#!/bin/bash

set -euo pipefail

if [[ $# -ne 2 ]]; then
   echo "$0 <concat_png_tb.exe> <make_png.exe>"
   exit 1
fi


CONCAT=$1
MAKE_PNG=$2

INPUT1=$(mktemp -p .)
INPUT2=$(mktemp -p .)
EXPECTED_TXT=$(mktemp -p .)
EXPECTED=$(mktemp -p .)
ACTUAL=$(mktemp -p .)

function die
{
   echo "$1"
   rm -f "$INPUT1" "$INPUT2" "$EXPECTED_TXT" "$EXPECTED" "$ACTUAL"
   exit 1
}

# Testing inputs with matching widths.
"./$MAKE_PNG" 4 3 1 2 3 > "$INPUT1"
"./$MAKE_PNG" 4 2 10 20 30 > "$INPUT2"

cat <<EOT > "$EXPECTED_TXT"
P3
4 5
255
 1  2  3   1  2  3   1  2  3   1  2  3
 1  2  3   1  2  3   1  2  3   1  2  3
 1  2  3   1  2  3   1  2  3   1  2  3
10 20 30  10 20 30  10 20 30  10 20 30
10 20 30  10 20 30  10 20 30  10 20 30
EOT

ppmtoppm < "$EXPECTED_TXT" > "$EXPECTED"
"./$CONCAT" "$INPUT1" "$INPUT2" > "$ACTUAL"

if ! ( pngtopnm "$ACTUAL" | ppmtoppm | diff -q "$EXPECTED" - ); then
   die "$LINENO: Output mismatched"
fi


# Testing inputs with mismatched widths.
"./$MAKE_PNG" 1 4 1 2 3 > "$INPUT1"
"./$MAKE_PNG" 4 1 10 20 30 > "$INPUT2"

cat <<EOT > "$EXPECTED_TXT"
P3
4 5
255
 1  2  3   0  0  0   0  0  0   0  0  0
 1  2  3   0  0  0   0  0  0   0  0  0
 1  2  3   0  0  0   0  0  0   0  0  0
 1  2  3   0  0  0   0  0  0   0  0  0
10 20 30  10 20 30  10 20 30  10 20 30
EOT

ppmtoppm < "$EXPECTED_TXT" > "$EXPECTED"
"./$CONCAT" "$INPUT1" "$INPUT2" > "$ACTUAL"

if ! ( pngtopnm -mix -background rgb:00/00/00 "$ACTUAL" | ppmtoppm | diff -q "$EXPECTED" - ); then
   die "$LINENO: Output mismatched"
fi


# Try again with a different background color to verify alpha.
# Also switch the order for variety.
cat <<EOT > "$EXPECTED_TXT"
P3
4 5
255
10 20 30  10 20 30  10 20 30  10 20 30
 1  2  3   9  8  7   9  8  7   9  8  7
 1  2  3   9  8  7   9  8  7   9  8  7
 1  2  3   9  8  7   9  8  7   9  8  7
 1  2  3   9  8  7   9  8  7   9  8  7
EOT

ppmtoppm < "$EXPECTED_TXT" > "$EXPECTED"
"./$CONCAT" "$INPUT2" "$INPUT1" > "$ACTUAL"

if ! ( pngtopnm -mix -background rgb:09/08/07 "$ACTUAL" | ppmtoppm | diff -q "$EXPECTED" - ); then
   die "$LINENO: Output mismatched"
fi


# Try reading from stdin twice.
cat <<EOT > "$INPUT1"
P3
4 3
255
 1  2  3   4  5  6   7  8  9  10 11 12
13 14 15  16 17 18  19 20 21  22 23 24
25 26 27  28 29 30  31 32 33  34 35 36
EOT

cat <<EOT > "$EXPECTED_TXT"
P3
4 6
255
 1  2  3   4  5  6   7  8  9  10 11 12
13 14 15  16 17 18  19 20 21  22 23 24
25 26 27  28 29 30  31 32 33  34 35 36
 1  2  3   4  5  6   7  8  9  10 11 12
13 14 15  16 17 18  19 20 21  22 23 24
25 26 27  28 29 30  31 32 33  34 35 36
EOT

ppmtoppm < "$EXPECTED_TXT" > "$EXPECTED"
pnmtopng "$INPUT1" | "./$CONCAT" - - > "$ACTUAL"

if ! ( pngtopnm "$ACTUAL" | ppmtoppm | diff -q "$EXPECTED" - ); then
   die "$LINENO: Output mismatched"
fi

rm -f "$INPUT1" "$INPUT2" "$EXPECTED_TXT" "$EXPECTED" "$ACTUAL"