: Bearer ' . $assistant_api_token,
                            )),
                            'content' => $assistant_payload,
                            'timeout' => 120,
                            'ignore_errors' => true,
                        ),
                    ));
                    $assistant_raw_response = @file_get_contents($assistant_api_url, false, $assistant_context);
                    $assistant_response_data = is_string($assistant_raw_response) ? json_decode($assistant_raw_response, true) : null;
                    if (is_array($assistant_response_data) && isset($assistant_response_data['data']['reply'])) {
                        $assistant_reply = (string) $assistant_response_data['data']['reply'];
                        $assistant_candidate = trim($assistant_reply);
                        if (preg_match('/```(?:json)?\s*(\{[\s\S]*\})\s*```/i', $assistant_candidate, $assistant_match)) {
                            $assistant_candidate = trim($assistant_match[1]);
                        }
                        $assistant_plan_data = json_decode($assistant_candidate, true);
                        $assistant_normalized_plan = $assistant_normalize_plan($assistant_plan_data);
                        if (is_array($assistant_plan_data) && (array_key_exists('operations', $assistant_plan_data) || array_key_exists('edits', $assistant_plan_data))) {
                            $assistant_plan_payload = array(
                                'summary' => $assistant_normalized_plan['summary'],
                                'operations' => $assistant_normalized_plan['operations'],
                            );
                            $assistant_plan_json = json_encode($assistant_plan_payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT);
                            $assistant_plan_summary = $assistant_normalized_plan['summary'];
                            $assistant_plan_operations = $assistant_normalized_plan['operations'];
                        } else {
                            $assistant_error = 'Model nevratil validny plan zmien (JSON). Skus preformulovat poziadavku.';
                        }
                    } else {
                        $assistant_error = 'Assistant response is invalid.';
                    }
                }
            }
        }
    }

    if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['assistant_apply'])) {
        if ($assistant_api_token === '') {
            $assistant_error = 'API token pre interny zapis nie je nakonfigurovany.';
        } elseif ($assistant_workspace_error !== '') {
            $assistant_error = $assistant_workspace_error;
        } elseif ($assistant_plan_json === '') {
            $assistant_error = 'Najprv vytvor plan zmien.';
        } else {
            $assistant_normalized_plan = $assistant_normalize_plan(json_decode($assistant_plan_json, true));
            $assistant_plan_operations = $assistant_normalized_plan['operations'];
            if (empty($assistant_plan_operations)) {
                $assistant_error = 'Plan zmien je neplatny.';
            } else {
                $assistant_apply_require_confirmation = !$assistant_session_auto_apply && $assistant_require_confirmation;
                if ($assistant_apply_require_confirmation && empty($assistant_confirmed_operations)) {
                    $assistant_error = 'Vyber aspon jednu operaciu na potvrdenie, alebo vypni potvrdenie pre session.';
                }

                $assistant_apply_payload = json_encode(array(
                    'operations' => $assistant_plan_operations,
                    'require_confirmation' => $assistant_apply_require_confirmation,
                    'confirmed' => $assistant_confirmed_operations,
                ), JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
                if ($assistant_apply_payload === false) {
                    $assistant_error = 'Nepodarilo sa pripravit zapis zmien.';
                } elseif ($assistant_error === '') {
                    $assistant_base_path = rtrim(str_replace('\\', '/', dirname(isset($_SERVER['SCRIPT_NAME']) ? $_SERVER['SCRIPT_NAME'] : '')), '/');
                    if ($assistant_base_path === '.' || $assistant_base_path === '/') {
                        $assistant_base_path = '';
                    }
                    $assistant_apply_url = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https://' : 'http://') . $_SERVER['HTTP_HOST'] . $assistant_base_path . '/api.php?action=assistant_apply';

                    if (function_exists('curl_init')) {
                        $assistant_apply_curl = curl_init($assistant_apply_url);
                        curl_setopt_array($assistant_apply_curl, array(
                            CURLOPT_RETURNTRANSFER => true,
                            CURLOPT_POST => true,
                            CURLOPT_POSTFIELDS => $assistant_apply_payload,
                            CURLOPT_HTTPHEADER => array(
                                'Content-Type: application/json',
                                'Accept: application/json',
                                'Authorization: Bearer ' . $assistant_api_token,
                            ),
                            CURLOPT_CONNECTTIMEOUT => 20,
                            CURLOPT_TIMEOUT => 120,
                        ));
                        $assistant_apply_raw = curl_exec($assistant_apply_curl);
                        if ($assistant_apply_raw === false) {
                            $assistant_error = 'Apply request failed: ' . curl_error($assistant_apply_curl);
                        } else {
                            $assistant_apply_status = (int) curl_getinfo($assistant_apply_curl, CURLINFO_HTTP_CODE);
                            $assistant_apply_data = json_decode($assistant_apply_raw, true);
                            if ($assistant_apply_status < 200 || $assistant_apply_status >= 300) {
                                $assistant_error = is_array($assistant_apply_data) && isset($assistant_apply_data['data']['error'])
                                    ? (string) $assistant_apply_data['data']['error']
                                    : 'Apply request failed.';
                            } else {
                                $assistant_apply_ok = 'Operacie boli uspesne aplikovane.';
                                $assistant_plan_json = '';
                                $assistant_plan_operations = array();
                                $assistant_plan_summary = '';
                            }
                        }
                        curl_close($assistant_apply_curl);
                    } else {
                        $assistant_error = 'Server nepodporuje cURL pre aplikovanie zmien.';
                    }
                }
            }
        }
    }

    $assistant_base_path = rtrim(str_replace('\\', '/', dirname(isset($_SERVER['SCRIPT_NAME']) ? $_SERVER['SCRIPT_NAME'] : '')), '/');
    if ($assistant_base_path === '.' || $assistant_base_path === '/') {
        $assistant_base_path = '';
    }
    $assistant_current_url = '?p=' . urlencode(FM_PATH) . '&assistant_browser=1' . ($assistant_current_rel_path !== '' ? '&ajp=' . urlencode($assistant_current_rel_path) : '');
    ?>
    <style>
        body { background: linear-gradient(180deg, #eef4ff 0%, #f8fbff 45%, #ffffff 100%); }
        .assistant-shell { padding: 1.25rem; }
        .assistant-hero { background: linear-gradient(135deg, #0f172a 0%, #1d4ed8 55%, #38bdf8 100%); color: #fff; border-radius: 1rem; padding: 1.25rem 1.5rem; box-shadow: 0 14px 30px rgba(15, 23, 42, 0.18); }
        .assistant-card { border: 0; border-radius: 1rem; box-shadow: 0 10px 24px rgba(15, 23, 42, 0.08); overflow: hidden; }
        .assistant-card .card-header { background: rgba(255, 255, 255, 0.88); backdrop-filter: blur(8px); }
        .assistant-files { max-height: 62vh; overflow: auto; }
        .assistant-file-row { display:flex; align-items:center; gap:.65rem; padding:.6rem .75rem; border-bottom: 1px solid rgba(148, 163, 184, 0.18); }
        .assistant-file-row:last-child { border-bottom: 0; }
        .assistant-file-meta { color: #64748b; font-size: .85rem; }
        .assistant-output { white-space: pre-wrap; background: #0b1220; color: #e5eefc; border-radius: .9rem; padding: 1rem; min-height: 12rem; }
    </style>
    <div class="assistant-shell">
        <div class="assistant-hero mb-3">
            <div class="d-flex flex-wrap justify-content-between align-items-start gap-3">
                <div>
                    <h2 class="h4 mb-1">AI browser</h2>
                    <div class="opacity-75">Vyber súbory, pošli prompt a prehľadávaj projekty v izolovanom pracovisku Joyee.</div>
                </div>
                <div class="text-end">
                    <a class="btn btn-light btn-sm" href="<?php echo $assistant_current_url; ?>"><i class="fa fa-refresh"></i> Obnoviť</a>
                    <a class="btn btn-outline-light btn-sm" href="?p=<?php echo urlencode(FM_PATH); ?>"><i class="fa fa-folder-open"></i> Klasický pohľad</a>
                </div>
            </div>
        </div>

        <div class="row g-3">
            <div class="col-xl-4">
                <div class="card assistant-card h-100">
                    <div class="card-header d-flex align-items-center justify-content-between">
                        <strong>Prompt</strong>
                        <span class="badge text-bg-primary">OpenAI</span>
                    </div>
                    <div class="card-body">
                        <?php if ($assistant_error !== ''): ?>
                            <div class="alert alert-danger"><?php echo fm_enc($assistant_error); ?></div>
                        <?php endif; ?>
                        <?php if ($assistant_apply_ok !== ''): ?>
                            <div class="alert alert-success"><?php echo fm_enc($assistant_apply_ok); ?></div>
                        <?php endif; ?>
                        <?php if ($assistant_workspace_error !== ''): ?>
                            <div class="alert alert-warning"><?php echo fm_enc($assistant_workspace_error); ?></div>
                        <?php endif; ?>
                        <form method="post" action="<?php echo $assistant_current_url; ?>" id="assistant-browser-form">
                            <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>">
                            <input type="hidden" name="assistant_path" value="<?php echo fm_enc($assistant_current_rel_path); ?>">
                            <input type="hidden" name="assistant_plan_json" value="<?php echo fm_enc($assistant_plan_json); ?>">
                            <input type="hidden" name="assistant_require_confirmation" value="<?php echo $assistant_require_confirmation ? '1' : '0'; ?>">
                            <div class="mb-3">
                                <label for="assistant_message" class="form-label">Otázka alebo úloha</label>
                                <textarea id="assistant_message" name="assistant_message" class="form-control" rows="8" placeholder="Napr. skontroluj tento súbor a navrhni opravy"><?php echo fm_enc($assistant_message); ?></textarea>
                            </div>
                            <div class="form-check form-switch mb-3">
                                <input class="form-check-input" type="checkbox" role="switch" id="assistant_confirm_switch" <?php echo $assistant_require_confirmation ? 'checked' : ''; ?> <?php echo $assistant_session_auto_apply ? 'disabled' : ''; ?> onchange="document.querySelector('input[name=assistant_require_confirmation]').value = this.checked ? '1' : '0';">
                                <label class="form-check-label" for="assistant_confirm_switch">Potvrdiť operácie jednotlivo</label>
                            </div>
                            <div class="d-flex flex-wrap gap-2 mb-3">
                                <button type="submit" class="btn btn-primary" name="assistant_run" value="1"><i class="fa fa-lightbulb-o"></i> Navrhnúť zmeny</button>
                                <button type="submit" class="btn btn-success" name="assistant_apply" value="1" <?php echo empty($assistant_plan_operations) ? 'disabled' : ''; ?>><i class="fa fa-check"></i> Použiť zmeny</button>
                                <?php if (!$assistant_session_auto_apply): ?>
                                    <button type="submit" class="btn btn-outline-success" name="assistant_session_allow" value="1"><i class="fa fa-unlock"></i> Povoliť pre session</button>
                                <?php else: ?>
                                    <button type="submit" class="btn btn-outline-warning" name="assistant_session_reset" value="1"><i class="fa fa-lock"></i> Zrušiť session režim</button>
                                <?php endif; ?>
                                <button type="button" class="btn btn-outline-secondary" onclick="document.querySelectorAll('.assistant-file-check').forEach(function(el){ el.checked = true; });">Vybrať všetko</button>
                                <button type="button" class="btn btn-outline-secondary" onclick="document.querySelectorAll('.assistant-file-check').forEach(function(el){ el.checked = false; });">Zrušiť výber</button>
                            </div>
                        </form>

                        <?php if (!empty($assistant_plan_operations)): ?>
                            <div class="alert alert-secondary">
                                <strong>Plan zmien</strong>
                                <?php if ($assistant_plan_summary !== ''): ?>
                                    <div class="small mt-1"><?php echo fm_enc($assistant_plan_summary); ?></div>
                                <?php endif; ?>
                                <div class="small mt-1 mb-2"><?php echo $assistant_session_auto_apply ? 'Session režim: bez potvrdenia.' : ($assistant_require_confirmation ? 'Režim: vyžaduje potvrdenie operácií.' : 'Režim: bez potvrdenia operácií.'); ?></div>
                                <ul class="mb-0 mt-2">
                                    <?php foreach ($assistant_plan_operations as $assistant_op_index => $assistant_operation): ?>
                                        <?php
                                        $assistant_op_action = isset($assistant_operation['action']) ? strtolower((string) $assistant_operation['action']) : 'write';
                                        $assistant_op_target = isset($assistant_operation['path']) ? (string) $assistant_operation['path'] : ((isset($assistant_operation['to']) ? (string) $assistant_operation['to'] : (isset($assistant_operation['from']) ? (string) $assistant_operation['from'] : '(bez cesty)')));
                                        ?>
                                        <li>
                                            <?php if (!$assistant_session_auto_apply && $assistant_require_confirmation): ?>
                                                <input type="checkbox" name="assistant_confirmed[]" value="<?php echo (int) $assistant_op_index; ?>" form="assistant-browser-form" class="me-1" <?php echo in_array((int) $assistant_op_index, $assistant_confirmed_operations, true) ? 'checked' : ''; ?>>
                                            <?php endif; ?>
                                            <strong><?php echo fm_enc($assistant_op_action); ?></strong> - <?php echo fm_enc($assistant_op_target); ?>
                                        </li>
                                    <?php endforeach; ?>
                                </ul>
                            </div>
                        <?php endif; ?>

                        <?php if ($assistant_reply !== ''): ?>
                            <div class="assistant-output"><?php echo fm_enc($assistant_reply); ?></div>
                        <?php else: ?>
                            <div class="alert alert-info mb-0">Odpoveď sa zobrazí tu po odoslaní promptu.</div>
                        <?php endif; ?>
                    </div>
                </div>
            </div>

            <div class="col-xl-8">
                <div class="card assistant-card h-100">
                    <div class="card-header d-flex flex-wrap justify-content-between align-items-center gap-2">
                        <strong>Prehliadač súborov</strong>
                        <span class="assistant-file-meta">Joyee/<?php echo fm_enc($assistant_current_rel_path !== '' ? $assistant_current_rel_path : ''); ?></span>
                    </div>
                    <div class="card-body p-0">
                        <div class="assistant-files">
                            <?php if ($assistant_parent_rel_path !== false): ?>
                                <a class="assistant-file-row text-decoration-none" href="?p=<?php echo urlencode(FM_PATH); ?>&assistant_browser=1<?php echo $assistant_parent_rel_path !== '' ? '&ajp=' . urlencode($assistant_parent_rel_path) : ''; ?>">
                                    <i class="fa fa-level-up"></i>
                                    <span>..</span>
                                </a>
                            <?php endif; ?>

                            <?php foreach ($assistant_folder_items as $folder): ?>
                                <?php $assistant_folder_rel = trim($assistant_current_rel_path . '/' . $folder, '/'); ?>
                                <a class="assistant-file-row text-decoration-none" href="?p=<?php echo urlencode(FM_PATH); ?>&assistant_browser=1&amp;ajp=<?php echo urlencode($assistant_folder_rel); ?>">
                                    <i class="fa fa-folder text-warning"></i>
                                    <span class="flex-grow-1"><?php echo fm_enc($folder); ?></span>
                                    <span class="assistant-file-meta">priečinok</span>
                                </a>
                            <?php endforeach; ?>

                            <?php foreach ($assistant_file_items as $file): ?>
                                <?php $assistant_file_path = trim($assistant_current_rel_path . '/' . $file, '/'); ?>
                                <label class="assistant-file-row mb-0" for="assistant-file-<?php echo md5($assistant_file_path); ?>">
                                    <input class="assistant-file-check form-check-input mt-0" type="checkbox" id="assistant-file-<?php echo md5($assistant_file_path); ?>" name="assistant_files[]" value="<?php echo fm_enc($assistant_file_path); ?>" form="assistant-browser-form">
                                    <i class="fa fa-file-text-o text-primary"></i>
                                    <span class="flex-grow-1"><?php echo fm_enc($file); ?></span>
                                    <span class="assistant-file-meta"><?php echo fm_enc(fm_get_filesize(fm_get_size($assistant_current_abs_path . '/' . $file))); ?></span>
                                </label>
                            <?php endforeach; ?>

                            <?php if (empty($assistant_folder_items) && empty($assistant_file_items)): ?>
                                <div class="p-4 text-center text-body-secondary">Tento priečinok je prázdny.</div>
                            <?php endif; ?>
                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>
    <?php
    fm_show_footer();
    exit;
}

// upload form
if (isset($_GET['upload']) && (!FM_READONLY || FM_UPLOAD_ONLY) && FM_CAN_WRITE_IN_PATH) {
    fm_show_header(); // HEADER
    fm_show_nav_path(FM_PATH); // current path
    ?>
    <?php print_external('css-dropzone'); ?>
    <div class="path">

        <div class="card mb-2 fm-upload-wrapper" data-bs-theme="<?php echo FM_THEME; ?>">
            <div class="card-header">
                <ul class="nav nav-tabs card-header-tabs">
                    <li class="nav-item">
                        <a class="nav-link active" href="#fileUploader" data-bs-toggle="tab" data-bs-target="#fileUploader"><i class="fa fa-arrow-circle-o-up"></i> <?php echo lng('UploadingFiles') ?></a>
                    </li>
                    <li class="nav-item">
                        <a class="nav-link js-url-upload" href="#urlUploader" data-bs-toggle="tab" data-bs-target="#urlUploader"><i class="fa fa-link"></i> <?php echo lng('Upload from URL') ?></a>
                    </li>
                </ul>
            </div>
            <div class="card-body">
                <p class="card-text">
                    <a href="?p=<?php echo FM_PATH ?>" class="float-right"><i class="fa fa-chevron-circle-left go-back"></i> <?php echo lng('Back') ?></a>
                    <strong><?php echo lng('DestinationFolder') ?></strong>: <?php echo fm_enc(fm_convert_win(FM_PATH)) ?>
                </p>
                <p class="text-muted small mb-2">Súbor sa odošle automaticky po výbere.</p>

                <form action="<?php echo htmlspecialchars(FM_SELF_URL) . '?p=' . fm_enc(FM_PATH) ?>" method="POST" class="dropzone card-tabs-container" id="fileUploader" enctype="multipart/form-data">
                    <input type="hidden" name="p" value="<?php echo fm_enc(FM_PATH) ?>">
                    <input type="hidden" name="upload_dir" id="upload_dir" value="<?php echo fm_enc(FM_PATH) ?>">
                    <input type="hidden" name="fullpath" id="fullpath" value="">
                    <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>">
                    <div class="fallback">
                        <input name="file" type="file" multiple />
                        <button type="submit" class="btn btn-primary mt-2"><?php echo lng('Upload') ?></button>
                    </div>
                </form>

                <div class="tab-pane fade upload-url-wrapper" id="urlUploader">
                    <form id="js-form-url-upload" class="row row-cols-lg-auto g-3 align-items-center" onsubmit="return upload_from_url(this);" method="POST" action="">
                        <input type="hidden" name="type" value="upload" aria-label="hidden" aria-hidden="true">
                        <input type="hidden" name="upload_dir" value="<?php echo fm_enc(FM_PATH) ?>">
                        <input type="url" placeholder="URL" name="uploadurl" required class="form-control" style="width: 80%">
                        <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>">
                        <button type="submit" class="btn btn-primary ms-3"><?php echo lng('Upload') ?></button>
                        <div class="lds-facebook">
                            <div></div>
                            <div></div>
                            <div></div>
                        </div>
                    </form>
                    <div id="js-url-upload__list" class="col-9 mt-3"></div>
                </div>
            </div>
        </div>
    </div>
    <?php print_external('js-dropzone'); ?>
    <?php
    $fm_assets_base = rtrim(str_replace('\\', '/', dirname(FM_SELF_PATH)), '/');
    if ($fm_assets_base === '/' || $fm_assets_base === '.') {
        $fm_assets_base = '';
    }
    $fm_assets_version = fm_get_release_version();
    if ($fm_assets_version === 'dev') {
        $fm_assets_version = (string) VERSION;
    }
    $fm_upload_config = array(
        'chunkSize' => UPLOAD_CHUNK_SIZE,
        'maxFileSize' => MAX_UPLOAD_SIZE,
        'acceptedFiles' => getUploadExt(),
    );
    ?>
    <script type="application/json" id="fm-upload-config"><?php echo json_encode($fm_upload_config, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT); ?></script>
    <script src="<?php echo fm_enc($fm_assets_base . '/src/assets/js/fm-upload.js?v=' . rawurlencode((string) $fm_assets_version)); ?>"></script>
<?php
    fm_show_footer();
    exit;
}

// copy form POST
if (isset($_POST['copy']) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $copy_files = isset($_POST['file']) ? $_POST['file'] : null;
    $mass_move_requested = isset($_POST['move']);
    if (!is_array($copy_files) || empty($copy_files)) {
        fm_set_msg(lng('Nothing selected'), 'alert');
        $FM_PATH = FM_PATH;
        fm_redirect(FM_SELF_URL . '?p=' . urlencode($FM_PATH));
    }

    fm_show_header(); // HEADER
    fm_show_nav_path(FM_PATH); // current path
?>
    <div class="path">
        <div class="card" data-bs-theme="<?php echo FM_THEME; ?>">
            <div class="card-header">
                <h6><?php echo $mass_move_requested ? lng('Move') : lng('Copying'); ?></h6>
            </div>
            <div class="card-body">
                <form action="" method="post">
                    <input type="hidden" name="p" value="<?php echo fm_enc(FM_PATH) ?>">
                    <input type="hidden" name="finish" value="1">
                    <?php
                    foreach ($copy_files as $cf) {
                        echo '<input type="hidden" name="file[]" value="' . fm_enc($cf) . '">' . PHP_EOL;
                    }
                    ?>
                    <p class="break-word"><strong><?php echo lng('Files') ?></strong>: <b><?php echo implode('</b>, <b>', $copy_files) ?></b></p>
                    <p class="break-word"><strong><?php echo lng('SourceFolder') ?></strong>: <?php echo fm_enc(fm_convert_win(FM_ROOT_PATH . '/' . FM_PATH)) ?><br>
                        <label for="inp_copy_to"><strong><?php echo lng('DestinationFolder') ?></strong>:</label>
                        <?php echo FM_ROOT_PATH ?>/<input type="text" name="copy_to" id="inp_copy_to" value="<?php echo fm_enc(FM_PATH) ?>">
                    </p>
                    <p class="custom-checkbox custom-control"><input type="checkbox" name="move" value="1" id="js-move-files" class="custom-control-input" <?php echo $mass_move_requested ? 'checked' : ''; ?>>
                        <label for="js-move-files" class="custom-control-label ms-2"><?php echo lng('Move') ?></label>
                    </p>
                    <p>
                        <b><a href="?p=<?php echo urlencode(FM_PATH) ?>" class="btn btn-outline-danger"><i class="fa fa-times-circle"></i> <?php echo lng('Cancel') ?></a></b>&nbsp;
                        <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>">
                        <button type="submit" class="btn btn-success"><i class="fa fa-check-circle"></i> <?php echo $mass_move_requested ? lng('Move') : lng('Copy'); ?></button>
                    </p>
                </form>
            </div>
        </div>
    </div>
<?php
    fm_show_footer();
    exit;
}

// copy form
if (isset($_GET['copy']) && !isset($_GET['finish']) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $copy = $_GET['copy'];
    $copy = fm_clean_path($copy);
    if ($copy == '' || !file_exists(FM_ROOT_PATH . '/' . $copy)) {
        fm_set_msg(lng('File not found'), 'error');
        $FM_PATH = FM_PATH;
        fm_redirect(FM_SELF_URL . '?p=' . urlencode($FM_PATH));
    }

    fm_show_header(); // HEADER
    fm_show_nav_path(FM_PATH); // current path
?>
    <div class="path">
        <p><b>Copying</b></p>
        <p class="break-word">
            <strong>Source path:</strong> <?php echo fm_enc(fm_convert_win(FM_ROOT_PATH . '/' . $copy)) ?><br>
            <strong>Destination folder:</strong> <?php echo fm_enc(fm_convert_win(FM_ROOT_PATH . '/' . FM_PATH)) ?>
        </p>
        <p>
            <b><a href="?p=<?php echo urlencode(FM_PATH) ?>&amp;copy=<?php echo urlencode($copy) ?>&amp;finish=1"><i class="fa fa-check-circle"></i> Copy</a></b> &nbsp;
            <b><a href="?p=<?php echo urlencode(FM_PATH) ?>&amp;copy=<?php echo urlencode($copy) ?>&amp;finish=1&amp;move=1"><i class="fa fa-check-circle"></i> Move</a></b> &nbsp;
            <b><a href="?p=<?php echo urlencode(FM_PATH) ?>" class="text-danger"><i class="fa fa-times-circle"></i> Cancel</a></b>
        </p>
        <p><i><?php echo lng('Select folder') ?></i></p>
        <ul class="folders break-word">
            <?php
            if ($parent !== false) {
            ?>
                <li><a href="?p=<?php echo urlencode($parent) ?>&amp;copy=<?php echo urlencode($copy) ?>"><i class="fa fa-chevron-circle-left"></i> ..</a></li>
            <?php
            }
            foreach ($folders as $f) {
            ?>
                <li>
                    <a href="?p=<?php echo urlencode(trim(FM_PATH . '/' . $f, '/')) ?>&amp;copy=<?php echo urlencode($copy) ?>"><i class="fa fa-folder-o"></i> <?php echo fm_convert_win($f) ?></a>
                </li>
            <?php
            }
            ?>
        </ul>
    </div>
<?php
    fm_show_footer();
    exit;
}

if (isset($_GET['settings']) && ((FM_USE_AUTH && !empty($_SESSION[FM_SESSION_ID]['logged'])) || (!FM_READONLY && FM_CAN_WRITE_IN_PATH))) {
    fm_show_header(); // HEADER
    fm_show_nav_path(FM_PATH); // current path
    global $cfg, $lang, $lang_list;
    $settings_current_user = isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : '';
    $fallback_log_enabled = !empty($cfg->data['fallback_logging']);
    $fallback_log_path = fm_runtime_state_dir() . '/fallback-events.log';
    $fallback_log_exists = is_file($fallback_log_path);
    $fallback_log_bytes = $fallback_log_exists ? (int) @filesize($fallback_log_path) : 0;
    if ($fallback_log_bytes < 0) {
        $fallback_log_bytes = 0;
    }
    $fallback_log_lines = 0;
    if ($fallback_log_exists) {
        $fallback_log_handle = @fopen($fallback_log_path, 'r');
        if ($fallback_log_handle) {
            while (!feof($fallback_log_handle)) {
                $fallback_log_line = fgets($fallback_log_handle);
                if ($fallback_log_line !== false) {
                    $fallback_log_lines++;
                }
            }
            fclose($fallback_log_handle);
        }
    }
    $fallback_log_updated = $fallback_log_exists && @filemtime($fallback_log_path) ? date('Y-m-d H:i:s', (int) @filemtime($fallback_log_path)) : '';
    $fallback_log_status_text = 'NIZKE';
    $fallback_log_status_class = 'success';
    if ($fallback_log_bytes >= 220000 || $fallback_log_lines >= 900) {
        $fallback_log_status_text = 'VYSOKE';
        $fallback_log_status_class = 'danger';
    } elseif ($fallback_log_bytes >= 131072 || $fallback_log_lines >= 600) {
        $fallback_log_status_text = 'STREDNE';
        $fallback_log_status_class = 'warning';
    }
?>

    <div class="col-md-8 offset-md-2 pt-3">
        <div class="card mb-2" data-bs-theme="<?php echo FM_THEME; ?>">
            <h6 class="card-header d-flex justify-content-between">
                <span><i class="fa fa-cog"></i> <?php echo lng('Settings') ?></span>
                <a href="?p=<?php echo FM_PATH ?>" class="text-danger"><i class="fa fa-times-circle-o"></i> <?php echo lng('Cancel') ?></a>
            </h6>
            <div class="card-body">
                <form id="js-settings-form" action="" method="post" data-type="ajax" onsubmit="return save_settings(this)">
                    <input type="hidden" name="type" value="settings" aria-label="hidden" aria-hidden="true">
                    <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>" aria-label="hidden" aria-hidden="true">
                    <div class="form-group row">
                        <label for="js-language" class="col-sm-3 col-form-label"><?php echo lng('Language') ?></label>
                        <div class="col-sm-5">
                            <select class="form-select" id="js-language" name="js-language">
                                <?php
                                foreach ($lang_list as $k => $v) {
                                    echo "<option value='$k' " . getSelected($k) . ">$v</option>";
                                }
                                ?>
                            </select>
                        </div>
                    </div>
                    <?php if (!FM_UPLOAD_ONLY): ?>
                    <div class="mt-3 mb-3 row ">
                        <label for="js-error-report" class="col-sm-3 col-form-label"><?php echo lng('ErrorReporting') ?></label>
                        <div class="col-sm-9">
                            <div class="form-check form-switch">
                                <input class="form-check-input" type="checkbox" role="switch" id="js-error-report" name="js-error-report" value="true" <?php echo $report_errors ? 'checked' : ''; ?> />
                            </div>
                        </div>
                    </div>

                    <div class="mb-3 row">
                        <label for="js-show-hidden" class="col-sm-3 col-form-label"><?php echo lng('ShowHiddenFiles') ?></label>
                        <div class="col-sm-9">
                            <div class="form-check form-switch">
                                <input class="form-check-input" type="checkbox" role="switch" id="js-show-hidden" name="js-show-hidden" value="true" <?php echo $show_hidden_files ? 'checked' : ''; ?> />
                            </div>
                        </div>
                    </div>
                    <?php endif; ?>
                    <?php if (FM_UPLOAD_ONLY): ?>
                    <div class="alert alert-info py-2 px-3" role="alert">
                        <i class="fa fa-info-circle" aria-hidden="true"></i>
                        <?php echo lng('Some internal options are available only for managers'); ?>
                    </div>
                    <?php endif; ?>

                    <div class="mb-3 row">
                        <label for="js-hide-cols" class="col-sm-3 col-form-label"><?php echo lng('HideColumns') ?></label>
                        <div class="col-sm-9">
                            <div class="form-check form-switch">
                                <input class="form-check-input" type="checkbox" role="switch" id="js-hide-cols" name="js-hide-cols" value="true" <?php echo $hide_Cols ? 'checked' : ''; ?> />
                            </div>
                        </div>
                    </div>

                    <div class="mb-3 row">
                        <label for="js-3-1" class="col-sm-3 col-form-label"><?php echo lng('Theme') ?></label>
                        <div class="col-sm-5">
                            <select class="form-select w-100 text-capitalize" id="js-3-0" name="js-theme-3">
                                <option value='light' <?php if ($theme == "light") {
                                                            echo "selected";
                                                        } ?>>
                                    <?php echo lng('light') ?>
                                </option>
                                <option value='dark' <?php if ($theme == "dark") {
                                                            echo "selected";
                                                        } ?>>
                                    <?php echo lng('dark') ?>
                                </option>
                            </select>
                        </div>
                    </div>

