cmake_minimum_required(VERSION 3.10)
project(DataRouter 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(ARM_MATRIX
            "cm3;      -mcpu=cortex-m3     -mthumb -mfloat-abi=soft"
            "cm4-soft; -mcpu=cortex-m4     -mthumb -mfloat-abi=soft"
            "cm4-hard; -mcpu=cortex-m4     -mthumb -mfpu=fpv4-sp-d16  -mfloat-abi=hard"
            "cm7-soft; -mcpu=cortex-m7     -mthumb -mfloat-abi=soft"
            "cm7-hard; -mcpu=cortex-m7     -mthumb -mfpu=fpv5-d16     -mfloat-abi=hard"
        )
        foreach(ENTRY ${ARM_MATRIX})
            string(REPLACE ";" "|" ENTRY "${ENTRY}")
            string(REPLACE "|" ";" ITEM "${ENTRY}")
            list(GET ITEM 0 VARIANT)
            list(REMOVE_AT ITEM 0)
            string(REPLACE ";" " " FLAGS "${ITEM}")
            set(TARGET "check_${VARIANT}")
            add_custom_target(${TARGET}
                COMMAND ${ARM_GCC} ${FLAGS}
                        -c ${CMAKE_CURRENT_SOURCE_DIR}/datarouter.c
                        -I${CMAKE_CURRENT_SOURCE_DIR}
                        -o ${CMAKE_CURRENT_BINARY_DIR}/${TARGET}.o
                COMMENT "Compile check: ${VARIANT} (${FLAGS})"
            )
            message(STATUS "  compile check: ${VARIANT}  (make ${TARGET})")
        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 ${CMAKE_CURRENT_SOURCE_DIR})

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()