#!/bin/bash
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