import 'dart:async';

import 'package:flutter/foundation.dart' show ValueNotifier;
import 'package:sunny_mochi/core/observability/talker_setup.dart';
import 'package:sunny_mochi/core/storage/secure_storage.dart'
    show secureStorageProvider;
import 'package:riverpod_annotation/riverpod_annotation.dart';

part 'auth_status_provider.g.dart';

/// 同步可读的登录态门面 — 给 GoRouter `redirect` 用。
///
/// 三态语义：
/// - `null`  → 启动期未知（异步 storage 还没读完，redirect 应不动）
/// - `true`  → 已登录
/// - `false` → 未登录（redirect 把非 /login 的访问跳 /login）
class AuthStatusController {
  AuthStatusController() : _notifier = ValueNotifier<bool?>(null);

  final ValueNotifier<bool?> _notifier;

  ValueNotifier<bool?> get listenable => _notifier;

  bool? get value => _notifier.value;

  void markLoggedIn() {
    appTalker.info('[AuthStatus] markLoggedIn');
    _notifier.value = true;
  }

  void markLoggedOut() {
    appTalker.info('[AuthStatus] markLoggedOut');
    _notifier.value = false;
  }

  void dispose() => _notifier.dispose();
}

@Riverpod(keepAlive: true)
AuthStatusController authStatus(Ref ref) {
  final controller = AuthStatusController();
  unawaited(_bootstrap(ref, controller));
  ref.onDispose(controller.dispose);
  return controller;
}

Future<void> _bootstrap(Ref ref, AuthStatusController controller) async {
  try {
    final token = await ref.read(secureStorageProvider).getToken();
    final loggedIn = token != null && token.isNotEmpty;
    if (loggedIn) {
      controller.markLoggedIn();
    } else {
      controller.markLoggedOut();
    }
  } on Object catch (e, st) {
    appTalker.warning('[AuthStatus] bootstrap 异常 → 视为未登录', e, st);
    controller.markLoggedOut();
  }
}