CMakeLists.txt

#  @file CMakeLists.txt
#  @author Gaspard Kirira
#
#  Copyright 2025, Gaspard Kirira. All rights reserved.
#  https://github.com/vixcpp/vix
#  Use of this source code is governed by a MIT license
#  that can be found in the License file.
#
# ====================================================================
# Vix.cpp - Log Module
# ====================================================================
# Purpose:
#   Public logging facade for Vix built on top of vix::utils::Logger.
#   This module does not reimplement a logger. It exposes a stable
#   vix::log API that delegates to the existing utils logger backend.
#
#   Builds as STATIC when sources exist, otherwise as a header-only
#   INTERFACE target.
#
# Public Targets:
#   - vix_log  : The actual library target (STATIC or INTERFACE)
#   - vix::log : Namespaced alias for consumers
#
# Public Dependencies:
#   - vix::utils
#
# Installation/Export:
#   - Umbrella build exports into: VixTargets
#   - Standalone build exports into: vix_logTargets
# ====================================================================

cmake_minimum_required(VERSION 3.20)
project(vix_log VERSION 0.1.0 LANGUAGES CXX)

include(GNUInstallDirs)
include(CMakePackageConfigHelpers)

# --------------------------------------------------------------------
# Global settings
# --------------------------------------------------------------------
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_POSITION_INDEPENDENT_CODE ON)

# --------------------------------------------------------------------
# Export set selection
# --------------------------------------------------------------------
if (DEFINED VIX_UMBRELLA_BUILD AND VIX_UMBRELLA_BUILD)
  set(VIX_LOG_EXPORT_SET VixTargets)
else()
  set(VIX_LOG_EXPORT_SET vix_logTargets)
endif()

# --------------------------------------------------------------------
# Umbrella build policy:
# When building inside the Vix umbrella, dependencies are managed by the
# umbrella. In that mode, log must not auto-fetch utils.
# --------------------------------------------------------------------
option(VIX_LOG_FETCH_UTILS "Auto-fetch vix::utils if missing" ON)
option(VIX_LOG_FETCH_THIRD_PARTY "Auto-fetch third-party dependencies needed by fetched vix::utils" ON)

if (DEFINED VIX_UMBRELLA_BUILD AND VIX_UMBRELLA_BUILD)
  set(VIX_LOG_FETCH_UTILS OFF CACHE BOOL "Auto-fetch vix::utils if missing" FORCE)
  set(VIX_LOG_FETCH_THIRD_PARTY OFF CACHE BOOL "Auto-fetch third-party dependencies needed by fetched vix::utils" FORCE)
endif()

# --------------------------------------------------------------------
# Sources discovery
# --------------------------------------------------------------------
file(GLOB_RECURSE LOG_SOURCES CONFIGURE_DEPENDS
  "${CMAKE_CURRENT_SOURCE_DIR}/src/*.cpp"
)

function(vix_log_prepare_utils_third_party)
  if (TARGET spdlog::spdlog_header_only OR TARGET spdlog::spdlog)
    if (TARGET fmt::fmt-header-only OR TARGET fmt::fmt)
      return()
    endif()
  endif()

  find_package(fmt CONFIG QUIET)
  find_package(spdlog CONFIG QUIET)

  if ((TARGET spdlog::spdlog_header_only OR TARGET spdlog::spdlog) AND
      (TARGET fmt::fmt-header-only OR TARGET fmt::fmt))
    return()
  endif()

  if (NOT VIX_LOG_FETCH_THIRD_PARTY)
    return()
  endif()

  include(FetchContent)

  if (NOT TARGET fmt::fmt-header-only AND NOT TARGET fmt::fmt)
    message(STATUS "[log] Fetching fmt for vix::utils")
    set(FMT_DOC OFF CACHE BOOL "" FORCE)
    set(FMT_TEST OFF CACHE BOOL "" FORCE)
    set(FMT_INSTALL ON CACHE BOOL "" FORCE)
    FetchContent_Declare(vix_fmt
      GIT_REPOSITORY https://github.com/fmtlib/fmt.git
      GIT_TAG        10.2.1
    )
    FetchContent_MakeAvailable(vix_fmt)
  endif()

