set(UCD_VERSION 14.0.0)
set(CLDR_VERSION 40.0.0)

set(UCD_PATH "${CMAKE_BINARY_DIR}/UCD" CACHE PATH "Download location for UCD files")
set(CLDR_PATH "${CMAKE_BINARY_DIR}/CLDR" CACHE PATH "Download location for CLDR files")

set(UCD_VERSION_FILE "${UCD_PATH}/version.txt")
set(CLDR_VERSION_FILE "${CLDR_PATH}/version.txt")

set(UNICODE_DATA_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/UnicodeData.txt")
set(UNICODE_DATA_PATH "${UCD_PATH}/UnicodeData.txt")

set(SPECIAL_CASING_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/SpecialCasing.txt")
set(SPECIAL_CASING_PATH "${UCD_PATH}/SpecialCasing.txt")

set(DERIVED_GENERAL_CATEGORY_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/extracted/DerivedGeneralCategory.txt")
set(DERIVED_GENERAL_CATEGORY_PATH "${UCD_PATH}/DerivedGeneralCategory.txt")

set(PROP_LIST_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/PropList.txt")
set(PROP_LIST_PATH "${UCD_PATH}/PropList.txt")

set(DERIVED_CORE_PROP_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/DerivedCoreProperties.txt")
set(DERIVED_CORE_PROP_PATH "${UCD_PATH}/DerivedCoreProperties.txt")

set(DERIVED_BINARY_PROP_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/extracted/DerivedBinaryProperties.txt")
set(DERIVED_BINARY_PROP_PATH "${UCD_PATH}/DerivedBinaryProperties.txt")

set(PROP_ALIAS_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/PropertyAliases.txt")
set(PROP_ALIAS_PATH "${UCD_PATH}/PropertyAliases.txt")

set(PROP_VALUE_ALIAS_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/PropertyValueAliases.txt")
set(PROP_VALUE_ALIAS_PATH "${UCD_PATH}/PropertyValueAliases.txt")

set(NAME_ALIAS_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/NameAliases.txt")
set(NAME_ALIAS_PATH "${UCD_PATH}/NameAliases.txt")

set(SCRIPTS_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/Scripts.txt")
set(SCRIPTS_PATH "${UCD_PATH}/Scripts.txt")

set(SCRIPT_EXTENSIONS_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/ScriptExtensions.txt")
set(SCRIPT_EXTENSIONS_PATH "${UCD_PATH}/ScriptExtensions.txt")

set(EMOJI_DATA_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/emoji/emoji-data.txt")
set(EMOJI_DATA_PATH "${UCD_PATH}/emoji-data.txt")

set(NORM_PROPS_URL "https://www.unicode.org/Public/${UCD_VERSION}/ucd/DerivedNormalizationProps.txt")
set(NORM_PROPS_PATH "${UCD_PATH}/DerivedNormalizationProps.txt")

set(CLDR_ZIP_URL "https://github.com/unicode-org/cldr-json/releases/download/${CLDR_VERSION}/cldr-${CLDR_VERSION}-json-modern.zip")
set(CLDR_ZIP_PATH "${CLDR_PATH}/cldr.zip")

set(CLDR_CORE_SOURCE cldr-core)
set(CLDR_CORE_PATH "${CLDR_PATH}/${CLDR_CORE_SOURCE}")

set(CLDR_DATES_SOURCE cldr-dates-modern)
set(CLDR_DATES_PATH "${CLDR_PATH}/${CLDR_DATES_SOURCE}")

set(CLDR_LOCALES_SOURCE cldr-localenames-modern)
set(CLDR_LOCALES_PATH "${CLDR_PATH}/${CLDR_LOCALES_SOURCE}")

set(CLDR_MISC_SOURCE cldr-misc-modern)
set(CLDR_MISC_PATH "${CLDR_PATH}/${CLDR_MISC_SOURCE}")

set(CLDR_NUMBERS_SOURCE cldr-numbers-modern)
set(CLDR_NUMBERS_PATH "${CLDR_PATH}/${CLDR_NUMBERS_SOURCE}")

set(CLDR_UNITS_SOURCE cldr-units-modern)
set(CLDR_UNITS_PATH "${CLDR_PATH}/${CLDR_UNITS_SOURCE}")

function(remove_unicode_data_if_version_changed version version_file cache_path)
    set(version_differs YES)

    if (EXISTS "${version_file}")
        file(STRINGS "${version_file}" active_version)
        if (version STREQUAL active_version)
            set(version_differs NO)
        endif()
    endif()

    if (version_differs)
        message(STATUS "Removing outdated ${cache_path} for version ${version}")
        file(REMOVE_RECURSE "${cache_path}")
        file(WRITE "${version_file}" "${version}")
    endif()
endfunction()

