#!/bin/bash
# Compare splitting function of a particular PNG splitter.
#
# Note that temporary files are generated relative to current directory
# as opposed to the default place (usually /tmp).  This is needed because
# mingw can't access /tmp.

set -euo pipefail

if [[ $# -ne 4 ]]; then
   echo "$0 <split_png.exe> <verify_split.exe> <stack_png.exe> <input.png>"
   exit 1
fi

SPLITTER=$1
CHECKER=$2
STACKER=$3
INPUT=$4

# Disable leak checking for ASAN, since we intentionally don't free memory.
export ASAN_OPTIONS=detect_leaks=0

OUTPUT1=$(mktemp -p .)
OUTPUT2=$(mktemp -p .)

"./$SPLITTER" "$INPUT" "$OUTPUT1" "$OUTPUT2"
if ! ( "./$CHECKER" "$INPUT" "$OUTPUT1" "$OUTPUT2" ); then
   rm -f "$OUTPUT1" "$OUTPUT2"
   exit 1
fi

COMBINED=$(mktemp -p .)
"./$STACKER" "$OUTPUT1" "$OUTPUT2" > "$COMBINED"

EXPECTED=$(mktemp -p .)
ACTUAL=$(mktemp -p .)
pngtopnm "$INPUT" | ppmtoppm | md5sum > "$EXPECTED"
pngtopnm "$COMBINED" | ppmtoppm | md5sum > "$ACTUAL"

if ( diff -q "$EXPECTED" "$ACTUAL" ); then
   rm -f "$OUTPUT1" "$OUTPUT2" "$COMBINED" "$EXPECTED" "$ACTUAL"
else
   rm -f "$OUTPUT1" "$OUTPUT2" "$COMBINED" "$EXPECTED" "$ACTUAL"
   exit 1
fi