import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../api/api_client.dart';
import '../api/auth_api.dart';
import '../models/user.dart';

final apiClientProvider = Provider<ApiClient>((ref) => ApiClient());

final authApiProvider = Provider<AuthApi>((ref) {
  return AuthApi(ref.read(apiClientProvider));
});

class AuthState {
  final bool isLoggedIn;
  final User? user;
  final String? token;
  final bool isLoading;
  final String? error;

  const AuthState({
    this.isLoggedIn = false,
    this.user,
    this.token,
    this.isLoading = false,
    this.error,
  });

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

class AuthNotifier extends StateNotifier<AuthState> {
  final AuthApi _api;
  final ApiClient _client;

  AuthNotifier(this._api, this._client) : super(const AuthState());

  Future<void> login(String phone, String password) async {
    state = state.copyWith(isLoading: true, error: null);
    try {
      final res = await _api.login(phone, password);
      if (res['success'] == true) {
        final token = res['data']['token'] as String;
        final user = User.fromJson(res['data']['user']);
        await _client.saveToken(token);
        state = AuthState(isLoggedIn: true, user: user, token: token);
      } else {
        state = state.copyWith(isLoading: false, error: res['error'] as String?);
      }
    } catch (e) {
      state = state.copyWith(isLoading: false, error: '网络错误: $e');
    }
  }

  Future<void> register(String phone, String password, String nickname) async {
    state = state.copyWith(isLoading: true, error: null);
    try {
      final res = await _api.register(phone, password, nickname);
      if (res['success'] == true) {
        final token = res['data']['token'] as String;
        final user = User.fromJson(res['data']['user']);
        await _client.saveToken(token);
        state = AuthState(isLoggedIn: true, user: user, token: token);
      } else {
        state = state.copyWith(isLoading: false, error: res['error'] as String?);
      }
    } catch (e) {
      state = state.copyWith(isLoading: false, error: '网络错误: $e');
    }
  }

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

  Future<void> restoreSession() async {
    final token = await _client.getToken();
    if (token == null) return;
    try {
      final res = await _api.getProfile();
      if (res['success'] == true) {
        state = AuthState(isLoggedIn: true, user: User.fromJson(res['data']), token: token);
      } else {
        await _client.clearToken();
      }
    } catch (_) {
      // offline - keep token for retry
    }
  }

  void clearError() {
    state = state.copyWith(error: null);
  }
}

final authProvider = StateNotifierProvider<AuthNotifier, AuthState>((ref) {
  final api = ref.read(authApiProvider);
  final client = ref.read(apiClientProvider);
  return AuthNotifier(api, client);
});