import 'package:flutter/foundation.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:firebase_auth/firebase_auth.dart' as fb;

import '../../shared/models/user.dart';
import '../api/api_client.dart';
import '../config/app_config.dart';
import '../locale/language_provider.dart';
import 'auth_service.dart';
import 'secure_storage.dart';

enum AuthStatus { unknown, authenticated, unauthenticated }

class AuthState {
  final AuthStatus status;
  final User? user;
  final bool isLoading;
  final String? error;

  const AuthState({
    this.status = AuthStatus.unknown,
    this.user,
    this.isLoading = false,
    this.error,
  });

  AuthState copyWith({
    AuthStatus? status,
    User? user,
    bool? isLoading,
    String? error,
  }) {
    return AuthState(
      status: status ?? this.status,
      user: user ?? this.user,
      isLoading: isLoading ?? this.isLoading,
      error: error,
    );
  }
}

class AuthNotifier extends StateNotifier<AuthState> {
  final AuthService? _authService;

  AuthNotifier(AuthService authService) : _authService = authService, super(const AuthState()) {
    _checkAuth();
  }

  @visibleForTesting
  AuthNotifier.test(super.initialState)
      : _authService = null;

  Future<void> _checkAuth() async {
    final isAuth = await _authService!.isAuthenticated();
    state = state.copyWith(
      status: isAuth ? AuthStatus.authenticated : AuthStatus.unauthenticated,
    );
  }

  Future<void> signInWithEmail(String email, String password) async {
    state = state.copyWith(isLoading: true, error: null);
    try {
      final user = await _authService!.signInWithEmail(email, password);
      state = AuthState(
        status: AuthStatus.authenticated,
        user: user,
      );
    } catch (e) {
      state = state.copyWith(
        isLoading: false,
        error: _mapError(e),
      );
    }
  }

  Future<void> signInWithGoogle() async {
    state = state.copyWith(isLoading: true, error: null);
    try {
      final user = await _authService!.signInWithGoogle();
      state = AuthState(
        status: AuthStatus.authenticated,
        user: user,
      );
    } catch (e) {
      state = state.copyWith(
        isLoading: false,
        error: _mapError(e),
      );
    }
  }

  Future<void> register(String email, String password, String name) async {
    state = state.copyWith(isLoading: true, error: null);
    try {
      final user =
          await _authService!.registerWithEmail(email, password, name);
      state = AuthState(
        status: AuthStatus.authenticated,
        user: user,
      );
    } catch (e) {
      state = state.copyWith(
        isLoading: false,
        error: _mapError(e),
      );
    }
  }

  Future<void> signOut() async {
    await _authService!.signOut();
    state = const AuthState(status: AuthStatus.unauthenticated);
  }

  String _mapError(dynamic e) {
    if (e is fb.FirebaseAuthException) {
      switch (e.code) {
        case 'wrong-password':
        case 'user-not-found':
          return 'Неверный email или пароль';
        case 'email-already-in-use':
          return 'Email уже зарегистрирован';
        case 'weak-password':
          return 'Пароль слишком простой';
        case 'invalid-email':
          return 'Некорректный email';
        default:
          return 'Ошибка авторизации: ${e.message}';
      }
    }
    return 'Произошла ошибка. Попробуйте позже.';
  }
}

final appConfigProvider = Provider<AppConfig>((ref) {
  return AppConfig.development;
});

final secureStorageProvider = Provider<SecureStorageService>((ref) {
  return SecureStorageService();
});

final apiClientProvider = Provider<ApiClient>((ref) {
  final config = ref.read(appConfigProvider);
  final storage = ref.read(secureStorageProvider);
  return ApiClient(
    baseUrl: config.apiBaseUrl,
    storage: storage,
    languageGetter: () => ref.read(languageProvider),
  );
});

final authServiceProvider = Provider<AuthService>((ref) {
  return AuthService(
    firebaseAuth: fb.FirebaseAuth.instance,
    apiClient: ref.read(apiClientProvider),
    storage: ref.read(secureStorageProvider),
  );
});

final authProvider = StateNotifierProvider<AuthNotifier, AuthState>((ref) {
  return AuthNotifier(ref.read(authServiceProvider));
});