#----------------------------------*-sh-*--------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2018-2021 OpenCFD Ltd.
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
#
# Script
#     have_metis
#
# Description
#     Detection/setup of METIS
#
# Requires
#     config.sh/metis
#
# Functions provided
#     have_metis, no_metis, echo_metis, query_metis, search_metis
#
# Variables set on success
#     HAVE_METIS
#     METIS_ARCH_PATH
#     METIS_INC_DIR
#     METIS_LIB_DIR
#     METIS_LIBNAME_SUFFIX [optional]
#
#------------------------------------------------------------------------------
. ${WM_PROJECT_DIR:?}/wmake/scripts/sysFunctions    # General system functions

#------------------------------------------------------------------------------

# Reset
no_metis()
{
    unset HAVE_METIS METIS_ARCH_PATH METIS_INC_DIR METIS_LIB_DIR
    unset METIS_VERSION METIS_LIBNAME_SUFFIX
}


# Report
echo_metis()
{
    echo "metis=${HAVE_METIS:-false}"
    echo "root=\"$METIS_ARCH_PATH\""
    echo "include=\"$METIS_INC_DIR\""
    echo "library=\"$METIS_LIB_DIR\""
    if [ -n "$METIS_LIBNAME_SUFFIX" ]
    then
        echo "libsuffix=\"$METIS_LIBNAME_SUFFIX\""
    fi
}


# Search
# $1 : prefix (*_ARCH_PATH, system, ...)
#
# On success, return 0 and export variables
# -> HAVE_METIS, METIS_ARCH_PATH, METIS_INC_DIR, METIS_LIB_DIR
search_metis()
{
    local warn="==> skip metis"
    local incName="metis.h"
    local libName="libmetis"

    local prefix="${1:-system}"
    local header library

    # ----------------------------------
    if isNone "$prefix"
    then
        [ -n "$warn" ] && echo "$warn (disabled)"
        return 1
    elif hasAbsdir "$prefix"
    then
        header=$(findFirstFile "$prefix/include/$incName")
        library="-extlib"  # Delay search...
    elif isSystem "$prefix"
    then
        header=$(findSystemInclude -name="$incName")
        prefix=$(sysPrefix "$header")
    else
        unset prefix
    fi
    # ----------------------------------

    # Header
    [ -n "$header" ] || {
        [ -n "$warn" ] && echo "$warn (no header)"
        return 2
    }

    # ----------------------------------
    # Extract IDXTYPEWIDTH from metis.h: regex as per ThirdParty makeMETIS
    # - ensure consistent size between OpenFOAM and metis header

    local label
    if [ -f "$header" ]
    then
        label=$(sed -ne \
            's/^.*#define  *IDXTYPEWIDTH  *\([1-9][0-9]\).*/\1/p' \
            "$header")
    fi
    : "${label:=unknown}"  # Safety

    # Transform (32 | 64) -> (int32 | int64)
    case "$label" in (32|64) label="int${label}" ;; esac

    if [ "$library" = "-extlib" ]
    then
        library=$(findExtLib "${libName}-${label}" "$libName")
    fi

    # Library
    [ -n "$library" ] \
    || library=$(findLibrary -prefix="$prefix" -name="$libName") \
    || {
        [ -n "$warn" ] && echo "$warn (no library)"
        return 2
    }

    # Library name suffix (-int32 | -int64)
    case "${library##*/}" in
    (*-int32.*) export METIS_LIBNAME_SUFFIX="-int32" ;;
    (*-int64.*) export METIS_LIBNAME_SUFFIX="-int64" ;;
    esac

    # OK
    echo "metis (${label}) - $prefix"
    export HAVE_METIS=true
    export METIS_ARCH_PATH="$prefix"
    export METIS_INC_DIR="${header%/*}"     # Basename
    export METIS_LIB_DIR="${library%/*}"    # Basename

    ##echo "DEBUG: header=$header" 1>&2
    ##echo "DEBUG: library=$library" 1>&2
}


# Output as per search_* function
have_metis()
{
    local warn="==> skip metis"
    local config="config.sh/metis"
    local file

    if file="$("$WM_PROJECT_DIR"/bin/foamEtcFile "$config")"
    then
        . "$file"
    else
        [ -n "$warn" ] && echo "$warn (no $config)"
        return 2
    fi

    search_metis "$METIS_ARCH_PATH"
}


# Query settings
query_metis()
{
    local config="config.sh/metis"
    local file

    if file="$("$WM_PROJECT_DIR"/bin/foamEtcFile -mode=o "$config")"
    then
        . "$file"
        _process_query metis "$METIS_ARCH_PATH"
    else
        echo "(no $config)" 1>&2
        echo "metis=unknown"
    fi
}


#------------------------------------------------------------------------------

# Reset variables
no_metis

# Test/query
case "$1" in
-test | -debug-test)
    [ "$1" = "-debug-test" ] && set -x
    have_metis
    [ "$1" = "-debug-test" ] && set +x
    echo_metis
    ;;
-query)
    query_metis
    ;;
esac

#------------------------------------------------------------------------------