cmake_minimum_required(VERSION 3.20)

project(GW LANGUAGES C ASM)

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_C_STANDARD 99)
set(CMAKE_C_STANDARD_REQUIRED ON)
set(CMAKE_C_EXTENSIONS OFF)

set(GW_TARGET GW.elf)
set(GW_LINKER_SCRIPT "${CMAKE_CURRENT_SOURCE_DIR}/Project_Settings/Linker_Files/linker_flash.ld")

if(NOT EXISTS "${GW_LINKER_SCRIPT}")
    message(FATAL_ERROR "Linker script not found: ${GW_LINKER_SCRIPT}")
endif()

if(NOT DEFINED ENV{S32_SDK_PATH})
    message(FATAL_ERROR "S32_SDK_PATH is not set. It must point to the PlatformSDK_S32K3_2021_03 directory.")
endif()

file(TO_CMAKE_PATH "$ENV{S32_SDK_PATH}" S32_SDK_PATH)
set(S32_RTD_ROOT "${S32_SDK_PATH}/SW32K3_RTD_4_4_0_9_0_D2103")

if(CMAKE_SYSROOT)
    set(GW_SYSROOT_FLAG "--sysroot=${CMAKE_SYSROOT}")
else()
    set(GW_SYSROOT_FLAG "")
endif()

foreach(required_sdk_dir
        "${S32_RTD_ROOT}/Base_TS_T40D34M9I0R0/header"
        "${S32_RTD_ROOT}/Base_TS_T40D34M9I0R0/include"
        "${S32_RTD_ROOT}/Platform_TS_T40D34M9I0R0/include"
        "${S32_RTD_ROOT}/Platform_TS_T40D34M9I0R0/startup/include")
    if(NOT EXISTS "${required_sdk_dir}")
        message(FATAL_ERROR "Required SDK include directory not found: ${required_sdk_dir}")
    endif()
endforeach()

set(GW_SOURCE_ROOTS
    "${CMAKE_CURRENT_SOURCE_DIR}/Project_Settings/Startup_Code"
    "${CMAKE_CURRENT_SOURCE_DIR}/RTD/src"
    "${CMAKE_CURRENT_SOURCE_DIR}/board"
    "${CMAKE_CURRENT_SOURCE_DIR}/generate/include"
    "${CMAKE_CURRENT_SOURCE_DIR}/generate/src"
    "${CMAKE_CURRENT_SOURCE_DIR}/src"
)

set(GW_DIRECT_INCLUDE_DIRS
    "${CMAKE_CURRENT_SOURCE_DIR}"
)

set(GW_RECURSIVE_INCLUDE_ROOTS
    "${CMAKE_CURRENT_SOURCE_DIR}/RTD/include"
    "${CMAKE_CURRENT_SOURCE_DIR}/board"
    "${CMAKE_CURRENT_SOURCE_DIR}/generate/include"
    "${CMAKE_CURRENT_SOURCE_DIR}/generate/src"
    "${CMAKE_CURRENT_SOURCE_DIR}/src"
    "${CMAKE_CURRENT_SOURCE_DIR}/src/HAL/watchdog_hal/inc"
    "${CMAKE_CURRENT_SOURCE_DIR}/src/uds"
    "${S32_RTD_ROOT}/Base_TS_T40D34M9I0R0/header"
    "${S32_RTD_ROOT}/Base_TS_T40D34M9I0R0/include"
    "${S32_RTD_ROOT}/Platform_TS_T40D34M9I0R0/include"
    "${S32_RTD_ROOT}/Platform_TS_T40D34M9I0R0/startup/include"
)

function(gw_collect_directories out_var)
    set(result "")
    foreach(root IN LISTS ARGN)
        if(EXISTS "${root}")
            list(APPEND result "${root}")
            file(GLOB_RECURSE children LIST_DIRECTORIES true CONFIGURE_DEPENDS "${root}/*")
            foreach(child IN LISTS children)
                if(IS_DIRECTORY "${child}")
                    list(APPEND result "${child}")
                endif()
            endforeach()
        endif()
    endforeach()
    list(REMOVE_DUPLICATES result)
    set(${out_var} "${result}" PARENT_SCOPE)
endfunction()

