#----------------------------------*-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_scotch
#
# Description
#     Detection/setup of SCOTCH
#
# Requires
#     config.sh/scotch
#
# Functions provided
#     have_ptscotch, search_ptscotch
#
# Variables set on success
#     HAVE_SCOTCH
#     SCOTCH_ARCH_PATH
#     SCOTCH_INC_DIR
#     SCOTCH_LIB_DIR
#     SCOTCH_LIBNAME_SUFFIX [optional]
#
# Functions provided [Must call have_scotch first]
#     have_ptscotch, search_ptscotch
#
# Variables set on success
#     HAVE_PTSCOTCH
#     PTSCOTCH_ARCH_PATH
#     PTSCOTCH_INC_DIR
#     PTSCOTCH_LIB_DIR
#
#
# System files can be hiding in a large variety of locations.
# For x86_64 system:
#
# ArchLinux
# ---------
#     scotch   include: /usr/include/scotch
#     scotch   library: /usr/lib64
#
#     ptscotch include: /usr/include/ptscotch
#     ptscotch library: /usr/lib64
#
#
# Debian/Ubuntu
# -------------
#     scotch   include: /usr/include/scotch-int32
#     scotch   library: /usr/lib/x86_64-linux-gnu
#
#     ptscotch include: /usr/include/scotch-int32
#     ptscotch library: /usr/lib/x86_64-linux-gnu
#
#
# RedHat
# ------
#     scotch   include: /usr/include
#     scotch   library: /usr/lib64
#
#     ptscotch include: /usr/include/openmpi-x86_64
#     ptscotch library: /usr/lib64/openmpi/lib
#
# when MPI_ARCH_PATH=/usr/lib64/openmpi
# and mpicc --showme:compile -> -I/usr/include/openmpi-x86_64
#
# NB: for RedHat (8+) /usr/include/scotch.h is a wrapper that includes
#    /usr/include/scotch-64.h  (LP64 mode)
# or /usr/include/scotch-32.h  (ILP32 mode)
# In either case, int is 32 bits
#
# openSUSE
# --------
#     scotch   include: /usr/include
#     scotch   library: /usr/lib64
#
#     ptscotch include: /usr/lib64/mpi/gcc/openmpi2/include
#     ptscotch library: /usr/lib64/mpi/gcc/openmpi2/lib64
#
# when MPI_ARCH_PATH=/usr/lib64/mpi/gcc/openmpi2
#
#------------------------------------------------------------------------------
. ${WM_PROJECT_DIR:?}/wmake/scripts/sysFunctions    # General system functions

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

# Reset
no_scotch()
{
    unset HAVE_SCOTCH SCOTCH_ARCH_PATH SCOTCH_INC_DIR SCOTCH_LIB_DIR
    unset SCOTCH_VERSION SCOTCH_LIBNAME_SUFFIX
    unset HAVE_PTSCOTCH PTSCOTCH_ARCH_PATH PTSCOTCH_INC_DIR PTSCOTCH_LIB_DIR
}


# Report
echo_scotch()
{
    echo "scotch=${HAVE_SCOTCH:-false}"
    echo "root=\"$SCOTCH_ARCH_PATH\""
    echo "include=\"$SCOTCH_INC_DIR\""
    echo "library=\"$SCOTCH_LIB_DIR\""
    if [ -n "$SCOTCH_LIBNAME_SUFFIX" ]
    then
        echo "libsuffix=\"$SCOTCH_LIBNAME_SUFFIX\""
    fi
    echo
    echo "ptscotch=${HAVE_PTSCOTCH:-false}"
    echo "root=\"$PTSCOTCH_ARCH_PATH\""
    echo "include=\"$PTSCOTCH_INC_DIR\""
    echo "library=\"$PTSCOTCH_LIB_DIR\""
    if [ -n "$SCOTCH_LIBNAME_SUFFIX" ]
    then
        echo "libsuffix=\"$SCOTCH_LIBNAME_SUFFIX\""
    fi
}


# Search
# $1 : prefix (*_ARCH_PATH, system, ...)
#
# On success, return 0 and export variables
# -> HAVE_SCOTCH, SCOTCH_ARCH_PATH, SCOTCH_INC_DIR, SCOTCH_LIB_DIR
search_scotch()
{
    local warn="==> skip scotch"
    local incName="scotch.h"
    local libName="libscotch"
    local localDir="scotch-int$WM_LABEL_SIZE"

    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/$localDir/$incName" \
            "$prefix/include/scotch/$incName" \
            "$prefix/include/$incName" \
        )
        library="-extlib"  # Delay search...
    elif isSystem "$prefix"
    then
        header=$(findFirstFile \
            "/usr/local/include/$localDir/$incName" \
            "/usr/local/include/scotch/$incName" \
            "/usr/local/include/$incName" \
            "/usr/include/$localDir/$incName" \
            "/usr/include/scotch/$incName" \
            "/usr/include/$incName" \
        )
        prefix=$(sysPrefix "$header")
    else
        unset prefix
    fi
    # ----------------------------------
    equalBaseName "${header%/*}" "$localDir" || unset localDir

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

    # ----------------------------------
    # Extract 'typedef int64_t SCOTCH_Num' etc from header file
    # - ensure consistent size between OpenFOAM and scotch header
    # - for some systems, scotch.h includes scotch-64.h (for example).

    local label
    for hdr in \
        "$header" \
        "${header%/*}"/scotch-64.h \
        "${header%/*}"/scotch-32.h \
    ;
    do
        if [ -f "$hdr" ]
        then
            label=$(sed -ne \
                's/^.*typedef *\([^ ]*\) *SCOTCH_Num.*/\1/p' \
                "$hdr")

            if [ -n "$label" ]
            then
                header="$hdr"  # Appears successful
                break
            fi
        fi
    done
    : "${label:=unknown}"  # Safety

