fix: keep track of download count

lib/AppInfo/Application.php

@@ -12,6 +12,7 @@
 use OCA\DAV\Events\SabrePluginAddEvent;
 use OCA\Files\Event\LoadSidebar;
 use OCA\Files_DownloadLimit\Capabilities;
+use OCA\Files_DownloadLimit\Listener\BeforeNodeReadListener;
 use OCA\Files_DownloadLimit\Listener\BeforeTemplateRenderedListener;
 use OCA\Files_DownloadLimit\Listener\LoadSidebarListener;
 use OCA\Files_DownloadLimit\Listener\SabrePluginAddListener;
@@ -22,6 +23,7 @@
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
+use OCP\Files\Events\Node\BeforeNodeReadEvent;
 
 class Application extends App implements IBootstrap {
 	public const APP_ID = 'files_downloadlimit';
@@ -36,6 +38,8 @@ public function register(IRegistrationContext $context): void {
 		$context->registerEventListener(BeforeTemplateRenderedEvent::class, BeforeTemplateRenderedListener::class);
 		$context->registerEventListener(LoadSidebar::class, LoadSidebarListener::class);
 		$context->registerEventListener(ShareLinkAccessedEvent::class, ShareLinkAccessedListener::class);
+		$context->registerEventListener(BeforeNodeReadEvent::class, BeforeNodeReadListener::class);
+
 
 		$context->registerCapability(Capabilities::class);
 	}

lib/Listener/BeforeNodeReadListener.php

@@ -0,0 +1,165 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Files_DownloadLimit\Listener;
+
+use OCA\Files_DownloadLimit\Db\LimitMapper;
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\Files\Events\BeforeZipCreatedEvent;
+use OCP\Files\Events\Node\BeforeNodeReadEvent;
+use OCP\Files\File;
+use OCP\Files\Folder;
+use OCP\Files\NotFoundException;
+use OCP\Files\Storage\ISharedStorage;
+use OCP\ICache;
+use OCP\ICacheFactory;
+use OCP\IRequest;
+use OCP\ISession;
+use OCP\Share\IManager;
+use OCP\Share\IShare;
+use Psr\Log\LoggerInterface;
+
+/**
+ * @template-implements IEventListener<BeforeNodeReadEvent|BeforeZipCreatedEvent|Event>
+ */
+class BeforeNodeReadListener implements IEventListener {
+	private ICache $cache;
+	public function __construct(
+		private IManager $manager,
+		private LimitMapper $mapper,
+		private LoggerInterface $logger,
+		private IRequest $request,
+		private ISession $session,
+		ICacheFactory $cacheFactory,
+	) {
+		$this->cache = $cacheFactory->createDistributed('files_downloadlimit_event');
+	}
+
+	public function handle(Event $event): void {
+		if ($event instanceof BeforeZipCreatedEvent) {
+			$this->handleBeforeZipCreatedEvent($event);
+		} elseif ($event instanceof BeforeNodeReadEvent) {
+			$this->handleBeforeNodeReadEvent($event);
+		}
+	}
+
+	public function handleBeforeZipCreatedEvent(BeforeZipCreatedEvent $event): void {
+		$files = $event->getFiles();
+		if (count($files) !== 0) {
+			/* No need to do anything, count will be triggered for each file in the zip by the BeforeNodeReadEvent */
+			return;
+		}
+
+		$node = $event->getFolder();
+		if (!($node instanceof Folder)) {
+			return;
+		}
+
+		try {
+			$storage = $node->getStorage();
+		} catch (NotFoundException) {
+			return;
+		}
+
+		if (!$storage->instanceOfStorage(ISharedStorage::class)) {
+			return;
+		}
+
+		/** @var ISharedStorage $storage */
+		$share = $storage->getShare();
+
+		if (!in_array($share->getShareType(), [IShare::TYPE_EMAIL, IShare::TYPE_LINK])) {
+			return;
+		}
+
+		/* Cache that that folder download activity was published */
+		$this->cache->set($this->request->getId(), $node->getPath(), 3600);
+
+		$this->singleFileDownloaded($share);
+	}
+
+	public function handleBeforeNodeReadEvent(BeforeNodeReadEvent $event): void {
+		$node = $event->getNode();
+		if (!($node instanceof File)) {
+			return;
+		}
+
+		try {
+			$storage = $node->getStorage();
+		} catch (NotFoundException) {
+			return;
+		}
+
+		if (!$storage->instanceOfStorage(ISharedStorage::class)) {
+			return;
+		}
+
+		/** @var ISharedStorage $storage */
+		$share = $storage->getShare();
+
+		if (!in_array($share->getShareType(), [IShare::TYPE_EMAIL, IShare::TYPE_LINK])) {
+			return;
+		}
+
+		$path = $this->cache->get($this->request->getId());
+		if (is_string($path) && str_starts_with($node->getPath(), $path)) {
+			/* An activity was published for a containing folder already */
+			return;
+		}
+
+		/* Avoid publishing several activities for one video playing */
+		$cacheKey = $node->getId() . $node->getPath() . $this->session->getId();
+		if (($this->request->getHeader('range') !== '') && ($this->cache->get($cacheKey) === 'true')) {
+			/* This is a range request and an activity for the same file was published in the same session */
+			return;
+		}
+		$this->cache->set($cacheKey, 'true', 3600);
+
+
+		$this->singleFileDownloaded($share);
+	}
+
+	protected function singleFileDownloaded(IShare $share): void {
+
+		$token = $share->getToken();
+		if ($token === null) {
+			return;
+		}
+		// Make sure we have a valid limit
+		try {
+			$shareLimit = $this->mapper->get($token);
+			$limit = $shareLimit->getLimit();
+
+			// Increment this download event
+			$downloads = $shareLimit->getDownloads() + 1;
+
+			// If we reached the maximum allowed download count
+			if ($downloads >= $limit) {
+				// Delete share
+				$this->manager->deleteShare($share);
+				// Delete limit
+				$this->mapper->delete($shareLimit);
+				return;
+			}
+
+			// Else, we just update the current download count
+			$shareLimit->setDownloads($downloads);
+			$this->mapper->update($shareLimit);
+		} catch (DoesNotExistException $e) {
+			// No limit is set, ignore
+		} catch (\Exception $e) {
+			$this->logger->error('Error while handling share link accessed event: ' . $e->getMessage());
+		}
+
+
+	}
+
+}