function(download_ucd_file url path)
    if (NOT EXISTS "${path}")
        get_filename_component(file "${path}" NAME)
        message(STATUS "Downloading UCD ${file} from ${url}...")
        file(DOWNLOAD "${url}" "${path}" INACTIVITY_TIMEOUT 10)
    endif()
endfunction()

function(extract_cldr_file source path)
    if(EXISTS "${CLDR_ZIP_PATH}" AND NOT EXISTS "${path}")
        message(STATUS "Extracting CLDR ${source} from ${CLDR_ZIP_PATH}...")
        execute_process(COMMAND unzip -q "${CLDR_ZIP_PATH}" "${source}/**" -d "${CLDR_PATH}" RESULT_VARIABLE unzip_result)
        if (NOT unzip_result EQUAL 0)
            message(FATAL_ERROR "Failed to unzip ${source} from ${CLDR_ZIP_PATH} with status ${unzip_result}")
        endif()
    endif()
endfunction()

function(invoke_generator name generator header implementation)
    cmake_parse_arguments(invoke_generator "" "" "arguments" ${ARGN})

    add_custom_command(
        OUTPUT "${header}" "${implementation}"
        COMMAND $<TARGET_FILE:${generator}> -h "${header}.tmp" -c "${implementation}.tmp" ${invoke_generator_arguments}
        COMMAND "${CMAKE_COMMAND}" -E copy_if_different "${header}.tmp" "${header}"
        COMMAND "${CMAKE_COMMAND}" -E copy_if_different "${implementation}.tmp" "${implementation}"
        COMMAND "${CMAKE_COMMAND}" -E remove "${header}.tmp" "${implementation}.tmp"
        VERBATIM
        DEPENDS ${generator} "${UCD_VERSION_FILE}" "${CLDR_VERSION_FILE}"
    )

    add_custom_target(generate_${UNICODE_META_TARGET_PREFIX}${name} DEPENDS "${header}" "${implementation}")
    add_dependencies(all_generated generate_${UNICODE_META_TARGET_PREFIX}${name})
endfunction()

if (ENABLE_UNICODE_DATABASE_DOWNLOAD)
    remove_unicode_data_if_version_changed("${UCD_VERSION}" "${UCD_VERSION_FILE}" "${UCD_PATH}")
    remove_unicode_data_if_version_changed("${CLDR_VERSION}" "${CLDR_VERSION_FILE}" "${CLDR_PATH}")

    download_ucd_file("${UNICODE_DATA_URL}" "${UNICODE_DATA_PATH}")
    download_ucd_file("${SPECIAL_CASING_URL}" "${SPECIAL_CASING_PATH}")
    download_ucd_file("${DERIVED_GENERAL_CATEGORY_URL}" "${DERIVED_GENERAL_CATEGORY_PATH}")
    download_ucd_file("${PROP_LIST_URL}" "${PROP_LIST_PATH}")
    download_ucd_file("${DERIVED_CORE_PROP_URL}" "${DERIVED_CORE_PROP_PATH}")
    download_ucd_file("${DERIVED_BINARY_PROP_URL}" "${DERIVED_BINARY_PROP_PATH}")
    download_ucd_file("${PROP_ALIAS_URL}" "${PROP_ALIAS_PATH}")
    download_ucd_file("${PROP_VALUE_ALIAS_URL}" "${PROP_VALUE_ALIAS_PATH}")
    download_ucd_file("${NAME_ALIAS_URL}" "${NAME_ALIAS_PATH}")
    download_ucd_file("${SCRIPTS_URL}" "${SCRIPTS_PATH}")
    download_ucd_file("${SCRIPT_EXTENSIONS_URL}" "${SCRIPT_EXTENSIONS_PATH}")
    download_ucd_file("${EMOJI_DATA_URL}" "${EMOJI_DATA_PATH}")
    download_ucd_file("${NORM_PROPS_URL}" "${NORM_PROPS_PATH}")

    if (NOT EXISTS "${CLDR_ZIP_PATH}")
        message(STATUS "Downloading CLDR database from ${CLDR_ZIP_URL}...")
        file(DOWNLOAD "${CLDR_ZIP_URL}" "${CLDR_ZIP_PATH}" INACTIVITY_TIMEOUT 10)
    endif()

    extract_cldr_file("${CLDR_CORE_SOURCE}" "${CLDR_CORE_PATH}")
    extract_cldr_file("${CLDR_DATES_SOURCE}" "${CLDR_DATES_PATH}")
    extract_cldr_file("${CLDR_LOCALES_SOURCE}" "${CLDR_LOCALES_PATH}")
    extract_cldr_file("${CLDR_MISC_SOURCE}" "${CLDR_MISC_PATH}")
    extract_cldr_file("${CLDR_NUMBERS_SOURCE}" "${CLDR_NUMBERS_PATH}")
    extract_cldr_file("${CLDR_UNITS_SOURCE}" "${CLDR_UNITS_PATH}")

