#!/bin/bash

set -euo pipefail

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

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

   rm -rf "$TEST_DIR"
   exit 1
}

# Encode a single message and verify output.
function run_single_test
{
   "$TOOL" "$2" > "$TEST_DIR/output.c" || die "$1 (encode)"

   echo -n -e "$2" > "$TEST_DIR/expected.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/actual.txt" \
      || die "$1 (decode gcc)"
   diff -q "$TEST_DIR/expected.txt" "$TEST_DIR/actual.txt" \
      || die "$1 (diff gcc)"

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

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

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

# 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)"
}


# Check for help message and nonzero exit code when ran without arguments.
"$TOOL" > "$TEST_DIR/help.txt" && die "$LINENO: unexpected success"
grep -qF "msg" "$TEST_DIR/help.txt" || die "$LINENO: missing help message"

# Run encoder tests.
run_single_test "$LINENO: empty" ""
run_single_test "$LINENO: one byte" "A"
run_single_test "$LINENO: escape (simple)" "\a\b\v\\\r\n\t"
run_single_test "$LINENO: escape (hex mix)" "\x1\x011\x2g\x33G"
hex255=$(perl -e "printf '\\x%x', \$_ foreach(1..255);")
run_single_test "$LINENO: escape (hex exhaustive)" "$hex255"

run_test "$LINENO: empty" "" ""
run_test "$LINENO: one byte (same)" "a" "a"
run_test "$LINENO: one byte (different)" "a" "b"
run_test "$LINENO: multiple bytes (same)" "test" "test"
run_test "$LINENO: multiple bytes (8 bit differences)" "hoge" "PIYO"
run_test "$LINENO: multiple bytes (4 bit differences)" "AbCdEf" "aBStFg"
run_test "$LINENO: different length (0 vs 1)" "" "1"
run_test "$LINENO: different length (1 vs 0)" "1" ""
run_test "$LINENO: different length (2 vs 6)" "uv" "uvwxyz"
run_test "$LINENO: different length (6 vs 2)" "UVWXYZ" "UV"

random1=$(perl -e "srand 1;foreach(1..192){printf '\\x%x', int(rand(254))+1;}")
random2=$(perl -e "srand 2;foreach(1..256){printf '\\x%x', int(rand(254))+1;}")
run_test "$LINENO: random (192)" "$random1" "$random1"
run_test "$LINENO: random (256)" "$random2" "$random2"
run_test "$LINENO: random (192 vs 256)" "$random1" "$random2"
run_test "$LINENO: random (256 vs 192)" "$random2" "$random1"

rm -rf "$TEST_DIR"
exit 0