  if (NOT TARGET spdlog::spdlog_header_only AND NOT TARGET spdlog::spdlog)
    message(STATUS "[log] Fetching spdlog for vix::utils")
    set(SPDLOG_FMT_EXTERNAL ON CACHE BOOL "" FORCE)
    set(SPDLOG_BUILD_EXAMPLE OFF CACHE BOOL "" FORCE)
    set(SPDLOG_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
    set(SPDLOG_BUILD_TESTS OFF CACHE BOOL "" FORCE)
    set(SPDLOG_BUILD_BENCH OFF CACHE BOOL "" FORCE)
    set(SPDLOG_INSTALL ON CACHE BOOL "" FORCE)
    FetchContent_Declare(vix_spdlog
      GIT_REPOSITORY https://github.com/gabime/spdlog.git
      GIT_TAG        v1.14.1
    )
    FetchContent_MakeAvailable(vix_spdlog)
  endif()
endfunction()

# --------------------------------------------------------------------
# Utils dependency
# --------------------------------------------------------------------
set(VIX_UTILS_TARGET "")

# 1) Reuse already available umbrella/local target
if (TARGET vix::utils)
  message(STATUS "[log] Using existing target vix::utils")
  set(VIX_UTILS_TARGET vix::utils)

elseif (TARGET vix_utils)
  message(STATUS "[log] Using existing target vix_utils")
  set(VIX_UTILS_TARGET vix_utils)

elseif (TARGET utils)
  message(STATUS "[log] Using existing target utils")
  set(VIX_UTILS_TARGET utils)

else()
  # 2) Try local sibling layouts
  get_filename_component(_VIX_MODULES_DIR "${CMAKE_CURRENT_SOURCE_DIR}/.." ABSOLUTE)
  set(_VIX_UTILS_DIR "${_VIX_MODULES_DIR}/utils")

  if (EXISTS "${_VIX_UTILS_DIR}/CMakeLists.txt")
    message(STATUS "[log] Adding local sibling utils: ${_VIX_UTILS_DIR}")
    add_subdirectory("${_VIX_UTILS_DIR}" "${CMAKE_BINARY_DIR}/_vix_utils")
  endif()

  if (TARGET vix::utils)
    set(VIX_UTILS_TARGET vix::utils)
  elseif (TARGET vix_utils)
    set(VIX_UTILS_TARGET vix_utils)
  elseif (TARGET utils)
    set(VIX_UTILS_TARGET utils)
  else()
    # 3) Try installed packages
    find_package(vix_utils CONFIG QUIET)
    find_package(utils CONFIG QUIET)

    if (TARGET vix::utils)
      set(VIX_UTILS_TARGET vix::utils)
    elseif (TARGET vix_utils)
      set(VIX_UTILS_TARGET vix_utils)
    elseif (TARGET utils)
      set(VIX_UTILS_TARGET utils)
    endif()
  endif()

  # 4) Optional fetch only as last resort
  if (NOT VIX_UTILS_TARGET AND VIX_LOG_FETCH_UTILS)
    include(FetchContent)
    vix_log_prepare_utils_third_party()
    message(STATUS "[log] Fetching vix::utils via FetchContent")
    FetchContent_Declare(vix_utils
      GIT_REPOSITORY https://github.com/vixcpp/utils.git
      GIT_TAG        v1.14.7
    )
    FetchContent_MakeAvailable(vix_utils)

    if (TARGET vix::utils)
      set(VIX_UTILS_TARGET vix::utils)
    elseif (TARGET vix_utils)
      set(VIX_UTILS_TARGET vix_utils)
    elseif (TARGET utils)
      set(VIX_UTILS_TARGET utils)
    endif()
  endif()
endif()

if (NOT VIX_UTILS_TARGET)
  message(FATAL_ERROR
    "vix::utils not found.\n"
    "Expected one of:\n"
    "  - existing target: vix::utils / vix_utils / utils\n"
    "  - local sibling module in ../utils\n"
    "  - installed package via find_package(vix_utils CONFIG) or find_package(utils CONFIG)\n"
  )
endif()

# --------------------------------------------------------------------
# Library target
# --------------------------------------------------------------------
if (LOG_SOURCES)
  message(STATUS "[log] Building STATIC library with detected sources.")