    set(UNICODE_DATA_HEADER LibUnicode/UnicodeData.h)
    set(UNICODE_DATA_IMPLEMENTATION LibUnicode/UnicodeData.cpp)

    set(UNICODE_DATE_TIME_FORMAT_HEADER LibUnicode/UnicodeDateTimeFormat.h)
    set(UNICODE_DATE_TIME_FORMAT_IMPLEMENTATION LibUnicode/UnicodeDateTimeFormat.cpp)

    set(UNICODE_LOCALE_HEADER LibUnicode/UnicodeLocale.h)
    set(UNICODE_LOCALE_IMPLEMENTATION LibUnicode/UnicodeLocale.cpp)

    set(UNICODE_NUMBER_FORMAT_HEADER LibUnicode/UnicodeNumberFormat.h)
    set(UNICODE_NUMBER_FORMAT_IMPLEMENTATION LibUnicode/UnicodeNumberFormat.cpp)

    set(UNICODE_META_TARGET_PREFIX LibUnicode_)

    if (CMAKE_CURRENT_BINARY_DIR MATCHES ".*/LibUnicode") # Serenity build.
        set(UNICODE_DATA_HEADER UnicodeData.h)
        set(UNICODE_DATA_IMPLEMENTATION UnicodeData.cpp)

        set(UNICODE_DATE_TIME_FORMAT_HEADER UnicodeDateTimeFormat.h)
        set(UNICODE_DATE_TIME_FORMAT_IMPLEMENTATION UnicodeDateTimeFormat.cpp)

        set(UNICODE_LOCALE_HEADER UnicodeLocale.h)
        set(UNICODE_LOCALE_IMPLEMENTATION UnicodeLocale.cpp)

        set(UNICODE_NUMBER_FORMAT_HEADER UnicodeNumberFormat.h)
        set(UNICODE_NUMBER_FORMAT_IMPLEMENTATION UnicodeNumberFormat.cpp)

        set(UNICODE_META_TARGET_PREFIX "")
    endif()

    invoke_generator(
        "UnicodeData"
        Lagom::GenerateUnicodeData
        "${UNICODE_DATA_HEADER}"
        "${UNICODE_DATA_IMPLEMENTATION}"
        arguments -u "${UNICODE_DATA_PATH}" -s "${SPECIAL_CASING_PATH}" -g "${DERIVED_GENERAL_CATEGORY_PATH}" -p "${PROP_LIST_PATH}" -d "${DERIVED_CORE_PROP_PATH}" -b "${DERIVED_BINARY_PROP_PATH}" -a "${PROP_ALIAS_PATH}" -v "${PROP_VALUE_ALIAS_PATH}" -r "${SCRIPTS_PATH}" -x "${SCRIPT_EXTENSIONS_PATH}" -e "${EMOJI_DATA_PATH}" -m "${NAME_ALIAS_PATH}" -n "${NORM_PROPS_PATH}"
    )
    invoke_generator(
        "UnicodeDateTimeFormat"
        Lagom::GenerateUnicodeDateTimeFormat
        "${UNICODE_DATE_TIME_FORMAT_HEADER}"
        "${UNICODE_DATE_TIME_FORMAT_IMPLEMENTATION}"
        arguments -r "${CLDR_CORE_PATH}" -d "${CLDR_DATES_PATH}"
    )
    invoke_generator(
        "UnicodeLocale"
        Lagom::GenerateUnicodeLocale
        "${UNICODE_LOCALE_HEADER}"
        "${UNICODE_LOCALE_IMPLEMENTATION}"
        arguments -r "${CLDR_CORE_PATH}" -l "${CLDR_LOCALES_PATH}" -m "${CLDR_MISC_PATH}" -n "${CLDR_NUMBERS_PATH}" -d "${CLDR_DATES_PATH}"
    )
    invoke_generator(
        "UnicodeNumberFormat"
        Lagom::GenerateUnicodeNumberFormat
        "${UNICODE_NUMBER_FORMAT_HEADER}"
        "${UNICODE_NUMBER_FORMAT_IMPLEMENTATION}"
        arguments -n "${CLDR_NUMBERS_PATH}" -u "${CLDR_UNITS_PATH}"
    )

    set(UNICODE_DATA_SOURCES
        ${UNICODE_DATA_HEADER}
        ${UNICODE_DATA_IMPLEMENTATION}
        ${UNICODE_DATE_TIME_FORMAT_HEADER}
        ${UNICODE_DATE_TIME_FORMAT_IMPLEMENTATION}
        ${UNICODE_LOCALE_HEADER}
        ${UNICODE_LOCALE_IMPLEMENTATION}
        ${UNICODE_NUMBER_FORMAT_HEADER}
        ${UNICODE_NUMBER_FORMAT_IMPLEMENTATION}
    )
endif()