#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2020-2022 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, orte-info
#
# 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, -n      Report but do not write config files
  -no-mpicc         Bypass any use of mpicc (or orte-info)
  -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
optUseMpicc=true

# Get installation directory for system openmpi
# - from "orte-info"
# - from "mpicc --showme:link"
# - manual fallback
#
# The orte-info content looks like this:
# ----
# path:prefix:/usr/lib64/mpi/gcc/openmpi2
# ----
#
# The mpicc content looks like this:
# ----
# ... -L/usr/lib64/mpi/gcc/openmpi/lib64 -lmpi
# ... -L/usr/lib64/mpi/gcc/openmpi2/lib64 -lmpi
# ... -L/usr/lib64/openmpi/lib -lmpi
# ----

query_system_openmpi()
{
    unset arch_path

    # Query as per etc/config.sh/mpi
    if [ -n "$optUseMpicc" ]
    then
        # On the assumption that this is being called during compilation,
        # skip orte-info and just take mpicc information
        ## Use <orte-info> (openmpi only command) to query configuration.
        ## Parse "path:prefix:<pathname>" type of output
        #arch_path="$(orte-info --path prefix --parsable 2>/dev/null | sed -e 's#^path:[^:]*:##')"

        # Use <mpicc> to get the link information and (slight hack)
        # strip off 'lib' to get the prefix directory
        if [ -z "$arch_path" ]
        then
            arch_path="$(mpicc --showme:link 2>/dev/null | sed -ne 's#.*-L\([^ ]*\).*#\1#p')"
            arch_path="${arch_path%/*}"  # Prefix from libdir
        fi

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

        echo "No orte-info or mpicc found. Attempt manually" 1>&2
    fi

    # Manual discovery

    # Handle debian multi-arch...
    # but dpkg-architecture command may also be missing
    target_multiarch="$DEB_TARGET_MULTIARCH"
    if [ -z "$target_multiarch" ] && [ -f /etc/debian_version ]
    then
        target_multiarch="$(dpkg-architecture -qDEB_TARGET_MULTIARCH 2>/dev/null || true)"
        if [ -z "$target_multiarch" ] && [ "$(uname -s)" = Linux ]
        then
            # Reasonable guess at a multi-arch name (eg, x86_64-linux-gnu)
            # TODO: aarch64 -> arm64 ?
            target_multiarch="$(uname -m)-linux-gnu"
        fi
    fi

    # Include is under /usr/lib...  (eg, debian, openSUSE)
    # Note this cannot handle (openmpi | openmpi1 | openmpi2 | ...) include directories
    # unless we also try to grab information out of PATH or LD_LIBRARY_PATH
    for testdir in \
        /usr/lib64/mpi/gcc/openmpi \
        /usr/lib/"${target_multiarch}${target_multiarch:+/}"openmpi \
        /usr/lib/openmpi \
    ;
    do
        if [ -e "$testdir/include/mpi.h" ]
        then
            echo "$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

    # Partial env from RedHat "module load mpi/openmpi-x86_64"
    #
    ## MPI_COMPILER=openmpi-x86_64
    ## MPI_HOME=/usr/lib64/openmpi
    ## MPI_BIN=/usr/lib64/openmpi/bin
    ## MPI_LIB=/usr/lib64/openmpi/lib
    ## MPI_INCLUDE=/usr/include/openmpi-x86_64
    ## MPI_SUFFIX=_openmpi


    # 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"

    # MPI-name without trailing major version
    mpiName="${FOAM_MPI%[0-9]}"

    # The prefs name
    prefsName="prefs.$mpiName"

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

        case "$mpiName" in
        (sys-openmpi | openmpi-system)

            # POSIX shell
            prefsFile="etc/config.sh/$prefsName"
            if [ -d "${prefsFile%/*}" ] || [ -n "$optDryRun" ]
            then
            (
                if [ -n "$optDryRun" ]
                then
                    exec 1>&2
                else
                    exec 1> "$prefsFile"
                fi

                echo "${optDryRun}Write $prefsFile" 1>&2
                cat << CONTENT
# $prefsFile
#
# Packaging configured value for $FOAM_MPI
export MPI_ARCH_PATH="$MPI_ARCH_PATH"
#----
CONTENT
            )
            else
                echo "Cannot write $prefsFile - no directory" 1>&2
            fi


            # C-shell
            prefsFile="etc/config.csh/$prefsName"
            if [ -d "${prefsFile%/*}" ] || [ -n "$optDryRun" ]
            then
            (
                if [ -n "$optDryRun" ]
                then
                    exec 1>&2
                else
                    exec 1> "$prefsFile"
                fi

                echo "${optDryRun}Write $prefsFile" 1>&2
                cat << CONTENT
# $prefsFile
#
# Packaging configured value for $FOAM_MPI
setenv MPI_ARCH_PATH "$MPI_ARCH_PATH"
#----
CONTENT
            )
            else
                echo "Cannot write $prefsFile - no directory" 1>&2
            fi
            ;;
        esac
    else
        echo "Warning: $FOAM_MPI with bad MPI_ARCH_PATH: $MPI_ARCH_PATH" 1>&2
        # TBD - remove old/bad entries?
        #
        # rm -f "etc/config.sh/$prefsName" "etc/config.csh/$prefsName"
    fi
}


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

# Parse options
while [ "$#" -gt 0 ]
do
    case "$1" in
    '') true ;; # Discard empty arguments
    -h | -help* | --help*) printHelp ;;
    -n | -dry-run) optDryRun="(dry-run) " ;;

    -no-mpicc)
        unset optUseMpicc
        ;;

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

    -write-openmpi | -write-system-openmpi)
        if MPI_ARCH_PATH=$(query_system_openmpi)
        then
            FOAM_MPI="sys-openmpi" 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

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