macro(generate_pkgconfig_link_flags LIBS_LIST OUTPUT_VAR)
    set(${OUTPUT_VAR} "")
    foreach(LIB IN LISTS ${LIBS_LIST})
        if(${OUTPUT_VAR})
            set(${OUTPUT_VAR} "${${OUTPUT_VAR}} -l${LIB}")
        else()
            set(${OUTPUT_VAR} "-l${LIB}")
        endif()
    endforeach()
endmacro()

# this function is based on the unity build function described at: https://cheind.wordpress.com/2009/12/10/reducing-compilation-time-unity-builds/
function(enable_unity_build UNITY_SUFFIX SOURCE_FILES)
    set(MAX_TRANSLATION_UNITS_PER_UNITY_UNIT 500)

    set(files ${${SOURCE_FILES}})
    list(LENGTH files length)

    set(UNITY_FILE_COUNT "")
    if (length GREATER ${MAX_TRANSLATION_UNITS_PER_UNITY_UNIT})
        set(UNITY_FILE_COUNT 1)
    endif()

    set(SOURCE_FILE_COUNT 0)

    # Generate a unique filename for the unity build translation unit
    set(unity_build_file ${CMAKE_CURRENT_BINARY_DIR}/ub${UNITY_FILE_COUNT}_${UNITY_SUFFIX}.cpp)

    # Exclude all translation units from compilation
    set_source_files_properties(${files} PROPERTIES HEADER_FILE_ONLY true)

    # Open the ub file
    if (length GREATER ${MAX_TRANSLATION_UNITS_PER_UNITY_UNIT})
        FILE(WRITE ${unity_build_file} "// Unity Build Volume ${UNITY_FILE_COUNT} generated by CMake\n")
    else()
        FILE(WRITE ${unity_build_file} "// Unity Build generated by CMake\n")
    endif()

    # Complement list of translation units with the name of ub
    list(APPEND ${SOURCE_FILES} "${unity_build_file}")
    set(${SOURCE_FILES} ${${SOURCE_FILES}} PARENT_SCOPE)

    set(CLIENT_UB_VOLUME 0)
    set(CLIENT_FILE_LIST "")
    foreach(source_file ${files} )
        if ("${source_file}" MATCHES ".*source\/.*Client([0-9]+)?.cpp$")
            list(APPEND CLIENT_FILE_LIST "${source_file}")
        else ()
            if (SOURCE_FILE_COUNT EQUAL ${MAX_TRANSLATION_UNITS_PER_UNITY_UNIT})
                MATH(EXPR UNITY_FILE_COUNT "${UNITY_FILE_COUNT}+1")
                set(SOURCE_FILE_COUNT 0)

                set(unity_build_file ${CMAKE_CURRENT_BINARY_DIR}/ub${UNITY_FILE_COUNT}_${UNITY_SUFFIX}.cpp)
                # Open the ub file
                FILE(WRITE ${unity_build_file} "// Unity Build Volume ${UNITY_FILE_COUNT} generated by CMake\n")

                # Complement list of translation units with the name of ub
                list(APPEND ${SOURCE_FILES} "${unity_build_file}")
                set(${SOURCE_FILES} ${${SOURCE_FILES}} PARENT_SCOPE)
            endif()

            # Add include statement for each translation unit
            FILE( APPEND ${unity_build_file} "#include <${source_file}>\n")

            MATH(EXPR SOURCE_FILE_COUNT "${SOURCE_FILE_COUNT}+1")
        endif ()
    endforeach(source_file)
    set(CLIENT_UB_COUNT 1)
    foreach(client_file ${CLIENT_FILE_LIST})
        if (CLIENT_UB_COUNT GREATER UNITY_FILE_COUNT)
            set(CLIENT_UB_COUNT 1)
        endif ()
        if (UNITY_FILE_COUNT STREQUAL "")
            set(client_build_file ${CMAKE_CURRENT_BINARY_DIR}/ub_${UNITY_SUFFIX}.cpp)
        else ()
            set(client_build_file ${CMAKE_CURRENT_BINARY_DIR}/ub${CLIENT_UB_COUNT}_${UNITY_SUFFIX}.cpp)
        endif ()
        FILE(APPEND ${client_build_file} "#include <${client_file}>\n")
        MATH(EXPR CLIENT_UB_COUNT "${CLIENT_UB_COUNT}+1")
    endforeach(client_file)
endfunction(enable_unity_build)

macro(setup_install)
    if(SIMPLE_INSTALL)
        configure_file("${AWS_NATIVE_SDK_ROOT}/toolchains/pkg-config.pc.in" "${PROJECT_NAME}.pc" @ONLY)

        install( TARGETS ${PROJECT_NAME}
                EXPORT "${PROJECT_NAME}-targets"
                ARCHIVE DESTINATION ${ARCHIVE_DIRECTORY}
                LIBRARY DESTINATION ${LIBRARY_DIRECTORY}
                RUNTIME DESTINATION ${BINARY_DIRECTORY} )

        if (BUILD_SHARED_LIBS)
            install(
                FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc"
                DESTINATION ${LIBRARY_DIRECTORY}/pkgconfig)
        endif()
    else()
        if(PLATFORM_CUSTOM)
            install_custom_library(${PROJECT_NAME})
        else()
            install (TARGETS ${PROJECT_NAME}
                     ARCHIVE DESTINATION ${ARCHIVE_DIRECTORY}/${SDK_INSTALL_BINARY_PREFIX}/${PLATFORM_INSTALL_QUALIFIER}/\${CMAKE_INSTALL_CONFIG_NAME}
                     LIBRARY DESTINATION ${LIBRARY_DIRECTORY}/${SDK_INSTALL_BINARY_PREFIX}/${PLATFORM_INSTALL_QUALIFIER}/\${CMAKE_INSTALL_CONFIG_NAME}
                     RUNTIME DESTINATION ${BINARY_DIRECTORY}/${SDK_INSTALL_BINARY_PREFIX}/${PLATFORM_INSTALL_QUALIFIER}/\${CMAKE_INSTALL_CONFIG_NAME})
        endif()
    endif()
endmacro()

macro(do_packaging)
    if(SIMPLE_INSTALL)
        write_basic_package_version_file(
            "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config-version.cmake"
            VERSION ${PROJECT_VERSION}
            COMPATIBILITY AnyNewerVersion
        )

        # TODO: Re-enable export after Aws Common Runtime exports their libraries.
        # export(EXPORT "${PROJECT_NAME}-targets"
        #     FILE "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-targets.cmake"
        # )

    if(${PROJECT_NAME} STREQUAL "aws-cpp-sdk-core")
        configure_file(
            "${AWS_NATIVE_SDK_ROOT}/toolchains/core-config.cmake"
            "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config.cmake"
            @ONLY)
    else()
        configure_file(
            "${AWS_NATIVE_SDK_ROOT}/toolchains/cmakeProjectConfig.cmake"
            "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config.cmake"
            @ONLY)
    endif()

        set(ConfigPackageLocation "${LIBRARY_DIRECTORY}/cmake/${PROJECT_NAME}")
        install(EXPORT "${PROJECT_NAME}-targets"
            FILE "${PROJECT_NAME}-targets.cmake"
            DESTINATION ${ConfigPackageLocation}
        )

        install(
            FILES
            "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config.cmake"
            "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config-version.cmake"
            DESTINATION
            ${ConfigPackageLocation}
            COMPONENT
            Devel)
    endif()
endmacro()