#cmake version
cmake_minimum_required(VERSION 3.31)

#project name
project(TSE-RTS)

# backend selection
option(USE_GLFW "Build with GLFW backend" OFF)
option(USE_SDL3 "Build with SDL3 backend" OFF)

# default backend: GLFW
if(NOT USE_GLFW AND NOT USE_SDL3)
    set(USE_GLFW ON)
endif()

# forbid enabling both at once
if(USE_GLFW AND USE_SDL3)
    message(FATAL_ERROR "USE_GLFW and USE_SDL3 cannot both be ON. Select exactly one backend.")
endif()

if(USE_GLFW)
    message(STATUS "Window backend: GLFW")
endif()

if(USE_SDL3)
    message(STATUS "Window backend: SDL3")
endif()

#cpp settings
find_program(CLANG_C NAMES clang)
find_program(CLANG_CXX NAMES clang++)

if(CLANG_C AND CLANG_CXX)
    message(STATUS "foung Clang, using as Compiler")
    set(CMAKE_C_COMPILER ${CLANG_C} CACHE STRING "C Compiler" FORCE)
    set(CMAKE_CXX_COMPILER ${CLANG_CXX} CACHE STRING "C++ Compiler" FORCE)
else()
    message(STATUS "Clang not found, using Standard-Compiler")
endif()
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED True)

#project output settings
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_SOURCE_DIR}/bin")
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG "${PROJECT_SOURCE_DIR}/bin")
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_RELEASE "${PROJECT_SOURCE_DIR}/bin")

#engine projects
add_subdirectory(TSE/TSE_Base)
add_subdirectory(TSE/TSE_Math)
add_subdirectory(TSE/TSE_Core)
add_subdirectory(TSE/TSE_Editor)
add_subdirectory(TSE/TSE_OpenGlImpl)

if(USE_GLFW)
    add_subdirectory(TSE/TSE_GlfwImpl)
endif()

if(USE_SDL3)
    add_subdirectory(TSE/TSE_Sdl3Impl)
endif()

#source files
file(GLOB CPP_SOURCE
    "${PROJECT_SOURCE_DIR}/TSE-RTS/src/*.cpp"
    "${PROJECT_SOURCE_DIR}/TSE-RTS/src/*/*.cpp"
    "${PROJECT_SOURCE_DIR}/TSE-RTS/src/*/*/*.cpp"
    "${PROJECT_SOURCE_DIR}/TSE-RTS/src/*/*/*/*.cpp"
    "${PROJECT_SOURCE_DIR}/TSE-RTS/src/*.c"
    "${PROJECT_SOURCE_DIR}/TSE-RTS/src/*/*.c"
    "${PROJECT_SOURCE_DIR}/TSE-RTS/src/*/*/*.c"
    "${PROJECT_SOURCE_DIR}/TSE-RTS/src/*/*/*/*.c"
)

#project def
add_executable(TSE-RTS ${CPP_SOURCE})

# includes
target_include_directories(TSE-RTS PRIVATE
    ${PROJECT_SOURCE_DIR}/TSE-RTS/src
    ${PROJECT_SOURCE_DIR}/TSE-RTS/include
    ${PROJECT_SOURCE_DIR}/TSE/TSE_Math/src
    ${PROJECT_SOURCE_DIR}/TSE/TSE_Core/src
    ${PROJECT_SOURCE_DIR}/TSE/TSE_Core/include
    ${PROJECT_SOURCE_DIR}/TSE/TSE_Base/src
    ${PROJECT_SOURCE_DIR}/TSE/TSE_Base/include
    ${PROJECT_SOURCE_DIR}/TSE/TSE_Editor/src
    ${PROJECT_SOURCE_DIR}/TSE/TSE_OpenGlImpl/src
    ${PROJECT_SOURCE_DIR}/TSE/TSE_OpenGlImpl/include
)

if(USE_GLFW)
    target_include_directories(TSE-RTS PRIVATE
        ${PROJECT_SOURCE_DIR}/TSE/TSE_GlfwImpl/src
        ${PROJECT_SOURCE_DIR}/TSE/TSE_GlfwImpl/include
    )
endif()

if(USE_SDL3)
    target_include_directories(TSE-RTS PRIVATE
        ${PROJECT_SOURCE_DIR}/TSE/TSE_Sdl3Impl/src
        ${PROJECT_SOURCE_DIR}/TSE/TSE_Sdl3Impl/include
    )
endif()

