# cmake-lint: disable=R0915

# From https://crascit.com/professional-cmake/
cmake_minimum_required(VERSION 3.20)

# Enable ccache compiler cache
function(useCompilerCache)
    if(NOT CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
        return()
    endif()
    find_program(CCACHE_EXECUTABLE ccache)
    if(NOT CCACHE_EXECUTABLE)
        return()
    endif()
    if(MSVC)
        # Disable use of separate PDB, Ccache won't cache things otherwise
        foreach(lang IN ITEMS C CXX)
            foreach(config IN LISTS CMAKE_BUILD_TYPE CMAKE_CONFIGURATION_TYPES)
                set(var CMAKE_${lang}_FLAGS)
                if(NOT config STREQUAL "")
                    string(TOUPPER "${config}" config)
                    string(APPEND var "_${config}")
                endif()
                string(REPLACE "/Zi" "/Z7" ${var} "${${var}}")
                string(REPLACE "/ZI" "/Z7" ${var} "${${var}}")
                set(${var} "${${var}}" PARENT_SCOPE)
            endforeach()
        endforeach()
    endif()
    # Use a cache variable so the user can override this
    set(CCACHE_ENV CCACHE_SLOPPINESS=pch_defines,time_macros
        CACHE STRING
              "List of environment variables for ccache, each in key=value form"
    )
    if(CMAKE_GENERATOR MATCHES "Ninja|Makefiles")
        foreach(lang IN ITEMS C CXX OBJC OBJCXX CUDA)
            set(CMAKE_${lang}_COMPILER_LAUNCHER
                ${CMAKE_COMMAND} -E env ${CCACHE_ENV} ${CCACHE_EXECUTABLE}
                PARENT_SCOPE
            )
        endforeach()
    elseif(CMAKE_GENERATOR STREQUAL Xcode)
        foreach(lang IN ITEMS C CXX)
            list(JOIN CCACHE_ENV "\nexport " setEnv)
            if(NOT setEnv STREQUAL "")
                string(PREPEND setEnv "export ")
            endif()
            set(launch${lang} ${CMAKE_BINARY_DIR}/launch-${lang})
            file(
                WRITE ${launch${lang}}
                "#!/bin/bash\n"
                "${setEnv}\n"
                "exec \"${CCACHE_EXECUTABLE}\" \"${CMAKE_${lang}_COMPILER}\" \"$@\"\n"
            )
            execute_process(COMMAND chmod a+rx ${launch${lang}})
        endforeach()
        set(CMAKE_XCODE_ATTRIBUTE_CC ${launchC} PARENT_SCOPE)
        set(CMAKE_XCODE_ATTRIBUTE_CXX ${launchCXX} PARENT_SCOPE)
        set(CMAKE_XCODE_ATTRIBUTE_LD ${launchC} PARENT_SCOPE)
        set(CMAKE_XCODE_ATTRIBUTE_LDPLUSPLUS ${launchCXX} PARENT_SCOPE)

    elseif(CMAKE_GENERATOR MATCHES "Visual Studio")
        cmake_path(NATIVE_PATH CCACHE_EXECUTABLE ccacheExe)
        list(JOIN CCACHE_ENV "\nset " setEnv)
        if(NOT setEnv STREQUAL "")
            string(PREPEND setEnv "set ")
        endif()
        file(WRITE ${CMAKE_BINARY_DIR}/launch-cl.cmd
             "@echo off\n" "${setEnv}\n"
             "\"${ccacheExe}\" \"${CMAKE_C_COMPILER}\" %*\n"
        )
        list(FILTER CMAKE_VS_GLOBALS EXCLUDE REGEX
             "^(CLTool(Path|Exe)|TrackFileAccess)=.*$"
        )
        list(APPEND CMAKE_VS_GLOBALS CLToolPath=${CMAKE_BINARY_DIR}
             CLToolExe=launch-cl.cmd TrackFileAccess=false
        )
        set(CMAKE_VS_GLOBALS "${CMAKE_VS_GLOBALS}" PARENT_SCOPE)
    endif()

    message(STATUS "Using ccache (${CCACHE_EXECUTABLE}).")

    if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
        set(CMAKE_DISABLE_PRECOMPILE_HEADERS ON CACHE BOOL "" FORCE)
        message(STATUS "Precompiled headers disabled because of non-Debug "
                       "build with ccache."
        )
    endif()
endfunction()