  add_library(vix_log STATIC ${LOG_SOURCES})
  add_library(vix::log ALIAS vix_log)

  target_compile_features(vix_log PUBLIC cxx_std_20)

  target_include_directories(vix_log
    PUBLIC
      $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
      $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
  )

  target_link_libraries(vix_log
    PUBLIC
      ${VIX_UTILS_TARGET}
  )

if (NOT MSVC)
  target_compile_options(vix_log PRIVATE
    -Wall
    -Wextra
    -Wpedantic
  )
endif()

if (VIX_ENABLE_SANITIZERS AND NOT MSVC)
  target_compile_options(vix_log PRIVATE
    -fno-omit-frame-pointer
    -fsanitize=address,undefined
  )
  target_link_options(vix_log PRIVATE
    -fsanitize=address,undefined
  )
endif()

  set_target_properties(vix_log PROPERTIES
    OUTPUT_NAME vix_log
    VERSION ${PROJECT_VERSION}
    SOVERSION 0
    EXPORT_NAME log
  )

  install(TARGETS vix_log
    EXPORT ${VIX_LOG_EXPORT_SET}
    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
  )

else()
  message(STATUS "[log] Building HEADER-ONLY library (no sources).")

  add_library(vix_log INTERFACE)
  add_library(vix::log ALIAS vix_log)

  target_compile_features(vix_log INTERFACE cxx_std_20)

  target_include_directories(vix_log INTERFACE
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
  )

  target_link_libraries(vix_log INTERFACE
    ${VIX_UTILS_TARGET}
  )

  install(TARGETS vix_log
    EXPORT ${VIX_LOG_EXPORT_SET}
    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
  )

endif()

# --------------------------------------------------------------------
# Install headers
# --------------------------------------------------------------------
if (NOT (DEFINED VIX_UMBRELLA_BUILD AND VIX_UMBRELLA_BUILD))
  install(DIRECTORY include/
    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
    FILES_MATCHING
      PATTERN "*.hpp"
      PATTERN "*.h"
  )
endif()

# --------------------------------------------------------------------
# Standalone package config/export
# Only for non-umbrella builds
# --------------------------------------------------------------------
if (NOT (DEFINED VIX_UMBRELLA_BUILD AND VIX_UMBRELLA_BUILD))

  configure_package_config_file(
    "${CMAKE_CURRENT_SOURCE_DIR}/cmake/vix_logConfig.cmake.in"
    "${CMAKE_CURRENT_BINARY_DIR}/vix_logConfig.cmake"
    INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/vix_log"
  )

  write_basic_package_version_file(
    "${CMAKE_CURRENT_BINARY_DIR}/vix_logConfigVersion.cmake"
    VERSION ${PROJECT_VERSION}
    COMPATIBILITY SameMajorVersion
  )

  install(FILES
    "${CMAKE_CURRENT_BINARY_DIR}/vix_logConfig.cmake"
    "${CMAKE_CURRENT_BINARY_DIR}/vix_logConfigVersion.cmake"
    DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/vix_log"
  )

  install(EXPORT vix_logTargets
    FILE vix_logTargets.cmake
    NAMESPACE vix::
    DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/vix_log"
  )

endif()

# --------------------------------------------------------------------
# Tests
# --------------------------------------------------------------------
option(VIX_LOG_BUILD_TESTS "Build log module tests" OFF)

if (VIX_LOG_BUILD_TESTS)
  include(CTest)
  enable_testing()
  add_subdirectory(test)
endif()

# --------------------------------------------------------------------
# Summary
# --------------------------------------------------------------------
message(STATUS "------------------------------------------------------")
message(STATUS "vix::log configured (${PROJECT_VERSION})")
if (LOG_SOURCES)
  message(STATUS "Mode: STATIC / sources found")
else()
  message(STATUS "Mode: HEADER-ONLY / no sources")
endif()
message(STATUS "Export set: ${VIX_LOG_EXPORT_SET}")
message(STATUS "Utils target: ${VIX_UTILS_TARGET}")
message(STATUS "Include dir: ${CMAKE_CURRENT_SOURCE_DIR}/include (for <vix/log/...>)")
message(STATUS "Build type: ${CMAKE_BUILD_TYPE}")
message(STATUS "------------------------------------------------------")