option (USE_INTERNAL_CCTZ_LIBRARY "Use internal cctz library" ON)

if (NOT USE_INTERNAL_CCTZ_LIBRARY)
    find_library (LIBRARY_CCTZ cctz)
    find_path (INCLUDE_CCTZ NAMES cctz/civil_time.h)

    if (LIBRARY_CCTZ AND INCLUDE_CCTZ)
        set (EXTERNAL_CCTZ_LIBRARY_FOUND 1)

        set(CMAKE_REQUIRED_LIBRARIES ${LIBRARY_CCTZ})
        set(CMAKE_REQUIRED_INCLUDES ${INCLUDE_CCTZ})
        check_cxx_source_compiles(
            "
            #include <cctz/civil_time.h>
            int main() {
                cctz::civil_day date;
            }
            "
            EXTERNAL_CCTZ_LIBRARY_WORKS
        )

        if (NOT EXTERNAL_CCTZ_LIBRARY_WORKS)
            message (${RECONFIGURE_MESSAGE_LEVEL} "External cctz is not working: ${LIBRARY_CCTZ} ${INCLUDE_CCTZ}")
        else()
            add_library (cctz UNKNOWN IMPORTED)
            set_property (TARGET cctz PROPERTY IMPORTED_LOCATION ${LIBRARY_CCTZ})
            set_property (TARGET cctz PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${INCLUDE_CCTZ})
        endif()

        set(SYSTEM_STORAGE_TZ_FILE "${CMAKE_BINARY_DIR}/src/Storages/System/StorageSystemTimeZones.generated.cpp")
        file(REMOVE ${SYSTEM_STORAGE_TZ_FILE})
        file(APPEND ${SYSTEM_STORAGE_TZ_FILE} "// autogenerated by ClickHouse/contrib/cctz-cmake/CMakeLists.txt\n")
        file(APPEND ${SYSTEM_STORAGE_TZ_FILE} "const char * auto_time_zones[] {nullptr};\n" )

    else()
        set (EXTERNAL_CCTZ_LIBRARY_FOUND 0)
        message (${RECONFIGURE_MESSAGE_LEVEL} "Can't find system cctz")
    endif()
endif()

if (NOT EXTERNAL_CCTZ_LIBRARY_FOUND OR NOT EXTERNAL_CCTZ_LIBRARY_WORKS)
    include(${ClickHouse_SOURCE_DIR}/cmake/embed_binary.cmake)
    set(USE_INTERNAL_CCTZ_LIBRARY 1)
    set(LIBRARY_DIR "${ClickHouse_SOURCE_DIR}/contrib/cctz")

    set (SRCS
        "${LIBRARY_DIR}/src/civil_time_detail.cc"
        "${LIBRARY_DIR}/src/time_zone_fixed.cc"
        "${LIBRARY_DIR}/src/time_zone_format.cc"
        "${LIBRARY_DIR}/src/time_zone_if.cc"
        "${LIBRARY_DIR}/src/time_zone_impl.cc"
        "${LIBRARY_DIR}/src/time_zone_info.cc"
        "${LIBRARY_DIR}/src/time_zone_libc.cc"
        "${LIBRARY_DIR}/src/time_zone_lookup.cc"
        "${LIBRARY_DIR}/src/time_zone_posix.cc"
        "${LIBRARY_DIR}/src/zone_info_source.cc"
    )

    add_library (cctz ${SRCS})
    target_include_directories (cctz PUBLIC "${LIBRARY_DIR}/include")

    if (OS_FREEBSD)
        # yes, need linux, because bsd check inside linux in time_zone_libc.cc:24
        target_compile_definitions (cctz PRIVATE __USE_BSD linux _XOPEN_SOURCE=600)
    endif ()

    # Related to time_zones table:
    # StorageSystemTimeZones.generated.cpp is autogenerated each time during a build
    # data in this file will be used to populate the system.time_zones table, this is specific to OS_LINUX
    # as the library that's built using embedded tzdata is also specific to OS_LINUX
    set(SYSTEM_STORAGE_TZ_FILE "${CMAKE_BINARY_DIR}/src/Storages/System/StorageSystemTimeZones.generated.cpp")
    # remove existing copies so that its generated fresh on each build.
    file(REMOVE ${SYSTEM_STORAGE_TZ_FILE})

    # get the list of timezones from tzdata shipped with cctz
    set(TZDIR "${LIBRARY_DIR}/testdata/zoneinfo")
    file(STRINGS "${LIBRARY_DIR}/testdata/version" TZDATA_VERSION)
    set_property(GLOBAL PROPERTY TZDATA_VERSION_PROP "${TZDATA_VERSION}")
    message(STATUS "Packaging with tzdata version: ${TZDATA_VERSION}")

    set(TIMEZONE_RESOURCE_FILES)

    # each file in that dir (except of tab and localtime) store the info about timezone
    execute_process(COMMAND
        bash -c "cd ${TZDIR} && find * -type f -and ! -name '*.tab' -and ! -name 'localtime' | LC_ALL=C sort | paste -sd ';' -"
        OUTPUT_STRIP_TRAILING_WHITESPACE
        OUTPUT_VARIABLE TIMEZONES)

    file(APPEND ${SYSTEM_STORAGE_TZ_FILE} "// autogenerated by ClickHouse/contrib/cctz-cmake/CMakeLists.txt\n")
    file(APPEND ${SYSTEM_STORAGE_TZ_FILE} "const char * auto_time_zones[] {\n" )

    foreach(TIMEZONE ${TIMEZONES})
        file(APPEND ${SYSTEM_STORAGE_TZ_FILE} "    \"${TIMEZONE}\",\n")
        list(APPEND TIMEZONE_RESOURCE_FILES "${TIMEZONE}")
    endforeach(TIMEZONE)
    file(APPEND ${SYSTEM_STORAGE_TZ_FILE} "    nullptr};\n")
    clickhouse_embed_binaries(
        TARGET tzdata
        RESOURCE_DIR "${TZDIR}"
        RESOURCES ${TIMEZONE_RESOURCE_FILES}
    )
    add_dependencies(cctz tzdata)
    target_link_libraries(cctz INTERFACE "-Wl,${WHOLE_ARCHIVE} $<TARGET_FILE:tzdata> -Wl,${NO_WHOLE_ARCHIVE}")
endif ()

message (STATUS "Using cctz")