# compile definitions for active backend
if(USE_GLFW)
    target_compile_definitions(TSE-RTS PRIVATE TSE_WINDOW_BACKEND_GLFW)
endif()

if(USE_SDL3)
    target_compile_definitions(TSE-RTS PRIVATE TSE_WINDOW_BACKEND_SDL3)
endif()

# external libs
set(LIB_SOURCE "")
set(BACKEND_LIBS "")
set(BACKEND_TARGETS "")

if(WIN32)
    if(CMAKE_BUILD_TYPE STREQUAL "Debug")
        set(DEBUGSPEC
            "${PROJECT_SOURCE_DIR}/TSE/TSE_Core/include/FreeImageLib.d.lib"
            "${PROJECT_SOURCE_DIR}/TSE/TSE_Core/include/box2dd.lib"
        )
    else()
        set(DEBUGSPEC
            "${PROJECT_SOURCE_DIR}/TSE/TSE_Core/include/FreeImageLib.r.lib"
            "${PROJECT_SOURCE_DIR}/TSE/TSE_Core/include/box2d.lib"
        )
    endif()

    set(LIB_SOURCE
        ${DEBUGSPEC}
    )

    if(USE_GLFW)
        list(APPEND LIB_SOURCE
            "${PROJECT_SOURCE_DIR}/TSE/TSE_GlfwImpl/include/glfw3.lib"
        )
        list(APPEND BACKEND_TARGETS TSE_GlfwImpl)
    endif()

    if(USE_SDL3)
        list(APPEND LIB_SOURCE
            "${PROJECT_SOURCE_DIR}/TSE/TSE_Sdl3Impl/include/SDL3-static.lib"
            "winmm"
            "setupapi"
            "cfgmgr32"
            "version"
        )
        list(APPEND BACKEND_TARGETS TSE_Sdl3Impl)
    endif()

else()
    set(LIB_SOURCE
        "${PROJECT_SOURCE_DIR}/TSE/TSE_Core/include/libfreeimage.a"
        "${PROJECT_SOURCE_DIR}/TSE/TSE_Core/include/libbox2d.a"
    )

    if(USE_GLFW)
        list(APPEND LIB_SOURCE
            "${PROJECT_SOURCE_DIR}/TSE/TSE_GlfwImpl/include/libglfw3.a"
        )
        list(APPEND BACKEND_TARGETS TSE_GlfwImpl)
    endif()

    if(USE_SDL3)
        list(APPEND LIB_SOURCE
            "${PROJECT_SOURCE_DIR}/TSE/TSE_Sdl3Impl/include/libSDL3.a"
        )
        list(APPEND BACKEND_TARGETS TSE_Sdl3Impl)
    endif()
endif()

# link
if(WIN32)
    target_link_libraries(TSE-RTS PUBLIC
        TSE_Base
        TSE_Math
        TSE_Core
        ${BACKEND_TARGETS}
        TSE_OpenGlImpl
        TSE_Editor
        ${LIB_SOURCE}
    )
else()
    target_link_libraries(TSE-RTS PUBLIC
        TSE_Editor
        TSE_OpenGlImpl
        ${BACKEND_TARGETS}
        TSE_Core
        TSE_Math
        TSE_Base
        ${LIB_SOURCE}
    )
endif()

# flags
target_compile_options(TSE-RTS PRIVATE -march=native)

set(TARGET_DIR "${PROJECT_SOURCE_DIR}/bin")

add_custom_command(
    TARGET TSE-RTS
    POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E copy_directory
            "${PROJECT_SOURCE_DIR}/TSE-RTS/Resources"
            "${TARGET_DIR}"
    COMMENT "📂 Kopiere Resources/ nach bin/ nach Buildabschluss\n"
)