#----------------------------------*-sh-*--------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | Copyright (C) 2018-2019 OpenCFD Ltd.
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, licensed under GNU General Public License
#     <http://www.gnu.org/licenses/>.
#
# Script
#     have_petsc
#
# Description
#     Detection/setup of PETSC
#
# Requires
#     PETSC_ARCH_PATH
#
# Functions provided
#     have_petsc, no_petsc, echo_petsc
#
# Variables set on success
#     HAVE_PETSC
#     PETSC_ARCH_PATH
#     PETSC_INC_DIR
#     PETSC_LIB_DIR
#
#------------------------------------------------------------------------------
. $WM_PROJECT_DIR/wmake/scripts/sysFunctions # General system functions

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

# Reset variables
no_petsc()
{
    unset HAVE_PETSC PETSC_INC_DIR PETSC_LIB_DIR
    return 0
}


# Reset variables
echo_petsc()
{
    echo "petsc=${HAVE_PETSC:-false}"
    echo "root=$PETSC_ARCH_PATH"
    echo "include=$PETSC_INC_DIR"
    echo "library=$PETSC_LIB_DIR"
}


# On success, return 0 and export variables
# -> HAVE_PETSC, PETSC_INC_DIR, PETSC_LIB_DIR
have_petsc()
{
    local prefix header library static settings warn
    warn="==> skip petsc"

    # Setup - prefer current environment value? (TDB)
    if [ ! -d "$PETSC_ARCH_PATH" ]
    then
        if settings=$($WM_PROJECT_DIR/bin/foamEtcFile config.sh/petsc)
        then
            . "$settings"
        else
            [ -n "$warn" ] && echo "$warn (no config.sh/petsc settings)"
            return 2
        fi
    fi

    # Location
    prefix="$PETSC_ARCH_PATH"

    # Header/library names
    header="petsc.h"
    library="libpetsc$extLibso"

    # ----------------------------------
    if isNone "$prefix"
    then
        [ -n "$warn" ] && echo "$warn (disabled)"
        return 1
    elif hasAbsdir "$prefix"
    then
        header=$(findFirstFile "$prefix/include/$header")

        library=$(findFirstFile \
            "$(thirdExtLib $library)" \
            "$prefix/lib/$library" \
            "$prefix/lib$WM_COMPILER_LIB_ARCH/$library" \
        )
    elif isSystem "$prefix"
    then
        prefix=/usr
        header=$(findFirstFile "/usr/local/include/$header" "/usr/include/$header")
        case "$header" in (/usr/local/*) prefix=/usr/local ;; esac

        library=$(findFirstFile \
            "$prefix/lib/$library" \
            "$prefix/lib$WM_COMPILER_LIB_ARCH/$library" \
        )
    else
        unset prefix header library
    fi
    # ----------------------------------

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

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

    # TODO: check size of petsc integer vs label

    # OK
    export HAVE_PETSC=true
    export PETSC_ARCH_PATH="$prefix"
    export PETSC_INC_DIR="${header%/*}"     # Basename
    export PETSC_LIB_DIR="${library%/*}"    # Basename
}


# Force reset of old variables
no_petsc

# Testing
if [ "$1" = "-test" ]
then
    have_petsc
    echo_petsc
fi

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