    # Transform (int32_t | int64_t) -> (int32 | int64)
    case "$label" in (int32_t | int64_t) label="${label%_t}" ;; esac

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

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

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

    # No SCOTCH_VERSION set? Try to obtain from header
    # extract #define SCOTCH_VERSION, SCOTCH_RELEASE, SCOTCH_PATCHLEVEL
    [ -n "$SCOTCH_VERSION" ] || \
    SCOTCH_VERSION=$(
        eval $(
            sed -ne \
            's/^ *#define *SCOTCH_\(VERSION\|RELEASE\|PATCHLEVEL\) *\([0-9][0-9]*\).*$/\1=\2/p' \
            "$header"
        )

        set -- $VERSION $RELEASE $PATCHLEVEL
        IFS="."
        [ "$#" -gt 0 ] && echo "scotch-$*"
    )
    : "${SCOTCH_VERSION:=scotch}"  # Failsafe value

    # Accept widening of OpenFOAM label to scotch label (SCOTCH_Num)
    # but reject narrowing here instead of in the code
    case "$WM_LABEL_SIZE:$label" in
    ( 32:int32 | 32:int \
    | 32:int64 | 32:long \
    | 64:int64 | 64:long )
        ;;

    (*)
        if [ -n "$warn" ]
        then
            echo "$warn (label='$WM_LABEL_SIZE', ${header##*/} has '$label')"
        fi
        no_scotch
        return 1
        ;;
    esac

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

    # OK
    echo "scotch ($label) - $prefix"
    export HAVE_SCOTCH=true
    export SCOTCH_ARCH_PATH="$prefix"
    export SCOTCH_INC_DIR="${header%/*}"     # Basename
    export SCOTCH_LIB_DIR="${library%/*}"    # Basename
    export SCOTCH_VERSION

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


# Search
# $1 : prefix (*_ARCH_PATH, system, ...)
#
# On success, return 0 and export variables
# -> HAVE_PTSCOTCH, PTSCOTCH_ARCH_PATH, PTSCOTCH_INC_DIR, PTSCOTCH_LIB_DIR
search_ptscotch()
{
    local warn="==> skip ptscotch"
    local incName="ptscotch.h"
    local libName="libptscotch"
    local localDir="scotch-int$WM_LABEL_SIZE"

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

    local mpiPrefix="$MPI_ARCH_PATH"
    local mpiName="${MPI_ARCH_PATH##*/}"

    # ----------------------------------
    if isNone "$prefix"
    then
        [ -n "$warn" ] && echo "$warn (disabled)"
        return 1
    elif hasAbsdir "$prefix"
    then
        header=$(findFirstFile  \
            "$prefix/include/$FOAM_MPI/$incName" \
            "$prefix/include/$localDir/$incName" \
            "$prefix/include/ptscotch/$incName" \
            "$prefix/include/scotch/$incName" \
            "$prefix/include/$incName" \
            "$mpiPrefix/include/$incName" \
            "$prefix/include/$mpiName/$incName" \
            "$prefix/include/${mpiName}-$(uname -m)/$incName" \
        )
        library=$(findExtLib \
            "$FOAM_MPI/$libName${SCOTCH_LIBNAME_SUFFIX}" \
            "$libName${SCOTCH_LIBNAME_SUFFIX}" \
            "$FOAM_MPI/$libName${SCOTCH_LIBNAME_SUFFIX}" \
        )
    elif isSystem "$prefix"
    then
        header=$(findFirstFile \
            "/usr/local/include/$localDir/$incName" \
            "/usr/local/include/ptscotch/$incName" \
            "/usr/local/include/scotch/$incName" \
            "/usr/local/include/$incName" \
            "/usr/include/$localDir/$incName" \
            "/usr/include/ptscotch/$incName" \
            "/usr/include/scotch/$incName" \
            "/usr/include/$incName" \
            "$mpiPrefix/include/$incName" \
            "/usr/include/$mpiName/$incName" \
            "$prefix/include/${mpiName}-$(uname -m)/$incName" \
        )
        prefix=$(sysPrefix "$header")
    else
        unset prefix
    fi
    # ----------------------------------
    equalBaseName "${header%/*}" "$localDir" || unset localDir

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

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

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

    # OK
    echo "ptscotch - $prefix"
    export HAVE_PTSCOTCH=true
    export PTSCOTCH_ARCH_PATH="$prefix"
    export PTSCOTCH_INC_DIR="${header%/*}"     # Basename
    export PTSCOTCH_LIB_DIR="${library%/*}"    # Basename

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


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

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

    search_scotch "$SCOTCH_ARCH_PATH"
}


# Output as per search_* function
have_ptscotch()
{
    local warn="==> skip ptscotch"

    if [ "$HAVE_SCOTCH" != true ]
    then
        echo "$warn (no serial scotch available?)"
        return 1
    fi

    # Reuse old settings
    [ -n "$PTSCOTCH_ARCH_PATH" ] || PTSCOTCH_ARCH_PATH="$SCOTCH_ARCH_PATH"

    search_ptscotch "$PTSCOTCH_ARCH_PATH"
}


# Query settings
query_scotch()
{
    local config="config.sh/scotch"
    local file

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


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

# Reset
no_scotch

# Test/query
case "$1" in
-test | -debug-test)
    [ "$1" = "-debug-test" ] && set -x
    have_scotch && have_ptscotch
    [ "$1" = "-debug-test" ] && set +x
    echo_scotch
    ;;
-query)
    query_scotch
    ;;
esac

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