#.rst:
# FindMETIS
# -------
#
# Find the METIS graph partitioning library.
#
# Imported targets
# ^^^^^^^^^^^^^^^^
#
# This module defines the following :prop_tgt:`IMPORTED` target:
#
# ``METIS::METIS``
#   The METIS library, if found.
#
# Result variables
# ^^^^^^^^^^^^^^^^
#
# This module will set the following variables in your project:
#
# ``METIS_INCLUDE_DIRS``
#   where to find metis.h or metis64.h
#
# ``METIS_HEADER``
#   either metis64.h or metis.h, dependent on which was found
#
# ``METIS_LIBRARIES``
#   the libraries to link against in order to use the METIS library.
#
# ``METIS_FOUND``
#   If false, do not try to use the METIS library.

find_path(
    METIS_INCLUDE_DIR
    NAMES metis64.h metis.h
    HINTS ${METIS_DIR}
    ENV METIS_DIR
    PATH_SUFFIXES include
)

if(METIS_INCLUDE_DIR)
    if(EXISTS ${METIS_INCLUDE_DIR}/metis64.h)
        set(METIS_HEADER metis64.h)
        set(METIS_LIB_NAME metis64)
    else()
        set(METIS_HEADER metis.h)
        set(METIS_LIB_NAME metis)
    endif()
    file(
        STRINGS
        ${METIS_INCLUDE_DIR}/${METIS_HEADER}
        metis_version_str_major
        REGEX "^#define[\t ]+METIS_VER_MAJOR[\t ]+.*"
    )
    file(
        STRINGS
        ${METIS_INCLUDE_DIR}/${METIS_HEADER}
        metis_version_str_minor
        REGEX "^#define[\t ]+METIS_VER_MINOR[\t ]+.*"
    )
    string(
        REGEX REPLACE
        "^#define[\t ]+METIS_VER_MAJOR[\t ]+([0-9]+).*"
        "\\1"
        METIS_VERSION_MAJOR
        "${metis_version_str_major}"
    )
    string(
        REGEX REPLACE
        "^#define[\t ]+METIS_VER_MINOR[\t ]+([0-9]+).*"
        "\\1"
        METIS_VERSION_MINOR
        "${metis_version_str_minor}"
    )
    set(METIS_VERSION ${METIS_VERSION_MAJOR}.${METIS_VERSION_MINOR})
    find_library(
        METIS_LIBRARY
        ${METIS_LIB_NAME}
        HINTS ${METIS_DIR}
        ENV METIS_DIR
        PATH_SUFFIXES lib lib64
    )
    if(METIS_VERSION VERSION_GREATER_EQUAL 5.0)
        include(CheckLibraryExists)
        check_library_exists(${METIS_LIBRARY} gk_getopt "" METIS_HAVE_GKLIB)
        if(METIS_HAVE_GKLIB)
            # set it to a non-empty value to satisfy find_package_handle_standard_args
            set(METIS_GKLIB_LIBRARY libGKlib.so)
        else()
            find_library(
                METIS_GKLIB_LIBRARY
                GKlib
                HINTS ${METIS_DIR}
                ENV METIS_DIR
                PATH_SUFFIXES lib lib64
            )
        endif()
    else()
        # set it to a non-empty value to satisfy find_package_handle_standard_args
        set(METIS_GKLIB_LIBRARY libGKlib.so)
    endif()
endif()

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(
    METIS
    REQUIRED_VARS METIS_LIBRARY METIS_GKLIB_LIBRARY METIS_INCLUDE_DIR
    VERSION_VAR METIS_VERSION
)

if(METIS_FOUND)
    set(METIS_LIBRARIES ${METIS_LIBRARY})
    set(METIS_GKLIB_LIBRARIES ${METIS_GKLIB_LIBRARY})
    set(METIS_INCLUDE_DIRS ${METIS_INCLUDE_DIR})
    unset(METIS_LIBRARY)
    unset(METIS_INCLUDE_DIR)
    unset(METIS_GKLIB_LIBRARY)

    if(NOT TARGET METIS::METIS)
        add_library(METIS::METIS UNKNOWN IMPORTED)
        set_target_properties(
            METIS::METIS
            PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${METIS_INCLUDE_DIRS}"
        )
        set_target_properties(
            METIS::METIS
            PROPERTIES
                IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                IMPORTED_LOCATION "${METIS_LIBRARIES}"
        )
        if(METIS_VERSION VERSION_GREATER_EQUAL 5.0 AND NOT METIS_HAVE_GKLIB)
            add_library(METIS::GKlib UNKNOWN IMPORTED)
            set_target_properties(
                METIS::GKlib
                PROPERTIES
                    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                    IMPORTED_LOCATION "${METIS_GKLIB_LIBRARIES}"
            )
            set_target_properties(
                METIS::METIS
                PROPERTIES IMPORTED_LINK_INTERFACE_LIBRARIES METIS::GKlib
            )
        endif()
    endif()
endif()