#!/usr/bin/env bash

set -uo pipefail

repo_root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
cd "$repo_root"

cases_dir="test/test_case"
result_root="test/test_result/run_tests"
asm_dir="$result_root/asm"
compiler="./build/bin/compiler"
cross_gcc="aarch64-linux-gnu-gcc"
qemu_bin="qemu-aarch64"
qemu_sysroot="/usr/aarch64-linux-gnu"

usage() {
  cat <<'EOF'
用法: ./test/run_tests.sh [case ...]

参数:
  case    可选。支持以下两种写法：
          - test/test_case/foo.sy
          - foo            (自动解析为 test/test_case/foo.sy)

行为:
  - 批量编译 test/test_case/*.sy 为 AArch64 汇编并链接可执行文件
  - 若存在同名 .in，则将其作为标准输入喂给程序
  - 采集程序标准输出，并将退出码追加为最后一行
  - 与同名 .out 做精确 diff，比对结果写入 test/test_result/run_tests/
EOF
}

require_tool() {
  local tool=$1
  if ! command -v "$tool" >/dev/null 2>&1; then
    echo "未找到依赖工具: $tool" >&2
    exit 1
  fi
}

resolve_case() {
  local arg=$1
  if [[ -f "$arg" ]]; then
    printf '%s\n' "$arg"
    return 0
  fi
  if [[ -f "$cases_dir/$arg.sy" ]]; then
    printf '%s\n' "$cases_dir/$arg.sy"
    return 0
  fi
  return 1
}

append_exit_code() {
  local stdout_file=$1
  local actual_file=$2
  local status=$3

  : > "$actual_file"
  if [[ -f "$stdout_file" ]]; then
    cat "$stdout_file" >> "$actual_file"
    if [[ -s "$stdout_file" ]]; then
      local last_byte
      last_byte=$(tail -c 1 "$stdout_file" | od -An -t x1 | tr -d ' \n')
      if [[ "$last_byte" != "0a" ]]; then
        printf '\n' >> "$actual_file"
      fi
    fi
  fi
  printf '%s\n' "$status" >> "$actual_file"
}

run_case() {
  local input_sy=$1
  local base stem expected input_txt case_dir asm_file exe_file
  local compile_log link_log stderr_log stdout_log actual_out diff_log
  local status

  base=$(basename "$input_sy")
  stem=${base%.sy}
  expected="${input_sy%.sy}.out"
  input_txt="${input_sy%.sy}.in"

  case_dir="$result_root/$stem"
  asm_file="$asm_dir/$stem.s"
  exe_file="$asm_dir/$stem"
  compile_log="$case_dir/compiler.log"
  link_log="$case_dir/link.log"
  stderr_log="$case_dir/stderr.log"
  stdout_log="$case_dir/stdout.log"
  actual_out="$case_dir/actual.out"
  diff_log="$case_dir/diff.log"

  rm -rf "$case_dir"
  mkdir -p "$case_dir"
  rm -f "$asm_file" "$exe_file"

  if [[ ! -f "$expected" ]]; then
    echo "[FAIL] $stem: 缺少预期输出文件 $expected"
    ((missing_expected_count += 1))
    failed_cases+=("$stem")
    return
  fi

  if ! "$compiler" --emit-asm "$input_sy" >"$asm_file" 2>"$compile_log"; then
    echo "[FAIL] $stem: 编译失败，详见 $compile_log"
    ((compile_fail_count += 1))
    failed_cases+=("$stem")
    return
  fi

  if ! "$cross_gcc" "$asm_file" -o "$exe_file" >"$link_log" 2>&1; then
    echo "[FAIL] $stem: 链接失败，详见 $link_log"
    ((link_fail_count += 1))
    failed_cases+=("$stem")
    return
  fi

  : > "$stdout_log"
  : > "$stderr_log"
  if [[ -f "$input_txt" ]]; then
    "$qemu_bin" -L "$qemu_sysroot" "$exe_file" <"$input_txt" >"$stdout_log" 2>"$stderr_log"
    status=$?
  else
    "$qemu_bin" -L "$qemu_sysroot" "$exe_file" >"$stdout_log" 2>"$stderr_log"
    status=$?
  fi

  append_exit_code "$stdout_log" "$actual_out" "$status"

  if diff -u "$expected" "$actual_out" >"$diff_log"; then
    rm -f "$diff_log"
    echo "[PASS] $stem"
    ((pass_count += 1))
  else
    echo "[FAIL] $stem: 输出不匹配，详见 $diff_log"
    ((diff_fail_count += 1))
    failed_cases+=("$stem")
  fi
}

if [[ ${1:-} == "-h" || ${1:-} == "--help" ]]; then
  usage
  exit 0
fi

if [[ ! -x "$compiler" ]]; then
  echo "未找到编译器: $compiler ，请先构建。" >&2
  exit 1
fi

require_tool "$cross_gcc"
require_tool "$qemu_bin"

mkdir -p "$asm_dir"

declare -a cases=()
declare -a failed_cases=()

if [[ $# -gt 0 ]]; then
  for arg in "$@"; do
    if ! resolved=$(resolve_case "$arg"); then
      echo "未找到测试用例: $arg" >&2
      exit 1
    fi
    cases+=("$resolved")
  done
else
  while IFS= read -r -d '' file; do
    cases+=("$file")
  done < <(find "$cases_dir" -maxdepth 1 -type f -name '*.sy' -print0 | sort -z)
fi

if [[ ${#cases[@]} -eq 0 ]]; then
  echo "未找到任何 .sy 测试用例。" >&2
  exit 1
fi

pass_count=0
compile_fail_count=0
link_fail_count=0
diff_fail_count=0
missing_expected_count=0

for case_path in "${cases[@]}"; do
  run_case "$case_path"
done

total_count=${#cases[@]}
fail_count=$((compile_fail_count + link_fail_count + diff_fail_count + missing_expected_count))

echo
echo "测试完成: $total_count 个用例"
echo "通过: $pass_count"
echo "失败: $fail_count"
echo "  编译失败: $compile_fail_count"
echo "  链接失败: $link_fail_count"
echo "  输出不匹配: $diff_fail_count"
echo "  缺少预期输出: $missing_expected_count"

if [[ ${#failed_cases[@]} -gt 0 ]]; then
  echo "失败用例: ${failed_cases[*]}"
  exit 1
fi

exit 0