import 'dart:convert';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'package:uuid/uuid.dart';
import '../models/cognitive_type.dart';
import '../models/assessment_data.dart'; 

// -----------------------------------------------------------------------------
// [Fix] UserSession 정의 및 isGuest 추가
// -----------------------------------------------------------------------------
class UserSession {
  final String userId;
  final String? userName;
  final String? email;
  final String? photoUrl;
  final String? provider; // 'google', 'apple', 'guest'

  UserSession({
    required this.userId,
    this.userName,
    this.email,
    this.photoUrl,
    this.provider,
  });

  // [Fix] 에러 해결: isGuest 게터 추가
  bool get isGuest => provider == 'guest' || provider == null;

  Map<String, dynamic> toJson() => {
    'userId': userId,
    'userName': userName,
    'email': email,
    'photoUrl': photoUrl,
    'provider': provider,
  };

  factory UserSession.fromJson(Map<String, dynamic> json) => UserSession(
    userId: json['userId'],
    userName: json['userName'],
    email: json['email'],
    photoUrl: json['photoUrl'],
    provider: json['provider'],
  );
}

// -----------------------------------------------------------------------------
// IdentityService 구현
// -----------------------------------------------------------------------------
class IdentityService {
  static const String _userIdKey = 'app_user_id';
  static const String _userSessionKey = 'app_user_session';
  static const String _userNameKey = 'app_user_name'; // 추가
  static const String _assessmentHistoryKey = 'cognitive_assessment_history';

  final _storage = const FlutterSecureStorage();
  final _uuid = const Uuid();

  IOSOptions _getIOSOptions() => const IOSOptions(accessibility: KeychainAccessibility.first_unlock);
  AndroidOptions _getAndroidOptions() => const AndroidOptions(encryptedSharedPreferences: true);

  // ===========================================================================
  // 1. 유저 세션 관리 (호환성 복구)
  // ===========================================================================

  Future<String> getOrCreateUser() async {
    String? userId = await _storage.read(key: _userIdKey, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
    if (userId == null) {
      userId = _uuid.v4();
      await _storage.write(key: _userIdKey, value: userId, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
    }
    return userId;
  }

  /// [Fix] SessionNotifier 에러 해결
  Future<UserSession?> getUserSession() async {
    String? jsonStr = await _storage.read(key: _userSessionKey, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
    if (jsonStr == null) return null;
    try {
      return UserSession.fromJson(jsonDecode(jsonStr));
    } catch (e) {
      return null;
    }
  }

  /// [Fix] SessionNotifier 에러 해결
  Future<UserSession> saveSocialLogin({
    required String userId,
    String? email,
    String? name,
    String? photoUrl,
    required String provider,
  }) async {
    final session = UserSession(
      userId: userId,
      email: email,
      userName: name,
      photoUrl: photoUrl,
      provider: provider,
    );
    await _storage.write(
      key: _userSessionKey,
      value: jsonEncode(session.toJson()),
      iOptions: _getIOSOptions(),
      aOptions: _getAndroidOptions()
    );
    await _storage.write(key: _userIdKey, value: userId, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
    
    return session;
  }

  /// [Fix] SessionNotifier 에러 해결
  Future<void> logout() async {
    await _storage.delete(key: _userSessionKey, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
  }

  /// [Fix] GameCompletionScreen 에러 해결
  Future<void> saveUserName(String name) async {
    await _storage.write(key: _userNameKey, value: name, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
    
    // 세션이 있다면 세션 이름도 업데이트
    final currentSession = await getUserSession();
    if (currentSession != null) {
      final newSession = UserSession(
        userId: currentSession.userId,
        userName: name,
        email: currentSession.email,
        photoUrl: currentSession.photoUrl,
        provider: currentSession.provider,
      );
      await _storage.write(
        key: _userSessionKey, 
        value: jsonEncode(newSession.toJson()),
        iOptions: _getIOSOptions(), 
        aOptions: _getAndroidOptions()
      );
    }
  }
  
