#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     | Website:  https://openfoam.org
#   \\  /    A nd           | Copyright (C) 2020-2024 OpenFOAM Foundation
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM.
#
#     OpenFOAM is free software: you can redistribute it and/or modify it
#     under the terms of the GNU General Public License as published by
#     the Free Software Foundation, either version 3 of the License, or
#     (at your option) any later version.
#
#     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
#     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
#     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
#     for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
#
# Script
#     foamVersionCompare
#
# Description
#     Compare two version numbers
#
#------------------------------------------------------------------------------

usage() {
    cat<<USAGE

Usage: ${0##*/} <version-1> <comparison> <version-2>

Compare two version numbers. The <comparison> argument can be one of; eq
(equal-to), lt (less-than), gt (greater-than), le (less-than-or-equal-to), or
ge (greater-than-or-equal-to). Returns a successful exit code if true.

Examples:
    foamVersionCompare 5.4.3 gt 5.5.1
    foamVersionCompare 5.4.3 gt 5.5.1 && echo True || echo False
    if foamVersionCompare 5.4.3 gt 5.5.1
    then
        echo "5.4.3 IS greater than 5.5.1"
    else
        echo "5.4.3 is NOT greater than 5.5.1"
    fi

USAGE
}

error() {
    exec 1>&2
    while [ "$#" -ge 1 ]; do echo "$1"; shift; done
    usage
    exit 1
}

# Define comparison functions
_foamVersionCompare_eq=0
_foamVersionCompare_lt=1
_foamVersionCompare_gt=2
_foamVersionCompare()
{
    a=$1.
    b=$2.

    while [ -n "$a" ] || [ -n "$b" ]
    do
        ai="${a%%.*}"
        bi="${b%%.*}"

        [ -z "$ai" ] && ai=0
        [ -z "$bi" ] && bi=0

        if [ "$ai" -lt "$bi" ]
        then
            return $_foamVersionCompare_lt
        fi

        if [ "$ai" -gt "$bi" ]
        then
            return $_foamVersionCompare_gt
        fi

        a="${a#*.}"
        b="${b#*.}"
    done

    return $_foamVersionCompare_eq
}
_foamVersionEq()
{
    _foamVersionCompare "$1" "$2"
    [ $? = $_foamVersionCompare_eq ] && return 0 || return 1
}
_foamVersionLt()
{
    _foamVersionCompare "$1" "$2"
    [ $? = $_foamVersionCompare_lt ] && return 0 || return 1
}
_foamVersionGt()
{
    _foamVersionCompare "$1" "$2"
    [ $? = $_foamVersionCompare_gt ] && return 0 || return 1
}
_foamVersionLe()
{
    _foamVersionCompare "$1" "$2"
    [ $? != $_foamVersionCompare_gt ] && return 0 || return 1
}
_foamVersionGe()
{
    _foamVersionCompare "$1" "$2"
    [ $? != $_foamVersionCompare_lt ] && return 0 || return 1
}

# Parse arguments
[ $# -eq 3 ] || error "Incorrect arguments specified"

# Extraction pattern
extract='s/^.*\([^0-9]\.\|[_-]\)[vV]\?\([0-9][0-9.]*[0-9]\)\(\|[._-].*\)$/\2/g'

# Get the first version number
v1=$(echo $1 | sed $extract)
shift 1

# Get the comparison operator
case $1 in
    -h | -help)
        usage && exit 0
        ;;
    eq)
        compare=_foamVersionEq
        ;;
    lt)
        compare=_foamVersionLt
        ;;
    gt)
        compare=_foamVersionGt
        ;;
    le)
        compare=_foamVersionLe
        ;;
    ge)
        compare=_foamVersionGe
        ;;
    *)
        error "unknown option: '$*'";
        ;;
esac
shift 1

# Get the second version number
v2=$(echo $1 | sed $extract)
shift 1

# Perform comparison and return
$compare "$v1" "$v2" && exit 0 || exit 1