#!/bin/bash
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     | Website:  https://openfoam.org
#   \\  /    A nd           | Copyright (C) 2025-2026 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
#     foamUnMergeCase
#
# Description
#     Reverse a merge operation performed with foamMergeCase. This should be
#     called with exactly the same arguments as foamMergeCase.
#
#------------------------------------------------------------------------------
usage() {
    cat<<USAGE

Usage: ${0##*/} <source case> <variant case 1> ... <variant case N>

Reverse a merge operation performed with foamMergeCase. This should be called
with exactly the same arguments as foamMergeCase.  For further information, run:

  foamMergeCase -help

USAGE
}

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

while [ "$#" -gt 0 ]
do
    case "$1" in
    -h | -help)
        usage && exit 0
        ;;
    -*)
        error "Unknown option: '$*'"
        ;;
    *)
        break
        ;;
    esac
done

[ $# -ge 1 ] || error "Incorrect arguments specified"

# Set the source directory
srcDir="$1"
[ -d "$srcDir" ] || error "Directory '$srcDir' not found"
shift

# Set the variant directories
varDirs=()
while [ "$#" -gt 0 ]
do
    [ -d "$1" ] || error "'Directory $1' not found"
    varDirs+=("$1")
    shift
done

# Remove all non-orig files that exist in the source and variant directories
while read -r file
do
    for varOrSrcDir in "${varDirs[@]}" "$srcDir"
    do
        [ -f "$varOrSrcDir/$file" ] || \
            [ -f "$varOrSrcDir/$file.orig" ] && \
            rm -f "$file"
    done
done < <(find ./[-0-9]* constant system -type f ! -name "*.orig" 2>/dev/null)

# Remove any empty directories
find . -type d -empty -delete 2>/dev/null

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