  Future<String?> getUserName() async {
    return await _storage.read(key: _userNameKey, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
  }

  // ===========================================================================
  // 2. 진단 기록 (Assessment)
  // ===========================================================================

  Future<void> saveAssessmentResult(Map<CognitiveArea, int> scores) async {
    final record = AssessmentRecord(
      id: _uuid.v4(),
      date: DateTime.now(),
      scores: scores,
    );
    final history = await getAssessmentHistory();
    history.add(record);
    
    final jsonString = jsonEncode(history.map((e) => e.toJson()).toList());
    await _storage.write(key: _assessmentHistoryKey, value: jsonString, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
  }

  Future<List<AssessmentRecord>> getAssessmentHistory() async {
    final jsonString = await _storage.read(key: _assessmentHistoryKey, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
    if (jsonString == null) return [];
    try {
      final List<dynamic> jsonList = jsonDecode(jsonString);
      return jsonList.map((e) => AssessmentRecord.fromJson(e)).toList();
    } catch (e) {
      return [];
    }
  }
  
  /// [Fix] SettingsScreen 에러 해결
  Future<void> clearAssessmentHistory() async {
    await _storage.delete(key: _assessmentHistoryKey, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
  }

  Future<Map<CognitiveArea, int>?> getCognitiveScores() async {
    final history = await getAssessmentHistory();
    if (history.isEmpty) return null;
    history.sort((a, b) => b.date.compareTo(a.date));
    return history.first.scores;
  }

  // ===========================================================================
  // 3. 게임 데이터 관리 (통합 + 레거시 호환)
  // ===========================================================================

  String _getMaxLevelKey(String gameType) => 'max_level_${gameType.toLowerCase()}';
  String _getRankMapKey(String gameType) => 'rank_map_${gameType.toLowerCase()}';

  Future<int> getMaxUnlockedLevel({String gameType = 'SUDOKU'}) async {
    final key = _getMaxLevelKey(gameType);
    String? levelString = await _storage.read(key: key, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
    return int.parse(levelString ?? '1');
  }

  /// [Fix] 기존 게임들이 호출하는 메서드 복구
  Future<void> saveMaxUnlockedLevel(int level, {String gameType = 'SUDOKU'}) async {
    await _storage.write(
      key: _getMaxLevelKey(gameType), 
      value: level.toString(), 
      iOptions: _getIOSOptions(), 
      aOptions: _getAndroidOptions()
    );
  }

  Future<Map<int, int>> getLastSavedRankMap({required String gameType}) async {
    final key = _getRankMapKey(gameType);
    String? jsonString = await _storage.read(key: key, iOptions: _getIOSOptions(), aOptions: _getAndroidOptions());
    if (jsonString == null) return {};
    try {
      final Map<String, dynamic> decodedMap = jsonDecode(jsonString);
      return decodedMap.map((k, v) => MapEntry(int.parse(k), v as int));
    } catch (e) {
      return {};
    }
  }
  
  /// [Fix] LobbyHelper 에러 해결
  Future<void> saveLastRankMap(Map<int, int> rankMap, {required String gameType}) async {
    final String jsonString = jsonEncode(rankMap.map((k, v) => MapEntry(k.toString(), v)));
    await _storage.write(
      key: _getRankMapKey(gameType), 
      value: jsonString, 
      iOptions: _getIOSOptions(), 
      aOptions: _getAndroidOptions()
    );
  }

  /// [신규] 게임 결과 통합 처리
  Future<void> submitGameResult({
    required String gameType,
    required int level,
    required int stars,
  }) async {
    final rankMap = await getLastSavedRankMap(gameType: gameType);
    final int oldStars = rankMap[level] ?? 0;
    if (stars > oldStars) {
      rankMap[level] = stars;
      await saveLastRankMap(rankMap, gameType: gameType);
    }

    final int currentMax = await getMaxUnlockedLevel(gameType: gameType);
    if (level >= currentMax) {
      await saveMaxUnlockedLevel(level + 1, gameType: gameType);
    }
  }
}