#----------------------------------*-sh-*--------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2018-2019 OpenCFD Ltd.
#------------------------------------------------------------------------------
# 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 prefix header library incName libName settings warn
    # warn="==> skip fftw"

    # Setup - from the current environment

    # Expected location, include/library names
    prefix="$FFTW_ARCH_PATH"
    incName="fftw3.h"
    libName="libfftw3"

    # ----------------------------------
    if isNone "$prefix"
    then
        [ -n "$warn" ] && echo "$warn (disabled)"
        return 1
    elif hasAbsdir "$prefix"
    then
        header=$(findFirstFile "$prefix/include/$incName")
        library="$(findExtLib $libName)"
    elif isSystem "$prefix"
    then
        header=$(findFirstFile "/usr/local/include/$incName" "/usr/include/$incName")
        prefix=$(sysPrefix "$header")
    else
        unset prefix
    fi
    # ----------------------------------

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

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

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

    # OK
    export HAVE_FFTW=true
    export FFTW_ARCH_PATH="$prefix"
    export FFTW_INC_DIR="${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

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