                    <div class="mb-3 row">
                        <label for="js-list-density" class="col-sm-3 col-form-label">Hustota zoznamu</label>
                        <div class="col-sm-5">
                            <select class="form-select w-100" id="js-list-density" name="js-list-density">
                                <option value="normal" <?php echo ($list_density === 'normal') ? 'selected' : ''; ?>>Normal</option>
                                <option value="compact" <?php echo ($list_density !== 'normal') ? 'selected' : ''; ?>>Compact</option>
                            </select>
                        </div>
                    </div>

                    <div class="mb-3 row">
                        <label for="js-fallback-log-enabled" class="col-sm-3 col-form-label">Logovanie fallback udalosti</label>
                        <div class="col-sm-9">
                            <div class="form-check form-switch">
                                <input class="form-check-input" type="checkbox" role="switch" id="js-fallback-log-enabled" name="js-fallback-log-enabled" value="true" <?php echo $fallback_log_enabled ? 'checked' : ''; ?> />
                            </div>
                            <small class="text-body-secondary">Loguje len self-service fallback udalosti. Automaticky orezane (max 256KB / 1000 riadkov, ponecha najnovsich 500).</small>
                            <div id="js-fallback-log-stats" class="mt-2 small text-body-secondary">
                                <strong>Zive info logu:</strong>
                                <span class="ms-1 badge bg-<?php echo fm_enc($fallback_log_status_class); ?>" id="js-fallback-log-status"><?php echo fm_enc($fallback_log_status_text); ?></span>
                                <span>existuje: <span id="js-fallback-log-exists"><?php echo $fallback_log_exists ? 'ano' : 'nie'; ?></span></span>,
                                <span>velkost: <span id="js-fallback-log-bytes"><?php echo (int) $fallback_log_bytes; ?></span> B</span>,
                                <span>riadky: <span id="js-fallback-log-lines"><?php echo (int) $fallback_log_lines; ?></span></span>,
                                <span>aktualizovane: <span id="js-fallback-log-updated"><?php echo fm_enc($fallback_log_updated); ?></span></span>
                            </div>
                        </div>
                    </div>

                    <div class="mb-3 row">
                        <div class="col-sm-10">
                            <button type="submit" class="btn btn-success"> <i class="fa fa-check-circle"></i> <?php echo lng('Save'); ?></button>
                            <?php if ($settings_current_user === 'admin'): ?>
                            <button type="button" class="btn btn-outline-danger ms-2" onclick="return clear_fallback_log()"><i class="fa fa-trash"></i> Clear fallback log</button>
                            <?php endif; ?>
                        </div>
                    </div>

                    <small class="text-body-secondary">* <?php echo lng('Sometimes the save action may not work on the first try, so please attempt it again') ?>.</small>
                </form>

                <?php if (!empty($_SESSION[FM_SESSION_ID]['logged'])): ?>
                <hr>
                <h6 class="mt-3 mb-3"><i class="fa fa-lock"></i> <?php echo lng('Change Password') ?></h6>
                <form id="js-changepwd-form" action="" method="post" onsubmit="return change_password(this)">
                    <input type="hidden" name="type" value="changepwd" aria-label="hidden" aria-hidden="true">
                    <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>" aria-label="hidden" aria-hidden="true">
                    <div class="mb-2 row">
                        <label class="col-sm-3 col-form-label"><?php echo lng('New password') ?></label>
                        <div class="col-sm-5">
                            <input type="password" class="form-control" name="new_password" autocomplete="new-password" minlength="6" required>
                        </div>
                    </div>
                    <div class="mb-3 row">
                        <label class="col-sm-3 col-form-label"><?php echo lng('Confirm password') ?></label>
                        <div class="col-sm-5">
                            <input type="password" class="form-control" name="confirm_password" autocomplete="new-password" minlength="6" required>
                        </div>
                    </div>
                    <div class="mb-3 row">
                        <div class="col-sm-10">
                            <button type="submit" class="btn btn-warning"><i class="fa fa-key"></i> <?php echo lng('Change Password') ?></button>
                        </div>
                    </div>
                </form>
                <?php endif; ?>
            </div>
        </div>
    </div>
<?php
    fm_show_footer();
    exit;
}

if (isset($_GET['help'])) {
    fm_show_header(); // HEADER
    fm_show_nav_path(FM_PATH); // current path
    global $cfg, $lang;
    $help_path_param = urlencode(FM_PATH);
?>

    <div class="col-md-8 offset-md-2 pt-3">
        <div class="card mb-2" data-bs-theme="<?php echo FM_THEME; ?>">
            <h6 class="card-header d-flex justify-content-between">
                <span><i class="fa fa-exclamation-circle"></i> <?php echo lng('Help') ?></span>
                <a href="<?php echo FM_SELF_URL; ?>?p=<?php echo $help_path_param; ?>" class="text-danger"><i class="fa fa-times-circle-o"></i> <?php echo lng('Cancel') ?></a>
            </h6>
            <div class="card-body">
                <div class="row">
                    <div class="col-xs-12 col-sm-6">
                        <p>
                        <h3><a href="https://github.com/prasathmani/tinyfilemanager" target="_blank" class="app-v-title"> Tiny File Manager <?php echo VERSION; ?></a></h3>
                        </p>
                        <p><strong>Autorský kolektív:</strong></p>
                        <p class="mb-1">1. Prasath Mani</p>
                        <p class="mb-1">2. Slavomir Piar</p>
                        <p class="mb-2">3. CCP Programmers &amp; PIAR team</p>
                        <p class="mb-2"><strong>S podporou AI modulov:</strong> GitHub Copilot a Joyee</p>
                        <p>Mail Us: <a href="mailto:ccpprogrammers@gmail.com">ccpprogrammers [at] gmail [dot] com</a></p>
                    </div>
                    <div class="col-xs-12 col-sm-6">
                        <div class="card">
                            <ul class="list-group list-group-flush">
                                <li class="list-group-item"><a href="<?php echo FM_SELF_URL; ?>?p=<?php echo $help_path_param; ?>&help_doc=user-guide"><i class="fa fa-book"></i> Používateľská príručka (lokálna)</a></li>
                                <li class="list-group-item"><a href="<?php echo FM_SELF_URL; ?>?p=<?php echo $help_path_param; ?>&help_doc=wiki-index"><i class="fa fa-question-circle"></i> Online dokumentácia (Wiki)</a></li>
                                <li class="list-group-item"><a href="<?php echo FM_SELF_URL; ?>?p=<?php echo $help_path_param; ?>&help_doc=security"><i class="fa fa-shield"></i> Bezpečnostné zásady</a></li>
                                <li class="list-group-item"><a href="https://github.com/prasathmani/tinyfilemanager/issues" target="_blank"><i class="fa fa-bug"></i> <?php echo lng('Report Issue') ?></a></li>
                                <?php if (!FM_READONLY) { ?>
                                    <li class="list-group-item"><a href="javascript:show_new_pwd();"><i class="fa fa-lock"></i> <?php echo lng('Generate new password hash') ?></a></li>
                                <?php } ?>
                            </ul>
                        </div>
                    </div>
                </div>
                <div class="row js-new-pwd hidden mt-2">
                    <div class="col-12">
                        <form class="form-inline" onsubmit="return new_password_hash(this)" method="POST" action="">
                            <input type="hidden" name="type" value="pwdhash" aria-label="hidden" aria-hidden="true">
                            <div class="form-group mb-2">
                                <label for="staticEmail2"><?php echo lng('Generate new password hash') ?></label>
                            </div>
                            <div class="form-group mx-sm-3 mb-2">
                                <label for="inputPassword2" class="sr-only"><?php echo lng('Password') ?></label>
                                <input type="text" class="form-control btn-sm" id="inputPassword2" name="inputPassword2" placeholder="<?php echo lng('Password') ?>" required>
                            </div>
                            <button type="submit" class="btn btn-success btn-sm mb-2"><?php echo lng('Generate') ?></button>
                        </form>
                        <textarea class="form-control" rows="2" readonly id="js-pwd-result"></textarea>
                    </div>
                </div>
            </div>
        </div>
    </div>
<?php
    fm_show_footer();
    exit;
}

if (isset($_GET['help_doc'])) {
    fm_show_header();
    fm_show_nav_path(FM_PATH);

    $doc_key = isset($_GET['help_doc']) ? trim((string) $_GET['help_doc']) : '';
    $help_path_param = urlencode(FM_PATH);
    $wiki_chapters = array(
        'wiki-index' => 'Prehľad',
        'wiki-home' => 'Domov',
        'wiki-get-started' => 'Začíname',
        'wiki-deploy-docker' => 'Nasadenie cez Docker',
        'wiki-security-users' => 'Bezpečnosť a správa používateľov',
        'wiki-exclude' => 'Vylúčenie súborov a priečinkov',
        'wiki-restriction-file-type' => 'Obmedzenie podľa typu súboru',
        'wiki-ip-rules' => 'IP blacklist a whitelist',
        'wiki-embedding' => 'Vloženie do iného skriptu',
        'wiki-config-flags' => 'Konfiguračné prepínače',
        'wiki-faq' => 'FAQ',
        'wiki-login-db' => 'Prihlásenie pomocou databázy',
        'wiki-authors' => 'Autori a prispievatelia',
        'wiki-our-extensions' => 'Naše rozšírenia',
    );
    $doc_map = array(
        'user-guide' => array(
            'title' => 'Používateľská príručka (lokálna)',
            'path' => __DIR__ . '/docs/USER_GUIDE_SK.md',
        ),
        'security' => array(
            'title' => 'Bezpečnostné zásady',
            'path' => __DIR__ . '/SECURITY.md',
        ),
        'wiki-index' => array(
            'title' => 'Online dokumentácia (Wiki SK)',
            'path' => __DIR__ . '/docs/wiki-sk/INDEX_SK.md',
        ),
        'wiki-home' => array(
            'title' => 'Wiki SK: Home',
            'path' => __DIR__ . '/docs/wiki-sk/Home.SK.md',
        ),
        'wiki-get-started' => array(
            'title' => 'Wiki SK: Get Started',
            'path' => __DIR__ . '/docs/wiki-sk/Get-Started.SK.md',
        ),
        'wiki-deploy-docker' => array(
            'title' => 'Wiki SK: Deploy by Docker',
            'path' => __DIR__ . '/docs/wiki-sk/Deploy-by-Docker.SK.md',
        ),
        'wiki-security-users' => array(
            'title' => 'Wiki SK: Security and User Management',
            'path' => __DIR__ . '/docs/wiki-sk/Security-and-User-Management.SK.md',
        ),
        'wiki-exclude' => array(
            'title' => 'Wiki SK: Exclude Files & Folders',
            'path' => __DIR__ . '/docs/wiki-sk/Exclude-Files-&-Folders.SK.md',
        ),
        'wiki-restriction-file-type' => array(
            'title' => 'Wiki SK: Restriction by file type',
            'path' => __DIR__ . '/docs/wiki-sk/Restriction-by-file-type.SK.md',
        ),
        'wiki-ip-rules' => array(
            'title' => 'Wiki SK: IP Blacklist and Whitelist',
            'path' => __DIR__ . '/docs/wiki-sk/IP-Blacklist-and-Whitelist.SK.md',
        ),
        'wiki-embedding' => array(
            'title' => 'Wiki SK: Embedding',
            'path' => __DIR__ . '/docs/wiki-sk/Embedding.SK.md',
        ),
        'wiki-config-flags' => array(
            'title' => 'Wiki SK: Config Flags',
            'path' => __DIR__ . '/docs/wiki-sk/Config-Flags.SK.md',
        ),
        'wiki-faq' => array(
            'title' => 'Wiki SK: FAQ',
            'path' => __DIR__ . '/docs/wiki-sk/FAQ.SK.md',
        ),
        'wiki-login-db' => array(
            'title' => 'Wiki SK: Login using Database',
            'path' => __DIR__ . '/docs/wiki-sk/Login-using-Database.SK.md',
        ),
        'wiki-authors' => array(
            'title' => 'Wiki SK: Authors and Contributors',
            'path' => __DIR__ . '/docs/wiki-sk/Authors-and-Contributors.SK.md',
        ),
        'wiki-our-extensions' => array(
            'title' => 'Wiki SK: Naše rozšírenia',
            'path' => __DIR__ . '/docs/wiki-sk/Nase-Rozsirenia.SK.md',
        ),
    );

    $doc_title = 'Dokument';
    $doc_content = '';
    $doc_error = '';
    $wiki_order_keys = array_keys($wiki_chapters);
    $wiki_current_index = array_search($doc_key, $wiki_order_keys, true);
    $wiki_prev_key = false;
    $wiki_next_key = false;
    if ($wiki_current_index !== false) {
        $wiki_prev_key = ($wiki_current_index > 0) ? $wiki_order_keys[$wiki_current_index - 1] : false;
        $wiki_next_key = ($wiki_current_index < count($wiki_order_keys) - 1) ? $wiki_order_keys[$wiki_current_index + 1] : false;
    }

    if (!isset($doc_map[$doc_key])) {
        $doc_error = 'Požadovaný dokument nie je dostupný.';
    } else {
        $doc_title = $doc_map[$doc_key]['title'];
        $doc_path = $doc_map[$doc_key]['path'];
        if (!is_file($doc_path) || !is_readable($doc_path)) {
            $doc_error = 'Dokument sa nepodarilo načítať.';
        } else {
            $doc_content = (string) file_get_contents($doc_path);
        }
    }
?>
    <div class="col-md-10 offset-md-1 pt-3">
        <div class="card mb-2" data-bs-theme="<?php echo FM_THEME; ?>">
            <h6 class="card-header d-flex justify-content-between">
                <span><i class="fa fa-book"></i> <?php echo htmlspecialchars($doc_title, ENT_QUOTES, 'UTF-8'); ?></span>
                <a href="<?php echo FM_SELF_URL; ?>?p=<?php echo $help_path_param; ?>&help=1" class="text-danger"><i class="fa fa-times-circle-o"></i> <?php echo lng('Cancel') ?></a>
            </h6>
            <div class="card-body">
                <?php if ($doc_error !== ''): ?>
                    <div class="alert alert-warning mb-0" role="alert"><?php echo htmlspecialchars($doc_error, ENT_QUOTES, 'UTF-8'); ?></div>
                <?php else: ?>
                    <style>
                        .fm-wiki-chapter-nav { margin-bottom: 0.9rem; }
                        .fm-wiki-chapter-nav .fm-wiki-link { display: inline-block; margin: 0 0.35rem 0.35rem 0; padding: 0.2rem 0.45rem; border: 1px solid rgba(0, 0, 0, 0.14); border-radius: 6px; text-decoration: none; }
                        .fm-wiki-chapter-nav .fm-wiki-link.is-active { font-weight: 600; border-color: rgba(13, 110, 253, 0.55); }
                        .fm-wiki-pager { border-top: 1px solid rgba(0, 0, 0, 0.12); margin-top: 1rem; padding-top: 0.8rem; display: flex; justify-content: space-between; gap: 1rem; }
                        .fm-wiki-pager .fm-wiki-prev, .fm-wiki-pager .fm-wiki-next { flex: 1 1 50%; }
                        .fm-wiki-pager .fm-wiki-next { text-align: right; }
                        .fm-help-markdown h1, .fm-help-markdown h2, .fm-help-markdown h3, .fm-help-markdown h4 { margin-top: 1.2rem; margin-bottom: 0.6rem; }
                        .fm-help-markdown p { margin-bottom: 0.7rem; }
                        .fm-help-markdown ul, .fm-help-markdown ol { margin-bottom: 0.8rem; padding-left: 1.3rem; }
                        .fm-help-markdown pre { background: rgba(0, 0, 0, 0.06); padding: 0.75rem; border-radius: 6px; overflow-x: auto; }
                        .fm-help-markdown code { background: rgba(0, 0, 0, 0.06); padding: 0.12rem 0.35rem; border-radius: 4px; }
                        .fm-help-markdown pre code { background: transparent; padding: 0; }
                    </style>
                    <?php if ($wiki_current_index !== false): ?>
                        <div class="fm-wiki-chapter-nav">
                            <?php foreach ($wiki_chapters as $wiki_key => $wiki_label): ?>
                                <?php $wiki_link = FM_SELF_URL . '?p=' . $help_path_param . '&help_doc=' . urlencode($wiki_key); ?>
                                <a class="fm-wiki-link<?php echo ($wiki_key === $doc_key) ? ' is-active' : ''; ?>" href="<?php echo $wiki_link; ?>"><?php echo htmlspecialchars($wiki_label, ENT_QUOTES, 'UTF-8'); ?></a>
                            <?php endforeach; ?>
                        </div>
                    <?php endif; ?>
                    <div class="fm-help-markdown"><?php echo fm_render_markdown_basic($doc_content); ?></div>
                    <?php if ($wiki_current_index !== false): ?>
                        <div class="fm-wiki-pager">
                            <div class="fm-wiki-prev">
                                <?php if ($wiki_prev_key !== false): ?>
                                    <a href="<?php echo FM_SELF_URL . '?p=' . $help_path_param . '&help_doc=' . urlencode($wiki_prev_key); ?>">&larr; Predošlá kapitola</a>
                                <?php endif; ?>
                            </div>
                            <div class="fm-wiki-next">
                                <?php if ($wiki_next_key !== false): ?>
                                    <a href="<?php echo FM_SELF_URL . '?p=' . $help_path_param . '&help_doc=' . urlencode($wiki_next_key); ?>">Nasledujúca kapitola &rarr;</a>
                                <?php endif; ?>
                            </div>
                        </div>
                    <?php endif; ?>
                <?php endif; ?>
            </div>
        </div>
    </div>
<?php
    fm_show_footer();
    exit;
}

// file viewer
if (isset($_GET['view'])) {
    $file_view_context_service = new TFM_FileViewContextService(FM_ROOT_PATH, FM_PATH);
    $file_view_context = $file_view_context_service->build($_GET['view']);

    $file = $file_view_context['file'];
    $file_url = $file_view_context['file_url'];
    $file_path = $file_view_context['file_path'];
    $view_info = $file_view_context['view_info'];

    fm_show_header(); // HEADER
    fm_show_nav_path(FM_PATH); // current path

    $ext = $view_info['ext'];
    $mime_type = $view_info['mime_type'];
    $is_image_mime = $view_info['is_image_mime'];
    $filesize_raw = $view_info['filesize_raw'];
    $filesize = $view_info['filesize'];
    $is_zip = $view_info['is_zip'];
    $is_gzip = $view_info['is_gzip'];
    $is_image = $view_info['is_image'];
    $is_audio = $view_info['is_audio'];
    $is_video = $view_info['is_video'];
    $is_pdf = $view_info['is_pdf'];
    $is_text = $view_info['is_text'];
    $is_onlineViewer = $view_info['is_onlineViewer'];
    $view_title = $view_info['view_title'];
    $filenames = $view_info['filenames'];
    $content = $view_info['content'];
    require __DIR__ . '/src/renderers/file-viewer.php';
    fm_show_footer();
    exit;
}

// file editor
if (isset($_GET['edit']) && !FM_READONLY && !FM_UPLOAD_ONLY && FM_CAN_WRITE_IN_PATH) {
    $file_editor_context_service = new TFM_FileEditorContextService(FM_ROOT_PATH, FM_PATH);
    $editor_context = $file_editor_context_service->build($_GET['edit'], $_GET, $_POST);

    $file = $editor_context['file'];
    $editFile = $editor_context['editFile'];
    $file_url = $editor_context['file_url'];
    $file_path = $editor_context['file_path'];
    $isNormalEditor = $editor_context['isNormalEditor'];
    $ext = $editor_context['ext'];
    $mime_type = $editor_context['mime_type'];
    $filesize = $editor_context['filesize'];
    $is_text = $editor_context['is_text'];
    $content = $editor_context['content'];

    header('X-XSS-Protection:0');
    fm_show_header(); // HEADER
    fm_show_nav_path(FM_PATH); // current path
    require __DIR__ . '/src/renderers/file-editor.php';
    fm_show_footer();
    exit;
}

// chmod (not for Windows)
if (isset($_GET['chmod']) && !FM_READONLY && !FM_UPLOAD_ONLY && !FM_IS_WIN && FM_CAN_WRITE_IN_PATH) {
    $chmod_page_context_service = new TFM_ChmodPageContextService(FM_ROOT_PATH, FM_PATH);
    $chmod_context = $chmod_page_context_service->build($_GET['chmod']);

    $file = $chmod_context['file'];
    $file_url = $chmod_context['file_url'];
    $file_path = $chmod_context['file_path'];
    $mode = $chmod_context['mode'];

    fm_show_header(); // HEADER
    fm_show_nav_path(FM_PATH); // current path
?>
    <div class="path">
        <div class="card mb-2" data-bs-theme="<?php echo FM_THEME; ?>">
            <h6 class="card-header">
                <?php echo lng('ChangePermissions') ?>
            </h6>
            <div class="card-body">
                <p class="card-text">
                    <?php $display_path = fm_get_display_path($file_path); ?>
                    <?php echo $display_path['label']; ?>: <?php echo $display_path['path']; ?><br>
                </p>
                <form action="" method="post">
                    <input type="hidden" name="p" value="<?php echo fm_enc(FM_PATH) ?>">
                    <input type="hidden" name="chmod" value="<?php echo fm_enc($file) ?>">

                    <table class="table compact-table" data-bs-theme="<?php echo FM_THEME; ?>">
                        <tr>
                            <td></td>
                            <td><b><?php echo lng('Owner') ?></b></td>
                            <td><b><?php echo lng('Group') ?></b></td>
                            <td><b><?php echo lng('Other') ?></b></td>
                        </tr>
                        <tr>
                            <td style="text-align: right"><b><?php echo lng('Read') ?></b></td>
                            <td><label><input type="checkbox" name="ur" value="1" <?php echo ($mode & 00400) ? ' checked' : '' ?>></label></td>
                            <td><label><input type="checkbox" name="gr" value="1" <?php echo ($mode & 00040) ? ' checked' : '' ?>></label></td>
                            <td><label><input type="checkbox" name="or" value="1" <?php echo ($mode & 00004) ? ' checked' : '' ?>></label></td>
                        </tr>
                        <tr>
                            <td style="text-align: right"><b><?php echo lng('Write') ?></b></td>
                            <td><label><input type="checkbox" name="uw" value="1" <?php echo ($mode & 00200) ? ' checked' : '' ?>></label></td>
                            <td><label><input type="checkbox" name="gw" value="1" <?php echo ($mode & 00020) ? ' checked' : '' ?>></label></td>
                            <td><label><input type="checkbox" name="ow" value="1" <?php echo ($mode & 00002) ? ' checked' : '' ?>></label></td>
                        </tr>
                        <tr>
                            <td style="text-align: right"><b><?php echo lng('Execute') ?></b></td>
                            <td><label><input type="checkbox" name="ux" value="1" <?php echo ($mode & 00100) ? ' checked' : '' ?>></label></td>
                            <td><label><input type="checkbox" name="gx" value="1" <?php echo ($mode & 00010) ? ' checked' : '' ?>></label></td>
                            <td><label><input type="checkbox" name="ox" value="1" <?php echo ($mode & 00001) ? ' checked' : '' ?>></label></td>
                        </tr>
                    </table>

                    <p>
                        <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>">
                        <b><a href="?p=<?php echo urlencode(FM_PATH) ?>" class="btn btn-outline-primary"><i class="fa fa-times-circle"></i> <?php echo lng('Cancel') ?></a></b>&nbsp;
                        <button type="submit" class="btn btn-success"><i class="fa fa-check-circle"></i> <?php echo lng('Change') ?></button>
                    </p>
                </form>
            </div>
        </div>
    </div>
<?php
    fm_show_footer();
    exit;
}

// --- ADMIN USERS PAGE (admin/manager) ---
if (isset($_GET['admin_users']) && FM_CAN_MANAGE_USERS) {
    fm_show_header();
    fm_show_nav_path(FM_PATH);
    require __DIR__ . '/src/renderers/admin-users.php';
    fm_show_footer();
    exit;
}

// --- TINYFILEMANAGER MAIN ---
fm_show_header(); // HEADER
fm_show_nav_path(FM_PATH); // current path

// show alert messages
fm_show_message();

$num_files = count($files);
$num_folders = count($folders);
    require __DIR__ . '/src/renderers/main-page.php';
fm_show_footer();

// --- END HTML ---

// Functions

/**
 * Verify CSRF TOKEN and remove after certified
 * @param string $token
 * @return bool
 */
function verifyToken($token)
{
    if (hash_equals($_SESSION['token'], $token)) {
        return true;
    }
    return false;
}

/**
 * Parse textarea directories input into normalized list.
 * @param string $input
 * @return array
 */
function fm_admin_parse_directories_input($input)
{
    $input = str_replace("\r", "\n", (string) $input);
    $chunks = preg_split('/[\n,]+/', $input);
    $out = array();
    foreach ($chunks as $chunk) {
        $dir = trim((string) $chunk);
        if ($dir !== '') {
            $out[] = $dir;
        }
    }
    return array_values(array_unique($out));
}

/**
 * Resolve a sensible default directory for newly created users.
 * Priority:
 *  1) Any configured directory that ends with /Mirko/free
 *  2) Any configured directory that ends with /free
 *  3) root_path/Mirko/free
 *  4) root_path/free
 *
 * @param array $directories_users
 * @param string $root_path
 * @return string
 */
function fm_admin_resolve_default_user_directory($directories_users, $root_path)
{
    $root_path = rtrim(str_replace('\\', '/', (string) $root_path), '/');
    $candidates = array();

    if (is_array($directories_users)) {
        foreach ($directories_users as $dirs_raw) {
            $dirs = is_array($dirs_raw) ? $dirs_raw : array($dirs_raw);
            foreach ($dirs as $dir_entry) {
                if (!is_string($dir_entry)) {
                    continue;
                }
                $dir = trim(str_replace('\\', '/', $dir_entry));
                if ($dir === '') {
                    continue;
                }

                $is_absolute = preg_match('/^(?:[a-zA-Z]:\/|\/)/', $dir) === 1;
                $candidate = $is_absolute ? $dir : ($root_path . '/' . ltrim($dir, '/'));
                $candidate = rtrim(str_replace('\\', '/', $candidate), '/');
                if ($candidate !== '') {
                    $candidates[] = $candidate;
                }
            }
        }
    }

    $candidates = array_values(array_unique($candidates));

    foreach ($candidates as $candidate) {
        if (preg_match('#/Mirko/free$#i', $candidate) === 1) {
            return $candidate;
        }
    }

    foreach ($candidates as $candidate) {
        if (preg_match('#/free$#i', $candidate) === 1) {
            return $candidate;
        }
    }

    if ($root_path !== '') {
        return $root_path . '/Mirko/free';
    }

    return '/Mirko/free';
}

/**
 * Normalize directory list for ownership inference.
 * @param mixed $dirs_raw
 * @param string $root_path
 * @return array
 */
function fm_admin_normalize_dirs_for_owner_map($dirs_raw, $root_path)
{
    $items = is_array($dirs_raw) ? $dirs_raw : array($dirs_raw);
    $root_path = rtrim(str_replace('\\', '/', (string) $root_path), '/');
    $out = array();

    foreach ($items as $entry) {
        if (!is_string($entry)) {
            continue;
        }

        $dir = trim(str_replace('\\', '/', $entry));
        if ($dir === '') {
            continue;
        }

        $is_absolute = preg_match('/^(?:[a-zA-Z]:\/|\/)/', $dir) === 1;
        $candidate = $is_absolute ? $dir : ($root_path . '/' . ltrim($dir, '/'));
        $candidate = rtrim(str_replace('\\', '/', $candidate), '/');
        if ($candidate === '') {
            continue;
        }

        $resolved = realpath($candidate);
        if ($resolved !== false) {
            $candidate = rtrim(str_replace('\\', '/', $resolved), '/');
        }

        $out[] = $candidate;
    }

    $out = array_values(array_unique(array_filter($out, 'strlen')));
    sort($out, SORT_NATURAL | SORT_FLAG_CASE);
    return $out;
}

/**
 * Build ownership mapping plan used by admin helper UI.
 * @param array $auth_users
 * @param array $manager_users
 * @param array $directories_users
 * @param array $existing_owners
 * @param string $root_path
 * @param bool $rebuild
 * @return array
 */
function fm_admin_build_owner_map_plan(array $auth_users, array $manager_users, array $directories_users, array $existing_owners, $root_path, $rebuild = false)
{
    $manager_users = array_values(array_unique(array_map('strval', $manager_users)));
    sort($manager_users, SORT_NATURAL | SORT_FLAG_CASE);
    $manager_set = array_fill_keys($manager_users, true);

    $known_users = array_values(array_unique(array_map('strval', array_keys($auth_users))));
    sort($known_users, SORT_NATURAL | SORT_FLAG_CASE);

    $normalized_existing = fm_admin_normalize_user_manager_owners($existing_owners, $manager_users, $auth_users);
    $user_dirs = array();
    foreach ($known_users as $username) {
        $raw_dirs = array_key_exists($username, $directories_users) ? $directories_users[$username] : array();
        $user_dirs[$username] = fm_admin_normalize_dirs_for_owner_map($raw_dirs, (string) $root_path);
    }

    $rows = array();
    $result_owners = array();
    $changed = 0;

    foreach ($known_users as $username) {
        $current_owner = isset($normalized_existing[$username]) ? (string) $normalized_existing[$username] : '-';
        $reason = '';

        if ($username === 'admin' || isset($manager_set[$username])) {
            $new_owner = 'admin';
            $reason = 'forced_admin_or_manager';
        } elseif (!$rebuild && isset($normalized_existing[$username])) {
            $new_owner = $normalized_existing[$username];
            $reason = 'kept_existing';
        } else {
            $dirs = isset($user_dirs[$username]) ? $user_dirs[$username] : array();
            $matches = array();

            if (!empty($dirs)) {
                $dir_set = array_fill_keys($dirs, true);
                foreach ($manager_users as $manager_name) {
                    $manager_dirs = isset($user_dirs[$manager_name]) ? $user_dirs[$manager_name] : array();
                    $intersects = false;
                    foreach ($manager_dirs as $manager_dir) {
                        if (isset($dir_set[$manager_dir])) {
                            $intersects = true;
                            break;
                        }
                    }
                    if ($intersects) {
                        $matches[] = $manager_name;
                    }
                }
            }

            if (count($matches) === 1) {
                $new_owner = $matches[0];
                $reason = 'inferred_single_manager_match';
            } elseif (count($matches) > 1) {
                $new_owner = 'admin';
                $reason = 'fallback_ambiguous_managers:' . implode('|', $matches);
            } else {
                $new_owner = 'admin';
                $reason = 'fallback_no_manager_match';
            }
        }

        $result_owners[$username] = $new_owner;
        $is_changed = ($current_owner !== $new_owner);
        if ($is_changed) {
            $changed++;
        }

        $rows[] = array(
            'username' => $username,
            'current_owner' => $current_owner,
            'new_owner' => $new_owner,
            'reason' => $reason,
            'changed' => $is_changed,
        );
    }

    ksort($result_owners);
    return array(
        'owners' => $result_owners,
        'rows' => $rows,
        'summary' => array(
            'users_total' => count($known_users),
            'changed' => $changed,
            'rebuild' => (bool) $rebuild,
        ),
    );
}

