#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2020 OpenCFD Ltd.
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
#
# Script
#     bin/tools/create-mpi-config
#
# Description
#     Define hard-coded packaging settings for MPI flavours,
#     primarily for system openmpi.
#     This eliminates a runtime dependency on mpicc, for example.
#
#     Instead of querying/parsing 'mpicc --showme:link' each time,
#     it is done once during packaging.
#
# Environment
#     FOAM_MPI, MPI_ARCH_PATH, DEB_TARGET_MULTIARCH
#
# Possible Dependencies
#     - dpkg-architecture
#     - mpicc
#
# Notes
#     Run from top-level directory when creating config files
#
#------------------------------------------------------------------------------
printHelp() {
    exec 1>&2
    while [ "$#" -ge 1 ]; do echo "$1"; shift; done
    cat<<USAGE

usage: ${0##*/} options

options:
  -dry-run          Report but do not write config files
  -no-mpicc         Bypass any use of mpicc
  -query-openmpi    Report installation directory for system openmpi
  -write-openmpi    Query system openmpi and write config files
  -write            Write config files using FOAM_MPI, MPI_ARCH_PATH

Define hard-coded packaging settings for MPI flavours.

Equivalent options:
  -write-system-openmpi | -write-openmpi
  -query-system-openmpi | -query-openmpi

USAGE
    exit 0  # A clean exit
}


# Report error and exit
die()
{
    exec 1>&2
    echo
    echo "Error encountered:"
    while [ "$#" -ge 1 ]; do echo "    $1"; shift; done
    echo
    echo "See '${0##*/} -help' for usage"
    echo
    exit 1
}


#------------------------------------------------------------------------------
# Options
unset optDryRun
useMpicc=true

# Get installation directory for system openmpi
# - from "mpicc --showme:link"
# - manual fallback
#
# The mpicc content looks like this:
# ----
# -pthread -L/usr/lib64/mpi/gcc/openmpi/lib64 -lmpi
# ----

query_system_openmpi()
{
    unset arch_path

    if [ "$useMpicc" = true ]
    then
        arch_path=$(mpicc --showme:link 2>/dev/null | sed -e 's#^.*-L\([^ ]*\).*#\1#')
        arch_path="${arch_path%/*}"

        if [ -n "$arch_path" ]
        then
            echo "$arch_path"
            return 0  # Clean exit
        fi

        echo "No mpicc found. Attempt manually" 1>&2
    fi


    # Manual discovery
    if [ -z "$DEB_TARGET_MULTIARCH" ]
    then
        DEB_TARGET_MULTIARCH=$(dpkg-architecture -qDEB_TARGET_MULTIARCH 2>/dev/null || true)
    fi

    # Include is under /usr/lib...  (eg, debian, openSUSE)
    for testdir in \
        /usr/lib/"${DEB_TARGET_MULTIARCH:+${DEB_TARGET_MULTIARCH}/}"openmpi/include \
        /usr/lib64/mpi/gcc/openmpi/include \
    ;
    do
        if [ -e "$testdir/mpi.h" ]
        then
            echo "${testdir%/*}"
            return 0  # Clean exit
        fi
    done

    # Include is under /usr/include (eg, RedHat)
    for testdir in \
        /usr/include/openmpi-"$(uname -m)" \
        /usr/include/openmpi \
    ;
    do
        if [ -e "$testdir/mpi.h" ]
        then
            echo "/usr"
            return 0  # Clean exit
        fi
    done

    # Failed (should not happen)
    # - report '/usr', but with error code 2
    echo "/usr"
    return 2
}


# Generate etc/config.{csh,sh}/MPI-TYPE files
# based on the values for FOAM_MPI and MPI_ARCH_PATH

create_files()
{
    [ -n "$FOAM_MPI" ] || die "FOAM_MPI not set"

    if [ -d "$MPI_ARCH_PATH" ]
    then
        echo "Define $FOAM_MPI with $MPI_ARCH_PATH" 1>&2

        case "$FOAM_MPI" in
        (openmpi-system)
            configDir="etc/config.sh"
            if [ "$optDryRun" = true ]
            then
                cat << CONTENT 1>&2
dry-run: $configDir/$FOAM_MPI
#
# Packaging configured value for $FOAM_MPI
export MPI_ARCH_PATH="$MPI_ARCH_PATH"

CONTENT
            elif [ -d "$configDir" ]
            then
                echo "Write $configDir/$FOAM_MPI" 1>&2
                cat << CONTENT > "$configDir/$FOAM_MPI"
# $configDir/$FOAM_MPI
#
# Packaging configured value for $FOAM_MPI

export MPI_ARCH_PATH="$MPI_ARCH_PATH"
#----
CONTENT
            else
                echo "Cannot write $configDir/$FOAM_MPI - no directory" 1>&2
            fi

            configDir="etc/config.csh"
            if [ "$optDryRun" = true ]
            then
                cat << CONTENT 1>&2
dry-run: $configDir/$FOAM_MPI
#
# Packaging configured value for $FOAM_MPI
setenv MPI_ARCH_PATH "$MPI_ARCH_PATH"

CONTENT
            elif [ -d "$configDir" ]
            then
                echo "Write $configDir/$FOAM_MPI" 1>&2
                cat << CONTENT > "$configDir/$FOAM_MPI"
# $configDir/$FOAM_MPI
#
# Packaging configured value for $FOAM_MPI

setenv MPI_ARCH_PATH "$MPI_ARCH_PATH"
#----
CONTENT
            else
                echo "Cannot write $configDir/$FOAM_MPI - no directory" 1>&2
            fi
            ;;
        esac
    else
        echo "Warning: $FOAM_MPI with bad MPI_ARCH_PATH: $MPI_ARCH_PATH" 1>&2
        # TBD - remove old/bad entries?
        #
        # for file in "etc/config.sh/$FOAM_MPI" "etc/config.csh/$FOAM_MPI"
        # do
        #     [ -f "$file" ] && rm -f "$file"
        # done
    fi
}


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

# Parse options
while [ "$#" -gt 0 ]
do
    case "$1" in
    -h | -help* | --help*)
        printHelp
        ;;
    '')
        # Discard empty arguments
        ;;

    -dry-run)
        optDryRun=true
        ;;

    -no-mpicc)
        unset useMpicc
        ;;

    -query-openmpi | -query-system-openmpi)
        query_system_openmpi
        exit $?
        ;;

    -write-openmpi | -write-system-openmpi)
        if MPI_ARCH_PATH=$(query_system_openmpi)
        then
            FOAM_MPI="openmpi-system"
            create_files
        else
            die "Failed query for system openmpi"
        fi
        ;;

    -write)
        create_files
        ;;

    *)
        echo "Ignore unknown option/argument: '$1'" 1>&2
        ;;
    esac
    shift
done

exit 0 # A clean exit, if we get this far

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