cmake_minimum_required(VERSION 3.16)
set(namespace "fggl")

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED YES)

option(FGGL_EXAMPLES "Should we build examples or just the library" ON)
option(FGGL_TESTS "Should we enable the testing suite?" ON)
option(FGGL_DOCS "Should we build documentation?" ON)

##
# Windows
# When on windows, integrate vcpkg
##
if(DEFINED ENV{VCPKG_ROOT} AND NOT DEFINED CMAKE_TOOLCHAIN_FILE)
  set(CMAKE_TOOLCHAIN_FILE "$ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake"
      CACHE STRING "")
endif()
##
# /windows
##

# Define the project
project(fggl
	VERSION 0.1
	DESCRIPTION "FOSS Galaxy Game Library, for use in Education, and Games"
	HOMEPAGE_URL "https://git.fossgalaxy.com/gamedev/fggl"
	LANGUAGES C CXX)

# export compile commands for vim/neovim users
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

# vendor dependencies
add_subdirectory( vendor/imgui )
add_subdirectory( vendor/header_only )

# engine headers
file(GLOB_RECURSE public_headers
	${PROJECT_SOURCE_DIR}/include/fggl/*.hpp
)

# engine sources, enable strict compiler warnings
add_subdirectory( fggl )
target_compile_options( fggl PRIVATE -Wall -Wpedantic -Wextra -Wodr -fno-strict-aliasing -fno-strict-overflow )
set_property(TARGET fggl PROPERTY INTERPROCEDURAL_OPTIMIZATION True)

# vendor dependencies
add_subdirectory( integrations/entt )

# Unit Tests
if (FGGL_TESTS)
	include(CTest)
	add_subdirectory(tests)
endif()

# Documentation support
if (FGGL_DOCS)
	find_package(Doxygen)
	if (Doxygen_FOUND)
		add_subdirectory( docs )
	else()
		message(STATUS "Doxygen not found, not building docs")
	endif()
endif()

# Demo project
if (FGGL_EXAMPLES)
  add_subdirectory(demo)
  target_compile_options( demo PRIVATE -Wall -Wextra -Wodr -Wdouble-promotion -fno-strict-aliasing -fno-strict-overflow )
  set_property(TARGET demo PROPERTY INTERPROCEDURAL_OPTIMIZATION True)
endif()

##
# INSTALL PHASE
# see https://decovar.dev/blog/2021/03/08/cmake-cpp-library/
##
include(GNUInstallDirs)

# Structure preserving header macro
foreach(header ${public_headers})
    file(RELATIVE_PATH header_file_path "${CMAKE_CURRENT_SOURCE_DIR}/include" "${header}")
    get_filename_component(header_directory_path "${header_file_path}" DIRECTORY)
    install(
        FILES ${header}
        DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/${header_directory_path}"
    )
endforeach()

set_target_properties(${PROJECT_NAME} PROPERTIES DEBUG_POSTFIX "d")

include(CMakePackageConfigHelpers)
set(FGGL_CONFIG_PATH "${CMAKE_INSTALL_LIBDIR}/cmake/fggl")

# generate and install export file
install(EXPORT "${PROJECT_NAME}Targets"
	    FILE "${PROJECT_NAME}Targets.cmake"
	    NAMESPACE ${namespace}::
	    DESTINATION "${FGGL_CONFIG_PATH}"
)

# generate the version file for the config file
write_basic_package_version_file(
    "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake"
    VERSION "${version}"
    COMPATIBILITY AnyNewerVersion
)
configure_package_config_file(${CMAKE_CURRENT_SOURCE_DIR}/Config.cmake.in
    "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
    INSTALL_DESTINATION "${FGGL_CONFIG_PATH}"
)
# install config files
install(FILES
    "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
    "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake"
    DESTINATION "${FGGL_CONFIG_PATH}"
)
# generate the export targets for the build tree
install(TARGETS ${PROJECT_NAME}
		EXPORT fgglTargets
			DESTINATION "${CMAKE_INSTALL_LIBDIR}"
		PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}
		INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
)

export(EXPORT "${PROJECT_NAME}Targets"
    FILE "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Targets.cmake"
    NAMESPACE ${namespace}::
)

# 3rd party integrations
add_subdirectory( integrations/bullet )