/**
 * Parse explicit owner map submitted from admin UI.
 * @param string $json
 * @param array $auth_users
 * @param array $manager_users
 * @return array
 */
function fm_admin_parse_owner_map_submission($json, array $auth_users, array $manager_users)
{
    $json = trim((string) $json);
    if ($json === '') {
        return array('ok' => false, 'error' => 'Owner map is empty.');
    }

    $decoded = json_decode($json, true);
    if (!is_array($decoded)) {
        return array('ok' => false, 'error' => 'Invalid owner map JSON.');
    }

    $isList = array_keys($decoded) === range(0, count($decoded) - 1);
    if ($isList) {
        return array('ok' => false, 'error' => 'Owner map JSON must be an object.');
    }

    $known_users = array_fill_keys(array_values(array_unique(array_map('strval', array_keys($auth_users)))), true);
    $manager_set = array_fill_keys(array_values(array_unique(array_map('strval', $manager_users))), true);
    $out = array();

    foreach ($decoded as $username_raw => $owner_raw) {
        $username = trim((string) $username_raw);
        $owner = trim((string) $owner_raw);

        if ($username === '' || !isset($known_users[$username])) {
            return array('ok' => false, 'error' => 'Unknown user in owner map: ' . $username_raw);
        }

        if ($username === 'admin' || isset($manager_set[$username])) {
            $out[$username] = 'admin';
            continue;
        }

        if ($owner !== 'admin' && !isset($manager_set[$owner])) {
            return array('ok' => false, 'error' => 'Invalid owner for ' . $username . '.');
        }

        $out[$username] = $owner;
    }

    ksort($out);
    return array('ok' => true, 'owners' => $out);
}

/**
 * Normalize ownership mapping to valid manager/admin values for known users.
 * @param array $owners
 * @param array $manager_users
 * @param array $auth_users
 * @return array
 */
function fm_admin_normalize_user_manager_owners(array $owners, array $manager_users, array $auth_users)
{
    $manager_set = array_fill_keys(array_values(array_unique(array_map('strval', $manager_users))), true);
    $known_users = array_fill_keys(array_values(array_unique(array_map('strval', array_keys($auth_users)))), true);
    $normalized = array();

    foreach ($owners as $username => $owner) {
        $username = trim((string) $username);
        $owner = trim((string) $owner);
        if ($username === '' || !isset($known_users[$username])) {
            continue;
        }

        if ($owner === 'admin' || isset($manager_set[$owner])) {
            $normalized[$username] = $owner;
        }
    }

    return $normalized;
}

/**
 * Resolve user's manager owner id.
 * Returns manager username or 'admin'.
 * @param string $username
 * @param array $owners
 * @param array $manager_users
 * @return string
 */
function fm_admin_get_user_manager_owner($username, array $owners, array $manager_users)
{
    $username = trim((string) $username);
    if ($username === '' || $username === 'admin') {
        return 'admin';
    }

    if (in_array($username, $manager_users, true)) {
        return 'admin';
    }

    if (isset($owners[$username])) {
        $owner = trim((string) $owners[$username]);
        if ($owner === 'admin' || in_array($owner, $manager_users, true)) {
            return $owner;
        }
    }

    return 'admin';
}

/**
 * Manager can only manage non-manager users explicitly owned by that manager.
 * @param string $manager_username
 * @param string $target_username
 * @param array $manager_users
 * @param array $owners
 * @return bool
 */
function fm_admin_manager_can_manage_user($manager_username, $target_username, array $manager_users, array $owners)
{
    $manager_username = trim((string) $manager_username);
    $target_username = trim((string) $target_username);
    if ($manager_username === '' || $target_username === '' || $target_username === 'admin') {
        return false;
    }

    if (!in_array($manager_username, $manager_users, true)) {
        return false;
    }

    if ($target_username === $manager_username) {
        return false;
    }

    if (in_array($target_username, $manager_users, true)) {
        return false;
    }

    return fm_admin_get_user_manager_owner($target_username, $owners, $manager_users) === $manager_username;
}

/**
 * Load user-related arrays from config.php in isolated scope.
 * @param string $config_file
 * @return array
 */
function fm_admin_load_user_config_arrays($config_file)
{
    if (!is_file($config_file) || !is_readable($config_file)) {
        return array('ok' => false, 'error' => 'Configuration file is not readable.');
    }

    $loader = static function ($__config_file) {
        $auth_users = array();
        $readonly_users = array();
        $upload_only_users = array();
        $manager_users = array();
        $directories_users = array();
        $user_manager_owners = array();
        $user_notes = array();
        $bulk_actions_disabled_users = array();
        $user_welcome_messages = array();
        $welcome_message_shown_users = array();
        include $__config_file;
        return array(
            'auth_users' => is_array($auth_users) ? $auth_users : array(),
            'readonly_users' => is_array($readonly_users) ? $readonly_users : array(),
            'upload_only_users' => is_array($upload_only_users) ? $upload_only_users : array(),
            'manager_users' => is_array($manager_users) ? $manager_users : array(),
            'directories_users' => is_array($directories_users) ? $directories_users : array(),
            'user_manager_owners' => is_array($user_manager_owners) ? $user_manager_owners : array(),
            'user_notes' => is_array($user_notes) ? $user_notes : array(),
            'bulk_actions_disabled_users' => is_array($bulk_actions_disabled_users) ? $bulk_actions_disabled_users : array(),
            'user_welcome_messages' => is_array($user_welcome_messages) ? $user_welcome_messages : array(),
            'welcome_message_shown_users' => is_array($welcome_message_shown_users) ? $welcome_message_shown_users : array(),
        );
    };

    $data = $loader($config_file);

    // Prefer current runtime scope values when DB-backed runtime config is active.
    // This keeps admin tools (owner map, user edits, delete) consistent with snapshot restore.
    if (function_exists('fm_config_store_load_scope')) {
        $runtime_data = fm_config_store_load_scope('runtime_config', 'global');
        if (is_array($runtime_data) && !empty($runtime_data)) {
            $array_keys = array(
                'auth_users',
                'readonly_users',
                'upload_only_users',
                'manager_users',
                'directories_users',
                'user_manager_owners',
                'user_notes',
                'bulk_actions_disabled_users',
                'user_welcome_messages',
                'welcome_message_shown_users',
            );
            foreach ($array_keys as $array_key) {
                if (isset($runtime_data[$array_key]) && is_array($runtime_data[$array_key])) {
                    $data[$array_key] = $runtime_data[$array_key];
                }
            }
        }
    }

    $data['ok'] = true;
    return $data;
}

/**
 * Export scalar config value, preferring __DIR__ paths when possible.
 * @param mixed $value
 * @param string $config_dir
 * @return string
 */
function fm_admin_export_config_scalar($value, $config_dir)
{
    if (!is_string($value)) {
        return var_export($value, true);
    }

    $config_dir_norm = rtrim(str_replace('\\', '/', (string) $config_dir), '/');
    $val_norm = str_replace('\\', '/', $value);
    if ($config_dir_norm !== '' && strpos($val_norm, $config_dir_norm . '/') === 0) {
        $rel = substr($val_norm, strlen($config_dir_norm));
        $rel = str_replace("'", "\\'", $rel);
        return "__DIR__ . '" . $rel . "'";
    }

    return "'" . str_replace(array('\\', "'"), array('\\\\', "\\'"), $value) . "'";
}

/**
 * Export associative array as PHP array(...) code block.
 * @param string $name
 * @param array $arr
 * @param string $config_dir
 * @return string
 */
function fm_admin_export_assoc_array_code($name, array $arr, $config_dir)
{
    ksort($arr);
    $code = '$' . $name . ' = array(' . "\n";
    foreach ($arr as $k => $v) {
        $key = "'" . str_replace(array('\\', "'"), array('\\\\', "\\'"), (string) $k) . "'";
        if (is_array($v)) {
            $code .= '    ' . $key . ' => array(' . "\n";
            foreach ($v as $item) {
                $code .= '        ' . fm_admin_export_config_scalar($item, $config_dir) . ',' . "\n";
            }
            $code .= '    ),' . "\n";
        } else {
            $code .= '    ' . $key . ' => ' . fm_admin_export_config_scalar($v, $config_dir) . ',' . "\n";
        }
    }
    $code .= ');';
    return $code;
}

/**
 * Export list array as PHP array(...) code block.
 * @param string $name
 * @param array $arr
 * @return string
 */
function fm_admin_export_list_array_code($name, array $arr)
{
    $arr = array_values(array_unique(array_map('strval', $arr)));
    sort($arr);
    $code = '$' . $name . ' = array(' . "\n";
    foreach ($arr as $v) {
        $code .= "    '" . str_replace(array('\\', "'"), array('\\\\', "\\'"), $v) . "'," . "\n";
    }
    $code .= ');';
    return $code;
}

/**
 * Replace a config array assignment by variable name.
 * Supports both array(...) and [...] syntax. If variable is not found,
 * appends a new assignment near the end of config.php so save can proceed.
 * @param string $content
 * @param string $var_name
 * @param string $new_code
 * @return array
 */
function fm_admin_replace_config_array_assignment($content, $var_name, $new_code)
{
    $quoted_name = preg_quote((string) $var_name, '/');
    $patterns = array(
        '/\$' . $quoted_name . '\s*=\s*array\s*\((?:.|[\r\n])*?\)\s*;/U',
        '/\$' . $quoted_name . '\s*=\s*\[(?:.|[\r\n])*?\]\s*;/U',
    );

    foreach ($patterns as $pattern) {
        $count = 0;
        $updated = preg_replace_callback(
            $pattern,
            static function () use ($new_code) {
                return $new_code;
            },
            $content,
            1,
            $count
        );
        if (is_string($updated) && $count === 1) {
            return array('ok' => true, 'content' => $updated, 'mode' => 'replaced');
        }
    }

    // Fallback for non-standard config formatting: append assignment.
    if (preg_match('/\?>\s*$/', $content) === 1) {
        $updated = preg_replace('/\?>\s*$/', "\n\n" . $new_code . "\n?>", $content, 1);
    } else {
        $updated = rtrim($content) . "\n\n" . $new_code . "\n";
    }

    if (!is_string($updated) || $updated === '') {
        return array('ok' => false, 'error' => 'Failed to append $' . $var_name . ' in config.php');
    }

    return array('ok' => true, 'content' => $updated, 'mode' => 'appended');
}

/**
 * Persist user arrays to config.php by replacing known array declarations.
 * @param string $config_file
 * @param array $auth_users
 * @param array $readonly_users
 * @param array $upload_only_users
 * @param array $manager_users
 * @param array $directories_users
 * @return array
 */
function fm_admin_persist_user_config_arrays($config_file, array $auth_users, array $readonly_users, array $upload_only_users, array $manager_users, array $directories_users, array $user_notes = array(), array $bulk_actions_disabled_users = array(), array $user_welcome_messages = array(), array $welcome_message_shown_users = array(), array $user_manager_owners = array())
{
    $original_content = @file_get_contents($config_file);
    if ($original_content === false) {
        return array('ok' => false, 'error' => 'Failed to read configuration file.');
    }

    $content = $original_content;

    $config_dir = dirname($config_file);
    $replacements = array(
        'auth_users' => fm_admin_export_assoc_array_code('auth_users', $auth_users, $config_dir),
        'readonly_users' => fm_admin_export_list_array_code('readonly_users', $readonly_users),
        'upload_only_users' => fm_admin_export_list_array_code('upload_only_users', $upload_only_users),
        'manager_users' => fm_admin_export_list_array_code('manager_users', $manager_users),
        'directories_users' => fm_admin_export_assoc_array_code('directories_users', $directories_users, $config_dir),
        'user_manager_owners' => fm_admin_export_assoc_array_code('user_manager_owners', $user_manager_owners, $config_dir),
        'user_notes' => fm_admin_export_assoc_array_code('user_notes', $user_notes, $config_dir),
        'bulk_actions_disabled_users' => fm_admin_export_list_array_code('bulk_actions_disabled_users', $bulk_actions_disabled_users),
        'user_welcome_messages' => fm_admin_export_assoc_array_code('user_welcome_messages', $user_welcome_messages, $config_dir),
        'welcome_message_shown_users' => fm_admin_export_list_array_code('welcome_message_shown_users', $welcome_message_shown_users),
    );

    foreach ($replacements as $var_name => $new_code) {
        $replace_result = fm_admin_replace_config_array_assignment($content, $var_name, $new_code);
        if (empty($replace_result['ok'])) {
            return array(
                'ok' => false,
                'error' => isset($replace_result['error']) ? $replace_result['error'] : ('Failed to update $' . $var_name . ' in config.php')
            );
        }
        $content = isset($replace_result['content']) ? (string) $replace_result['content'] : $content;
    }

    $backup_file = $config_file . '.bak.' . date('Ymd_His');
    if (@file_put_contents($backup_file, $original_content) === false) {
        return array('ok' => false, 'error' => 'Failed to create config backup.');
    }

    if (@file_put_contents($config_file, $content) === false) {
        return array('ok' => false, 'error' => 'Failed to write updated config.php');
    }

    if (function_exists('fm_config_store_save_runtime_config') && function_exists('fm_config_store_runtime_keys')) {
        $runtime_values = array();
        $runtime_keys = fm_config_store_runtime_keys();
        foreach ($runtime_keys as $runtime_key) {
            $runtime_key = (string) $runtime_key;
            if ($runtime_key !== '' && array_key_exists($runtime_key, $GLOBALS)) {
                $runtime_values[$runtime_key] = $GLOBALS[$runtime_key];
            }
        }

        $runtime_values['auth_users'] = $auth_users;
        $runtime_values['readonly_users'] = array_values(array_unique(array_map('strval', $readonly_users)));
        $runtime_values['upload_only_users'] = array_values(array_unique(array_map('strval', $upload_only_users)));
        $runtime_values['manager_users'] = array_values(array_unique(array_map('strval', $manager_users)));
        $runtime_values['directories_users'] = $directories_users;
        $runtime_values['user_notes'] = $user_notes;
        $runtime_values['bulk_actions_disabled_users'] = array_values(array_unique(array_map('strval', $bulk_actions_disabled_users)));
        $runtime_values['user_welcome_messages'] = $user_welcome_messages;
        $runtime_values['welcome_message_shown_users'] = array_values(array_unique(array_map('strval', $welcome_message_shown_users)));
        $runtime_values['user_manager_owners'] = $user_manager_owners;

        $actor = isset($_SESSION[FM_SESSION_ID]['logged']) ? (string) $_SESSION[FM_SESSION_ID]['logged'] : 'system';
        $runtime_save = fm_config_store_save_runtime_config($runtime_values, array(
            'created_by' => $actor,
            'updated_by' => $actor,
            'source' => 'admin_users',
            'label' => 'Admin users config sync',
            'reason' => 'sync_after_config_php_write',
            'snapshot_reason' => 'admin_users_sync',
            'snapshot_label' => 'Admin users sync',
        ));

        if (!is_array($runtime_save) || empty($runtime_save['ok'])) {
            return array(
                'ok' => false,
                'error' => 'Config file was updated, but runtime config sync failed: ' . (isset($runtime_save['error']) ? (string) $runtime_save['error'] : 'unknown error')
            );
        }

        // Keep current request state consistent with persisted runtime values.
        foreach ($runtime_values as $runtime_key => $runtime_value) {
            $GLOBALS[(string) $runtime_key] = $runtime_value;
        }
    }

    return array('ok' => true);
}

/**
 * Build normalized relative preview target from current path and filename.
 * @param string $path
 * @param string $file
 * @return string
 */
function fm_preview_relative_target($path, $file)
{
    $path = fm_clean_path((string) $path);
    // Preserve '+' when file names come from directory entries and signed URLs.
    $file = rawurldecode((string) $file);
    $file = fm_clean_path($file, false);
    $file = str_replace('/', '', $file);
    if ($file === '') {
        return '';
    }
    return ltrim(($path !== '' ? $path . '/' : '') . $file, '/');
}

/**
 * Derive preview signing secret from runtime configuration.
 * @return string
 */
function fm_preview_secret()
{
    static $secret = null;
    if ($secret !== null) {
        return $secret;
    }

    global $root_path, $auth_users;
    $secret = hash('sha256', __FILE__ . '|' . (string) $root_path . '|' . json_encode($auth_users));
    return $secret;
}

/**
 * Sign preview target for time-limited public access.
 * @param string $relative_target
 * @param int $expires
 * @return string
 */
function fm_preview_signature($relative_target, $expires)
{
    return hash_hmac('sha256', (string) $expires . '|' . $relative_target, fm_preview_secret());
}

/**
 * Build signed preview query string.
 * @param string $path
 * @param string $file
 * @param int $ttl
 * @return string
 */
function fm_build_preview_query($path, $file, $ttl = 900)
{
    $path = fm_clean_path((string) $path);
    // Preserve '+' when file names come from directory entries and signed URLs.
    $raw_file = rawurldecode((string) $file);
    $file = str_replace('/', '', fm_clean_path($raw_file, false));
    $relative_target = fm_preview_relative_target($path, $file);

    $ttl = max(60, (int) $ttl);
    $expires = time() + $ttl;
    $sig = fm_preview_signature($relative_target, $expires);

    return 'p=' . urlencode($path) . '&preview=' . urlencode($file) . '&exp=' . $expires . '&sig=' . $sig;
}

/**
 * Verify signed preview request.
 * @param string $path
 * @param string $file
 * @param mixed $expires
 * @param string $sig
 * @return bool
 */
function fm_has_valid_preview_signature($path, $file, $expires, $sig)
{
    if (!is_numeric($expires) || !is_string($sig) || $sig === '') {
        return false;
    }

    $expires = (int) $expires;
    if ($expires < (time() - 30) || $expires > (time() + 86400)) {
        return false;
    }

    $relative_target = fm_preview_relative_target($path, $file);
    if ($relative_target === '') {
        return false;
    }

    return hash_equals(fm_preview_signature($relative_target, $expires), $sig);
}

/**
 * Delete  file or folder (recursively)
 * @param string $path
 * @return bool
 */
function fm_rdelete($path)
{
    if (is_link($path)) {
        return unlink($path);
    } elseif (is_dir($path)) {
        $objects = scandir($path);
        $ok = true;
        if (is_array($objects)) {
            foreach ($objects as $file) {
                if ($file != '.' && $file != '..') {
                    if (!fm_rdelete($path . '/' . $file)) {
                        $ok = false;
                    }
                }
            }
        }
        return ($ok) ? rmdir($path) : false;
    } elseif (is_file($path)) {
        return unlink($path);
    }
    return false;
}

/**
 * Recursive chmod
 * @param string $path
 * @param int $filemode
 * @param int $dirmode
 * @return bool
 * @todo Will use in mass chmod
 */
function fm_rchmod($path, $filemode, $dirmode)
{
    if (is_dir($path)) {
        if (!chmod($path, $dirmode)) {
            return false;
        }
        $objects = scandir($path);
        if (is_array($objects)) {
            foreach ($objects as $file) {
                if ($file != '.' && $file != '..') {
                    if (!fm_rchmod($path . '/' . $file, $filemode, $dirmode)) {
                        return false;
                    }
                }
            }
        }
        return true;
    } elseif (is_link($path)) {
        return true;
    } elseif (is_file($path)) {
        return chmod($path, $filemode);
    }
    return false;
}

/**
 * Check the file extension which is allowed or not
 * @param string $filename
 * @return bool
 */
function fm_is_valid_ext($filename)
{
    $allowed = (FM_FILE_EXTENSION) ? explode(',', FM_FILE_EXTENSION) : false;

    $ext = pathinfo($filename, PATHINFO_EXTENSION);
    $isFileAllowed = ($allowed) ? in_array($ext, $allowed) : true;

    return ($isFileAllowed) ? true : false;
}

/**
 * Safely rename
 * @param string $old
 * @param string $new
 * @return bool|null
 */
function fm_rename($old, $new)
{
    $isFileAllowed = fm_is_valid_ext($new);

    if (!is_dir($old)) {
        if (!$isFileAllowed) return false;
    }

    return (!file_exists($new) && file_exists($old)) ? rename($old, $new) : null;
}

/**
 * Copy file or folder (recursively).
 * @param string $path
 * @param string $dest
 * @param bool $upd Update files
 * @param bool $force Create folder with same names instead file
 * @return bool
 */
function fm_rcopy($path, $dest, $upd = true, $force = true)
{
    if (!is_dir($path) && !is_file($path)) {
        return false;
    }

    if (is_dir($path)) {
        if (!fm_mkdir($dest, $force)) {
            return false;
        }

        $objects = array_diff(scandir($path), ['.', '..']);

        foreach ($objects as $file) {
            if (!fm_rcopy("$path/$file", "$dest/$file", $upd, $force)) {
                return false;
            }
        }

        return true;
    }

    // Handle file copying
    return fm_copy($path, $dest, $upd);
}


/**
 * Safely create folder
 * @param string $dir
 * @param bool $force
 * @return bool
 */
function fm_mkdir($dir, $force)
{
    if (file_exists($dir)) {
        if (is_dir($dir)) {
            return $dir;
        } elseif (!$force) {
            return false;
        }
        unlink($dir);
    }
    return mkdir($dir, 0777, true);
}

/**
 * Safely copy file
 * @param string $f1
 * @param string $f2
 * @param bool $upd Indicates if file should be updated with new content
 * @return bool
 */
function fm_copy($f1, $f2, $upd)
{
    $time1 = filemtime($f1);
    if (file_exists($f2)) {
        $time2 = filemtime($f2);
        if ($time2 >= $time1 && $upd) {
            return false;
        }
    }
    $ok = copy($f1, $f2);
    if ($ok) {
        touch($f2, $time1);
    }
    return $ok;
}

/**
 * Get mime type
 * @param string $file_path
 * @return mixed|string
 */
function fm_get_mime_type($file_path)
{
    if (function_exists('finfo_open')) {
        $finfo = finfo_open(FILEINFO_MIME_TYPE);
        $mime = finfo_file($finfo, $file_path);
        finfo_close($finfo);
        return $mime;
    } elseif (function_exists('mime_content_type')) {
        return mime_content_type($file_path);
    } elseif (!stristr(ini_get('disable_functions'), 'shell_exec')) {
        $file = escapeshellarg($file_path);
        $mime = shell_exec('file -bi ' . $file);
        return $mime;
    } else {
        return '--';
    }
}

/**
 * Resolve runtime state directory used for internal app metadata.
 * Can be overridden from config.php via $state_storage_path.
 *
 * @return string
 */
function fm_runtime_state_dir()
{
    static $resolved = null;
    if (is_string($resolved) && $resolved !== '') {
        return $resolved;
    }

    global $state_storage_path;

    $candidate = '';
    $configured = false;
    if (isset($state_storage_path) && is_string($state_storage_path)) {
        $candidate = trim($state_storage_path);
        $configured = ($candidate !== '');
    }

    if ($candidate === '') {
        $candidate = __DIR__ . '/.fm_usercfg';
    }

    // Relative configured paths are anchored to app directory.
    if (!preg_match('/^(?:[a-zA-Z]:[\\\\\/]|\/)/', $candidate)) {
        $candidate = __DIR__ . '/' . ltrim($candidate, '/\\');
    }

    $candidate = rtrim(str_replace('\\', '/', $candidate), '/');
    if ($candidate === '') {
        $candidate = __DIR__ . '/.fm_usercfg';
    }

    if (!@is_dir($candidate)) {
        @mkdir($candidate, 0750, true);
    }

    // Optional one-way migration from legacy app-local directory.
    if ($configured) {
        $legacyDir = __DIR__ . '/.fm_usercfg';
        if (@is_dir($legacyDir)) {
            $stateFiles = array(
                'online_users.json',
                'chat.sqlite',
                'owner-meta.json',
                'owner-meta.sqlite',
                'admin-users-audit.log',
                'fallback-events.log',
            );

            foreach ($stateFiles as $fileName) {
                $from = $legacyDir . '/' . $fileName;
                $to = $candidate . '/' . $fileName;
                if (@is_file($from) && !@file_exists($to)) {
                    @copy($from, $to);
                }
            }
        }
    }

    $htaccess = $candidate . '/.htaccess';
    if (!@file_exists($htaccess)) {
        @file_put_contents($htaccess, "Order Deny,Allow\nDeny from all\n");
    }

    $resolved = $candidate;
    return $resolved;
}

/**
 * Check whether MIME type is an image MIME.
 * @param mixed $mime_type
 * @return bool
 */
function fm_is_image_mime_type($mime_type)
{
    if (!is_string($mime_type) || $mime_type === '' || $mime_type === '--') {
        return false;
    }
    return strpos(strtolower($mime_type), 'image/') === 0;
}

/**
 * HTTP Redirect
 * @param string $url
 * @param int $code
 */
function fm_redirect($url, $code = 302)
{
    header('Location: ' . $url, true, $code);
    exit;
}

/**
 * Track active authenticated users for manager/admin footer badges.
 */
function fm_online_state_file()
{
    $dir = fm_runtime_state_dir();
    return $dir . '/online_users.json';
}

function fm_online_touch_user($username)
{
    if (!is_string($username) || $username === '') {
        return;
    }

    $file = fm_online_state_file();
    $now = time();
    $ttl = 900;
    $current_session_id = (string) session_id();

    $fh = @fopen($file, 'c+');
    if ($fh === false) {
        return;
    }

    if (!@flock($fh, LOCK_EX)) {
        @fclose($fh);
        return;
    }

    $raw = stream_get_contents($fh);
    $data = json_decode($raw ?: '{}', true);
    if (!is_array($data)) {
        $data = array();
    }

    foreach ($data as $user => $entry) {
        $ts = null;
        $sid = '';

        if (is_numeric($entry)) {
            $ts = (int) $entry;
        } elseif (is_array($entry) && isset($entry['ts']) && is_numeric($entry['ts'])) {
            $ts = (int) $entry['ts'];
            $sid = isset($entry['sid']) && is_string($entry['sid']) ? $entry['sid'] : '';
        }

        if ($ts === null || $ts < ($now - $ttl)) {
            unset($data[$user]);
            continue;
        }

        // Same browser session can only represent one active account.
        if ($current_session_id !== '' && $sid !== '' && $sid === $current_session_id && $user !== $username) {
            unset($data[$user]);
        }
    }

    $data[$username] = array(
        'ts' => $now,
        'sid' => $current_session_id,
    );
    ksort($data);

    ftruncate($fh, 0);
    rewind($fh);
    fwrite($fh, json_encode($data));
    fflush($fh);
    flock($fh, LOCK_UN);
    fclose($fh);
}

function fm_online_remove_user($username)
{
    if (!is_string($username) || $username === '') {
        return;
    }

    $file = fm_online_state_file();
    $fh = @fopen($file, 'c+');
    if ($fh === false) {
        return;
    }

    if (!@flock($fh, LOCK_EX)) {
        @fclose($fh);
        return;
    }

    $raw = stream_get_contents($fh);
    $data = json_decode($raw ?: '{}', true);
    if (!is_array($data)) {
        $data = array();
    }

    unset($data[$username]);

    ftruncate($fh, 0);
    rewind($fh);
    fwrite($fh, json_encode($data));
    fflush($fh);
    flock($fh, LOCK_UN);
    fclose($fh);
}

function fm_online_get_users()
{
    $file = fm_online_state_file();
    if (!@file_exists($file)) {
        return array();
    }

    $raw = @file_get_contents($file);
    $data = json_decode($raw ?: '{}', true);
    if (!is_array($data)) {
        return array();
    }

    $now = time();
    $ttl = 900;
    $users = array();
    foreach ($data as $user => $entry) {
        $ts = null;
        if (is_numeric($entry)) {
            $ts = (int) $entry;
        } elseif (is_array($entry) && isset($entry['ts']) && is_numeric($entry['ts'])) {
            $ts = (int) $entry['ts'];
        }

        if (is_string($user) && $user !== '' && $ts !== null && $ts >= ($now - $ttl)) {
            $users[] = $user;
        }
    }

    sort($users, SORT_NATURAL | SORT_FLAG_CASE);
    return $users;
}

function fm_chat_resolve_user_scope_dirs($username, array $directories_users, $root_path, $home_root_rel = '')
{
    $username = (string) $username;
    $root_path = rtrim(str_replace('\\', '/', (string) $root_path), '/');
    if ($username === '' || $root_path === '' || !@is_dir($root_path)) {
        return array();
    }

    $out = array();
    $raw_dirs = array();
    if (array_key_exists($username, $directories_users)) {
        $raw_dirs = $directories_users[$username];
        if (!is_array($raw_dirs)) {
            $raw_dirs = array($raw_dirs);
        }
    }

    foreach ($raw_dirs as $dir) {
        if (!is_string($dir) || trim($dir) === '') {
            continue;
        }

        $dir = str_replace('\\', '/', trim($dir));
        $is_absolute = preg_match('/^(?:[a-zA-Z]:\/|\/)/', $dir) === 1;
        $candidate = $is_absolute ? $dir : ($root_path . '/' . ltrim($dir, '/'));
        $candidate = rtrim(str_replace('\\', '/', $candidate), '/');
        if ($candidate === '' || !@is_dir($candidate) || !fm_is_path_inside($candidate, $root_path)) {
            continue;
        }

        $resolved = realpath($candidate);
        if ($resolved !== false) {
            $candidate = rtrim(str_replace('\\', '/', $resolved), '/');
        }
        $out[] = $candidate;
    }

    if (empty($out) && is_string($home_root_rel) && trim($home_root_rel) !== '') {
        $home_abs = rtrim($root_path, '/\\') . '/' . ltrim((string) $home_root_rel, '/');
        $home_abs = rtrim(str_replace('\\', '/', $home_abs), '/');
        if ($home_abs !== '' && @is_dir($home_abs) && fm_is_path_inside($home_abs, $root_path)) {
            $resolved_home = realpath($home_abs);
            if ($resolved_home !== false) {
                $home_abs = rtrim(str_replace('\\', '/', $resolved_home), '/');
            }
            $out[] = $home_abs;
        }
    }

    if (empty($out)) {
        $resolved_root = realpath($root_path);
        $out[] = rtrim(str_replace('\\', '/', $resolved_root !== false ? $resolved_root : $root_path), '/');
    }

    $out = array_values(array_unique(array_filter($out, 'strlen')));
    sort($out, SORT_NATURAL | SORT_FLAG_CASE);
    return $out;
}

function fm_chat_paths_overlap(array $paths_a, array $paths_b)
{
    $normalized_b = array();
    foreach ($paths_b as $b) {
        $b = rtrim(str_replace('\\', '/', (string) $b), '/');
        if ($b !== '') {
            $normalized_b[$b] = true;
        }
    }

    if (empty($normalized_b)) {
        return false;
    }

    foreach ($paths_a as $a) {
        $a = rtrim(str_replace('\\', '/', (string) $a), '/');
        if ($a === '') {
            continue;
        }

        if (isset($normalized_b[$a])) {
            return true;
        }
    }

    return false;
}

function fm_chat_get_manager_contact_grants($username, array $manager_users)
{
    $username = trim((string) $username);
    if ($username === '' || empty($manager_users)) {
        return array();
    }

