import 'package:dio/dio.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';

import '../../../common/network/api_exception.dart';
import '../../../common/network/dio_provider.dart';
import '../../../common/storage/preferences_storage.dart';
import '../../../common/storage/storage_keys.dart';
import '../data/auth_api.dart';
import '../data/auth_models.dart';
import 'auth_session_coordinator.dart';

const _legacyMockLoggedInKey = 'jinzhi_mock_logged_in';

final authProvider =
    StateNotifierProvider<AuthController, AsyncValue<AuthState>>((ref) {
      return AuthController(
        ref.read(dioProvider),
        preferences: ref.read(preferencesStorageProvider),
        coordinator: ref.read(authSessionCoordinatorProvider),
      );
    });

class AuthController extends StateNotifier<AsyncValue<AuthState>> {
  AuthController(
    this._dio, {
    required PreferencesStorage preferences,
    required AuthSessionCoordinator coordinator,
    bool autoBootstrap = true,
  }) : _preferences = preferences,
       _coordinator = coordinator,
       super(const AsyncLoading()) {
    _coordinator.addListener(_onSessionEnded);
    if (autoBootstrap) _bootstrap();
  }

  final Dio _dio;
  final PreferencesStorage _preferences;
  final AuthSessionCoordinator _coordinator;

  AuthApi get _api => AuthApi(_dio);

  Future<void> retryBootstrap() => _bootstrap();

  Future<void> _bootstrap() async {
    state = const AsyncLoading();
    final token = await _coordinator.restore();
    if (token == null || token.isEmpty) {
      state = const AsyncData(GuestAuthState());
      return;
    }
    final cached = _readCachedProfile();
    if (cached != null) {
      state = AsyncData(
        LoggedInAuthState(user: cached, token: token, isVerified: false),
      );
      await _persistProfile(cached);
    }
    await _verifyProfile(token, _coordinator.generation);
  }

  Future<void> _verifyProfile(String token, int generation) async {
    try {
      final user = await _api.getProfile();
      if (generation != _coordinator.generation) return;
      await _persistProfile(user);
      state = AsyncData(
        LoggedInAuthState(user: user, token: token, isVerified: true),
      );
    } catch (error, stackTrace) {
      if (generation != _coordinator.generation) return;
      final exception = ApiException.from(error, stackTrace: stackTrace);
      if (await _coordinator.expireIfNeeded(exception)) {
        return;
      }
      // Any non-session error (transport, 403, 429, 5xx, decode) preserves a
      // stale cached session. With no profile there is nothing safe to render,
      // but the credential still remains available for retry.
      if (state.valueOrNull is LoggedInAuthState) return;
      state = AsyncError(exception, stackTrace);
    }
  }

  Future<void> sendCode(String phone) => _api.sendSmsCode(phone);

  Future<void> verifyCode(String phone, String code) async {
    final reply = await _api.verifySmsCode(phone, code);
    await _persistLogin(reply);
  }

  Future<void> verifyOneKeyLogin(String loginToken) async {
    final reply = await _api.verifyOneKeyLogin(loginToken);
    await _persistLogin(reply);
  }

  Future<void> _persistLogin(AuthLoginResult reply) async {
    await _coordinator.startSession(reply.accessToken);
    await _persistProfile(reply.user);
    state = AsyncData(
      LoggedInAuthState(user: reply.user, token: reply.accessToken),
    );
  }

  Future<void> logout() async {
    await _coordinator.logout();
  }

  Future<void> deleteAccount(String code) async {
    final normalized = code.trim();
    if (normalized.isEmpty) {
      throw ArgumentError.value(code, 'code', 'must not be empty');
    }
    await _api.deleteAccount(normalized);
    await _coordinator.accountDeleted();
  }

  Future<void> _persistProfile(JinzhiUser user) async {
    await _preferences.setString(storageUserId, user.id);
    await _preferences.setString(storageUserPhone, user.phone);
    await _preferences.setString(storageUserCreatedAt, user.createdAt);
    await _preferences.remove(_legacyMockLoggedInKey);
  }

  JinzhiUser? _readCachedProfile() {
    final id = _preferences.getString(storageUserId)?.trim() ?? '';
    final phone =
        (_preferences.getString(storageUserPhone) ??
                _preferences.getString(_legacyMockLoggedInKey) ??
                '')
            .trim();
    final createdAt =
        _preferences.getString(storageUserCreatedAt)?.trim() ?? '';
    if (id.isEmpty && phone.isEmpty) return null;
    return JinzhiUser(id: id, phone: phone, createdAt: createdAt);
  }

  void _onSessionEnded(SessionEndReason reason) {
    state = AsyncData(
      reason == SessionEndReason.expired
          ? const SessionExpiredAuthState()
          : const GuestAuthState(),
    );
  }

  bool get isLoggedIn => state.valueOrNull is LoggedInAuthState;

  @override
  void dispose() {
    _coordinator.removeListener(_onSessionEnded);
    super.dispose();
  }
}