cmake_minimum_required(VERSION 3.10)
project(DataRouter VERSION 1.1.0 LANGUAGES C)

set(CMAKE_C_STANDARD 11)

# ── 选项 ──────────────────────────────────────────────────────

option(DR_SOURCE_ONLY    "Provide source/include vars instead of building lib" OFF)
option(DR_COMPILE_CHECK  "Build compile-compatibility tests for each Cortex-M variant" OFF)

# 源码路径变量：嵌入式项目直接 target_sources() 使用
set(DR_SOURCES  ${CMAKE_CURRENT_SOURCE_DIR}/datarouter.c  CACHE INTERNAL "")
set(DR_INCLUDES ${CMAKE_CURRENT_SOURCE_DIR}               CACHE INTERNAL "")

# ── 编译兼容性矩阵 (仅在 host 编译器和 ARM GCC 均可用时生效) ──

if(DR_COMPILE_CHECK)
    find_program(ARM_GCC arm-none-eabi-gcc)
    if(ARM_GCC)
        message(STATUS "ARM GCC found: ${ARM_GCC}")
        set(VARIANTS cm3 cm4-soft cm4-hard cm7-soft cm7-hard)
        set(FLAG_LIST
            "-mcpu=cortex-m3 -mthumb -mfloat-abi=soft"
            "-mcpu=cortex-m4 -mthumb -mfloat-abi=soft"
            "-mcpu=cortex-m4 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=hard"
            "-mcpu=cortex-m7 -mthumb -mfloat-abi=soft"
            "-mcpu=cortex-m7 -mthumb -mfpu=fpv5-d16 -mfloat-abi=hard"
        )
        list(LENGTH VARIANTS VN)
        math(EXPR VN "${VN} - 1")
        foreach(I RANGE ${VN})
            list(GET VARIANTS ${I} V)
            list(GET FLAG_LIST ${I} F)
            set(TGT "check_${V}")
            add_custom_target(${TGT}
                COMMAND ${ARM_GCC} ${F}
                        -c ${CMAKE_CURRENT_SOURCE_DIR}/datarouter.c
                        -I${CMAKE_CURRENT_SOURCE_DIR}
                        -o ${CMAKE_CURRENT_BINARY_DIR}/${TGT}.o
                COMMENT "Compile check: ${V}  (${F})"
            )
            message(STATUS "  compile check: ${V}  (make ${TGT})")
        endforeach()
    else()
        message(WARNING "arm-none-eabi-gcc not found; skipping ARM compile checks")
    endif()
    return()
endif()

# ── 源码直用模式（嵌入式项目） ──────────────────────────────

if(DR_SOURCE_ONLY)
    return()
endif()

# ── 常规库构建 ────────────────────────────────────────────────

add_library(DataRouter STATIC datarouter.c)
target_include_directories(DataRouter PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
)

if(BUILD_EXAMPLES OR NOT DEFINED BUILD_EXAMPLES)
    add_executable(example example.c)
    target_link_libraries(example DataRouter)
endif()

if(BUILD_TESTING OR NOT DEFINED BUILD_TESTING)
    enable_testing()
    add_executable(test_datarouter tests/test_datarouter.c)
    target_link_libraries(test_datarouter DataRouter)
    add_test(NAME datarouter COMMAND test_datarouter)
endif()

# ── 安装规则（用于打包发布） ─────────────────────────────

include(GNUInstallDirs)
include(CMakePackageConfigHelpers)

set(DataRouter_INSTALL_CMAKEDIR "${CMAKE_INSTALL_LIBDIR}/cmake/DataRouter")

install(TARGETS DataRouter
    EXPORT DataRouterTargets
    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
)

install(FILES
    ${CMAKE_CURRENT_SOURCE_DIR}/datarouter.h
    ${CMAKE_CURRENT_SOURCE_DIR}/datarouter_config.h
    ${CMAKE_CURRENT_SOURCE_DIR}/datarouter_config_template.h
    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
)

# ── CMake 包配置文件（find_package(DataRouter) 用） ────

set(PACKAGE_INCLUDE_INSTALL_DIR ${CMAKE_INSTALL_INCLUDEDIR})
set(PACKAGE_LIB_INSTALL_DIR     ${CMAKE_INSTALL_LIBDIR})

configure_package_config_file(
    ${CMAKE_CURRENT_SOURCE_DIR}/cmake/DataRouterConfig.cmake.in
    ${CMAKE_CURRENT_BINARY_DIR}/DataRouterConfig.cmake
    INSTALL_DESTINATION ${DataRouter_INSTALL_CMAKEDIR}
    PATH_VARS PACKAGE_INCLUDE_INSTALL_DIR PACKAGE_LIB_INSTALL_DIR
)

write_basic_package_version_file(
    ${CMAKE_CURRENT_BINARY_DIR}/DataRouterConfigVersion.cmake
    VERSION ${PROJECT_VERSION}
    COMPATIBILITY AnyNewerVersion
)

install(EXPORT DataRouterTargets
    FILE DataRouterTargets.cmake
    DESTINATION ${DataRouter_INSTALL_CMAKEDIR}
)

install(FILES
    ${CMAKE_CURRENT_BINARY_DIR}/DataRouterConfig.cmake
    ${CMAKE_CURRENT_BINARY_DIR}/DataRouterConfigVersion.cmake
    DESTINATION ${DataRouter_INSTALL_CMAKEDIR}
)