    $db = fm_chat_get_db();
    if (!$db) {
        return array();
    }

    $manager_users = array_values(array_unique(array_filter(array_map('strval', $manager_users), 'strlen')));
    if (empty($manager_users)) {
        return array();
    }

    $placeholders = array();
    foreach ($manager_users as $idx => $unused_name) {
        $placeholders[] = ':m' . $idx;
    }

    $sql = 'SELECT DISTINCT sender FROM fm_chat_messages WHERE recipient = :recipient AND sender IN (' . implode(',', $placeholders) . ')';
    $stmt = $db->prepare($sql);
    if (!$stmt) {
        return array();
    }

    $stmt->bindValue(':recipient', $username, SQLITE3_TEXT);
    foreach ($manager_users as $idx => $manager_name) {
        $stmt->bindValue(':m' . $idx, $manager_name, SQLITE3_TEXT);
    }

    $result = $stmt->execute();
    if ($result === false) {
        return array();
    }

    $grants = array();
    while (($row = $result->fetchArray(SQLITE3_ASSOC)) !== false) {
        $sender = isset($row['sender']) ? trim((string) $row['sender']) : '';
        if ($sender !== '') {
            $grants[] = $sender;
        }
    }
    $result->finalize();

    $grants = array_values(array_unique($grants));
    sort($grants, SORT_NATURAL | SORT_FLAG_CASE);
    return $grants;
}

function fm_chat_get_visible_peers($current_user, array $auth_users, array $directories_users, $root_path, $home_root_rel = '', array $manager_users = array(), array $user_manager_owners = array())
{
    $current_user = (string) $current_user;
    if ($current_user === '' || !isset($auth_users[$current_user])) {
        return array();
    }

    $manager_users = array_values(array_unique(array_filter(array_map('strval', $manager_users), 'strlen')));
    $user_manager_owners = fm_admin_normalize_user_manager_owners($user_manager_owners, $manager_users, $auth_users);

    if ($current_user === 'admin') {
        $all_peers = array_values(array_diff(array_keys($auth_users), array($current_user)));
        sort($all_peers, SORT_NATURAL | SORT_FLAG_CASE);
        return $all_peers;
    }

    $current_scopes = fm_chat_resolve_user_scope_dirs($current_user, $directories_users, $root_path, $home_root_rel);
    if (empty($current_scopes)) {
        return array();
    }

    $current_is_manager = in_array($current_user, $manager_users, true);
    $current_owner = fm_admin_get_user_manager_owner($current_user, $user_manager_owners, $manager_users);
    $manager_contact_grants = $current_is_manager ? array() : fm_chat_get_manager_contact_grants($current_user, $manager_users);

    $peers = array();
    foreach ($auth_users as $peer => $unused_hash) {
        $peer = (string) $peer;
        if ($peer === '' || $peer === $current_user) {
            continue;
        }

        $peer_scopes = fm_chat_resolve_user_scope_dirs($peer, $directories_users, $root_path, $home_root_rel);
        if (empty($peer_scopes)) {
            continue;
        }

        $same_scope = fm_chat_paths_overlap($current_scopes, $peer_scopes);
        $peer_is_manager = in_array($peer, $manager_users, true);
        $peer_owner = fm_admin_get_user_manager_owner($peer, $user_manager_owners, $manager_users);
        $allowed = false;

        if ($current_is_manager) {
            // Manager can see users in exactly same end scopes.
            $allowed = $same_scope;
        } else {
            if ($peer_is_manager) {
                // Direct superior manager is visible only with exact scope match.
                if ($peer === $current_owner && $same_scope) {
                    $allowed = true;
                }
                // Special case: once a manager contacted this user, keep chat access.
                if (in_array($peer, $manager_contact_grants, true)) {
                    $allowed = true;
                }
            } else {
                // Peer users are visible only under same manager owner and exact same end scope.
                if ($peer_owner === $current_owner && $same_scope) {
                    $allowed = true;
                }
            }
        }

        if ($allowed) {
            $peers[] = $peer;
        }
    }

    $peers = array_values(array_unique($peers));
    sort($peers, SORT_NATURAL | SORT_FLAG_CASE);
    return $peers;
}

function fm_chat_db_path()
{
    $dir = fm_runtime_state_dir();
    return $dir . '/chat.sqlite';
}

function fm_admin_audit_log_path()
{
    $dir = fm_runtime_state_dir();
    return $dir . '/admin-users-audit.log';
}

/**
 * Write one admin user management audit event as JSON line.
 * @param string $action
 * @param string $actor
 * @param string $target
 * @param array $meta
 * @return void
 */
function fm_admin_write_audit_event($action, $actor, $target, array $meta = array())
{
    $record = array(
        'ts' => date('c'),
        'action' => (string) $action,
        'actor' => (string) $actor,
        'target' => (string) $target,
        'ip' => isset($_SERVER['REMOTE_ADDR']) ? (string) $_SERVER['REMOTE_ADDR'] : '',
        'meta' => $meta,
    );

    $line = json_encode($record, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
    if (!is_string($line) || $line === '') {
        return;
    }

    $fh = @fopen(fm_admin_audit_log_path(), 'ab');
    if ($fh === false) {
        return;
    }

    if (@flock($fh, LOCK_EX)) {
        @fwrite($fh, $line . "\n");
        @fflush($fh);
        @flock($fh, LOCK_UN);
    }

    @fclose($fh);
}

/**
 * Read recent admin user audit events (newest first).
 * @param int $limit
 * @return array
 */
function fm_admin_read_audit_events($limit = 50)
{
    $limit = (int) $limit;
    if ($limit < 1) {
        $limit = 1;
    }
    if ($limit > 500) {
        $limit = 500;
    }

    $file = fm_admin_audit_log_path();
    if (!@is_file($file) || !@is_readable($file)) {
        return array();
    }

    $lines = @file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
    if (!is_array($lines) || empty($lines)) {
        return array();
    }

    $slice = array_slice($lines, -$limit);
    $events = array();
    foreach (array_reverse($slice) as $line) {
        $row = json_decode((string) $line, true);
        if (is_array($row)) {
            $events[] = $row;
        }
    }

    return $events;
}

function fm_owner_meta_store_path()
{
    $dir = fm_runtime_state_dir();
    return $dir . '/owner-meta.json';
}

function fm_owner_meta_normalize_path($path)
{
    $path = str_replace('\\', '/', (string) $path);
    $path = preg_replace('#/+#', '/', $path);
    if ($path === null) {
        $path = '';
    }
    if ($path !== '/' && $path !== '') {
        $path = rtrim($path, '/');
    }
    return $path;
}

function fm_owner_meta_rel_path($absolutePath)
{
    if (!defined('FM_ROOT_PATH')) {
        return '';
    }

    $root = fm_owner_meta_normalize_path(FM_ROOT_PATH);
    $path = fm_owner_meta_normalize_path($absolutePath);

    if ($root === '' || $path === '') {
        return '';
    }

    if ($path === $root) {
        return '';
    }

    $prefix = $root . '/';
    if (strpos($path, $prefix) !== 0) {
        return '';
    }

    return ltrim(substr($path, strlen($prefix)), '/');
}

function fm_owner_meta_scope_key()
{
    if (!defined('FM_ROOT_PATH')) {
        return 'default';
    }
    return sha1((string) FM_ROOT_PATH);
}

function fm_owner_meta_read_all()
{
    if (isset($GLOBALS['_fm_owner_meta_cache']) && is_array($GLOBALS['_fm_owner_meta_cache'])) {
        return $GLOBALS['_fm_owner_meta_cache'];
    }

    $file = fm_owner_meta_store_path();
    if (!@is_file($file)) {
        $GLOBALS['_fm_owner_meta_cache'] = array('version' => 1, 'scopes' => array());
        return $GLOBALS['_fm_owner_meta_cache'];
    }

    $raw = @file_get_contents($file);
    $data = json_decode((string) $raw, true);
    if (!is_array($data)) {
        $data = array('version' => 1, 'scopes' => array());
    }
    if (!isset($data['scopes']) || !is_array($data['scopes'])) {
        $data['scopes'] = array();
    }

    $GLOBALS['_fm_owner_meta_cache'] = $data;
    return $GLOBALS['_fm_owner_meta_cache'];
}

function fm_owner_meta_write_all(array $data)
{
    $file = fm_owner_meta_store_path();
    $dir = dirname($file);
    if (!@is_dir($dir)) {
        @mkdir($dir, 0755, true);
    }

    $fh = @fopen($file, 'c+');
    if ($fh === false) {
        return false;
    }

    if (!@flock($fh, LOCK_EX)) {
        @fclose($fh);
        return false;
    }

    ftruncate($fh, 0);
    rewind($fh);
    $json = json_encode($data, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
    if (!is_string($json) || $json === '') {
        $json = '{"version":1,"scopes":{}}';
    }
    @fwrite($fh, $json);
    @fflush($fh);
    @flock($fh, LOCK_UN);
    @fclose($fh);

    $GLOBALS['_fm_owner_meta_cache'] = $data;
    return true;
}

function fm_owner_meta_db_path()
{
    $dir = fm_runtime_state_dir();
    return $dir . '/owner-meta.sqlite';
}

function fm_owner_meta_sqlite_row_to_record(array $row)
{
    return array(
        'created_at' => isset($row['created_at']) ? (int) $row['created_at'] : 0,
        'created_by' => isset($row['created_by']) ? (string) $row['created_by'] : '',
        'updated_at' => isset($row['updated_at']) ? (int) $row['updated_at'] : 0,
        'updated_by' => isset($row['updated_by']) ? (string) $row['updated_by'] : '',
        'owner_source' => isset($row['owner_source']) ? (string) $row['owner_source'] : 'system',
        'last_action' => isset($row['last_action']) ? (string) $row['last_action'] : '',
    );
}

function fm_owner_meta_sqlite_fetch($db, $scope, $rel)
{
    $stmt = $db->prepare('SELECT created_at, created_by, updated_at, updated_by, owner_source, last_action
        FROM fm_owner_meta_records
        WHERE scope_key = :scope AND rel_path = :rel
        LIMIT 1');
    if (!$stmt) {
        return null;
    }

    $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
    $stmt->bindValue(':rel', (string) $rel, SQLITE3_TEXT);
    $result = $stmt->execute();
    if (!$result) {
        return null;
    }

    $row = $result->fetchArray(SQLITE3_ASSOC);
    $result->finalize();
    if (!is_array($row)) {
        return null;
    }

    return fm_owner_meta_sqlite_row_to_record($row);
}

function fm_owner_meta_sqlite_upsert($db, $scope, $rel, array $record)
{
    $stmt = $db->prepare('INSERT OR REPLACE INTO fm_owner_meta_records
        (scope_key, rel_path, created_at, created_by, updated_at, updated_by, owner_source, last_action)
        VALUES (:scope, :rel, :created_at, :created_by, :updated_at, :updated_by, :owner_source, :last_action)');
    if (!$stmt) {
        return false;
    }

    $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
    $stmt->bindValue(':rel', (string) $rel, SQLITE3_TEXT);
    $stmt->bindValue(':created_at', isset($record['created_at']) ? (int) $record['created_at'] : 0, SQLITE3_INTEGER);
    $stmt->bindValue(':created_by', isset($record['created_by']) ? (string) $record['created_by'] : '', SQLITE3_TEXT);
    $stmt->bindValue(':updated_at', isset($record['updated_at']) ? (int) $record['updated_at'] : 0, SQLITE3_INTEGER);
    $stmt->bindValue(':updated_by', isset($record['updated_by']) ? (string) $record['updated_by'] : '', SQLITE3_TEXT);
    $stmt->bindValue(':owner_source', isset($record['owner_source']) ? (string) $record['owner_source'] : 'system', SQLITE3_TEXT);
    $stmt->bindValue(':last_action', isset($record['last_action']) ? (string) $record['last_action'] : '', SQLITE3_TEXT);

    $result = $stmt->execute();
    if ($result) {
        $result->finalize();
    }
    return $result !== false;
}

function fm_owner_meta_migrate_json_to_sqlite($db)
{
    static $migrationChecked = false;
    if ($migrationChecked) {
        return;
    }
    $migrationChecked = true;

    $countResult = $db->querySingle('SELECT COUNT(1) FROM fm_owner_meta_records');
    if (is_numeric($countResult) && (int) $countResult > 0) {
        return;
    }

    $legacyFile = fm_owner_meta_store_path();
    if (!@is_file($legacyFile) || !@is_readable($legacyFile)) {
        return;
    }

    $raw = @file_get_contents($legacyFile);
    $data = json_decode((string) $raw, true);
    if (!is_array($data) || !isset($data['scopes']) || !is_array($data['scopes'])) {
        return;
    }

    $db->exec('BEGIN IMMEDIATE');
    foreach ($data['scopes'] as $scopeKey => $scopeRows) {
        if (!is_array($scopeRows)) {
            continue;
        }
        foreach ($scopeRows as $relPath => $record) {
            if (!is_array($record) || !is_string($relPath) || $relPath === '') {
                continue;
            }

            $normalized = array(
                'created_at' => isset($record['created_at']) ? (int) $record['created_at'] : 0,
                'created_by' => isset($record['created_by']) ? (string) $record['created_by'] : '',
                'updated_at' => isset($record['updated_at']) ? (int) $record['updated_at'] : 0,
                'updated_by' => isset($record['updated_by']) ? (string) $record['updated_by'] : '',
                'owner_source' => isset($record['owner_source']) ? (string) $record['owner_source'] : fm_owner_meta_infer_source($record),
                'last_action' => isset($record['last_action']) ? (string) $record['last_action'] : '',
            );
            fm_owner_meta_sqlite_upsert($db, (string) $scopeKey, (string) $relPath, $normalized);
        }
    }
    $db->exec('COMMIT');
}

function fm_owner_meta_get_db()
{
    static $db = null;
    if ($db !== null) {
        return $db;
    }

    if (!class_exists('SQLite3')) {
        return null;
    }

    try {
        $db = new SQLite3(fm_owner_meta_db_path());
        $db->busyTimeout(3000);
        $db->exec('CREATE TABLE IF NOT EXISTS fm_owner_meta_records (
            scope_key TEXT NOT NULL,
            rel_path TEXT NOT NULL,
            created_at INTEGER NOT NULL DEFAULT 0,
            created_by TEXT NOT NULL DEFAULT "",
            updated_at INTEGER NOT NULL DEFAULT 0,
            updated_by TEXT NOT NULL DEFAULT "",
            owner_source TEXT NOT NULL DEFAULT "system",
            last_action TEXT NOT NULL DEFAULT "",
            PRIMARY KEY (scope_key, rel_path)
        )');
        $db->exec('CREATE INDEX IF NOT EXISTS idx_fm_owner_meta_scope_updated ON fm_owner_meta_records(scope_key, updated_at)');
        fm_owner_meta_migrate_json_to_sqlite($db);
    } catch (Exception $e) {
        $db = null;
    }

    return $db;
}

function fm_owner_meta_current_user()
{
    if (defined('FM_USE_AUTH') && FM_USE_AUTH && isset($_SESSION[FM_SESSION_ID]['logged']) && $_SESSION[FM_SESSION_ID]['logged'] !== '') {
        return (string) $_SESSION[FM_SESSION_ID]['logged'];
    }
    return '';
}

function fm_owner_meta_get($absolutePath)
{
    $rel = fm_owner_meta_rel_path($absolutePath);
    if ($rel === '') {
        return null;
    }

    $db = fm_owner_meta_get_db();
    if ($db) {
        $scope = fm_owner_meta_scope_key();
        return fm_owner_meta_sqlite_fetch($db, $scope, $rel);
    }

    $data = fm_owner_meta_read_all();
    $scope = fm_owner_meta_scope_key();
    if (!isset($data['scopes'][$scope]) || !is_array($data['scopes'][$scope])) {
        return null;
    }

    return isset($data['scopes'][$scope][$rel]) && is_array($data['scopes'][$scope][$rel])
        ? $data['scopes'][$scope][$rel]
        : null;
}

function fm_owner_meta_is_app_creation_action($action)
{
    $action = strtolower((string) $action);
    return in_array($action, array('create', 'mkdir', 'upload', 'upload_url', 'copy'), true);
}

function fm_owner_meta_infer_source(array $record)
{
    if (isset($record['owner_source']) && ($record['owner_source'] === 'app' || $record['owner_source'] === 'system')) {
        return (string) $record['owner_source'];
    }

    $createdBy = isset($record['created_by']) ? trim((string) $record['created_by']) : '';
    if ($createdBy !== '' && strtolower($createdBy) !== 'system') {
        return 'app';
    }

    return 'system';
}

function fm_lng_plain($key)
{
    return html_entity_decode((string) lng((string) $key), ENT_QUOTES, 'UTF-8');
}

function fm_owner_meta_action_label($action, $isDirectory = false)
{
    $action = strtolower(trim((string) $action));
    $isDirectory = (bool) $isDirectory;

    $actionLabelKeyMap = array(
        'create_file' => 'ActionCreateFile',
        'create_folder' => 'ActionCreateFolder',
        'mkdir' => 'ActionMkdir',
        'upload' => 'ActionUpload',
        'upload_url' => 'ActionUploadUrl',
        'copy' => 'ActionCopy',
        'move' => 'ActionMove',
        'rename' => 'ActionRename',
        'edit' => 'ActionEdit',
        'update' => 'ActionUpdate',
        'write' => 'ActionWrite',
        'delete' => 'ActionDelete',
        'remove' => 'ActionRemove',
    );

    if ($action === 'create') {
        $key = $isDirectory ? $actionLabelKeyMap['create_folder'] : $actionLabelKeyMap['create_file'];
        $translated = fm_lng_plain($key);
        if ($translated !== $key) {
            return $translated;
        }
        return fm_lng_plain('Created') . ' ' . fm_lng_plain($isDirectory ? 'Folder' : 'File');
    }

    if (!isset($actionLabelKeyMap[$action])) {
        return ucfirst(str_replace('_', ' ', $action));
    }

    $actionLabelKey = $actionLabelKeyMap[$action];
    $translated = fm_lng_plain($actionLabelKey);
    if ($translated !== $actionLabelKey) {
        return $translated;
    }

    // Backward-compatible fallback for older translation packs without Action* keys.
    $fallbackMap = array(
        'mkdir' => array('Created', 'Folder'),
        'upload' => array('Upload'),
        'upload_url' => array('Upload'),
        'copy' => array('Copy'),
        'move' => array('Move'),
        'rename' => array('Rename'),
        'edit' => array('Edit'),
        'update' => array('Edit'),
        'write' => array('Save'),
        'delete' => array('Delete'),
        'remove' => array('Delete'),
    );

    if (!isset($fallbackMap[$action])) {
        return ucfirst(str_replace('_', ' ', $action));
    }

    $parts = array();
    foreach ($fallbackMap[$action] as $key) {
        $parts[] = fm_lng_plain($key);
    }
    return trim(implode(' ', $parts));
}

function fm_owner_meta_touch($absolutePath, $action = 'update', $actor = '')
{
    $rel = fm_owner_meta_rel_path($absolutePath);
    if ($rel === '') {
        return false;
    }

    if ($actor === '') {
        $actor = fm_owner_meta_current_user();
    }

    $db = fm_owner_meta_get_db();
    if ($db) {
        $scope = fm_owner_meta_scope_key();
        $action = (string) $action;
        $record = fm_owner_meta_sqlite_fetch($db, $scope, $rel);
        if (!is_array($record)) {
            $record = array();
        }

        $now = time();
        if (!isset($record['created_at']) || !is_numeric($record['created_at']) || (int) $record['created_at'] <= 0) {
            $record['created_at'] = $now;
        }

        $isNewRecord = empty($record) || (!isset($record['updated_at']) && !isset($record['updated_by']) && !isset($record['created_by']));
        $ownerSource = fm_owner_meta_infer_source($record);

        if ($isNewRecord) {
            if (fm_owner_meta_is_app_creation_action($action)) {
                $ownerSource = 'app';
                $record['created_by'] = $actor !== '' ? $actor : '';
            } else {
                $ownerSource = 'system';
                $record['created_by'] = '';
            }
        } elseif ($ownerSource === 'app' && (!isset($record['created_by']) || trim((string) $record['created_by']) === '') && $actor !== '') {
            $record['created_by'] = $actor;
        }

        $record['owner_source'] = $ownerSource;
        $record['updated_at'] = $now;
        $record['updated_by'] = $actor !== '' ? $actor : (isset($record['updated_by']) && trim((string) $record['updated_by']) !== '' ? (string) $record['updated_by'] : (isset($record['created_by']) ? (string) $record['created_by'] : 'system'));
        $record['last_action'] = $action;

        return fm_owner_meta_sqlite_upsert($db, $scope, $rel, $record);
    }

    $data = fm_owner_meta_read_all();
    $scope = fm_owner_meta_scope_key();
    if (!isset($data['scopes'][$scope]) || !is_array($data['scopes'][$scope])) {
        $data['scopes'][$scope] = array();
    }

    $action = (string) $action;
    $record = isset($data['scopes'][$scope][$rel]) && is_array($data['scopes'][$scope][$rel])
        ? $data['scopes'][$scope][$rel]
        : array();

    $now = time();
    if (!isset($record['created_at']) || !is_numeric($record['created_at'])) {
        $record['created_at'] = $now;
    }

    $isNewRecord = empty($record) || (!isset($record['updated_at']) && !isset($record['updated_by']) && !isset($record['created_by']));
    $ownerSource = fm_owner_meta_infer_source($record);

    if ($isNewRecord) {
        if (fm_owner_meta_is_app_creation_action($action)) {
            $ownerSource = 'app';
            $record['created_by'] = $actor !== '' ? $actor : '';
        } else {
            // Existing filesystem object edited by app: keep system ownership, track last editor separately.
            $ownerSource = 'system';
            $record['created_by'] = '';
        }
    } elseif ($ownerSource === 'app' && (!isset($record['created_by']) || trim((string) $record['created_by']) === '') && $actor !== '') {
        $record['created_by'] = $actor;
    }

    $record['owner_source'] = $ownerSource;
    $record['updated_at'] = $now;
    $record['updated_by'] = $actor !== '' ? $actor : (isset($record['updated_by']) && trim((string) $record['updated_by']) !== '' ? (string) $record['updated_by'] : (isset($record['created_by']) ? (string) $record['created_by'] : 'system'));
    $record['last_action'] = $action;

    $data['scopes'][$scope][$rel] = $record;
    return fm_owner_meta_write_all($data);
}

function fm_owner_meta_move($oldAbsolutePath, $newAbsolutePath, $actor = '')
{
    $oldRel = fm_owner_meta_rel_path($oldAbsolutePath);
    $newRel = fm_owner_meta_rel_path($newAbsolutePath);
    if ($oldRel === '' || $newRel === '') {
        return false;
    }

    if ($actor === '') {
        $actor = fm_owner_meta_current_user();
    }

    $db = fm_owner_meta_get_db();
    if ($db) {
        $scope = fm_owner_meta_scope_key();
        $now = time();
        $record = fm_owner_meta_sqlite_fetch($db, $scope, $oldRel);
        if (!is_array($record)) {
            $record = array(
                'created_at' => $now,
                'created_by' => '',
                'owner_source' => 'system',
            );
        }

        $record['owner_source'] = fm_owner_meta_infer_source($record);
        $record['updated_at'] = $now;
        $record['updated_by'] = $actor !== '' ? $actor : (isset($record['updated_by']) && trim((string) $record['updated_by']) !== '' ? (string) $record['updated_by'] : (isset($record['created_by']) ? (string) $record['created_by'] : 'system'));
        $record['last_action'] = 'move';

        $stmt = $db->prepare('SELECT rel_path, created_at, created_by, updated_at, updated_by, owner_source, last_action
            FROM fm_owner_meta_records
            WHERE scope_key = :scope AND rel_path LIKE :prefix');
        $descendants = array();
        if ($stmt) {
            $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
            $stmt->bindValue(':prefix', $oldRel . '/%', SQLITE3_TEXT);
            $result = $stmt->execute();
            if ($result) {
                while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
                    if (is_array($row) && isset($row['rel_path'])) {
                        $descendants[] = $row;
                    }
                }
                $result->finalize();
            }
        }

        $db->exec('BEGIN IMMEDIATE');
        $ok = fm_owner_meta_sqlite_upsert($db, $scope, $newRel, $record);
        if ($ok) {
            foreach ($descendants as $childRow) {
                $childRel = (string) $childRow['rel_path'];
                $suffix = substr($childRel, strlen($oldRel));
                $targetRel = $newRel . $suffix;
                $ok = fm_owner_meta_sqlite_upsert($db, $scope, $targetRel, fm_owner_meta_sqlite_row_to_record($childRow));
                if (!$ok) {
                    break;
                }
            }
        }

        if ($ok) {
            $deleteStmt = $db->prepare('DELETE FROM fm_owner_meta_records
                WHERE scope_key = :scope AND (rel_path = :rel OR rel_path LIKE :prefix)');
            if ($deleteStmt) {
                $deleteStmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
                $deleteStmt->bindValue(':rel', (string) $oldRel, SQLITE3_TEXT);
                $deleteStmt->bindValue(':prefix', $oldRel . '/%', SQLITE3_TEXT);
                $deleteRes = $deleteStmt->execute();
                if ($deleteRes) {
                    $deleteRes->finalize();
                }
                $ok = $deleteRes !== false;
            } else {
                $ok = false;
            }
        }

        if ($ok) {
            $db->exec('COMMIT');
            return true;
        }

        $db->exec('ROLLBACK');
        return false;
    }

    $data = fm_owner_meta_read_all();
    $scope = fm_owner_meta_scope_key();
    if (!isset($data['scopes'][$scope]) || !is_array($data['scopes'][$scope])) {
        $data['scopes'][$scope] = array();
    }

    $scopeData = $data['scopes'][$scope];
    $now = time();

    $record = isset($scopeData[$oldRel]) && is_array($scopeData[$oldRel])
        ? $scopeData[$oldRel]
        : array(
            'created_at' => $now,
            'created_by' => '',
            'owner_source' => 'system',
        );

    $record['owner_source'] = fm_owner_meta_infer_source($record);
    $record['updated_at'] = $now;
    $record['updated_by'] = $actor !== '' ? $actor : (isset($record['updated_by']) && trim((string) $record['updated_by']) !== '' ? (string) $record['updated_by'] : (isset($record['created_by']) ? (string) $record['created_by'] : 'system'));
    $record['last_action'] = 'move';
    $scopeData[$newRel] = $record;

    foreach ($scopeData as $key => $value) {
        if ($key === $oldRel || strpos($key, $oldRel . '/') === 0) {
            unset($scopeData[$key]);
            if ($key !== $oldRel) {
                $suffix = substr($key, strlen($oldRel));
                $scopeData[$newRel . $suffix] = $value;
            }
        }
    }

    $data['scopes'][$scope] = $scopeData;
    return fm_owner_meta_write_all($data);
}

function fm_owner_meta_copy($srcAbsolutePath, $destAbsolutePath, $actor = '')
{
    $srcRel = fm_owner_meta_rel_path($srcAbsolutePath);
    $destRel = fm_owner_meta_rel_path($destAbsolutePath);
    if ($srcRel === '' || $destRel === '') {
        return false;
    }

    if ($actor === '') {
        $actor = fm_owner_meta_current_user();
    }

    $db = fm_owner_meta_get_db();
    if ($db) {
        $scope = fm_owner_meta_scope_key();
        $sourceRecord = fm_owner_meta_sqlite_fetch($db, $scope, $srcRel);
        if (!is_array($sourceRecord)) {
            $sourceRecord = array();
        }
        $now = time();

        $newRecord = $sourceRecord;
        $newRecord['created_at'] = $now;
        $newRecord['owner_source'] = 'app';
        $newRecord['created_by'] = $actor !== '' ? $actor : (isset($sourceRecord['created_by']) ? (string) $sourceRecord['created_by'] : '');
        if (trim((string) $newRecord['created_by']) === '') {
            $newRecord['created_by'] = 'system';
        }
        $newRecord['updated_at'] = $now;
        $newRecord['updated_by'] = $newRecord['created_by'];
        $newRecord['last_action'] = 'copy';

        $stmt = $db->prepare('SELECT rel_path, created_at, created_by, updated_at, updated_by, owner_source, last_action
            FROM fm_owner_meta_records
            WHERE scope_key = :scope AND rel_path LIKE :prefix');
        $descendants = array();
        if ($stmt) {
            $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
            $stmt->bindValue(':prefix', $srcRel . '/%', SQLITE3_TEXT);
            $result = $stmt->execute();
            if ($result) {
                while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
                    if (is_array($row) && isset($row['rel_path'])) {
                        $descendants[] = $row;
                    }
                }
                $result->finalize();
            }
        }

        $db->exec('BEGIN IMMEDIATE');
        $ok = fm_owner_meta_sqlite_upsert($db, $scope, $destRel, $newRecord);
        if ($ok) {
            foreach ($descendants as $childRow) {
                $childRel = (string) $childRow['rel_path'];
                $suffix = substr($childRel, strlen($srcRel));
                $targetRel = $destRel . $suffix;
                $child = fm_owner_meta_sqlite_row_to_record($childRow);
                $child['owner_source'] = 'app';
                $child['created_at'] = $now;
                $child['created_by'] = $newRecord['created_by'];
                $child['updated_at'] = $now;
                $child['updated_by'] = $newRecord['created_by'];
                $child['last_action'] = 'copy';
                $ok = fm_owner_meta_sqlite_upsert($db, $scope, $targetRel, $child);
                if (!$ok) {
                    break;
                }
            }
        }

        if ($ok) {
            $db->exec('COMMIT');
            return true;
        }

        $db->exec('ROLLBACK');
        return false;
    }

    $data = fm_owner_meta_read_all();
    $scope = fm_owner_meta_scope_key();
    if (!isset($data['scopes'][$scope]) || !is_array($data['scopes'][$scope])) {
        $data['scopes'][$scope] = array();
    }

    $scopeData = $data['scopes'][$scope];
    $sourceRecord = isset($scopeData[$srcRel]) && is_array($scopeData[$srcRel]) ? $scopeData[$srcRel] : array();
    $now = time();

    $newRecord = $sourceRecord;
    $newRecord['created_at'] = $now;
    $newRecord['owner_source'] = 'app';
    $newRecord['created_by'] = $actor !== '' ? $actor : (isset($sourceRecord['created_by']) ? (string) $sourceRecord['created_by'] : '');
    if (trim((string) $newRecord['created_by']) === '') {
        $newRecord['created_by'] = 'system';
    }
    $newRecord['updated_at'] = $now;
    $newRecord['updated_by'] = $newRecord['created_by'];
    $newRecord['last_action'] = 'copy';
    $scopeData[$destRel] = $newRecord;

    foreach ($scopeData as $key => $value) {
        if ($key !== $srcRel && strpos($key, $srcRel . '/') === 0) {
            $suffix = substr($key, strlen($srcRel));
            $child = is_array($value) ? $value : array();
            $child['owner_source'] = 'app';
            $child['created_at'] = $now;
            $child['created_by'] = $newRecord['created_by'];
            $child['updated_at'] = $now;
            $child['updated_by'] = $newRecord['created_by'];
            $child['last_action'] = 'copy';
            $scopeData[$destRel . $suffix] = $child;
        }
    }

