import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../core/storage/local_storage.dart';
import '../models/auth_response.dart';
import '../utils/jwt_util.dart';

class AuthState {
  final String? token;
  final UserInfo? user;

  const AuthState({this.token, this.user});

  bool get isLoggedIn => token != null && token!.isNotEmpty;

  const AuthState.initial() : this._();

  const AuthState._({this.token, this.user});
}

class AuthNotifier extends Notifier<AuthState> {
  @override
  AuthState build() => const AuthState.initial();

  /// App 启动时从本地存储恢复登录态。
  /// 若 token 已在本地可判定过期，直接清理，避免带着废 token 进入主界面。
  Future<void> load() async {
    final token = LocalStorage.instance.getToken();
    if (token == null || token.isEmpty) return;

    if (isJwtExpired(token)) {
      await LocalStorage.instance.clearAuth();
      return;
    }

    final userInfo = LocalStorage.instance.getUserInfo();
    state = AuthState(token: token, user: userInfo == null ? null : UserInfo.fromJson(userInfo));
  }

  /// 登录/注册成功后调用：持久化并更新状态
  Future<void> loginSuccess(AuthResponse response) async {
    final user = UserInfo(
      username: response.username ?? '',
      nickname: response.nickname ?? response.username ?? '',
    );
    await LocalStorage.instance.setAuth(token: response.token, userInfo: user.toJson());
    state = AuthState(token: response.token, user: user);
  }

  Future<void> logout() async {
    await LocalStorage.instance.clearAuth();
    state = const AuthState.initial();
  }
}

final authProvider = NotifierProvider<AuthNotifier, AuthState>(AuthNotifier.new);