#!/bin/bash

set -euo pipefail

if [[ $# -ne 2 ]]; then
   echo "$0 {kurumi} {base_byte}"
   exit 1
fi
TOOL=$1
BASE_BYTE=$2
TEST_DIR=$(mktemp -d)

# Delete temporary directory and exit with nonzero status.
function die
{
   echo "$1"

   rm -rf "$TEST_DIR"
   exit 1
}

# Encode two messages and verify output.
function run_test
{
   "$TOOL" "$2" "$3" > "$TEST_DIR/output.c" || die "$1 (encode)"

   echo -n -e "$2" > "$TEST_DIR/expected1.txt"
   echo -n -e "$3" > "$TEST_DIR/expected2.txt"

   gcc -Wno-div-by-zero "$TEST_DIR/output.c" -o "$TEST_DIR/output.exe" \
      || die "$1 (compile)"

   gcc -c "$TEST_DIR/output.c" -o /dev/null 2>&1 \
      | "$TEST_DIR/output.exe" > "$TEST_DIR/actual1.txt" \
      || die "$1 (decode gcc)"
   diff -q "$TEST_DIR/expected1.txt" "$TEST_DIR/actual1.txt" \
      || die "$1 (diff gcc)"

   clang -c "$TEST_DIR/output.c" -o /dev/null 2>&1 \
      | "$TEST_DIR/output.exe" > "$TEST_DIR/actual2.txt" \
      || die "$1 (decode clang)"
   diff -q "$TEST_DIR/expected2.txt" "$TEST_DIR/actual2.txt" \
      || die "$1 (diff clang)"

   ruby "$TEST_DIR/output.c" \
      | "$TEST_DIR/output.exe" > "$TEST_DIR/actual1.txt" \
      || die "$1 (decode ruby)"
   diff -q "$TEST_DIR/expected1.txt" "$TEST_DIR/actual1.txt" \
      || die "$1 (diff ruby)"

   perl "$TEST_DIR/output.c" \
      | "$TEST_DIR/output.exe" > "$TEST_DIR/actual2.txt" \
      || die "$1 (decode perl)"
   diff -q "$TEST_DIR/expected2.txt" "$TEST_DIR/actual2.txt" \
      || die "$1 (diff perl)"
}


# First message is the base byte repeated 257 times, while second message
# is every byte value from 0x01 to 0xff.  First message is longer than
# second message so that we would also test the base byte value against
# the 0x00 combination.
msg1=$(perl -e "foreach(1..257){ print '\\x$BASE_BYTE'; }")
msg2=$(perl -e "foreach(1..255){ printf '\\x%x', \$_; }")
run_test "$LINENO: exhaustive $BASE_BYTE" "$msg1" "$msg2"

# Previous test covered (base,0), we need one more to cover (0,base).
run_test "$LINENO: zero $BASE_BYTE" "" "\x$BASE_BYTE"

rm -rf "$TEST_DIR"
exit 0