    $data['scopes'][$scope] = $scopeData;
    return fm_owner_meta_write_all($data);
}

function fm_owner_meta_remove($absolutePath)
{
    $rel = fm_owner_meta_rel_path($absolutePath);
    if ($rel === '') {
        return false;
    }

    $db = fm_owner_meta_get_db();
    if ($db) {
        $scope = fm_owner_meta_scope_key();
        $stmt = $db->prepare('DELETE FROM fm_owner_meta_records
            WHERE scope_key = :scope AND (rel_path = :rel OR rel_path LIKE :prefix)');
        if (!$stmt) {
            return false;
        }
        $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
        $stmt->bindValue(':rel', (string) $rel, SQLITE3_TEXT);
        $stmt->bindValue(':prefix', $rel . '/%', SQLITE3_TEXT);
        $result = $stmt->execute();
        if ($result) {
            $result->finalize();
        }
        return $result !== false;
    }

    $data = fm_owner_meta_read_all();
    $scope = fm_owner_meta_scope_key();
    if (!isset($data['scopes'][$scope]) || !is_array($data['scopes'][$scope])) {
        return true;
    }

    foreach ($data['scopes'][$scope] as $key => $value) {
        if ($key === $rel || strpos($key, $rel . '/') === 0) {
            unset($data['scopes'][$scope][$key]);
        }
    }

    return fm_owner_meta_write_all($data);
}

function fm_chat_get_db()
{
    static $db = null;
    if ($db !== null) {
        return $db;
    }

    if (!class_exists('SQLite3')) {
        return null;
    }

    try {
        $db = new SQLite3(fm_chat_db_path());
        $db->busyTimeout(3000);
        $db->exec('CREATE TABLE IF NOT EXISTS fm_chat_messages (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            sender TEXT NOT NULL,
            recipient TEXT NOT NULL,
            message TEXT NOT NULL,
            created_at INTEGER NOT NULL
        )');
        $db->exec('CREATE INDEX IF NOT EXISTS idx_fm_chat_pair_time ON fm_chat_messages(sender, recipient, created_at)');
        $db->exec('CREATE TABLE IF NOT EXISTS fm_chat_read_state (
            username TEXT NOT NULL,
            peer TEXT NOT NULL,
            last_read_id INTEGER NOT NULL DEFAULT 0,
            updated_at INTEGER NOT NULL,
            PRIMARY KEY (username, peer)
        )');
        $db->exec('CREATE INDEX IF NOT EXISTS idx_fm_chat_read_state_user_peer ON fm_chat_read_state(username, peer)');
    } catch (Exception $e) {
        $db = null;
    }

    return $db;
}

function fm_format_welcome_message_for_user($template, $username)
{
    $message = trim((string) $template);
    $username = trim((string) $username);
    if ($message === '' || $username === '') {
        return $message;
    }

    $formatted = strtr($message, array(
        '{username}' => $username,
        '{{username}}' => $username,
        '%username%' => $username,
        ':username' => $username,
    ));

    $contains_username = function_exists('mb_stripos')
        ? (mb_stripos($formatted, $username, 0, 'UTF-8') !== false)
        : (stripos($formatted, $username) !== false);
    if (!$contains_username) {
        $formatted = 'Ahoj ' . $username . ', ' . $formatted;
    }

    return trim($formatted);
}

function fm_maybe_issue_first_login_welcome($username)
{
    global $auth_users;

    $username = trim((string) $username);
    if ($username === '' || $username === 'admin' || !isset($auth_users[$username])) {
        return '';
    }

    $config_file = __DIR__ . '/config.php';
    $config_data = fm_admin_load_user_config_arrays($config_file);
    if (empty($config_data['ok'])) {
        return '';
    }

    $shown_users = isset($config_data['welcome_message_shown_users']) && is_array($config_data['welcome_message_shown_users'])
        ? array_values(array_unique(array_map('strval', $config_data['welcome_message_shown_users'])))
        : array();
    if (in_array($username, $shown_users, true)) {
        return '';
    }

    $templates = isset($config_data['user_welcome_messages']) && is_array($config_data['user_welcome_messages'])
        ? $config_data['user_welcome_messages']
        : array();
    $template = isset($templates[$username]) ? (string) $templates[$username] : '';
    $message = fm_format_welcome_message_for_user($template, $username);
    if ($message === '') {
        return '';
    }

    $shown_users[] = $username;
    $shown_users = array_values(array_unique($shown_users));
    $persist_result = fm_admin_persist_user_config_arrays(
        $config_file,
        isset($config_data['auth_users']) && is_array($config_data['auth_users']) ? $config_data['auth_users'] : array(),
        isset($config_data['readonly_users']) && is_array($config_data['readonly_users']) ? $config_data['readonly_users'] : array(),
        isset($config_data['upload_only_users']) && is_array($config_data['upload_only_users']) ? $config_data['upload_only_users'] : array(),
        isset($config_data['manager_users']) && is_array($config_data['manager_users']) ? $config_data['manager_users'] : array(),
        isset($config_data['directories_users']) && is_array($config_data['directories_users']) ? $config_data['directories_users'] : array(),
        isset($config_data['user_notes']) && is_array($config_data['user_notes']) ? $config_data['user_notes'] : array(),
        isset($config_data['bulk_actions_disabled_users']) && is_array($config_data['bulk_actions_disabled_users']) ? $config_data['bulk_actions_disabled_users'] : array(),
        $templates,
        $shown_users,
        isset($config_data['user_manager_owners']) && is_array($config_data['user_manager_owners']) ? $config_data['user_manager_owners'] : array()
    );

    if (empty($persist_result['ok'])) {
        return '';
    }

    return $message;
}

function fm_chat_save_message($sender, $recipient, $message)
{
    $db = fm_chat_get_db();
    if (!$db) {
        return false;
    }

    $stmt = $db->prepare('INSERT INTO fm_chat_messages (sender, recipient, message, created_at) VALUES (:sender, :recipient, :message, :created_at)');
    if (!$stmt) {
        return false;
    }

    $stmt->bindValue(':sender', (string) $sender, SQLITE3_TEXT);
    $stmt->bindValue(':recipient', (string) $recipient, SQLITE3_TEXT);
    $stmt->bindValue(':message', (string) $message, SQLITE3_TEXT);
    $stmt->bindValue(':created_at', time(), SQLITE3_INTEGER);

    $result = $stmt->execute();
    if ($result) {
        $result->finalize();
    }

    return $result !== false;
}

function fm_chat_get_conversation($user_a, $user_b, $limit = 100)
{
    $db = fm_chat_get_db();
    if (!$db) {
        return array();
    }

    $limit = (int) $limit;
    if ($limit < 1) {
        $limit = 1;
    }
    if ($limit > 300) {
        $limit = 300;
    }

    $stmt = $db->prepare('SELECT id, sender, recipient, message, created_at
        FROM fm_chat_messages
        WHERE (sender = :a AND recipient = :b) OR (sender = :b AND recipient = :a)
        ORDER BY id DESC
        LIMIT :limit');
    if (!$stmt) {
        return array();
    }

    $stmt->bindValue(':a', (string) $user_a, SQLITE3_TEXT);
    $stmt->bindValue(':b', (string) $user_b, SQLITE3_TEXT);
    $stmt->bindValue(':limit', $limit, SQLITE3_INTEGER);

    $result = $stmt->execute();
    if (!$result) {
        return array();
    }

    $messages = array();
    while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
        $messages[] = array(
            'id' => isset($row['id']) ? (int) $row['id'] : 0,
            'sender' => isset($row['sender']) ? (string) $row['sender'] : '',
            'recipient' => isset($row['recipient']) ? (string) $row['recipient'] : '',
            'message' => isset($row['message']) ? (string) $row['message'] : '',
            'created_at' => isset($row['created_at']) ? (int) $row['created_at'] : 0,
        );
    }

    $result->finalize();
    return array_reverse($messages);
}

function fm_chat_get_inbox($recipient, $limit = 50)
{
    $db = fm_chat_get_db();
    if (!$db) {
        return array();
    }

    $limit = (int) $limit;
    if ($limit < 1) {
        $limit = 1;
    }
    if ($limit > 200) {
        $limit = 200;
    }

    $stmt = $db->prepare('SELECT m1.id, m1.sender, m1.message, m1.created_at,
            COALESCE(rs.last_read_id, 0) AS last_read_id,
            (
                SELECT COUNT(1)
                FROM fm_chat_messages um
                WHERE um.sender = m1.sender
                  AND um.recipient = :recipient_unread
                  AND um.id > COALESCE(rs.last_read_id, 0)
            ) AS unread_count
        FROM fm_chat_messages m1
        INNER JOIN (
            SELECT sender, MAX(id) AS max_id
            FROM fm_chat_messages
            WHERE recipient = :recipient
            GROUP BY sender
        ) latest ON latest.max_id = m1.id
        LEFT JOIN fm_chat_read_state rs
            ON rs.username = :recipient_state
           AND rs.peer = m1.sender
        ORDER BY m1.id DESC
        LIMIT :limit');
    if (!$stmt) {
        return array();
    }

    $stmt->bindValue(':recipient', (string) $recipient, SQLITE3_TEXT);
    $stmt->bindValue(':recipient_unread', (string) $recipient, SQLITE3_TEXT);
    $stmt->bindValue(':recipient_state', (string) $recipient, SQLITE3_TEXT);
    $stmt->bindValue(':limit', $limit, SQLITE3_INTEGER);

    $result = $stmt->execute();
    if (!$result) {
        return array();
    }

    $items = array();
    while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
        $items[] = array(
            'id' => isset($row['id']) ? (int) $row['id'] : 0,
            'sender' => isset($row['sender']) ? (string) $row['sender'] : '',
            'message' => isset($row['message']) ? (string) $row['message'] : '',
            'created_at' => isset($row['created_at']) ? (int) $row['created_at'] : 0,
            'last_read_id' => isset($row['last_read_id']) ? (int) $row['last_read_id'] : 0,
            'unread_count' => isset($row['unread_count']) ? (int) $row['unread_count'] : 0,
            'unread' => isset($row['unread_count']) ? ((int) $row['unread_count'] > 0) : false,
        );
    }

    $result->finalize();
    return $items;
}

function fm_chat_get_last_read_id($username, $peer)
{
    $db = fm_chat_get_db();
    if (!$db) {
        return 0;
    }

    $stmt = $db->prepare('SELECT last_read_id
        FROM fm_chat_read_state
        WHERE username = :username AND peer = :peer
        LIMIT 1');
    if (!$stmt) {
        return 0;
    }

    $stmt->bindValue(':username', (string) $username, SQLITE3_TEXT);
    $stmt->bindValue(':peer', (string) $peer, SQLITE3_TEXT);

    $result = $stmt->execute();
    if (!$result) {
        return 0;
    }

    $row = $result->fetchArray(SQLITE3_ASSOC);
    $result->finalize();

    if (!is_array($row) || !isset($row['last_read_id'])) {
        return 0;
    }

    return (int) $row['last_read_id'];
}

function fm_chat_mark_read($username, $peer, $last_read_id = 0)
{
    $db = fm_chat_get_db();
    if (!$db) {
        return false;
    }

    $username = (string) $username;
    $peer = (string) $peer;
    $last_read_id = (int) $last_read_id;
    if ($username === '' || $peer === '') {
        return false;
    }

    if ($last_read_id <= 0) {
        $lookup = $db->prepare('SELECT MAX(id) AS max_id
            FROM fm_chat_messages
            WHERE sender = :peer AND recipient = :username');
        if ($lookup) {
            $lookup->bindValue(':peer', $peer, SQLITE3_TEXT);
            $lookup->bindValue(':username', $username, SQLITE3_TEXT);
            $lookup_result = $lookup->execute();
            if ($lookup_result) {
                $lookup_row = $lookup_result->fetchArray(SQLITE3_ASSOC);
                if (is_array($lookup_row) && isset($lookup_row['max_id'])) {
                    $last_read_id = (int) $lookup_row['max_id'];
                }
                $lookup_result->finalize();
            }
        }
    }

    if ($last_read_id <= 0) {
        return true;
    }

    $current_last_read_id = fm_chat_get_last_read_id($username, $peer);
    if ($last_read_id < $current_last_read_id) {
        $last_read_id = $current_last_read_id;
    }

    $stmt = $db->prepare('INSERT OR REPLACE INTO fm_chat_read_state (username, peer, last_read_id, updated_at)
        VALUES (:username, :peer, :last_read_id, :updated_at)');
    if (!$stmt) {
        return false;
    }

    $stmt->bindValue(':username', $username, SQLITE3_TEXT);
    $stmt->bindValue(':peer', $peer, SQLITE3_TEXT);
    $stmt->bindValue(':last_read_id', $last_read_id, SQLITE3_INTEGER);
    $stmt->bindValue(':updated_at', time(), SQLITE3_INTEGER);

    $result = $stmt->execute();
    if ($result) {
        $result->finalize();
    }

    return $result !== false;
}

function fm_markdown_inline($text)
{
    $escaped = htmlspecialchars((string) $text, ENT_QUOTES, 'UTF-8');

    // Inline code first to avoid formatting its content.
    $escaped = preg_replace_callback('/`([^`]+)`/', static function ($m) {
        return '<code>' . $m[1] . '</code>';
    }, $escaped);

    // Links: [label](https://example.com) and local help links like [x](?help_doc=...)
    $escaped = preg_replace_callback('/\[([^\]]+)\]\(([^\)\s]+)\)/', static function ($m) {
        $url = html_entity_decode($m[2], ENT_QUOTES, 'UTF-8');

        // Allow safe absolute URLs and safe local relative URLs.
        $is_absolute = (bool) preg_match('#^https?://#i', $url);
        $is_local = (bool) preg_match('~^(?:\?|/|\./|\.\./|#)~', $url);
        if (!$is_absolute && !$is_local) {
            return $m[1];
        }

        // Block dangerous schemes even if malformed input slips through.
        if (preg_match('#^(?:javascript|data|vbscript):#i', $url)) {
            return $m[1];
        }

        // Preserve current folder when navigating local help docs.
        if (preg_match('/^\?help_doc=/', $url) && defined('FM_PATH')) {
            $url = '?p=' . urlencode((string) FM_PATH) . '&' . ltrim($url, '?');
        }

        $safe_url = htmlspecialchars($url, ENT_QUOTES, 'UTF-8');
        if ($is_absolute) {
            return '<a href="' . $safe_url . '" target="_blank" rel="noopener noreferrer">' . $m[1] . '</a>';
        }

        return '<a href="' . $safe_url . '">' . $m[1] . '</a>';
    }, $escaped);

    $escaped = preg_replace('/\*\*([^\*\n]+)\*\*/', '<strong>$1</strong>', $escaped);
    $escaped = preg_replace('/\*([^\*\n]+)\*/', '<em>$1</em>', $escaped);

    return $escaped;
}

function fm_render_markdown_basic($markdown)
{
    $lines = preg_split('/\r\n|\r|\n/', (string) $markdown);
    $html = '';
    $in_code = false;
    $in_ul = false;
    $in_ol = false;
    $paragraph_lines = array();

    $flush_paragraph = static function () use (&$paragraph_lines, &$html) {
        if (!empty($paragraph_lines)) {
            $paragraph = implode('<br>', $paragraph_lines);
            $html .= '<p>' . $paragraph . '</p>';
            $paragraph_lines = array();
        }
    };

    $close_lists = static function () use (&$in_ul, &$in_ol, &$html) {
        if ($in_ul) {
            $html .= '</ul>';
            $in_ul = false;
        }
        if ($in_ol) {
            $html .= '</ol>';
            $in_ol = false;
        }
    };

    foreach ($lines as $line) {
        $trim = trim($line);

        if (preg_match('/^```/', $trim)) {
            $flush_paragraph();
            $close_lists();
            if (!$in_code) {
                $html .= '<pre><code>';
                $in_code = true;
            } else {
                $html .= '</code></pre>';
                $in_code = false;
            }
            continue;
        }

        if ($in_code) {
            $html .= htmlspecialchars($line, ENT_QUOTES, 'UTF-8') . "\n";
            continue;
        }

        if ($trim === '') {
            $flush_paragraph();
            $close_lists();
            continue;
        }

        if (preg_match('/^(#{1,4})\s+(.+)$/', $trim, $m)) {
            $flush_paragraph();
            $close_lists();
            $level = strlen($m[1]);
            $html .= '<h' . $level . '>' . fm_markdown_inline($m[2]) . '</h' . $level . '>';
            continue;
        }

        if (preg_match('/^[-\*]\s+(.+)$/', $trim, $m)) {
            $flush_paragraph();
            if ($in_ol) {
                $html .= '</ol>';
                $in_ol = false;
            }
            if (!$in_ul) {
                $html .= '<ul>';
                $in_ul = true;
            }
            $html .= '<li>' . fm_markdown_inline($m[1]) . '</li>';
            continue;
        }

        if (preg_match('/^[0-9]+\.\s+(.+)$/', $trim, $m)) {
            $flush_paragraph();
            if ($in_ul) {
                $html .= '</ul>';
                $in_ul = false;
            }
            if (!$in_ol) {
                $html .= '<ol>';
                $in_ol = true;
            }
            $html .= '<li>' . fm_markdown_inline($m[1]) . '</li>';
            continue;
        }

        $paragraph_lines[] = fm_markdown_inline($trim);
    }

    if ($in_code) {
        $html .= '</code></pre>';
    }
    $flush_paragraph();
    $close_lists();

    return $html;
}

/**
 * @param string $file
 * Recover all file sizes larger than > 2GB.
 * Works on php 32bits and 64bits and supports linux
 * @return int|string
 */
function fm_get_size($file)
{
    static $iswin = null;
    static $isdarwin = null;
    static $exec_works = null;

    // Set static variables once
    if ($iswin === null) {
        $iswin = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN';
        $isdarwin = strtoupper(PHP_OS) === 'DARWIN';
        $exec_works = function_exists('exec') && !ini_get('safe_mode') && @exec('echo EXEC') === 'EXEC';
    }

    // Attempt shell command if exec is available
    if ($exec_works) {
        $arg = escapeshellarg($file);
        $cmd = $iswin ? "for %F in (\"$file\") do @echo %~zF" : ($isdarwin ? "stat -f%z $arg" : "stat -c%s $arg");
        @exec($cmd, $output);

        if (!empty($output) && ctype_digit($size = trim(implode("\n", $output)))) {
            return $size;
        }
    }

    // Attempt Windows COM interface for Windows systems
    if ($iswin && class_exists('COM')) {
        try {
            $fsobj = new COM('Scripting.FileSystemObject');
            $f = $fsobj->GetFile(realpath($file));
            if (ctype_digit($size = $f->Size)) {
                return $size;
            }
        } catch (Exception $e) {
            // COM failed, fallback to filesize
        }
    }

    // Default to PHP's filesize function
    return filesize($file);
}


/**
 * Get nice filesize
 * @param int $size
 * @return string
 */
function fm_get_filesize($size)
{
    $size = (float) $size;
    $units = array('B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
    $power = ($size > 0) ? floor(log($size, 1024)) : 0;
    $power = ($power > (count($units) - 1)) ? (count($units) - 1) : $power;
    return sprintf('%s %s', round($size / pow(1024, $power), 2), $units[$power]);
}

/**
 * Get info about zip archive
 * @param string $path
 * @return array|bool
 */
function fm_get_zif_info($path, $ext)
{
    if ($ext == 'zip' && function_exists('zip_open')) {
        $arch = @zip_open($path);
        if ($arch) {
            $filenames = array();
            while ($zip_entry = @zip_read($arch)) {
                $zip_name = @zip_entry_name($zip_entry);
                $zip_folder = substr($zip_name, -1) == '/';
                $filenames[] = array(
                    'name' => $zip_name,
                    'filesize' => @zip_entry_filesize($zip_entry),
                    'compressed_size' => @zip_entry_compressedsize($zip_entry),
                    'folder' => $zip_folder
                    //'compression_method' => zip_entry_compressionmethod($zip_entry),
                );
            }
            @zip_close($arch);
            return $filenames;
        }
    } elseif ($ext == 'tar' && class_exists('PharData')) {
        $archive = new PharData($path);
        $filenames = array();
        foreach (new RecursiveIteratorIterator($archive) as $file) {
            $parent_info = $file->getPathInfo();
            $zip_name = str_replace("phar://" . $path, '', $file->getPathName());
            $zip_name = substr($zip_name, ($pos = strpos($zip_name, '/')) !== false ? $pos + 1 : 0);
            $zip_folder = $parent_info->getFileName();
            $zip_info = new SplFileInfo($file);
            $filenames[] = array(
                'name' => $zip_name,
                'filesize' => $zip_info->getSize(),
                'compressed_size' => $file->getCompressedSize(),
                'folder' => $zip_folder
            );
        }
        return $filenames;
    }
    return false;
}

/**
 * Encode html entities
 * @param string $text
 * @return string
 */
function fm_enc($text)
{
    return htmlspecialchars($text, ENT_QUOTES, 'UTF-8');
}

/**
 * Read release version from RELEASE_VERSION in project root.
 *
 * @return string
 */
function fm_get_release_version()
{
    $version_file = __DIR__ . '/RELEASE_VERSION';

    if (!is_file($version_file) || !is_readable($version_file)) {
        return 'neznáma';
    }

    $version = trim((string) @file_get_contents($version_file));
    if ($version === '') {
        return 'neznáma';
    }

    return $version;
}

/**
 * Prevent XSS attacks
 * @param string $text
 * @return string
 */
function fm_isvalid_filename($text)
{
    return (strpbrk($text, '/?%*:|"<>') === FALSE) ? true : false;
}

/**
 * Save message in session
 * @param string $msg
 * @param string $status
 */
function fm_set_msg($msg, $status = 'ok')
{
    $_SESSION[FM_SESSION_ID]['message'] = $msg;
    $_SESSION[FM_SESSION_ID]['status'] = $status;
}

/**
 * Check if string is in UTF-8
 * @param string $string
 * @return int
 */
function fm_is_utf8($string)
{
    return preg_match('//u', $string);
}

/**
 * Convert file name to UTF-8 in Windows
 * @param string $filename
 * @return string
 */
function fm_convert_win($filename)
{
    if (FM_IS_WIN && function_exists('iconv')) {
        $filename = iconv(FM_ICONV_INPUT_ENC, 'UTF-8//IGNORE', $filename);
    }
    return $filename;
}

/**
 * @param $obj
 * @return array
 */
function fm_object_to_array($obj)
{
    if (!is_object($obj) && !is_array($obj)) {
        return $obj;
    }
    if (is_object($obj)) {
        $obj = get_object_vars($obj);
    }
    return array_map('fm_object_to_array', $obj);
}

/**
 * Get CSS classname for file
 * @param string $path
 * @return string
 */
function fm_get_file_icon_class($path)
{
    // get extension
    $ext = strtolower(pathinfo($path, PATHINFO_EXTENSION));

    switch ($ext) {
        case 'ico':
        case 'gif':
        case 'jpg':
        case 'jpeg':
        case 'jpc':
        case 'jp2':
        case 'jpx':
        case 'xbm':
        case 'wbmp':
        case 'png':
        case 'bmp':
        case 'tif':
        case 'tiff':
        case 'webp':
        case 'avif':
        case 'svg':
            $img = 'fa fa-picture-o';
            break;
        case 'passwd':
        case 'ftpquota':
        case 'sql':
        case 'js':
        case 'ts':
        case 'jsx':
        case 'tsx':
        case 'hbs':
        case 'json':
        case 'sh':
        case 'config':
        case 'twig':
        case 'tpl':
        case 'md':
        case 'gitignore':
        case 'c':
        case 'cpp':
        case 'cs':
        case 'py':
        case 'rs':
        case 'map':
        case 'lock':
        case 'dtd':
        case 'ps1':
            $img = 'fa fa-file-code-o';
            break;
        case 'txt':
        case 'ini':
        case 'conf':
        case 'log':
        case 'htaccess':
        case 'yaml':
        case 'yml':
        case 'toml':
        case 'tmp':
        case 'top':
        case 'bot':
        case 'dat':
        case 'bak':
        case 'htpasswd':
        case 'pl':
            $img = 'fa fa-file-text-o';
            break;
        case 'css':
        case 'less':
        case 'sass':
        case 'scss':
            $img = 'fa fa-css3';
            break;
        case 'bz2':
        case 'tbz2':
        case 'tbz':
        case 'zip':
        case 'rar':
        case 'gz':
        case 'tgz':
        case 'tar':
        case '7z':
        case 'xz':
        case 'txz':
        case 'zst':
        case 'tzst':
            $img = 'fa fa-file-archive-o';
            break;
        case 'php':
        case 'php4':
        case 'php5':
        case 'phps':
        case 'phtml':
            $img = 'fa fa-code';
            break;
        case 'htm':
        case 'html':
        case 'shtml':
        case 'xhtml':
            $img = 'fa fa-html5';
            break;
        case 'xml':
        case 'xsl':
            $img = 'fa fa-file-excel-o';
            break;
        case 'wav':
        case 'mp3':
        case 'mp2':
        case 'm4a':
        case 'aac':
        case 'ogg':
        case 'oga':
        case 'wma':
        case 'mka':
        case 'flac':
        case 'ac3':
        case 'tds':
            $img = 'fa fa-music';
            break;
        case 'm3u':
        case 'm3u8':
        case 'pls':
        case 'cue':
        case 'xspf':
            $img = 'fa fa-headphones';
            break;
        case 'avi':
        case 'mpg':
        case 'mpeg':
        case 'mp4':
        case 'm4v':
        case 'flv':
        case 'f4v':
        case 'ogm':
        case 'ogv':
        case 'mov':
        case 'mkv':
        case '3gp':
        case 'asf':
        case 'wmv':
        case 'webm':
            $img = 'fa fa-file-video-o';
            break;
        case 'eml':
        case 'msg':
            $img = 'fa fa-envelope-o';
            break;
        case 'xls':
        case 'xlsx':
        case 'ods':
            $img = 'fa fa-file-excel-o';
            break;
        case 'csv':
            $img = 'fa fa-file-text-o';
            break;
        case 'bak':
        case 'swp':
            $img = 'fa fa-clipboard';
            break;
        case 'doc':
        case 'docx':
        case 'odt':
            $img = 'fa fa-file-word-o';
            break;
        case 'ppt':
        case 'pptx':
            $img = 'fa fa-file-powerpoint-o';
            break;
        case 'ttf':
        case 'ttc':
        case 'otf':
        case 'woff':
        case 'woff2':
        case 'eot':
        case 'fon':
            $img = 'fa fa-font';
            break;
        case 'pdf':
            $img = 'fa fa-file-pdf-o';
            break;
        case 'psd':
        case 'ai':
        case 'eps':
        case 'fla':
        case 'swf':
            $img = 'fa fa-file-image-o';
            break;
        case 'exe':
        case 'msi':
            $img = 'fa fa-file-o';
            break;
        case 'bat':
            $img = 'fa fa-terminal';
            break;
        default:
            $img = 'fa fa-info-circle';
    }

    return $img;
}

/**
 * Get image files extensions
 * @return array
 */
function fm_get_image_exts()
{
    return array('ico', 'gif', 'jpg', 'jpeg', 'jpc', 'jp2', 'jpx', 'xbm', 'wbmp', 'png', 'bmp', 'tif', 'tiff', 'psd', 'svg', 'webp', 'avif');
}

/**
 * Get video files extensions
 * @return array
 */
function fm_get_video_exts()
{
    return array('avi', 'webm', 'wmv', 'mp4', 'm4v', 'ogm', 'ogv', 'mov', 'mkv');
}

/**
 * Get audio files extensions
 * @return array
 */
function fm_get_audio_exts()
{
    return array('wav', 'mp3', 'ogg', 'm4a');
}

/**
 * Get text file extensions
 * @return array
 */
function fm_get_text_exts()
{
    return array(
        'txt',
        'css',
        'ini',
        'conf',
        'log',
        'htaccess',
        'passwd',
        'ftpquota',
        'sql',
        'js',
        'ts',
        'jsx',
        'tsx',
        'mjs',
        'json',
        'sh',
        'config',
        'php',
        'php4',
        'php5',
        'phps',
        'phtml',
        'htm',
        'html',
        'shtml',
        'xhtml',
        'xml',
        'xsl',
        'm3u',
        'm3u8',
        'pls',
        'cue',
        'bash',
        'vue',
        'eml',
        'msg',
        'csv',
        'bat',
        'twig',
        'tpl',
        'md',
        'gitignore',
        'less',
        'sass',
        'scss',
        'c',
        'cpp',
        'cs',
        'py',
        'go',
        'zsh',
        'swift',
        'map',
        'lock',
        'dtd',
        'svg',
        'asp',
        'aspx',
        'asx',
        'asmx',
        'ashx',
        'jsp',
        'jspx',
        'cgi',
        'dockerfile',
        'ruby',
        'yml',
        'yaml',
        'toml',
        'vhost',
        'scpt',
        'applescript',
        'csx',
        'cshtml',
        'c++',
        'coffee',
        'cfm',
        'rb',
        'graphql',
        'mustache',
        'jinja',
        'http',
        'handlebars',
        'java',
        'es',
        'es6',
        'markdown',
        'wiki',
        'tmp',
        'top',
        'bot',
        'dat',
        'bak',
        'htpasswd',
        'pl',
        'ps1'
    );
}

/**
 * Get mime types of text files
 * @return array
 */
function fm_get_text_mimes()
{
    return array(
        'application/xml',
        'application/javascript',
        'application/x-javascript',
        'image/svg+xml',
        'message/rfc822',
        'application/json',
    );
}

/**
 * Get file names of text files w/o extensions
 * @return array
 */
function fm_get_text_names()
{
    return array(
        'license',
        'readme',
        'authors',
        'contributors',
        'changelog',
    );
}

/**
 * Get online docs viewer supported files extensions
 * @return array
 */
function fm_get_onlineViewer_exts()
{
    return array('doc', 'docx', 'xls', 'xlsx', 'pdf', 'ppt', 'pptx', 'ai', 'psd', 'dxf', 'xps', 'rar', 'odt', 'ods');
}

/**
 * It returns the mime type of a file based on its extension.
 * @param extension The file extension of the file you want to get the mime type for.
 * @return string|string[] The mime type of the file.
 */
function fm_get_file_mimes($extension)
{
    $fileTypes['swf'] = 'application/x-shockwave-flash';
    $fileTypes['pdf'] = 'application/pdf';
    $fileTypes['exe'] = 'application/octet-stream';
    $fileTypes['zip'] = 'application/zip';
    $fileTypes['doc'] = 'application/msword';
    $fileTypes['xls'] = 'application/vnd.ms-excel';
    $fileTypes['ppt'] = 'application/vnd.ms-powerpoint';
    $fileTypes['gif'] = 'image/gif';
    $fileTypes['png'] = 'image/png';
    $fileTypes['jpeg'] = 'image/jpg';
    $fileTypes['jpg'] = 'image/jpg';
    $fileTypes['webp'] = 'image/webp';
    $fileTypes['avif'] = 'image/avif';
    $fileTypes['rar'] = 'application/rar';

