/// arb 完整性单测（P3 计划 Task 10：漏译检查）。
///
/// zh（模板）/en 两份 arb 直接按 JSON 解析比对：
/// 1. 消息键集合相等（任一侧新增/删除键即失败——杜绝漏译）；
/// 2. 每条消息的占位符 token 集合相等（en 用了 {count} 而 zh 没有即失败，
///    反之亦然——杜绝运行时 Intl 占位符缺失/多参崩溃）；
/// 3. `@key` 元数据键必须对应真实消息键，且其 placeholders 名称与
///    消息体中提取的 token 一致（两侧一致）。
library;

import 'dart:convert';
import 'dart:io';

import 'package:flutter_test/flutter_test.dart';

Map<String, Object?> _loadArb(String fileName) {
  final file = File('lib/l10n/$fileName');
  if (!file.existsSync()) {
    fail('arb 文件缺失: ${file.path}');
  }
  return jsonDecode(file.readAsStringSync()) as Map<String, Object?>;
}

/// `{name}` 占位符 token 提取（ICU 复数/选择子句的内层同名 token 同样
/// 命中；`{count, plural,` 等带参数形式不误报为 token）。
Set<String> _placeholdersOf(String message) =>
    RegExp(r'\{([a-zA-Z][a-zA-Z0-9_]*)\}')
        .allMatches(message)
        .map((m) => m.group(1)!)
        .toSet();

Set<String> _messageKeys(Map<String, Object?> arb) =>
    arb.keys.where((k) => !k.startsWith('@')).toSet();

void main() {
  final zh = _loadArb('app_zh.arb');
  final en = _loadArb('app_en.arb');
  final zhKeys = _messageKeys(zh);
  final enKeys = _messageKeys(en);

  test('zh/en 消息键集合相等（漏译防护）', () {
    final zhOnly = zhKeys.difference(enKeys).toList()..sort();
    final enOnly = enKeys.difference(zhKeys).toList()..sort();
    expect(zhOnly, isEmpty, reason: 'en 缺少这些键: $zhOnly');
    expect(enOnly, isEmpty, reason: 'zh 缺少这些键: $enOnly');
  });

  test('@@locale 元数据正确', () {
    expect(zh['@@locale'], 'zh');
    expect(en['@@locale'], 'en');
  });

  test('每条消息的占位符 token 两侧一致', () {
    final mismatched = <String>[];
    for (final key in zhKeys.intersection(enKeys)) {
      final zhValue = zh[key];
      final enValue = en[key];
      if (zhValue is! String || enValue is! String) continue;
      final zhTokens = _placeholdersOf(zhValue);
      final enTokens = _placeholdersOf(enValue);
      final sameSet = zhTokens.length == enTokens.length &&
          zhTokens.containsAll(enTokens);
      if (!sameSet) {
        mismatched.add(
          '$key: zh${zhTokens.toList()} vs en${enTokens.toList()}',
        );
      }
    }
    expect(mismatched, isEmpty, reason: '占位符不一致:\n${mismatched.join('\n')}');
  });

  test('@key 元数据与消息键对应且 placeholders 名称一致', () {
    for (final arb in [zh, en]) {
      final locale = arb['@@locale'] as String?;
      final messageKeys = _messageKeys(arb);
      final metaKeys = arb.keys
          .where((k) => k.startsWith('@') && k != '@@locale')
          .toSet();
      final dangling =
          {for (final k in metaKeys) k.substring(1)}
              .difference(messageKeys)
              .toList()
            ..sort();
      expect(
        dangling,
        isEmpty,
        reason: '$locale 存在无对应消息键的元数据: $dangling',
      );

      for (final metaKey in metaKeys) {
        final key = metaKey.substring(1);
        final meta = arb[metaKey];
        if (meta is! Map) continue;
        final declared = (meta['placeholders'] as Map<Object?, Object?>?)
            ?.keys
            .whereType<String>()
            .toSet();
        if (declared == null) continue;
        final message = arb[key];
        if (message is! String) continue;
        expect(
          _placeholdersOf(message),
          declared,
          reason: '$locale `$key` 消息体 token 与 @placeholders 声明不一致',
        );
      }
    }
  });

  test('生成的 AppLocalizations 覆盖全部 arb 消息键', () {
    // 拦截「改了 arb 忘了重新生成本地化代码」的漂移（flutter test 本身
    // 会触发生成，此处守护绕过 flutter 工具链的手工改动）。
    final generated =
        File('lib/l10n/app_localizations.dart').readAsStringSync();
    final missing = zhKeys
        .where((key) => !RegExp('\\b$key\\b').hasMatch(generated))
        .toList()
      ..sort();
    expect(missing, isEmpty, reason: '生成代码缺少这些键: $missing');
  });
}