cmake_minimum_required(VERSION 3.27)
project(HelloAstro)

# Define platform-specific paths and libraries
if(WIN32)
    # GLFW
    set(GLFW_PATH "C:/libs/glfw-3.3.8.bin.WIN64")
    include_directories(${GLFW_PATH}/include)
    link_directories(${GLFW_PATH}/lib-vc2022)

    # GLEW
    set(GLEW_PATH "C:/libs/glew-2.2.0")
    include_directories(${GLEW_PATH}/include)
    link_directories(${GLEW_PATH}/lib/Release/x64)

    # OpenGL
    find_package(OpenGL REQUIRED)
elseif(UNIX)
    find_package(PkgConfig REQUIRED)
    pkg_search_module(GLFW REQUIRED glfw3)
    find_package(GLEW REQUIRED)
    find_package(OpenGL REQUIRED)
elseif(APPLE)
    message(FATAL_ERROR "macOS is not supported yet.")
endif()

add_executable(${PROJECT_NAME} src/hello.cpp src/io.cpp)

if(WIN32)
    add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
        COMMAND ${CMAKE_COMMAND} -E copy_if_different
        "${GLEW_PATH}/bin/Release/x64/glew32.dll"
        $<TARGET_FILE_DIR:${PROJECT_NAME}>
    )

    target_link_libraries(${PROJECT_NAME} glfw3)
    target_link_libraries(${PROJECT_NAME} glew32)
    target_include_directories(${PROJECT_NAME} PRIVATE ${GLEW_INCLUDE_DIRS})
    target_link_libraries(${PROJECT_NAME} OpenGL::GL)
elseif(UNIX)
    include_directories(${GLFW_INCLUDE_DIRS})
    target_link_libraries(${PROJECT_NAME} ${GLFW_LIBRARIES})
    target_link_libraries(${PROJECT_NAME} GLEW::GLEW)
    target_link_libraries(${PROJECT_NAME} OpenGL::GL)
endif()

configure_file(${CMAKE_CURRENT_SOURCE_DIR}/vert.glsl
               ${CMAKE_CURRENT_BINARY_DIR}/vert.glsl COPYONLY)
configure_file(${CMAKE_CURRENT_SOURCE_DIR}/frag.glsl
               ${CMAKE_CURRENT_BINARY_DIR}/frag.glsl COPYONLY)

# Append Git version to built executable after it has been built
find_package(Git)
if (GIT_FOUND)
    if (WIN32)
        set(TARGET_EXTENSION ".exe")
    elseif(UNIX)
        set(TARGET_EXTENSION "")
    endif()
    add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
        COMMAND ${CMAKE_COMMAND}
            -DTARGET_DIR=$<TARGET_FILE_DIR:${PROJECT_NAME}>
            -DPROJECT_NAME=${PROJECT_NAME}
            -DTARGET_EXTENSION=${TARGET_EXTENSION}
            -P ${CMAKE_CURRENT_SOURCE_DIR}/add_git_version_to_executable.cmake
    )
else()
    message("Git not found - will not rename the exectuable.")
endif()

# Include header-only libraries
target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/lib/astro/include)
target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/lib/glm)