    $fileTypes['ra'] = 'audio/x-pn-realaudio';
    $fileTypes['ram'] = 'audio/x-pn-realaudio';
    $fileTypes['ogg'] = 'audio/x-pn-realaudio';

    $fileTypes['wav'] = 'video/x-msvideo';
    $fileTypes['wmv'] = 'video/x-msvideo';
    $fileTypes['avi'] = 'video/x-msvideo';
    $fileTypes['asf'] = 'video/x-msvideo';
    $fileTypes['divx'] = 'video/x-msvideo';

    $fileTypes['mp3'] = 'audio/mpeg';
    $fileTypes['mp4'] = 'video/mp4';
    $fileTypes['mpeg'] = 'video/mpeg';
    $fileTypes['mpg'] = 'video/mpeg';
    $fileTypes['mpe'] = 'video/mpeg';
    $fileTypes['mov'] = 'video/quicktime';
    $fileTypes['swf'] = 'video/quicktime';
    $fileTypes['3gp'] = 'video/quicktime';
    $fileTypes['m4a'] = 'video/quicktime';
    $fileTypes['aac'] = 'video/quicktime';
    $fileTypes['m3u'] = 'video/quicktime';

    $fileTypes['php'] = ['application/x-php'];
    $fileTypes['html'] = ['text/html'];
    $fileTypes['txt'] = ['text/plain'];
    //Unknown mime-types should be 'application/octet-stream'
    if (empty($fileTypes[$extension])) {
        $fileTypes[$extension] = ['application/octet-stream'];
    }
    return $fileTypes[$extension];
}

/**
 * This function scans the files and folder recursively, and return matching files
 * @param string $dir
 * @param string $filter
 * @return array|null
 */
function scan($dir = '', $filter = '')
{
    $dir = fm_clean_path((string) $dir);
    $base = rtrim((string) FM_ROOT_PATH, '/\\');
    $path = $base . ($dir !== '' ? '/' . ltrim($dir, '/') : '');

    if (!is_dir($path) || !fm_user_can_access_path($path, true)) {
        return array();
    }

    $needle = trim((string) $filter);
    $needle = function_exists('mb_strtolower') ? mb_strtolower($needle, 'UTF-8') : strtolower($needle);

    $files = array();
    $stack = array(array($path, ''));

    while (!empty($stack)) {
        $current = array_pop($stack);
        $currentAbs = $current[0];
        $currentRel = $current[1];

        $entries = @scandir($currentAbs);
        if ($entries === false) {
            // Skip unreadable directories and continue traversal.
            continue;
        }

        foreach ($entries as $entry) {
            if ($entry === '.' || $entry === '..') {
                continue;
            }

            $abs = $currentAbs . '/' . $entry;
            $rel = ltrim(($currentRel !== '' ? $currentRel . '/' : '') . $entry, '/');

            if (is_dir($abs)) {
                if (fm_user_can_access_path($abs, true)) {
                    $stack[] = array($abs, $rel);
                }
                continue;
            }

            if (!is_file($abs)) {
                continue;
            }

            if (!fm_user_can_access_path($abs, false)) {
                continue;
            }

            if ($needle !== '') {
                $haystack = function_exists('mb_strtolower') ? mb_strtolower($rel, 'UTF-8') : strtolower($rel);
                if (strpos($haystack, $needle) === false) {
                    continue;
                }
            }

            $location = str_replace($base, '', dirname($abs));
            $files[] = array(
                "name" => basename($abs),
                "type" => "file",
                "path" => $location,
            );
        }
    }

    return $files;
}

/**
 * SQLite DB path for recursive search index.
 * @return string
 */
function fm_search_index_db_path()
{
    return rtrim(fm_runtime_state_dir(), '/\\') . '/search-index.sqlite';
}

/**
 * Lightweight append-only search diagnostics log.
 * @param string $event
 * @param array $context
 * @return void
 */
function fm_search_log_event($event, array $context = array())
{
    $path = rtrim(fm_runtime_state_dir(), '/\\') . '/search-index.log';
    $entry = array(
        'ts' => date('c'),
        'event' => (string) $event,
        'context' => $context,
    );
    @file_put_contents($path, json_encode($entry, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . "\n", FILE_APPEND | LOCK_EX);
}

/**
 * Build a scope-scoped lock file path for search index preparation.
 * @param string $scope
 * @return string
 */
function fm_search_index_lock_path($scope)
{
    $scope = preg_replace('/[^a-f0-9]/i', '', (string) $scope);
    $scope = substr($scope, 0, 24);
    if ($scope === '') {
        $scope = 'default';
    }

    return rtrim(fm_runtime_state_dir(), '/\\') . '/search-index-' . $scope . '.lock';
}

/**
 * Count records for current scope.
 * @param SQLite3 $db
 * @param string $scope
 * @return int
 */
function fm_search_index_count_scope($db, $scope)
{
    $stmt = $db->prepare('SELECT COUNT(*) AS cnt FROM fm_file_index WHERE scope_key = :scope');
    if (!$stmt) {
        return 0;
    }

    $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
    $result = $stmt->execute();
    if (!$result) {
        return 0;
    }

    $row = $result->fetchArray(SQLITE3_ASSOC);
    return isset($row['cnt']) ? (int) $row['cnt'] : 0;
}

/**
 * Prepare the search index for the current permission scope.
 * Returns a structured status payload and never performs more than one rebuild in a request.
 * @param string $reason
 * @return array
 */
function fm_search_index_prepare($reason = 'request')
{
    static $cache = array();

    $scope = fm_search_scope_key();
    if (isset($cache[$scope])) {
        return $cache[$scope];
    }

    $started = microtime(true);
    $result = array(
        'success' => false,
        'status' => 'error',
        'rebuilt' => false,
        'count' => 0,
        'scope' => $scope,
        'last_full_index_at' => 0,
        'elapsed_ms' => 0,
        'message' => '',
    );

    fm_search_log_event('search_index_prepare_start', array(
        'scope' => $scope,
        'reason' => (string) $reason,
    ));

    $db = fm_search_index_get_db();
    if (!$db) {
        $result['message'] = 'Search index database is not available.';
        fm_search_log_event('search_index_prepare_error', array(
            'scope' => $scope,
            'reason' => (string) $reason,
            'message' => $result['message'],
        ));
        $result['elapsed_ms'] = (int) round((microtime(true) - $started) * 1000);
        $cache[$scope] = $result;
        $GLOBALS['fm_search_index_last_prepare_result'] = $result;
        return $result;
    }

    $meta = fm_search_index_get_meta($db, $scope);
    $result['count'] = fm_search_index_count_scope($db, $scope);
    $result['last_full_index_at'] = isset($meta['last_full_index_at']) ? (int) $meta['last_full_index_at'] : 0;

    if ((int) $meta['is_dirty'] === 0 && (int) $meta['last_full_index_at'] > 0) {
        $result['success'] = true;
        $result['status'] = 'ready';
        $result['message'] = 'Search index already prepared.';
        $result['elapsed_ms'] = (int) round((microtime(true) - $started) * 1000);
        fm_search_log_event('search_index_prepare_ready', array(
            'scope' => $scope,
            'reason' => (string) $reason,
            'count' => $result['count'],
            'elapsed_ms' => $result['elapsed_ms'],
        ));
        $cache[$scope] = $result;
        $GLOBALS['fm_search_index_last_prepare_result'] = $result;
        return $result;
    }

    $lockPath = fm_search_index_lock_path($scope);
    $lockHandle = @fopen($lockPath, 'c+');
    if (!$lockHandle) {
        $result['message'] = 'Search index lock is not available.';
        fm_search_log_event('search_index_prepare_error', array(
            'scope' => $scope,
            'reason' => (string) $reason,
            'message' => $result['message'],
        ));
        $result['elapsed_ms'] = (int) round((microtime(true) - $started) * 1000);
        $cache[$scope] = $result;
        return $result;
    }

    $timeoutMs = 3500;
    $pollUs = 150000;
    $deadline = microtime(true) + ($timeoutMs / 1000);
    $locked = false;

    while (microtime(true) <= $deadline) {
        if (@flock($lockHandle, LOCK_EX | LOCK_NB)) {
            $locked = true;
            break;
        }
        usleep($pollUs);
    }

    if (!$locked) {
        $meta = fm_search_index_get_meta($db, $scope);
        $result['count'] = fm_search_index_count_scope($db, $scope);
        $result['last_full_index_at'] = isset($meta['last_full_index_at']) ? (int) $meta['last_full_index_at'] : 0;
        if ((int) $meta['is_dirty'] === 0 && (int) $meta['last_full_index_at'] > 0) {
            $result['success'] = true;
            $result['status'] = 'ready';
            $result['message'] = 'Search index became ready while waiting.';
            fm_search_log_event('search_index_prepare_wait', array(
                'scope' => $scope,
                'reason' => (string) $reason,
                'count' => $result['count'],
                'elapsed_ms' => (int) round((microtime(true) - $started) * 1000),
            ));
        } else {
            $result['success'] = true;
            $result['status'] = 'preparing';
            $result['message'] = 'Search index is being prepared by another request.';
            fm_search_log_event('search_index_prepare_wait', array(
                'scope' => $scope,
                'reason' => (string) $reason,
                'count' => $result['count'],
                'elapsed_ms' => (int) round((microtime(true) - $started) * 1000),
            ));
        }

        $result['elapsed_ms'] = (int) round((microtime(true) - $started) * 1000);
        @fclose($lockHandle);
        $cache[$scope] = $result;
        return $result;
    }

    try {
        $meta = fm_search_index_get_meta($db, $scope);
        if ((int) $meta['is_dirty'] === 0 && (int) $meta['last_full_index_at'] > 0) {
            $result['success'] = true;
            $result['status'] = 'ready';
            $result['message'] = 'Search index already prepared.';
        } else {
            $rebuildStarted = microtime(true);
            fm_search_log_event('search_index_prepare_rebuild', array(
                'scope' => $scope,
                'reason' => (string) $reason,
            ));

            $ok = fm_search_index_rebuild($db, $scope, '');
            $result['rebuilt'] = $ok ? true : false;
            if ($ok) {
                $meta = fm_search_index_get_meta($db, $scope);
                $result['count'] = fm_search_index_count_scope($db, $scope);
                $result['last_full_index_at'] = isset($meta['last_full_index_at']) ? (int) $meta['last_full_index_at'] : 0;
                if ((int) $meta['is_dirty'] === 0 && (int) $meta['last_full_index_at'] > 0) {
                    $result['success'] = true;
                    $result['status'] = 'rebuilt';
                    $result['message'] = 'Search index rebuilt successfully.';
                } else {
                    $result['message'] = 'Search index rebuild finished but meta state is still dirty.';
                }
            } else {
                $result['message'] = 'Search index rebuild failed.';
            }

            $result['elapsed_ms'] = (int) round((microtime(true) - $started) * 1000);
            fm_search_log_event($ok ? 'search_index_prepare_ready' : 'search_index_prepare_error', array(
                'scope' => $scope,
                'reason' => (string) $reason,
                'count' => $result['count'],
                'elapsed_ms' => $result['elapsed_ms'],
                'rebuilt' => $result['rebuilt'] ? 1 : 0,
            ));
        }
    } catch (Exception $e) {
        $result['message'] = $e->getMessage();
        $result['elapsed_ms'] = (int) round((microtime(true) - $started) * 1000);
        fm_search_log_event('search_index_prepare_error', array(
            'scope' => $scope,
            'reason' => (string) $reason,
            'message' => $result['message'],
        ));
    }

    @flock($lockHandle, LOCK_UN);
    @fclose($lockHandle);
    $cache[$scope] = $result;
    $GLOBALS['fm_search_index_last_prepare_result'] = $result;
    return $result;
}

/**
 * Resolve scope key for search index records.
 * @return string
 */
function fm_search_scope_key()
{
    global $fm_user_allowed_dirs, $root_path;

    $baseRoot = defined('FM_ROOT_PATH') ? (string) FM_ROOT_PATH : (is_string($root_path) ? $root_path : __DIR__);
    $normalizedRoot = fm_search_index_normalize_abs_path($baseRoot);

    $normalizedAllowed = array();
    if (!empty($fm_user_allowed_dirs) && is_array($fm_user_allowed_dirs)) {
        foreach ($fm_user_allowed_dirs as $allowed) {
            $allowedPath = fm_search_index_normalize_abs_path((string) $allowed);
            if ($allowedPath === '' || !fm_is_path_inside($allowedPath, $normalizedRoot)) {
                continue;
            }
            $normalizedAllowed[] = $allowedPath;
        }
        $normalizedAllowed = array_values(array_unique($normalizedAllowed));
        sort($normalizedAllowed, SORT_STRING);
    }

    $allowedScope = empty($normalizedAllowed) ? '*' : implode('|', $normalizedAllowed);
    return hash('sha256', 'root=' . $normalizedRoot . ';allow=' . $allowedScope);
}

/**
 * Normalize absolute path into stable forward-slash format.
 * @param string $path
 * @return string
 */
function fm_search_index_normalize_abs_path($path)
{
    $path = trim((string) $path);
    if ($path === '') {
        return '';
    }

    $path = str_replace('\\', '/', $path);
    $path = preg_replace('#/+#', '/', $path);
    if (!is_string($path) || $path === '') {
        return '';
    }

    return rtrim($path, '/');
}

/**
 * Convert absolute path to relative path under FM_ROOT_PATH.
 * Returns empty string for root and null for outside-root paths.
 * @param string $absolutePath
 * @return string|null
 */
function fm_search_index_rel_from_abs($absolutePath)
{
    $root = fm_search_index_normalize_abs_path((string) FM_ROOT_PATH);
    $abs = fm_search_index_normalize_abs_path((string) $absolutePath);

    if ($root === '' || $abs === '' || !fm_is_path_inside($abs, $root)) {
        return null;
    }

    if ($abs === $root) {
        return '';
    }

    return ltrim(substr($abs, strlen($root)), '/');
}

/**
 * Build stable keyword bag for SQLite search matching.
 * @param string $relPath
 * @param string $name
 * @param bool $isDir
 * @return string
 */
function fm_search_index_build_keywords($relPath, $name, $isDir)
{
    $relPath = str_replace('\\', '/', (string) $relPath);
    $name = (string) $name;
    $parts = array();

    $parts[] = strtolower($name);

    $extension = strtolower((string) pathinfo($name, PATHINFO_EXTENSION));
    $baseName = strtolower((string) pathinfo($name, PATHINFO_FILENAME));
    if ($baseName !== '') {
        $parts[] = $baseName;
    }
    if (!$isDir && $extension !== '') {
        $parts[] = $extension;
    }

    $splitName = preg_split('/[\s._-]+/u', strtolower($name));
    if (is_array($splitName)) {
        foreach ($splitName as $token) {
            $token = trim((string) $token);
            if ($token !== '') {
                $parts[] = $token;
            }
        }
    }

    $dirPath = dirname($relPath);
    if ($dirPath !== '.' && $dirPath !== '') {
        $dirSegments = explode('/', strtolower($dirPath));
        foreach ($dirSegments as $segment) {
            $segment = trim((string) $segment);
            if ($segment !== '') {
                $parts[] = $segment;

                $segmentParts = preg_split('/[\s._-]+/u', $segment);
                if (is_array($segmentParts)) {
                    foreach ($segmentParts as $segmentPart) {
                        $segmentPart = trim((string) $segmentPart);
                        if ($segmentPart !== '') {
                            $parts[] = $segmentPart;
                        }
                    }
                }
            }
        }
    }

    $tokens = array();
    foreach ($parts as $token) {
        $token = strtolower(trim((string) $token));
        if ($token === '') {
            continue;
        }
        $tokens[] = $token;

        if (function_exists('iconv')) {
            $ascii = @iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', $token);
            if (is_string($ascii)) {
                $ascii = strtolower(trim($ascii));
                $ascii = preg_replace('/\s+/', ' ', $ascii);
                if (is_string($ascii) && $ascii !== '') {
                    $tokens[] = $ascii;
                }
            }
        }
    }

    $tokens = array_values(array_unique($tokens));
    return implode(' ', $tokens);
}

/**
 * Check if a SQLite table contains the requested column.
 * @param SQLite3 $db
 * @param string $table
 * @param string $column
 * @return bool
 */
function fm_search_index_has_column($db, $table, $column)
{
    $table = preg_replace('/[^a-zA-Z0-9_]/', '', (string) $table);
    $column = (string) $column;
    if ($table === '' || $column === '') {
        return false;
    }

    $result = @$db->query("PRAGMA table_info($table)");
    if (!$result) {
        return false;
    }

    while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
        if (isset($row['name']) && (string) $row['name'] === $column) {
            return true;
        }
    }

    return false;
}

/**
 * Open or initialize SQLite search index DB.
 * @return SQLite3|null
 */
function fm_search_index_get_db()
{
    static $db = null;
    static $ready = false;

    if ($ready) {
        return $db;
    }
    $ready = true;

    if (!class_exists('SQLite3')) {
        fm_search_log_event('search_index_unavailable', array('reason' => 'sqlite3_extension_missing'));
        return null;
    }

    try {
        $db = new SQLite3(fm_search_index_db_path());
        $db->exec('PRAGMA journal_mode = WAL');
        $db->exec('PRAGMA synchronous = NORMAL');
        $db->exec('CREATE TABLE IF NOT EXISTS fm_file_index (
            scope_key TEXT NOT NULL,
            rel_path TEXT NOT NULL,
            dir_path TEXT NOT NULL,
            name TEXT NOT NULL,
            name_lc TEXT NOT NULL,
            is_dir INTEGER NOT NULL DEFAULT 0,
            size INTEGER NOT NULL DEFAULT 0,
            mtime INTEGER NOT NULL DEFAULT 0,
            keywords TEXT NOT NULL DEFAULT \'\',
            indexed_at INTEGER NOT NULL DEFAULT 0,
            validated_at INTEGER NOT NULL DEFAULT 0,
            PRIMARY KEY(scope_key, rel_path)
        )');
        if (!fm_search_index_has_column($db, 'fm_file_index', 'is_dir')) {
            @$db->exec('ALTER TABLE fm_file_index ADD COLUMN is_dir INTEGER NOT NULL DEFAULT 0');
        }
        if (!fm_search_index_has_column($db, 'fm_file_index', 'keywords')) {
            @$db->exec('ALTER TABLE fm_file_index ADD COLUMN keywords TEXT NOT NULL DEFAULT \'\'');
        }
        if (!fm_search_index_has_column($db, 'fm_file_index', 'validated_at')) {
            @$db->exec('ALTER TABLE fm_file_index ADD COLUMN validated_at INTEGER NOT NULL DEFAULT 0');
        }
        $db->exec('CREATE TABLE IF NOT EXISTS fm_file_index_meta (
            scope_key TEXT PRIMARY KEY,
            is_dirty INTEGER NOT NULL DEFAULT 1,
            last_full_index_at INTEGER NOT NULL DEFAULT 0,
            last_mutation_at INTEGER NOT NULL DEFAULT 0,
            folder_tree_revision INTEGER NOT NULL DEFAULT 0,
            updated_at INTEGER NOT NULL DEFAULT 0
        )');
        if (!fm_search_index_has_column($db, 'fm_file_index_meta', 'folder_tree_revision')) {
            @$db->exec('ALTER TABLE fm_file_index_meta ADD COLUMN folder_tree_revision INTEGER NOT NULL DEFAULT 0');
        }
        $db->exec('CREATE INDEX IF NOT EXISTS idx_fm_file_index_scope_name ON fm_file_index(scope_key, name_lc)');
        $db->exec('CREATE INDEX IF NOT EXISTS idx_fm_file_index_scope_dir ON fm_file_index(scope_key, dir_path)');
        $db->exec('CREATE INDEX IF NOT EXISTS idx_fm_file_index_scope_dir_type ON fm_file_index(scope_key, dir_path, is_dir, name_lc)');
    } catch (Exception $e) {
        fm_search_log_event('search_index_init_failed', array('message' => $e->getMessage()));
        $db = null;
    }

    return $db;
}

/**
 * Mark current scope index as stale after filesystem mutation.
 * @param string $reason
 * @param string $path
 * @return void
 */
function fm_search_index_mark_dirty($reason = 'mutation', $path = '')
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return;
    }

    $scope = fm_search_scope_key();
    $now = time();

    $stmt = $db->prepare('INSERT INTO fm_file_index_meta (scope_key, is_dirty, last_full_index_at, last_mutation_at, updated_at, folder_tree_revision)
        VALUES (:scope, 1, 0, :now, :now, 0)
        ON CONFLICT(scope_key) DO UPDATE SET
            is_dirty = 1,
            last_mutation_at = :now2,
            updated_at = :now3');

    if ($stmt) {
        $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
        $stmt->bindValue(':now', (int) $now, SQLITE3_INTEGER);
        $stmt->bindValue(':now2', (int) $now, SQLITE3_INTEGER);
        $stmt->bindValue(':now3', (int) $now, SQLITE3_INTEGER);
        $stmt->execute();
    }

    $GLOBALS['fm_search_index_request_dirty'] = true;

    fm_search_log_event('search_index_mark_dirty', array(
        'reason' => (string) $reason,
        'path' => (string) $path,
    ));
}

/**
 * Return current folder-tree revision for active or provided scope.
 * @param string|null $scope
 * @return int
 */
function fm_search_index_get_tree_revision($scope = null)
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return 0;
    }

    $scope = $scope === null ? fm_search_scope_key() : (string) $scope;
    $stmt = $db->prepare('SELECT folder_tree_revision FROM fm_file_index_meta WHERE scope_key = :scope LIMIT 1');
    if (!$stmt) {
        return 0;
    }

    $stmt->bindValue(':scope', $scope, SQLITE3_TEXT);
    $result = $stmt->execute();
    if (!$result) {
        return 0;
    }

    $row = $result->fetchArray(SQLITE3_ASSOC);
    return isset($row['folder_tree_revision']) ? (int) $row['folder_tree_revision'] : 0;
}

/**
 * Increment folder-tree revision for active or provided scope.
 * @param string $reason
 * @param SQLite3|null $db
 * @param string|null $scope
 * @return int
 */
function fm_search_index_bump_tree_revision($reason = 'mutation', $db = null, $scope = null)
{
    $db = $db instanceof SQLite3 ? $db : fm_search_index_get_db();
    if (!$db) {
        return 0;
    }

    $scope = $scope === null ? fm_search_scope_key() : (string) $scope;
    $now = time();

    $stmt = $db->prepare('INSERT INTO fm_file_index_meta (scope_key, is_dirty, last_full_index_at, last_mutation_at, updated_at, folder_tree_revision)
        VALUES (:scope, 0, 0, :now, :now, 1)
        ON CONFLICT(scope_key) DO UPDATE SET
            folder_tree_revision = COALESCE(folder_tree_revision, 0) + 1,
            updated_at = :now2');
    if (!$stmt) {
        return 0;
    }

    $stmt->bindValue(':scope', $scope, SQLITE3_TEXT);
    $stmt->bindValue(':now', (int) $now, SQLITE3_INTEGER);
    $stmt->bindValue(':now2', (int) $now, SQLITE3_INTEGER);
    $ok = (bool) $stmt->execute();
    if (!$ok) {
        return 0;
    }

    fm_search_log_event('folder_tree_revision_bump', array(
        'reason' => (string) $reason,
        'scope' => $scope,
    ));

    return fm_search_index_get_tree_revision($scope);
}

/**
 * Load index metadata for current scope.
 * @param SQLite3 $db
 * @param string $scope
 * @return array
 */
function fm_search_index_get_meta($db, $scope)
{
    $stmt = $db->prepare('SELECT is_dirty, last_full_index_at, last_mutation_at, updated_at, folder_tree_revision
        FROM fm_file_index_meta
        WHERE scope_key = :scope
        LIMIT 1');

    if (!$stmt) {
        return array(
            'is_dirty' => 1,
            'last_full_index_at' => 0,
            'last_mutation_at' => 0,
            'folder_tree_revision' => 0,
            'updated_at' => 0,
        );
    }

    $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
    $result = $stmt->execute();
    if (!$result) {
        return array(
            'is_dirty' => 1,
            'last_full_index_at' => 0,
            'last_mutation_at' => 0,
            'folder_tree_revision' => 0,
            'updated_at' => 0,
        );
    }

    $row = $result->fetchArray(SQLITE3_ASSOC);
    if (!is_array($row)) {
        return array(
            'is_dirty' => 1,
            'last_full_index_at' => 0,
            'last_mutation_at' => 0,
            'folder_tree_revision' => 0,
            'updated_at' => 0,
        );
    }

    return array(
        'is_dirty' => isset($row['is_dirty']) ? (int) $row['is_dirty'] : 1,
        'last_full_index_at' => isset($row['last_full_index_at']) ? (int) $row['last_full_index_at'] : 0,
        'last_mutation_at' => isset($row['last_mutation_at']) ? (int) $row['last_mutation_at'] : 0,
        'folder_tree_revision' => isset($row['folder_tree_revision']) ? (int) $row['folder_tree_revision'] : 0,
        'updated_at' => isset($row['updated_at']) ? (int) $row['updated_at'] : 0,
    );
}

/**
 * Persist full-index metadata after successful rebuild.
 * @param SQLite3 $db
 * @param string $scope
 * @param int $ts
 * @return void
 */
function fm_search_index_set_clean_meta($db, $scope, $ts)
{
    $currentRevision = fm_search_index_get_tree_revision((string) $scope);

    $stmt = $db->prepare('INSERT INTO fm_file_index_meta (scope_key, is_dirty, last_full_index_at, last_mutation_at, updated_at, folder_tree_revision)
        VALUES (:scope, 0, :ts, :ts, :ts, :revision)
        ON CONFLICT(scope_key) DO UPDATE SET
            is_dirty = 0,
            last_full_index_at = :ts2,
            updated_at = :ts3,
            folder_tree_revision = COALESCE(folder_tree_revision, :revision2)');
    if ($stmt) {
        $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
        $stmt->bindValue(':ts', (int) $ts, SQLITE3_INTEGER);
        $stmt->bindValue(':ts2', (int) $ts, SQLITE3_INTEGER);
        $stmt->bindValue(':ts3', (int) $ts, SQLITE3_INTEGER);
        $stmt->bindValue(':revision', (int) $currentRevision, SQLITE3_INTEGER);
        $stmt->bindValue(':revision2', (int) $currentRevision, SQLITE3_INTEGER);
        $stmt->execute();
    }
}

/**
 * Upsert one file-system object into SQLite index for current scope.
 * @param string $absolutePath
 * @param SQLite3|null $db
 * @param string|null $scope
 * @param int|null $indexedAt
 * @return bool
 */
function fm_search_index_upsert_path($absolutePath, $db = null, $scope = null, $indexedAt = null)
{
    $db = $db instanceof SQLite3 ? $db : fm_search_index_get_db();
    if (!$db) {
        return false;
    }

    $absolutePath = fm_search_index_normalize_abs_path((string) $absolutePath);
    if ($absolutePath === '' || (!is_file($absolutePath) && !is_dir($absolutePath))) {
        return false;
    }

    $root = fm_search_index_normalize_abs_path((string) FM_ROOT_PATH);
    if ($root === '' || !fm_is_path_inside($absolutePath, $root)) {
        return false;
    }

    $isDir = is_dir($absolutePath);
    if (!fm_user_can_access_path($absolutePath, $isDir)) {
        return false;
    }

    $relPath = fm_search_index_rel_from_abs($absolutePath);
    if ($relPath === null || $relPath === '') {
        return false;
    }

    $dirPath = dirname($relPath);
    if ($dirPath === '.') {
        $dirPath = '';
    }
    $name = basename($absolutePath);
    $nameLc = strtolower($name);
    $indexedAtValue = is_int($indexedAt) ? $indexedAt : time();
    $validatedAtValue = $indexedAtValue;
    $keywords = fm_search_index_build_keywords($relPath, $name, $isDir);

    $insert = $db->prepare('INSERT OR REPLACE INTO fm_file_index (scope_key, rel_path, dir_path, name, name_lc, is_dir, size, mtime, keywords, indexed_at, validated_at)
        VALUES (:scope, :rel, :dir, :name, :name_lc, :is_dir, :size, :mtime, :keywords, :indexed_at, :validated_at)');
    if (!$insert) {
        return false;
    }

    $insert->bindValue(':scope', (string) ($scope === null ? fm_search_scope_key() : $scope), SQLITE3_TEXT);
    $insert->bindValue(':rel', (string) $relPath, SQLITE3_TEXT);
    $insert->bindValue(':dir', (string) $dirPath, SQLITE3_TEXT);
    $insert->bindValue(':name', (string) $name, SQLITE3_TEXT);
    $insert->bindValue(':name_lc', (string) $nameLc, SQLITE3_TEXT);
    $insert->bindValue(':is_dir', $isDir ? 1 : 0, SQLITE3_INTEGER);
    $insert->bindValue(':size', $isDir ? 0 : (int) @filesize($absolutePath), SQLITE3_INTEGER);
    $insert->bindValue(':mtime', (int) @filemtime($absolutePath), SQLITE3_INTEGER);
    $insert->bindValue(':keywords', (string) $keywords, SQLITE3_TEXT);
    $insert->bindValue(':indexed_at', (int) $indexedAtValue, SQLITE3_INTEGER);
    $insert->bindValue(':validated_at', (int) $validatedAtValue, SQLITE3_INTEGER);

    return (bool) $insert->execute();
}

/**
 * Remove one indexed path and optionally all descendants for current scope.
 * @param string $absolutePath
 * @param string $reason
 * @return bool
 */
function fm_search_index_remove_path($absolutePath, $reason = '')
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return false;
    }

    $scope = fm_search_scope_key();
    $absolutePath = fm_search_index_normalize_abs_path((string) $absolutePath);
    $relPath = fm_search_index_rel_from_abs($absolutePath);
    if ($relPath === null || $relPath === '') {
        fm_search_log_event('search_index_remove_path_skipped', array('reason' => (string) $reason, 'path' => (string) $absolutePath));
        return false;
    }

        $hadDir = false;
        $probe = $db->prepare('SELECT 1
                FROM fm_file_index
                WHERE scope_key = :scope
                    AND is_dir = 1
                    AND (
                        rel_path = :rel
                        OR rel_path LIKE :rel_prefix
                    )
                LIMIT 1');
        if ($probe) {
                $probe->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
                $probe->bindValue(':rel', (string) $relPath, SQLITE3_TEXT);
                $probe->bindValue(':rel_prefix', (string) ($relPath . '/%'), SQLITE3_TEXT);
                $probeResult = $probe->execute();
                if ($probeResult && $probeResult->fetchArray(SQLITE3_ASSOC)) {
                        $hadDir = true;
                }
        }

        $delete = $db->prepare('DELETE FROM fm_file_index
        WHERE scope_key = :scope
          AND (
            rel_path = :rel
            OR rel_path LIKE :rel_prefix
            OR dir_path = :rel
            OR dir_path LIKE :rel_prefix
          )');

    if (!$delete) {
        fm_search_index_mark_dirty('remove_prepare_failed', $absolutePath);
        fm_search_log_event('search_index_remove_path_failed', array('reason' => (string) $reason, 'path' => (string) $absolutePath, 'stage' => 'prepare'));
        return false;
    }

