#----------------------------------*-sh-*--------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | Copyright (C) 2018 OpenCFD Ltd.
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, licensed under GNU General Public License
#     <http://www.gnu.org/licenses/>.
#
# Script
#     have_fftw
#
# Description
#     Detection/setup of FFTW
#
# Requires
#     FFTW_ARCH_PATH
#
# Functions provided
#     have_fftw, no_fftw, echo_fftw
#
# Variables set on success
#     HAVE_FFTW
#     FFTW_ARCH_PATH
#     FFTW_INC_DIR
#     FFTW_LIB_DIR
#
#------------------------------------------------------------------------------
. $WM_PROJECT_DIR/wmake/scripts/sysFunctions # General system functions

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

# Reset variables
no_fftw()
{
    unset HAVE_FFTW FFTW_INC_DIR FFTW_LIB_DIR
    return 0
}


# Report
echo_fftw()
{
    echo "fftw=${HAVE_FFTW:-false}"
    echo "root=$FFTW_ARCH_PATH"
    echo "include=$FFTW_INC_DIR"
    echo "library=$FFTW_LIB_DIR"
}


# On success, return 0 and export variables
# -> HAVE_FFTW, FFTW_INC_DIR, FFTW_LIB_DIR
have_fftw()
{
    local header library static label settings warn
    # warn="==> skip fftw"

    # Basic setup/checks
    if isNone "$FFTW_ARCH_PATH"
    then
        [ -n "$warn" ] && echo "$warn (not available)"
        return 1
    fi


    # Header/library names
    header="fftw3.h"
    library="libfftw3$extLibso"


    if hasAbsdir "$FFTW_ARCH_PATH"
    then
        header=$(findFirstFile $FFTW_ARCH_PATH/include/$header)

        # FOAM_EXT_LIBBIN is allowed to be unset
        library=$(findFirstFile \
            $FOAM_EXT_LIBBIN/$library \
            $FFTW_ARCH_PATH/lib/$library \
            $FFTW_ARCH_PATH/lib$WM_COMPILER_LIB_ARCH/$library \
        )
    elif isSystem "$FFTW_ARCH_PATH"
    then
        header=$(findFirstFile /usr/local/include/$header /usr/include/$header)

        case "$header" in
        /usr/local/*)
            library=$(findFirstFile \
                /usr/local/lib/$library \
                /usr/local/lib$WM_COMPILER_LIB_ARCH/$library \
            )
            ;;

        *)
            library=$(findFirstFile \
                /usr/lib/$library \
                /usr/lib$WM_COMPILER_LIB_ARCH/$library \
            )
            ;;
        esac
    else
        unset header library
    fi


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

    # Library found?
    [ -n "$library" ] || {
        [ -n "$warn" ] && echo "$warn (missing library)"
        return 2
    }

    export HAVE_FFTW=true
    export FFTW_ARCH_PATH
    export FFTW_INC_DIR="${header%/*}"     # Basename
    export FFTW_LIB_DIR="${library%/*}"    # Basename
}


# Force reset of old variables
no_fftw

# Testing
if [ "$1" = "-test" ]
then
    have_fftw
    echo_fftw
fi

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