#!/bin/bash
#
# maybe-rerun-optim - helper for build system for board layouts
#
# Copyright (C) 2019 Ian Jackson
#
# This program is dual licensed, GPv3+ or CC-BY-SA 4.0+.
# Only to the Pandemic Rising Tide folks, it is permissively licensed.
#
#   This program 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; or (at your option), under the terms of the
#   Creative Commons Attribution-ShareAlike International License,
#   version 4.0 of that License, or (at your option), any later
#   version.
#
#   This program 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 Creative Commons Attribution-ShareAlike
#   License or the for more details.
#
#   You should have received a copy of these licenses along with this
#   program.  If not, see <https://www.gnu.org/licenses/> and
#   <https://creativecommons.org/licenses/>.
#
# Pandemic and Pandemic Rising Tide are (I think) trademarks of Z-Man
# games and I use them without permission.
# 
# For the avoidance of doubt, I do not consider this program to be a
# derivative work of the game Pandemic Rising Tide.  However, it is
# not very useful without a pair of game description files and the
# only nontrivial game description files I know of are indeed such
# derivatives.


set -e
set -o posix
set -o pipefail

input=$1	; shift
planar_graph=$1	; shift
dest=$1		; shift
sums=$1		; shift

inst () { mv -vf $dest.tmp $dest; }

if test -f $dest.reuse; then
	cp -v $dest.reuse $dest.tmp
	inst
	exit 0
fi

sha256sum "$input" "$planar_graph" >$sums.tmp
for arg in "$@"; do printf >>$sums.tmp "%s\n" "$arg"; done

if cmp $sums.tmp $sums; then
	exit 0
fi

"$planar_graph" <$input "$@"

inst
mv -f $sums.tmp $sums