    $prefix = $relPath . '/%';
    $delete->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
    $delete->bindValue(':rel', (string) $relPath, SQLITE3_TEXT);
    $delete->bindValue(':rel_prefix', (string) $prefix, SQLITE3_TEXT);
    $ok = (bool) $delete->execute();

    if (!$ok) {
        fm_search_index_mark_dirty('remove_execute_failed', $absolutePath);
    } elseif ($hadDir) {
        fm_search_index_bump_tree_revision('remove_path:' . (string) $reason, $db, $scope);
    }

    fm_search_log_event('search_index_remove_path', array(
        'reason' => (string) $reason,
        'path' => (string) $absolutePath,
        'ok' => $ok ? 1 : 0,
        'had_dir' => $hadDir ? 1 : 0,
    ));
    return $ok;
}

/**
 * Incrementally sync one path into current search index scope.
 * @param string $absolutePath
 * @param string $reason
 * @return bool
 */
function fm_search_index_sync_path($absolutePath, $reason = '')
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return false;
    }

    $absolutePath = fm_search_index_normalize_abs_path((string) $absolutePath);
    if (!is_file($absolutePath) && !is_dir($absolutePath)) {
        fm_search_log_event('search_index_sync_path_failed', array('reason' => (string) $reason, 'path' => (string) $absolutePath, 'stage' => 'missing'));
        fm_search_index_mark_dirty('sync_missing', $absolutePath);
        return false;
    }

    $scope = fm_search_scope_key();
    $indexedAt = time();
    $ok = false;
    $isDir = is_dir($absolutePath);
    try {
        $db->exec('BEGIN IMMEDIATE');
        $ok = fm_search_index_upsert_path($absolutePath, $db, $scope, $indexedAt);
        if ($ok) {
            $db->exec('COMMIT');
        } else {
            $db->exec('ROLLBACK');
        }
    } catch (Exception $e) {
        @ $db->exec('ROLLBACK');
        $ok = false;
        fm_search_log_event('search_index_sync_path_exception', array('reason' => (string) $reason, 'path' => (string) $absolutePath, 'message' => $e->getMessage()));
    }

    if (!$ok) {
        fm_search_index_mark_dirty('sync_failed', $absolutePath);
    } elseif ($isDir) {
        fm_search_index_bump_tree_revision('sync_path:' . (string) $reason, $db, $scope);
    }

    fm_search_log_event('search_index_sync_path', array(
        'reason' => (string) $reason,
        'path' => (string) $absolutePath,
        'ok' => $ok ? 1 : 0,
    ));

    return $ok;
}

/**
 * Incrementally sync a directory subtree into current search index scope.
 * @param string $absolutePath
 * @param string $reason
 * @return bool
 */
function fm_search_index_sync_subtree($absolutePath, $reason = '')
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return false;
    }

    $absolutePath = fm_search_index_normalize_abs_path((string) $absolutePath);
    if (!is_dir($absolutePath) || !fm_user_can_access_path($absolutePath, true)) {
        fm_search_log_event('search_index_sync_subtree_failed', array('reason' => (string) $reason, 'path' => (string) $absolutePath, 'stage' => 'invalid_dir'));
        fm_search_index_mark_dirty('sync_subtree_invalid', $absolutePath);
        return false;
    }

    $scope = fm_search_scope_key();
    $indexedAt = time();
    $ok = true;

    try {
        $db->exec('BEGIN IMMEDIATE');

        $relPath = fm_search_index_rel_from_abs($absolutePath);
        if ($relPath !== null && $relPath !== '') {
            $delete = $db->prepare('DELETE FROM fm_file_index
                WHERE scope_key = :scope
                  AND (
                    rel_path = :rel
                    OR rel_path LIKE :rel_prefix
                    OR dir_path = :rel
                    OR dir_path LIKE :rel_prefix
                  )');
            if ($delete) {
                $delete->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
                $delete->bindValue(':rel', (string) $relPath, SQLITE3_TEXT);
                $delete->bindValue(':rel_prefix', (string) ($relPath . '/%'), SQLITE3_TEXT);
                $delete->execute();
            }
        }

        if (!fm_search_index_upsert_path($absolutePath, $db, $scope, $indexedAt)) {
            throw new Exception('subtree_root_upsert_failed');
        }

        $stack = array($absolutePath);
        while (!empty($stack)) {
            $current = array_pop($stack);
            $entries = @scandir($current);
            if ($entries === false) {
                continue;
            }

            foreach ($entries as $entry) {
                if ($entry === '.' || $entry === '..') {
                    continue;
                }

                $child = fm_search_index_normalize_abs_path($current . '/' . $entry);
                $isDir = is_dir($child);
                if (!fm_user_can_access_path($child, $isDir)) {
                    continue;
                }

                if (!fm_search_index_upsert_path($child, $db, $scope, $indexedAt)) {
                    throw new Exception('subtree_upsert_failed');
                }

                if ($isDir) {
                    $stack[] = $child;
                }
            }
        }

        $db->exec('COMMIT');
    } catch (Exception $e) {
        @ $db->exec('ROLLBACK');
        $ok = false;
        fm_search_log_event('search_index_sync_subtree_exception', array('reason' => (string) $reason, 'path' => (string) $absolutePath, 'message' => $e->getMessage()));
    }

    if (!$ok) {
        fm_search_index_mark_dirty('sync_subtree_failed', $absolutePath);
    } else {
        fm_search_index_bump_tree_revision('sync_subtree:' . (string) $reason, $db, $scope);
    }

    fm_search_log_event('search_index_sync_subtree', array(
        'reason' => (string) $reason,
        'path' => (string) $absolutePath,
        'ok' => $ok ? 1 : 0,
    ));

    return $ok;
}

/**
 * Move indexed path by removing old path and syncing new path.
 * @param string $oldAbsolutePath
 * @param string $newAbsolutePath
 * @param string $reason
 * @return bool
 */
function fm_search_index_move_path($oldAbsolutePath, $newAbsolutePath, $reason = '')
{
    $removeOk = fm_search_index_remove_path($oldAbsolutePath, $reason . ':remove_old');
    $newAbsolutePath = fm_search_index_normalize_abs_path((string) $newAbsolutePath);

    $syncOk = false;
    if (is_dir($newAbsolutePath)) {
        $syncOk = fm_search_index_sync_subtree($newAbsolutePath, $reason . ':sync_new_subtree');
    } elseif (is_file($newAbsolutePath)) {
        $syncOk = fm_search_index_sync_path($newAbsolutePath, $reason . ':sync_new_path');
    } else {
        fm_search_index_mark_dirty('move_new_missing', $newAbsolutePath);
        fm_search_log_event('search_index_move_path_failed', array('reason' => (string) $reason, 'old_path' => (string) $oldAbsolutePath, 'new_path' => (string) $newAbsolutePath, 'stage' => 'missing_new'));
        return false;
    }

    $ok = $removeOk && $syncOk;
    $newIsDir = is_dir($newAbsolutePath);
    if (!$ok) {
        fm_search_index_mark_dirty('move_failed', $newAbsolutePath);
    } elseif ($newIsDir) {
        fm_search_index_bump_tree_revision('move_path:' . (string) $reason);
    }

    fm_search_log_event('search_index_move_path', array(
        'reason' => (string) $reason,
        'old_path' => (string) $oldAbsolutePath,
        'new_path' => (string) $newAbsolutePath,
        'ok' => $ok ? 1 : 0,
    ));
    return $ok;
}

/**
 * Return visible direct child directories from SQLite index for tree UI.
 * @param string $parentPath
 * @return array
 */
function fm_search_index_get_child_directories($parentPath = '')
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return array(
            'success' => false,
            'message' => 'Search index database is not available.',
            'path' => fm_clean_path((string) $parentPath),
            'children' => array(),
            'revision' => 0,
        );
    }

    $scope = fm_search_scope_key();
    $parentPath = fm_clean_path((string) $parentPath);
    $homePath = fm_clean_path((string) fm_get_navigation_home_root());

    if ($parentPath === '' && $homePath !== '') {
        $parentPath = $homePath;
    }

    $rootPath = rtrim(str_replace('\\', '/', (string) FM_ROOT_PATH), '/');
    if ($rootPath === '') {
        return array(
            'success' => false,
            'message' => 'Root path is not available.',
            'path' => $parentPath,
            'children' => array(),
            'revision' => 0,
        );
    }

    $absoluteParent = $rootPath . ($parentPath !== '' ? '/' . $parentPath : '');
    if (!fm_is_within_navigation_home($absoluteParent) || !fm_user_can_access_path($absoluteParent, true)) {
        return array(
            'success' => false,
            'message' => 'Access denied',
            'path' => $parentPath,
            'children' => array(),
            'revision' => fm_search_index_get_tree_revision($scope),
        );
    }

    if (!fm_search_index_ensure_fresh($db, $scope)) {
        return array(
            'success' => false,
            'message' => 'Search index is not ready yet.',
            'path' => $parentPath,
            'children' => array(),
            'revision' => fm_search_index_get_tree_revision($scope),
        );
    }

    try {
        $stmt = $db->prepare('SELECT
                c.name AS name,
                c.rel_path AS path,
                CASE WHEN EXISTS (
                    SELECT 1
                    FROM fm_file_index AS cc
                    WHERE cc.scope_key = c.scope_key
                      AND cc.is_dir = 1
                      AND cc.dir_path = c.rel_path
                    LIMIT 1
                ) THEN 1 ELSE 0 END AS has_children
            FROM fm_file_index AS c
            WHERE c.scope_key = :scope
              AND c.is_dir = 1
              AND c.dir_path = :parent
            ORDER BY c.name_lc ASC, c.name ASC');

        if (!$stmt) {
            return array(
                'success' => false,
                'message' => 'Search index query preparation failed.',
                'path' => $parentPath,
                'children' => array(),
                'revision' => fm_search_index_get_tree_revision($scope),
            );
        }

        $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
        $stmt->bindValue(':parent', (string) $parentPath, SQLITE3_TEXT);
        $result = $stmt->execute();
        if (!$result) {
            return array(
                'success' => false,
                'message' => 'Search index query execution failed.',
                'path' => $parentPath,
                'children' => array(),
                'revision' => fm_search_index_get_tree_revision($scope),
            );
        }

        $children = array();
        while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
            $name = isset($row['name']) ? (string) $row['name'] : '';
            $path = isset($row['path']) ? fm_clean_path((string) $row['path']) : '';
            if ($name === '' || $path === '') {
                continue;
            }
            if (!FM_SHOW_HIDDEN && substr($name, 0, 1) === '.') {
                continue;
            }

            $absolutePath = $rootPath . '/' . $path;
            if (!fm_is_within_navigation_home($absolutePath) || !fm_user_can_access_path($absolutePath, true)) {
                continue;
            }
            if (!fm_is_exclude_items($name, $absolutePath)) {
                continue;
            }

            $children[] = array(
                'name' => $name,
                'path' => $path,
                'has_children' => !empty($row['has_children']),
            );
        }

        return array(
            'success' => true,
            'message' => '',
            'path' => $parentPath,
            'children' => $children,
            'revision' => fm_search_index_get_tree_revision($scope),
        );
    } catch (Exception $e) {
        fm_search_log_event('folder_tree_children_query_failed', array(
            'parent' => $parentPath,
            'message' => $e->getMessage(),
        ));
        return array(
            'success' => false,
            'message' => 'Folder tree query failed.',
            'path' => $parentPath,
            'children' => array(),
            'revision' => fm_search_index_get_tree_revision($scope),
        );
    }
}

/**
 * Rebuild full search index once at the end of a request that changed filesystem state.
 * @return void
 */
function fm_search_index_register_shutdown_sync()
{
    static $registered = false;
    if ($registered) {
        return;
    }
    $registered = true;

    register_shutdown_function(function () {
        if (empty($GLOBALS['fm_search_index_request_dirty'])) {
            return;
        }

        $started = microtime(true);
        $ok = fm_search_index_rebuild_full();
        fm_search_log_event('search_index_shutdown_sync', array(
            'ok' => $ok ? 1 : 0,
            'elapsed_ms' => (int) round((microtime(true) - $started) * 1000),
        ));
    });
}

/**
 * Auto-create or refresh index on the first eligible request.
 * @param bool $enabled
 * @param string $reason
 * @return bool
 */
function fm_search_index_auto_bootstrap($enabled, $reason = 'request')
{
    static $attempted = false;
    if ($attempted || !$enabled) {
        return false;
    }
    $attempted = true;

    $db = fm_search_index_get_db();
    if (!$db) {
        return false;
    }

    $prepared = fm_search_index_prepare($reason);
    fm_search_log_event('search_index_auto_bootstrap', array(
        'reason' => (string) $reason,
        'ok' => isset($prepared['success']) && $prepared['success'] ? 1 : 0,
        'status' => isset($prepared['status']) ? (string) $prepared['status'] : 'error',
        'elapsed_ms' => isset($prepared['elapsed_ms']) ? (int) $prepared['elapsed_ms'] : 0,
    ));

    return isset($prepared['success']) && $prepared['success'];
}

/**
 * Rebuild index for files and directories under provided base directory.
 * @param SQLite3 $db
 * @param string $scope
 * @param string $baseDir
 * @return bool
 */
function fm_search_index_rebuild($db, $scope, $baseDir = '')
{
    $baseDir = fm_clean_path((string) $baseDir);
    $root = rtrim((string) FM_ROOT_PATH, '/\\');
    $startAbs = $root . ($baseDir !== '' ? '/' . ltrim($baseDir, '/') : '');

    if (!is_dir($startAbs) || !fm_user_can_access_path($startAbs, true)) {
        return false;
    }

    try {
        $db->exec('BEGIN IMMEDIATE');

        if ($baseDir === '') {
            $stmtDelete = $db->prepare('DELETE FROM fm_file_index WHERE scope_key = :scope');
            if ($stmtDelete) {
                $stmtDelete->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
                $stmtDelete->execute();
            }
        } else {
            $stmtDelete = $db->prepare('DELETE FROM fm_file_index WHERE scope_key = :scope AND (dir_path = :dir OR dir_path LIKE :prefix OR rel_path LIKE :prefix2)');
            if ($stmtDelete) {
                $stmtDelete->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
                $stmtDelete->bindValue(':dir', (string) $baseDir, SQLITE3_TEXT);
                $stmtDelete->bindValue(':prefix', $baseDir . '/%', SQLITE3_TEXT);
                $stmtDelete->bindValue(':prefix2', $baseDir . '/%', SQLITE3_TEXT);
                $stmtDelete->execute();
            }
        }

        $stack = array($startAbs);
        $indexedAt = time();

        if ($baseDir !== '' && !fm_search_index_upsert_path($startAbs, $db, $scope, $indexedAt)) {
            $db->exec('ROLLBACK');
            return false;
        }

        while (!empty($stack)) {
            $current = array_pop($stack);
            $entries = @scandir($current);
            if ($entries === false) {
                continue;
            }

            foreach ($entries as $entry) {
                if ($entry === '.' || $entry === '..') {
                    continue;
                }

                $abs = $current . '/' . $entry;
                $isDir = is_dir($abs);

                if ($isDir) {
                    if (!fm_user_can_access_path($abs, true)) {
                        continue;
                    }

                    if (!fm_search_index_upsert_path($abs, $db, $scope, $indexedAt)) {
                        $db->exec('ROLLBACK');
                        return false;
                    }

                    $stack[] = $abs;
                    continue;
                }

                if (!is_file($abs) || !fm_user_can_access_path($abs, false)) {
                    continue;
                }

                if (!fm_search_index_upsert_path($abs, $db, $scope, $indexedAt)) {
                    $db->exec('ROLLBACK');
                    return false;
                }
            }
        }

        if ($baseDir === '') {
            fm_search_index_set_clean_meta($db, $scope, $indexedAt);
        }

        $db->exec('COMMIT');
        return true;
    } catch (Exception $e) {
        @ $db->exec('ROLLBACK');
        fm_search_log_event('search_index_rebuild_failed', array('message' => $e->getMessage(), 'dir' => $baseDir));
        return false;
    }
}

/**
 * Ensure full index exists and is up-to-date for current scope.
 * @param SQLite3 $db
 * @param string $scope
 * @return bool
 */
function fm_search_index_ensure_fresh($db, $scope)
{
    $prepared = fm_search_index_prepare('ensure_fresh');
    $GLOBALS['fm_search_index_last_prepare_result'] = $prepared;
    return isset($prepared['success']) && $prepared['success'];
}

/**
 * Force full search index rebuild.
 * @return bool
 */
function fm_search_index_rebuild_full()
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return false;
    }

    return fm_search_index_rebuild($db, fm_search_scope_key(), '');
}

/**
 * Execute search via SQLite index. Returns null on DB failure.
 * @param string $dir
 * @param string $filter
 * @return array|null
 */
function fm_search_index_query($dir = '', $filter = '')
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return null;
    }

    $scope = fm_search_scope_key();
    $dir = fm_clean_path((string) $dir);
    $needle = trim((string) $filter);
    if ($needle === '') {
        return array();
    }

    if (!fm_search_index_ensure_fresh($db, $scope)) {
        return null;
    }

    $afterRebuild = false;
    if (isset($GLOBALS['fm_search_index_last_prepare_result']) && is_array($GLOBALS['fm_search_index_last_prepare_result'])) {
        $afterRebuild = !empty($GLOBALS['fm_search_index_last_prepare_result']['rebuilt']);
        unset($GLOBALS['fm_search_index_last_prepare_result']);
    }

    try {
                $stmt = $db->prepare('SELECT name, dir_path
            FROM fm_file_index
            WHERE scope_key = :scope
              AND is_dir = 0
              AND (:dir = "" OR dir_path = :dir OR dir_path LIKE :dirprefix)
                            AND (
                                name_lc LIKE :needle
                                OR keywords LIKE :needle
                                OR LOWER(rel_path) LIKE :needle
                            )
            ORDER BY dir_path ASC, name ASC
            LIMIT 2000');
        if (!$stmt) {
            return null;
        }

        $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
        $stmt->bindValue(':dir', (string) $dir, SQLITE3_TEXT);
        $stmt->bindValue(':dirprefix', ($dir === '' ? '' : $dir . '/%'), SQLITE3_TEXT);
        $stmt->bindValue(':needle', '%' . strtolower($needle) . '%', SQLITE3_TEXT);

        $result = $stmt->execute();
        if (!$result) {
            return null;
        }

        $rows = array();
        while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
            $dirPath = isset($row['dir_path']) ? (string) $row['dir_path'] : '';
            $rows[] = array(
                'name' => isset($row['name']) ? (string) $row['name'] : '',
                'type' => 'file',
                'path' => '/' . ltrim($dirPath, '/'),
            );
        }

        if ($afterRebuild) {
            fm_search_log_event('search_query_after_rebuild', array(
                'dir' => $dir,
                'filter' => $needle,
                'count' => count($rows),
            ));
        }
        return $rows;
    } catch (Exception $e) {
        fm_search_log_event('search_index_query_failed', array('message' => $e->getMessage(), 'dir' => $dir));
        return null;
    }
}

/**
 * Read indexed file map from SQLite for diagnostics and troubleshooting.
 * @param string $dir
 * @param int $limit
 * @return array
 */
function fm_search_index_map($dir = '', $limit = 1200)
{
    $db = fm_search_index_get_db();
    if (!$db) {
        return array(
            'success' => false,
            'msg' => 'Search index database is not available.',
            'items' => array(),
            'meta' => array('dir' => (string) $dir),
        );
    }

    $scope = fm_search_scope_key();
    $dir = fm_clean_path((string) $dir);
    $limit = (int) $limit;
    if ($limit < 50) {
        $limit = 50;
    }
    if ($limit > 5000) {
        $limit = 5000;
    }

    if (!fm_search_index_ensure_fresh($db, $scope)) {
        return array(
            'success' => false,
            'msg' => 'Search index is not ready yet.',
            'items' => array(),
            'meta' => array('dir' => $dir),
        );
    }

    $meta = fm_search_index_get_meta($db, $scope);

    try {
        $stmt = $db->prepare('SELECT rel_path, dir_path, name, is_dir, mtime, indexed_at
            FROM fm_file_index
            WHERE scope_key = :scope
              AND (
                :dir = ""
                OR dir_path = :dir
                OR dir_path LIKE :dirprefix
                OR rel_path = :dir
                OR rel_path LIKE :dirprefix
              )
            ORDER BY dir_path ASC, is_dir DESC, name ASC
            LIMIT :limit');
        if (!$stmt) {
            return array(
                'success' => false,
                'msg' => 'Search index query preparation failed.',
                'items' => array(),
                'meta' => array('dir' => $dir),
            );
        }

        $stmt->bindValue(':scope', (string) $scope, SQLITE3_TEXT);
        $stmt->bindValue(':dir', (string) $dir, SQLITE3_TEXT);
        $stmt->bindValue(':dirprefix', ($dir === '' ? '' : $dir . '/%'), SQLITE3_TEXT);
        $stmt->bindValue(':limit', (int) $limit, SQLITE3_INTEGER);

        $result = $stmt->execute();
        if (!$result) {
            return array(
                'success' => false,
                'msg' => 'Search index query execution failed.',
                'items' => array(),
                'meta' => array('dir' => $dir),
            );
        }

        $items = array();
        while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
            $items[] = array(
                'rel_path' => isset($row['rel_path']) ? (string) $row['rel_path'] : '',
                'dir_path' => isset($row['dir_path']) ? (string) $row['dir_path'] : '',
                'name' => isset($row['name']) ? (string) $row['name'] : '',
                'is_dir' => isset($row['is_dir']) ? (int) $row['is_dir'] : 0,
                'mtime' => isset($row['mtime']) ? (int) $row['mtime'] : 0,
                'indexed_at' => isset($row['indexed_at']) ? (int) $row['indexed_at'] : 0,
            );
        }

        return array(
            'success' => true,
            'msg' => '',
            'items' => $items,
            'meta' => array(
                'dir' => $dir,
                'count' => count($items),
                'limit' => $limit,
                'scope' => $scope,
                'last_full_index_at' => isset($meta['last_full_index_at']) ? (int) $meta['last_full_index_at'] : 0,
                'is_dirty' => isset($meta['is_dirty']) ? (int) $meta['is_dirty'] : 1,
                'db_path' => fm_search_index_db_path(),
            ),
        );
    } catch (Exception $e) {
        fm_search_log_event('search_index_map_failed', array('message' => $e->getMessage(), 'dir' => $dir));
        return array(
            'success' => false,
            'msg' => 'Search index map query failed.',
            'items' => array(),
            'meta' => array('dir' => $dir),
        );
    }
}

/**
 * Main search function with SQLite-first strategy and live-scan fallback.
 * @param string $dir
 * @param string $filter
 * @return array
 */
function fm_search_files($dir = '', $filter = '')
{
    $dir = fm_clean_path((string) $dir);
    $filter = trim((string) $filter);
    if ($filter === '') {
        return array();
    }

    $started = microtime(true);

    $indexed = fm_search_index_query($dir, $filter);
    if (is_array($indexed)) {
        fm_search_log_event('search_query', array(
            'mode' => 'index',
            'dir' => $dir,
            'filter' => $filter,
            'count' => count($indexed),
            'elapsed_ms' => (int) round((microtime(true) - $started) * 1000),
        ));
        return $indexed;
    }

    $fallback = scan($dir, $filter);
    fm_search_log_event('search_fallback_scan', array(
        'dir' => $dir,
        'filter' => $filter,
        'count' => count($fallback),
        'elapsed_ms' => (int) round((microtime(true) - $started) * 1000),
    ));
    return $fallback;
}

/**
 * Parameters: downloadFile(File Location, File Name,
 * max speed, is streaming
 * If streaming - videos will show as videos, images as images
 * instead of download prompt
 * https://stackoverflow.com/a/13821992/1164642
 */
function fm_download_file($fileLocation, $fileName, $chunkSize  = 1024)
{
    if (connection_status() != 0)
        return (false);
    $extension = pathinfo($fileName, PATHINFO_EXTENSION);

    $contentType = fm_get_file_mimes($extension);

    if (is_array($contentType)) {
        $contentType = implode(' ', $contentType);
    }

    $size = filesize($fileLocation);

    if ($size == 0) {
        fm_set_msg(lng('Zero byte file! Aborting download'), 'error');
        $FM_PATH = FM_PATH;
        fm_redirect(FM_SELF_URL . '?p=' . urlencode($FM_PATH));

        return (false);
    }

    @ini_set('magic_quotes_runtime', 0);
    $fp = fopen("$fileLocation", "rb");

    if ($fp === false) {
        fm_set_msg(lng('Cannot open file! Aborting download'), 'error');
        $FM_PATH = FM_PATH;
        fm_redirect(FM_SELF_URL . '?p=' . urlencode($FM_PATH));
        return (false);
    }

    // headers
    header('Content-Description: File Transfer');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Pragma: public');
    header("Content-Transfer-Encoding: binary");
    header("Content-Type: $contentType");

    $contentDisposition = 'attachment';

    if (strstr($_SERVER['HTTP_USER_AGENT'], "MSIE")) {
        $fileName = preg_replace('/\./', '%2e', $fileName, substr_count($fileName, '.') - 1);
        header("Content-Disposition: $contentDisposition;filename=\"$fileName\"");
    } else {
        header("Content-Disposition: $contentDisposition;filename=\"$fileName\"");
    }

    header("Accept-Ranges: bytes");
    $range = 0;

    if (isset($_SERVER['HTTP_RANGE'])) {
        list($a, $range) = explode("=", $_SERVER['HTTP_RANGE']);
        str_replace($range, "-", $range);
        $size2 = $size - 1;
        $new_length = $size - $range;
        header("HTTP/1.1 206 Partial Content");
        header("Content-Length: $new_length");
        header("Content-Range: bytes $range$size2/$size");
    } else {
        $size2 = $size - 1;
        header("Content-Range: bytes 0-$size2/$size");
        header("Content-Length: " . $size);
    }
    $fileLocation = realpath($fileLocation);
    while (ob_get_level()) ob_end_clean();
    readfile($fileLocation);

    fclose($fp);

    return ((connection_status() == 0) and !connection_aborted());
}

//--- Templates Functions ---

    /**
     * Show Header after login
     */
    function fm_show_header()
    {
        header("Content-Type: text/html; charset=utf-8");
        header("Expires: Sat, 26 Jul 1997 05:00:00 GMT");
        header("Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0");
        header("Pragma: no-cache");

        global $sticky_navbar, $favicon_path, $list_density;
        $isStickyNavBar = $sticky_navbar ? 'navbar-fixed' : 'navbar-normal';
        $densityClass = ($list_density === 'normal') ? 'fm-density-normal' : 'fm-density-compact';
        $pwa_icon = LOGIN_LOGO_PATH ? LOGIN_LOGO_PATH : $favicon_path;
?>
    <!DOCTYPE html>
    <html data-bs-theme="<?php echo FM_THEME; ?>">

    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
        <meta name="description" content="Web based File Manager in PHP, Manage your files efficiently and easily with Tiny File Manager">
        <meta name="author" content="CCP Programmers">
        <meta name="robots" content="noindex, nofollow">
        <meta name="googlebot" content="noindex">
        <meta name="theme-color" content="#1f6feb">
        <meta name="mobile-web-app-capable" content="yes">
        <meta name="apple-mobile-web-app-capable" content="yes">
        <meta name="apple-mobile-web-app-status-bar-style" content="default">
        <meta name="apple-mobile-web-app-title" content="<?php echo fm_enc(APP_TITLE); ?>">
        <link rel="manifest" href="<?php echo fm_enc(FM_SELF_URL . '?manifest=1'); ?>">
        <script>
            if ('serviceWorker' in navigator && window.isSecureContext) {
                window.addEventListener('load', function() {
                    navigator.serviceWorker.register(
                        <?php echo json_encode(FM_SELF_URL . '?sw=1', JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE); ?>,
                        {
                            scope: <?php echo json_encode(FM_SELF_DIR_URL, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE); ?>
                        }
                    ).catch(function() {
                        // Silent fallback to web mode when service worker cannot be registered.
                    });
                });
            }
        </script>
        <?php if ($favicon_path) {
            echo '<link rel="icon" href="' . fm_enc($favicon_path) . '" type="image/png">';
        } ?>
        <?php if ($pwa_icon) {
            echo '<link rel="apple-touch-icon" href="' . fm_enc($pwa_icon) . '">';
        } ?>
        <title><?php echo fm_enc(APP_TITLE) ?> | <?php echo (isset($_GET['view']) ? $_GET['view'] : ((isset($_GET['edit'])) ? $_GET['edit'] : "H3K")); ?></title>
        <?php print_external('pre-jsdelivr'); ?>
        <?php print_external('pre-cloudflare'); ?>
        <?php print_external('css-bootstrap'); ?>
        <?php print_external('css-font-awesome'); ?>
        <?php if (FM_USE_HIGHLIGHTJS && isset($_GET['view'])): ?>
            <?php print_external('css-highlightjs'); ?>
        <?php endif; ?>
        <style>
            html {
                -moz-osx-font-smoothing: grayscale;
                -webkit-font-smoothing: antialiased;
                text-rendering: optimizeLegibility;
                height: 100%;
                scroll-behavior: smooth;
            }

            :root {
                --fm-body-bg: #f7f7f7;
                --fm-body-color: #222222;
                --fm-row-odd: #ffffff;
                --fm-row-even: #f3f4f6;
                --fm-row-hover: #e9f2ff;
            }

            html[data-bs-theme="dark"] {
                --fm-body-bg: #1c2429;
                --fm-body-color: #cfd8dc;
                --fm-row-odd: #1f282e;
                --fm-row-even: #263238;
                --fm-row-hover: #32424a;
            }

            *,
            *::before,
            *::after {
                box-sizing: border-box;
            }

            body {
                font-size: 15px;
                color: var(--fm-body-color);
                background: var(--fm-body-bg);
                transition: background-color .2s ease, color .2s ease;
            }

            body.navbar-fixed {
                margin-top: 72px;
            }

            @media (max-width: 768px) {
                body.navbar-fixed {
                    margin-top: 96px;
                }
            }

            a,
            a:hover,
            a:visited,
            a:focus {
                text-decoration: none !important;
            }

            .filename,
            td,
            th {
                white-space: nowrap
            }

            .navbar-brand {
                font-weight: bold;
            }

            .nav-item.avatar a {
                cursor: pointer;
                text-transform: capitalize;
            }

            .nav-item.avatar a>i {
                font-size: 15px;
            }

            .nav-item.avatar .dropdown-menu a {
                font-size: 13px;
            }

            #search-addon {
                font-size: 12px;
                border-right-width: 0;
            }

            .main-nav .navbar-brand,
            .main-nav .navbar-nav .nav-link,
            .main-nav .navbar-nav .dropdown-toggle,
            .main-nav .navbar-nav .dropdown-item {
                font-size: 0.5rem !important;
                line-height: 1.2 !important;
            }

            .main-nav .nav-item.avatar .dropdown-toggle,
            .main-nav .nav-item.avatar .dropdown-item {
                font-size: 0.75rem !important;
                line-height: 1.2 !important;
            }