gw_collect_directories(GW_INCLUDE_DIRS ${GW_RECURSIVE_INCLUDE_ROOTS})
list(APPEND GW_INCLUDE_DIRS ${GW_DIRECT_INCLUDE_DIRS})
list(REMOVE_DUPLICATES GW_INCLUDE_DIRS)

set(GW_SOURCES "")
foreach(root IN LISTS GW_SOURCE_ROOTS)
    file(GLOB_RECURSE root_sources CONFIGURE_DEPENDS
        "${root}/*.c"
        "${root}/*.s"
        "${root}/*.S")
    list(APPEND GW_SOURCES ${root_sources})
endforeach()
list(REMOVE_DUPLICATES GW_SOURCES)

add_executable(${GW_TARGET} ${GW_SOURCES})

target_include_directories(${GW_TARGET} PRIVATE ${GW_INCLUDE_DIRS})

target_compile_definitions(${GW_TARGET} PRIVATE
    D_CACHE_ENABLE
    I_CACHE_ENABLE
    GCC
    S32K3XX
    CPU_S32K344
)

target_compile_options(${GW_TARGET} PRIVATE
    $<$<COMPILE_LANGUAGE:ASM>:-x$<SEMICOLON>assembler-with-cpp>
    $<$<COMPILE_LANGUAGE:C>:-std=c99>
    -Os
    -fshort-enums
    -funsigned-char
    -fstack-usage
    -fdump-ipa-all
    -fomit-frame-pointer
    -fno-zero-initialized-in-bss
    -ggdb3
    -pedantic
    -Wall
    -Wextra
    -fmessage-length=0
    -funsigned-bitfields
    -fno-common
    -Wunused
    -Wstrict-prototypes
    -Wsign-compare
    -Werror=implicit-function-declaration
    -Wundef
    -mcpu=cortex-m7
    -mthumb
    -mlittle-endian
    -mfloat-abi=soft
    -specs=nano.specs
    -specs=nosys.specs
    ${GW_SYSROOT_FLAG}
)

target_link_options(${GW_TARGET} PRIVATE
    -nostartfiles
    --entry=Reset_Handler
    -Wl,-Map,${CMAKE_CURRENT_BINARY_DIR}/GW.map
    -Wl,--gc-sections
    -Wl,-u,_printf_float
    -Wl,-u,_scanf_float
    -n
    -mcpu=cortex-m7
    -mthumb
    -mlittle-endian
    -mfloat-abi=soft
    -specs=nano.specs
    -specs=nosys.specs
    ${GW_SYSROOT_FLAG}
    -T${GW_LINKER_SCRIPT}
)

target_link_libraries(${GW_TARGET} PRIVATE c m gcc)
set_property(TARGET ${GW_TARGET} PROPERTY LINK_DEPENDS "${GW_LINKER_SCRIPT}")

if(CMAKE_OBJCOPY)
    set(ARM_OBJCOPY "${CMAKE_OBJCOPY}")
else()
    find_program(ARM_OBJCOPY arm-none-eabi-objcopy REQUIRED)
endif()

if(CMAKE_SIZE)
    set(ARM_SIZE "${CMAKE_SIZE}")
else()
    find_program(ARM_SIZE arm-none-eabi-size REQUIRED)
endif()

add_custom_command(
    TARGET ${GW_TARGET}
    POST_BUILD
    COMMAND ${ARM_OBJCOPY} -O srec $<TARGET_FILE:${GW_TARGET}> "${CMAKE_CURRENT_BINARY_DIR}/GW.srec"
    COMMAND ${ARM_SIZE} --format=berkeley $<TARGET_FILE:${GW_TARGET}>
    BYPRODUCTS "${CMAKE_CURRENT_BINARY_DIR}/GW.srec"
    COMMENT "Generating SREC and size report"
)