import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../api/api_client.dart';
import '../config/app_config.dart';
import '../config/secure_storage_config.dart';
import '../../features/auth/domain/auth_user.dart';
import 'auth_repository.dart';

/// État d'authentification de l'application.
class AuthState {
  const AuthState({
    this.user,
    this.accessToken,
    this.refreshToken,
    this.isLoading = false,
    this.error,
  });

  final AuthUser? user;
  final String? accessToken;
  final String? refreshToken;
  final bool isLoading;
  final String? error;

  bool get isAuthenticated => accessToken != null && accessToken!.isNotEmpty;

  AuthState copyWith({
    AuthUser? user,
    String? accessToken,
    String? refreshToken,
    bool? isLoading,
    String? error,
    bool clearError = false,
    bool clearUser = false,
  }) {
    return AuthState(
      user: clearUser ? null : (user ?? this.user),
      accessToken: accessToken ?? this.accessToken,
      refreshToken: refreshToken ?? this.refreshToken,
      isLoading: isLoading ?? this.isLoading,
      error: clearError ? null : (error ?? this.error),
    );
  }
}

/// Gestionnaire d'état Riverpod pour l'authentification.
class AuthNotifier extends StateNotifier<AuthState> {
  AuthNotifier(this._repository) : super(const AuthState(isLoading: true)) {
    _restoreSession();
  }

  final AuthRepository _repository;

  /// Tente de renouveler le token d'accès (appelé par le client API sur 401).
  Future<String?> refreshAccessToken() async {
    final refreshed = await _repository.refresh();
    if (refreshed == null) {
      return null;
    }

    state = state.copyWith(
      accessToken: refreshed.accessToken,
      refreshToken: refreshed.refreshToken,
      user: refreshed.user ?? state.user,
    );

    return refreshed.accessToken;
  }

  /// Session expirée après échec du refresh.
  Future<void> sessionExpired() async {
    await logout();
  }

  Future<void> _restoreSession() async {
    state = state.copyWith(isLoading: true, clearError: true);

    try {
      final stored = await _repository.loadStoredTokens();
      if (stored == null) {
        state = state.copyWith(isLoading: false);
        return;
      }

      state = state.copyWith(
        accessToken: stored.accessToken,
        refreshToken: stored.refreshToken,
      );

      final user = await _repository.fetchCurrentUser();
      state = state.copyWith(user: user, isLoading: false);
    } catch (_) {
      final refreshed = await _repository.refresh();
      if (refreshed != null) {
        final user = await _repository.fetchCurrentUser();
        state = state.copyWith(
          accessToken: refreshed.accessToken,
          refreshToken: refreshed.refreshToken,
          user: user,
          isLoading: false,
        );
      } else {
        await _repository.clearStoredTokens();
        state = const AuthState(isLoading: false);
      }
    }
  }

  Future<bool> login(String email, String password) async {
    state = state.copyWith(isLoading: true, clearError: true);

    try {
      final tokens = await _repository.login(email: email, password: password);
      final user = tokens.user ?? await _repository.fetchCurrentUser();

      state = state.copyWith(
        accessToken: tokens.accessToken,
        refreshToken: tokens.refreshToken,
        user: user,
        isLoading: false,
      );
      return true;
    } catch (e) {
      state = state.copyWith(
        isLoading: false,
        error: 'Connexion impossible. Vérifiez vos identifiants.',
      );
      return false;
    }
  }

  Future<bool> register({
    required String firstName,
    required String lastName,
    required String email,
    required String password,
    String? phone,
  }) async {
    state = state.copyWith(isLoading: true, clearError: true);

    try {
      final tokens = await _repository.register(
        firstName: firstName,
        lastName: lastName,
        email: email,
        password: password,
        phone: phone,
      );
      final user = tokens.user ?? await _repository.fetchCurrentUser();

      state = state.copyWith(
        accessToken: tokens.accessToken,
        refreshToken: tokens.refreshToken,
        user: user,
        isLoading: false,
      );
      return true;
    } catch (e) {
      state = state.copyWith(
        isLoading: false,
        error: 'Inscription impossible. L\'email est peut-être déjà utilisé.',
      );
      return false;
    }
  }

  Future<void> logout() async {
    await _repository.logout();
    state = const AuthState();
  }
}

final authRepositoryProvider = Provider<AuthRepository>((ref) {
  final storage = laverieSecureStorage;

  // Token lu depuis le stockage sécurisé (évite la dépendance circulaire avec authProvider).
  return AuthRepository(
    apiClient: ApiClient(
      baseUrl: kApiBaseUrl,
      getAccessToken: () => storage.read(key: AuthStorageKeys.accessToken),
    ),
    secureStorage: storage,
  );
});

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