            .main-nav .fm-nav-search-group {
                width: clamp(11rem, 21vw, 19rem) !important;
                min-width: 14ch !important;
            }

            .main-nav #search-addon,
            .main-nav .fm-nav-search-input {
                min-width: 12ch !important;
            }

            .brl-0 {
                background: transparent;
                border-left: 0;
                border-top-left-radius: 0;
                border-bottom-left-radius: 0;
            }

            .brr-0 {
                border-top-right-radius: 0;
                border-bottom-right-radius: 0;
            }

            .bread-crumb {
                color: #cccccc;
                font-style: normal;
            }

            #main-table {
                transition: transform .25s cubic-bezier(0.4, 0.5, 0, 1), width 0s .25s;
            }

            #main-table:not(.fm-list-clean) .filename a {
                color: #222222;
                font-weight: bold;
            }

            .table td,
            .table th {
                vertical-align: middle !important;
            }

            .table .custom-checkbox-td .custom-control.custom-checkbox,
            .table .custom-checkbox-header .custom-control.custom-checkbox {
                min-width: 18px;
                display: flex;
                align-items: center;
                justify-content: center;
            }

            .table-sm:not(#main-table) td,
            .table-sm:not(#main-table) th {
                padding: .4rem;
            }

            .table-bordered:not(#main-table) td,
            .table-bordered:not(#main-table) th {
                border: 1px solid #f1f1f1;
            }

            .hidden {
                display: none
            }

            pre.with-hljs {
                padding: 0;
                overflow: hidden;
            }

            pre.with-hljs code {
                margin: 0;
                border: 0;
                overflow: scroll;
            }

            code.maxheight,
            pre.maxheight {
                max-height: 512px
            }

            .fa.fa-caret-right {
                font-size: 1.2em;
                margin: 0 4px;
                vertical-align: middle;
                color: #ececec
            }

            .fa.fa-home {
                font-size: 1.3em;
                vertical-align: bottom
            }

            .path {
                margin-bottom: 10px
            }

            form.dropzone {
                min-height: 200px;
                border: 2px dashed #007bff;
                line-height: 6rem;
            }

            .right {
                text-align: right
            }

            .center,
            .close,
            .login-form,
            .preview-img-container {
                text-align: center
            }

            .message {
                padding: 4px 7px;
                border: 1px solid #ddd;
                background-color: #fff
            }

            .message.ok {
                border-color: green;
                color: green
            }

            .message.error {
                border-color: red;
                color: red
            }

            .message.alert {
                border-color: orange;
                color: orange
            }

            .preview-img {
                max-width: 100%;
                max-height: 80vh;
                background: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAIAAACQkWg2AAAAKklEQVR42mL5//8/Azbw+PFjrOJMDCSCUQ3EABZc4S0rKzsaSvTTABBgAMyfCMsY4B9iAAAAAElFTkSuQmCC);
                cursor: zoom-in
            }

            input#preview-img-zoomCheck[type=checkbox] {
                display: none
            }

            input#preview-img-zoomCheck[type=checkbox]:checked~label>img {
                max-width: none;
                max-height: none;
                cursor: zoom-out
            }

            .inline-actions>a>i {
                font-size: 1em;
                margin-left: 5px;
                background: #3785c1;
                color: #fff;
                padding: 3px 4px;
                border-radius: 3px;
            }

            .preview-video {
                position: relative;
                max-width: 100%;
                height: 0;
                padding-bottom: 62.5%;
                margin-bottom: 10px
            }

            .preview-video video {
                position: absolute;
                width: 100%;
                height: 100%;
                left: 0;
                top: 0;
                background: #000
            }

            .compact-table {
                border: 0;
                width: auto
            }

            .compact-table td,
            .compact-table th {
                width: 100px;
                border: 0;
                text-align: center
            }

            .compact-table tr:hover td {
                background-color: #fff
            }

            .filename {
                max-width: 420px;
                overflow: hidden;
                text-overflow: ellipsis
            }

            .break-word {
                word-wrap: break-word;
                margin-left: 30px
            }

            .break-word.float-left a {
                color: #7d7d7d
            }

            .break-word+.float-right {
                padding-right: 30px;
                position: relative
            }

            .break-word+.float-right>a {
                color: #7d7d7d;
                font-size: 1.2em;
                margin-right: 4px
            }

            #editor {
                position: absolute;
                right: 15px;
                top: 100px;
                bottom: 15px;
                left: 15px
            }

            @media (max-width:481px) {
                #editor {
                    top: 150px;
                }
            }

            #normal-editor {
                border-radius: 3px;
                border-width: 2px;
                padding: 10px;
                outline: none;
            }

            .btn-2 {
                padding: 4px 10px;
                font-size: small;
            }

            li.file:before,
            li.folder:before {
                font: normal normal normal 14px/1 FontAwesome;
                content: "\f016";
                margin-right: 5px
            }

            li.folder:before {
                content: "\f114"
            }

            i.fa.fa-folder-o {
                color: #0157b3
            }

            i.fa.fa-picture-o {
                color: #26b99a
            }

            i.fa.fa-file-archive-o {
                color: #da7d7d
            }

            .btn-2 i.fa.fa-file-archive-o {
                color: inherit
            }

            i.fa.fa-css3 {
                color: #f36fa0
            }

            i.fa.fa-file-code-o {
                color: #007bff
            }

            i.fa.fa-code {
                color: #cc4b4c
            }

            i.fa.fa-file-text-o {
                color: #0096e6
            }

            i.fa.fa-html5 {
                color: #d75e72
            }

            i.fa.fa-file-excel-o {
                color: #09c55d
            }

            i.fa.fa-file-powerpoint-o {
                color: #f6712e
            }

            i.go-back {
                font-size: 1.2em;
                color: #007bff;
            }

            .main-nav {
                padding: 0.2rem 1rem;
                box-shadow: 0 4px 5px 0 rgba(0, 0, 0, .14), 0 1px 10px 0 rgba(0, 0, 0, .12), 0 2px 4px -1px rgba(0, 0, 0, .2)
            }

            .fm-mobile-quickbar {
                gap: 6px;
            }

            .fm-mobile-quickbar .btn {
                min-width: 42px;
                min-height: 42px;
                display: inline-flex;
                align-items: center;
                justify-content: center;
                padding: 0;
            }

            .dataTables_filter {
                display: none;
            }

            table.dataTable thead .sorting {
                cursor: pointer;
                background-repeat: no-repeat;
                background-position: center right;
                background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABMAAAATCAQAAADYWf5HAAAAkElEQVQoz7XQMQ5AQBCF4dWQSJxC5wwax1Cq1e7BAdxD5SL+Tq/QCM1oNiJidwox0355mXnG/DrEtIQ6azioNZQxI0ykPhTQIwhCR+BmBYtlK7kLJYwWCcJA9M4qdrZrd8pPjZWPtOqdRQy320YSV17OatFC4euts6z39GYMKRPCTKY9UnPQ6P+GtMRfGtPnBCiqhAeJPmkqAAAAAElFTkSuQmCC');
            }

            table.dataTable thead .sorting_asc {
                cursor: pointer;
                background-repeat: no-repeat;
                background-position: center right;
                background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABMAAAATCAYAAAByUDbMAAAAZ0lEQVQ4y2NgGLKgquEuFxBPAGI2ahhWCsS/gDibUoO0gPgxEP8H4ttArEyuQYxAPBdqEAxPBImTY5gjEL9DM+wTENuQahAvEO9DMwiGdwAxOymGJQLxTyD+jgWDxCMZRsEoGAVoAADeemwtPcZI2wAAAABJRU5ErkJggg==');
            }

            table.dataTable thead .sorting_desc {
                cursor: pointer;
                background-repeat: no-repeat;
                background-position: center right;
                background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABMAAAATCAYAAAByUDbMAAAAZUlEQVQ4y2NgGAWjYBSggaqGu5FA/BOIv2PBIPFEUgxjB+IdQPwfC94HxLykus4GiD+hGfQOiB3J8SojEE9EM2wuSJzcsFMG4ttQgx4DsRalkZENxL+AuJQaMcsGxBOAmGvopk8AVz1sLZgg0bsAAAAASUVORK5CYII=');
            }

            table.dataTable thead tr:first-child th.custom-checkbox-header:first-child {
                background-image: none;
            }

            .footer-action li {
                margin-bottom: 10px;
            }

            .app-v-title {
                font-size: 24px;
                font-weight: 300;
                letter-spacing: -.5px;
                text-transform: uppercase;
            }

            hr.custom-hr {
                border-top: 1px dashed #8c8b8b;
                border-bottom: 1px dashed #fff;
            }

            #snackbar {
                visibility: hidden;
                min-width: 250px;
                margin-left: -125px;
                background-color: #333;
                color: #fff;
                text-align: center;
                border-radius: 2px;
                padding: 16px;
                position: fixed;
                z-index: 1;
                left: 50%;
                bottom: 30px;
                font-size: 17px;
            }

            #snackbar.show {
                visibility: visible;
                -webkit-animation: fadein 0.5s, fadeout 0.5s 2.5s;
                animation: fadein 0.5s, fadeout 0.5s 2.5s;
            }

            @-webkit-keyframes fadein {
                from {
                    bottom: 0;
                    opacity: 0;
                }

                to {
                    bottom: 30px;
                    opacity: 1;
                }
            }

            @keyframes fadein {
                from {
                    bottom: 0;
                    opacity: 0;
                }

                to {
                    bottom: 30px;
                    opacity: 1;
                }
            }

            @-webkit-keyframes fadeout {
                from {
                    bottom: 30px;
                    opacity: 1;
                }

                to {
                    bottom: 0;
                    opacity: 0;
                }
            }

            @keyframes fadeout {
                from {
                    bottom: 30px;
                    opacity: 1;
                }

                to {
                    bottom: 0;
                    opacity: 0;
                }
            }

            #main-table span.badge {
                border-bottom: 2px solid #f8f9fa
            }

            #main-table span.badge:nth-child(1) {
                border-color: #df4227
            }

            #main-table span.badge:nth-child(2) {
                border-color: #f8b600
            }

            #main-table span.badge:nth-child(3) {
                border-color: #00bd60
            }

            #main-table span.badge:nth-child(4) {
                border-color: #4581ff
            }

            #main-table span.badge:nth-child(5) {
                border-color: #ac68fc
            }

            #main-table span.badge:nth-child(6) {
                border-color: #45c3d2
            }

            @media only screen and (min-device-width:768px) and (max-device-width:1024px) and (orientation:landscape) and (-webkit-min-device-pixel-ratio:2) {
                .navbar-collapse .col-xs-6 {
                    padding: 0;
                }
            }

            .btn.active.focus,
            .btn.active:focus,
            .btn.focus,
            .btn.focus:active,
            .btn:active:focus,
            .btn:focus {
                outline: 0 !important;
                outline-offset: 0 !important;
                background-image: none !important;
                -webkit-box-shadow: none !important;
                box-shadow: none !important
            }

            .lds-facebook {
                display: none;
                position: relative;
                width: 64px;
                height: 64px
            }

            .lds-facebook div,
            .lds-facebook.show-me {
                display: inline-block
            }

            .lds-facebook div {
                position: absolute;
                left: 6px;
                width: 13px;
                background: #007bff;
                animation: lds-facebook 1.2s cubic-bezier(0, .5, .5, 1) infinite
            }

            .lds-facebook div:nth-child(1) {
                left: 6px;
                animation-delay: -.24s
            }

            .lds-facebook div:nth-child(2) {
                left: 26px;
                animation-delay: -.12s
            }

            .lds-facebook div:nth-child(3) {
                left: 45px;
                animation-delay: 0s
            }

            @keyframes lds-facebook {
                0% {
                    top: 6px;
                    height: 51px
                }

                100%,
                50% {
                    top: 19px;
                    height: 26px
                }
            }

            #search-wrapper {
                border: 1px solid #ecececcc;
                border-radius: 6px;
                min-height: 60px;
                padding: 6px;
            }

            .fm-search-results-table-wrap {
                max-height: 56vh;
                overflow: auto;
            }

            .fm-search-results-table thead th {
                position: sticky;
                top: 0;
                z-index: 1;
                background: #f8f9fa;
            }

            .fm-search-results-table code {
                font-size: 0.75rem;
                color: #495057;
            }

            .fm-search-results-table td {
                vertical-align: middle;
            }

            .c-preview-img {
                max-width: 300px;
            }

            .border-radius-0 {
                border-radius: 0;
            }

            .float-right {
                float: right;
            }

            .table-hover>tbody>tr:hover>td:first-child {
                border-left: 1px solid #1b77fd;
            }

            #main-table tbody tr:nth-child(odd)>td {
                background-color: var(--fm-row-odd);
            }

            #main-table tbody tr:nth-child(even)>td {
                background-color: var(--fm-row-even);
            }

            #main-table.table-hover>tbody>tr:hover>td {
                background-color: var(--fm-row-hover);
            }

            .filename>a>i {
                margin-right: 3px;
            }

            .fs-7 {
                font-size: 14px;
            }

            #fm-grid-view {
                margin-bottom: 12px;
            }

            .fm-grid {
                display: grid;
                grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
                gap: 12px;
            }

            .fm-grid-thumb {
                display: flex;
                align-items: center;
                justify-content: center;
                width: 100%;
                height: 120px;
                margin-bottom: 8px;
                background: #f8f9fa;
                border-radius: 4px;
                overflow: hidden;
                position: relative;
                cursor: pointer;
            }

            .fm-grid-thumb {
                height: 122px;
                background: linear-gradient(120deg, #f7f9fc, #eef3f8);
                display: flex;
                align-items: center;
                justify-content: center;
                overflow: hidden;
                position: relative;
                transition: opacity .15s ease, background .15s ease;
                cursor: pointer;
            }

            .fm-grid-thumb:hover {
                opacity: 0.85;
                background: linear-gradient(120deg, #f0f4f9, #e8eef8);
            }

            .fm-grid-thumb img,
            .fm-grid-thumb video {
                width: 100%;
                height: 100%;
                object-fit: cover;
                display: block;
            }

            .fm-grid-thumb video {
                background: #0e1218;
            }

            .fm-grid-thumb i {
                font-size: 34px;
            }

            .fm-grid-pdf-badge {
                position: absolute;
                top: 6px;
                right: 6px;
                background: #ff3b30;
                color: white;
                padding: 4px 8px;
                border-radius: 4px;
                font-size: 11px;
                font-weight: 600;
                text-transform: uppercase;
                z-index: 1;
            }

            .fm-grid-body {
                padding: 10px 12px 8px;
            }

            .fm-grid-name a {
                display: block;
                color: #1d2b3a;
                font-weight: 700;
                text-decoration: none;
                white-space: nowrap;
                overflow: hidden;
                text-overflow: ellipsis;
                cursor: pointer;
            }

            .fm-grid-name a:hover,
            .fm-grid-name a:focus {
                text-decoration: underline;
            }

            .fm-grid-name a.fm-grid-link-dir {
                color: #0a66c2;
                font-weight: 700;
            }

            .fm-grid-name a.fm-grid-link-file {
                color: #1d2b3a;
                font-weight: 600;
            }

            .fm-grid-item.fm-grid-parent .fm-grid-name a {
                color: #0066cc;
            }

            .fm-grid-item:not(.fm-grid-parent) .fm-grid-name a {
                color: #1d2b3a;
            }

            .theme-dark .fm-grid-item.fm-grid-parent .fm-grid-name a {
                color: #4da6ff;
            }

            .theme-dark .fm-grid-name a.fm-grid-link-dir {
                color: #6bb8ff;
            }

            .theme-dark .fm-grid-name a.fm-grid-link-file {
                color: #e2ecef;
            }

            .fm-grid-meta {
                margin-top: 6px;
                font-size: 12px;
                color: #7a8490;
                display: flex;
                justify-content: space-between;
                gap: 8px;
            }

            .fm-grid-path-row {
                margin-top: 6px;
                margin-bottom: 4px;
                font-size: 11px;
                color: #666;
                word-break: break-word;
            }

            .fm-grid-path {
                display: block;
                padding: 2px 4px;
                background: #f5f5f5;
                border-radius: 3px;
                font-family: monospace;
            }

            .fm-grid-actions {
                border-top: 1px solid #edf1f5;
                padding: 8px 10px;
                text-align: right;
            }

            .fm-grid-actions .inline-actions {
                white-space: nowrap;
            }

            .fm-grid-item.fm-grid-parent .fm-grid-thumb {
                background: linear-gradient(120deg, #eef6ff, #e5f1ff);
            }

            .theme-dark .fm-grid-item {
                background: #1f282e;
                border-color: #2f3b42;
                box-shadow: none;
            }

            .theme-dark .fm-grid-item:hover {
                box-shadow: 0 8px 18px rgba(0, 0, 0, .25);
            }

            .theme-dark .fm-grid-thumb {
                background: linear-gradient(120deg, #263238, #202a31);
            }

            .theme-dark .fm-grid-name a {
                color: #e2ecef;
            }

            .theme-dark .fm-grid-meta {
                color: #9fb0b7;
            }

            .theme-dark .fm-grid-actions {
                border-top-color: #2f3b42;
            }

            @media (max-width: 767.98px) {
                body {
                    padding-bottom: 76px;
                }

                .main-nav {
                    padding: 0.35rem 0.6rem;
                }

                .navbar-brand {
                    max-width: 44vw;
                    overflow: hidden;
                    text-overflow: ellipsis;
                    white-space: nowrap;
                }

                .main-nav .navbar-brand,
                .main-nav .navbar-nav .nav-link,
                .main-nav .navbar-nav .dropdown-toggle,
                .main-nav .navbar-nav .dropdown-item {
                    font-size: 0.75rem !important;
                }

                .main-nav .fm-nav-search-group,
                .main-nav #search-addon,
                .main-nav .fm-nav-search-input {
                    width: 100% !important;
                    min-width: 0 !important;
                }

                .navbar-collapse .col-xs-6 {
                    width: 100%;
                    max-width: 100%;
                    margin-bottom: 8px;
                }

                .navbar-nav .nav-link,
                .btn.btn-2,
                .inline-actions > a {
                    min-height: 44px;
                    display: inline-flex;
                    align-items: center;
                }

                #main-table:not(.fm-modern-table) td,
                #main-table:not(.fm-modern-table) th {
                    padding-top: .55rem;
                    padding-bottom: .55rem;
                }

                #fm-selection-bar {
                    position: fixed;
                    left: 8px;
                    right: 8px;
                    bottom: 8px;
                    z-index: 1040;
                    background: rgba(255, 255, 255, 0.96);
                    border: 1px solid #d9e0e8;
                    border-radius: 12px;
                    box-shadow: 0 8px 24px rgba(0, 0, 0, .16);
                    padding: 8px;
                    gap: 6px;
                    display: none;
                }

                body.theme-dark #fm-selection-bar {
                    background: rgba(27, 35, 40, 0.96);
                    border-color: #2f3b42;
                }

                #fm-selection-bar .btn {
                    flex: 1 1 calc(50% - 6px);
                    justify-content: center;
                }

                #fm-selection-bar #fm-selection-count {
                    flex: 1 0 100%;
                    justify-content: center;
                }
            }

            @media (max-width: 479.98px) {
                #main-table.fm-compact-mobile .fm-col-modified,
                #main-table.fm-compact-mobile .fm-col-perms,
                #main-table.fm-compact-mobile .fm-col-owner {
                    display: none;
                }

                #main-table.fm-compact-mobile .fm-col-size,
                #main-table.fm-compact-mobile .fm-col-actions {
                    white-space: nowrap;
                    width: 1%;
                }

                #main-table.fm-compact-mobile .inline-actions > a {
                    padding-left: .2rem;
                    padding-right: .2rem;
                }
            }
        </style>
        <?php
        if (FM_THEME == "dark"): ?>
            <style>
                :root {
                    --bs-bg-opacity: 1;
                    --bg-color: #f3daa6;
                    --bs-dark-rgb: 28, 36, 41 !important;
                    --bs-bg-opacity: 1;
                }

                body.theme-dark {
                    background-image: linear-gradient(90deg, #1c2429, #263238);
                    color: #CFD8DC;
                }

                .list-group .list-group-item {
                    background: #343a40;
                }

                .theme-dark .navbar-nav i,
                .navbar-nav .dropdown-toggle,
                .break-word {
                    color: #CFD8DC;
                }

                .theme-dark .navbar-nav a,
                .theme-dark .break-word a,
                .theme-dark .path a,
                #main-table:not(.fm-list-clean) .filename a,
                i.fa.fa-folder-o,
                i.go-back {
                    color: var(--bg-color);
                }

                .theme-dark .fm-search-results-table thead th {
                    background: #2a3339;
                }

                .theme-dark .fm-search-results-table code {
                    color: #cfd8dc;
                }

                .theme-dark .btn-outline-primary {
                    color: #b8e59c;
                    border-color: #b8e59c;
                }

                .theme-dark .btn-outline-primary:hover,
                .theme-dark .btn-outline-primary:active {
                    background-color: #2d4121;
                }

                .theme-dark input.form-control {
                    background-color: #101518;
                    color: #CFD8DC;
                }

                .theme-dark .dropzone {
                    background: transparent;
                }

                .theme-dark .inline-actions>a>i {
                    background: #79755e;
                }

                .theme-dark .text-white {
                    color: #CFD8DC !important;
                }

                .theme-dark .table-bordered:not(#main-table) td,
                .theme-dark .table-bordered:not(#main-table) th {
                    border-color: #343434;
                }

                .theme-dark .table-bordered td .custom-control-input,
                .theme-dark .table-bordered th .custom-control-input {
                    opacity: 0.678;
                }

                .message {
                    background-color: #212529;
                }

                form.dropzone {
                    border-color: #79755e;
                }
            </style>
        <?php endif; ?>
        <link rel="stylesheet" href="src/assets/css/fm-modern-theme.css?v=<?php echo rawurlencode((string) VERSION); ?>">
    </head>

    <body class="<?php echo (FM_THEME == "dark") ? 'theme-dark' : ''; ?> <?php echo $isStickyNavBar; ?> <?php echo $densityClass; ?>">
        <div id="wrapper" class="container-fluid">
            <!-- New Item creation -->
            <div class="modal fade" id="createNewItem" tabindex="-1" role="dialog" data-bs-backdrop="static" data-bs-keyboard="false" aria-labelledby="newItemModalLabel" aria-hidden="true" data-bs-theme="<?php echo FM_THEME; ?>">
                <div class="modal-dialog" role="document">
                    <form class="modal-content" method="post">
                        <div class="modal-header">
                            <h5 class="modal-title" id="newItemModalLabel"><i class="fa fa-plus-square fa-fw"></i><?php echo lng('CreateNewItem') ?></h5>
                            <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
                        </div>
                        <div class="modal-body">
                            <p><label for="newfile"><?php echo lng('ItemType') ?> </label></p>
                            <div class="form-check form-check-inline">
                                <input class="form-check-input" type="radio" name="newfile" id="customRadioInline1" name="newfile" value="file">
                                <label class="form-check-label" for="customRadioInline1"><?php echo lng('File') ?></label>
                            </div>
                            <div class="form-check form-check-inline">
                                <input class="form-check-input" type="radio" name="newfile" id="customRadioInline2" value="folder" checked>
                                <label class="form-check-label" for="customRadioInline2"><?php echo lng('Folder') ?></label>
                            </div>

                            <p class="mt-3"><label for="newfilename"><?php echo lng('ItemName') ?> </label></p>
                            <input type="text" name="newfilename" id="newfilename" value="" class="form-control" placeholder="<?php echo lng('Enter here...') ?>" required>
                        </div>
                        <div class="modal-footer">
                            <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>">
                            <button type="button" class="btn btn-outline-primary" data-bs-dismiss="modal"><i class="fa fa-times-circle"></i> <?php echo lng('Cancel') ?></button>
                            <button type="submit" class="btn btn-success"><i class="fa fa-check-circle"></i> <?php echo lng('CreateNow') ?></button>
                        </div>
                    </form>
                </div>
            </div>

            <!-- Advance Search Modal -->
            <div class="modal fade" id="searchModal" tabindex="-1" role="dialog" aria-labelledby="searchModalLabel" aria-hidden="true" data-bs-theme="<?php echo FM_THEME; ?>">
                <div class="modal-dialog modal-lg" role="document">
                    <div class="modal-content">
                        <div class="modal-header">
                            <h5 class="modal-title col-10" id="searchModalLabel">
                                <div class="input-group mb-3">
                                    <input type="text" class="form-control" placeholder="<?php echo lng('Search') ?> <?php echo lng('a files') ?>" aria-label="<?php echo lng('Search') ?>" aria-describedby="search-addon3" id="advanced-search" autofocus required>
                                    <button type="button" class="input-group-text" id="search-addon3" aria-label="<?php echo lng('Search') ?>"><i class="fa fa-search"></i></button>
                                    <button type="button" class="btn btn-outline-secondary" id="js-search-map-btn" title="Zobrazit mapu suborov zo SQL indexu" aria-label="Zobrazit mapu suborov zo SQL indexu"><i class="fa fa-sitemap"></i></button>
                                </div>
                            </h5>
                            <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
                        </div>
                        <div class="modal-body">
                            <form action="" method="post">
                                <div class="lds-facebook">
                                    <div></div>
                                    <div></div>
                                    <div></div>
                                </div>
                                <div id="fm-search-index-status" class="small text-muted mb-2" aria-live="polite" style="display:none;"></div>
                                <div id="search-wrapper">
                                    <p class="m-2"><?php echo lng('Search file in folder and subfolders...') ?></p>
                                </div>
                            </form>
                        </div>
                    </div>
                </div>
            </div>

            <!--Rename Modal -->
            <div class="modal modal-alert" data-bs-backdrop="static" data-bs-keyboard="false" tabindex="-1" role="dialog" id="renameDailog" data-bs-theme="<?php echo FM_THEME; ?>">
                <div class="modal-dialog" role="document">
                    <form class="modal-content rounded-3 shadow" method="post" autocomplete="off">
                        <div class="modal-body p-4 text-center">
                            <h5 class="mb-3"><?php echo lng('Are you sure want to rename?') ?></h5>
                            <p class="mb-1">
                                <input type="text" name="rename_to" id="js-rename-to" class="form-control" placeholder="<?php echo lng('Enter new file name') ?>" required>
                                <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>">
                                <input type="hidden" name="rename_from" id="js-rename-from">
                            </p>
                        </div>
                        <div class="modal-footer flex-nowrap p-0">
                            <button type="button" class="btn btn-lg btn-link fs-6 text-decoration-none col-6 m-0 rounded-0 border-end" data-bs-dismiss="modal"><?php echo lng('Cancel') ?></button>
                            <button type="submit" class="btn btn-lg btn-link fs-6 text-decoration-none col-6 m-0 rounded-0"><strong><?php echo lng('Okay') ?></strong></button>
                        </div>
                    </form>
                </div>
            </div>

            <!-- Confirm Modal -->
            <script type="text/html" id="js-tpl-confirm">
                <div class="modal modal-alert confirmDailog" data-bs-backdrop="static" data-bs-keyboard="false" tabindex="-1" role="dialog" id="confirmDailog-<%this.id%>" data-bs-theme="<?php echo FM_THEME; ?>">
                    <div class="modal-dialog" role="document">
                        <form class="modal-content rounded-3 shadow" method="post" autocomplete="off" action="<%this.action%>">
                            <div class="modal-body p-4 text-center">
                                <h5 class="mb-2"><?php echo lng('Are you sure want to') ?> <%this.title%> ?</h5>
                                <p class="mb-1"><%this.content%></p>
                            </div>
                            <div class="modal-footer flex-nowrap p-0">
                                <button type="button" class="btn btn-lg btn-link fs-6 text-decoration-none col-6 m-0 rounded-0 border-end" data-bs-dismiss="modal"><?php echo lng('Cancel') ?></button>
                                <input type="hidden" name="token" value="<?php echo $_SESSION['token']; ?>">
                                <button type="submit" class="btn btn-lg btn-link fs-6 text-decoration-none col-6 m-0 rounded-0" data-bs-dismiss="modal"><strong><?php echo lng('Okay') ?></strong></button>
                            </div>
                        </form>
                    </div>
                </div>
            </script>
        <?php
    }

    /**
     * Show page footer after login
     */
    function fm_show_footer()
    {
        ?>
        </div>
        <?php print_external('js-jquery'); ?>
        <?php print_external('js-bootstrap'); ?>
        <?php print_external('js-jquery-datatables'); ?>
        <?php
        $fm_assets_base = rtrim(str_replace('\\', '/', dirname(FM_SELF_PATH)), '/');
        if ($fm_assets_base === '/' || $fm_assets_base === '.') {
            $fm_assets_base = '';
        }
        $fm_assets_version = fm_get_release_version();
        if ($fm_assets_version === 'dev') {
            $fm_assets_version = (string) VERSION;
        }
        $fm_runtime_config = array(
            'csrfToken' => $_SESSION['token'],
            'highlightCurrentView' => FM_USE_HIGHLIGHTJS && isset($_GET['view']),
            'isManagerOrAdmin' => FM_MANAGER || (!FM_READONLY && !FM_UPLOAD_ONLY),
            'folderEmptyText' => lng('Folder is empty'),
            'selectedLabel' => lng('Selected'),
            'searchIndexPreparingText' => lng('Preparing search map...'),
            'searchIndexReadyText' => lng('Search map is ready.'),
            'searchIndexPrepareErrorText' => lng('Search map could not be prepared. Search will use fallback mode.'),
            'searchIndexPreparingBusyText' => lng('Preparing search map...'),
            'searchIndexRetryText' => lng('Retrying search after index preparation...'),
        );
        ?>
        <?php if (FM_USE_HIGHLIGHTJS && isset($_GET['view'])): ?>
            <?php print_external('js-highlightjs'); ?>
        <?php endif; ?>
        <script type="application/json" id="fm-runtime-config"><?php echo json_encode($fm_runtime_config, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT); ?></script>
        <script src="<?php echo fm_enc($fm_assets_base . '/src/assets/js/fm-main.js?v=' . rawurlencode((string) $fm_assets_version)); ?>"></script>
        <script src="<?php echo fm_enc($fm_assets_base . '/src/assets/js/fm-search-enhanced.js?v=' . rawurlencode((string) $fm_assets_version)); ?>"></script>

        <?php if (isset($_GET['edit']) && isset($_GET['env']) && FM_EDIT_FILE && !FM_READONLY):
            $ext = pathinfo($_GET['edit'], PATHINFO_EXTENSION);
            $ext = $ext == 'js' ? 'javascript' : $ext;
            $fm_ace_config = array(
                'initialMode' => $ext,
            );
        ?>
            <?php print_external('js-ace'); ?>
            <script type="application/json" id="fm-ace-config"><?php echo json_encode($fm_ace_config, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT); ?></script>
            <script src="<?php echo fm_enc($fm_assets_base . '/src/assets/js/fm-ace.js?v=' . rawurlencode((string) $fm_assets_version)); ?>"></script>
        <?php endif; ?>
        <div id="snackbar"></div>
    </body>

    </html>
<?php
    }

?>