import 'package:flutter/material.dart';
import 'package:package_info_plus/package_info_plus.dart';
import 'package:patbond_flutter/analytics/analytics_page_name.dart';
import 'package:patbond_flutter/analytics/analytics_route_observer.dart';
import 'package:patbond_flutter/analytics/analytics_service.dart';
import 'package:patbond_flutter/analytics/page_view_tracker.dart';
import 'package:patbond_flutter/analytics/session_tracker.dart';
import 'package:patbond_flutter/core/network/api_client.dart';
import 'package:patbond_flutter/core/network/token_refresher.dart';
import 'package:patbond_flutter/core/theme/app_theme.dart';
import 'package:patbond_flutter/features/auth/auth_repository.dart';
import 'package:patbond_flutter/features/auth/login_page.dart';
import 'package:patbond_flutter/features/auth/session_manager.dart';
import 'package:patbond_flutter/features/auth/splash_page.dart';
import 'package:patbond_flutter/features/main/main_shell_page.dart';
import 'package:patbond_flutter/state/app_state.dart';

class App extends StatefulWidget {
  const App({super.key, this.sessionManager, this.authRepository});

  /// 测试注入口；生产默认走安全存储 + 真实 API。
  final SessionManager? sessionManager;
  final AuthRepository? authRepository;

  @override
  State<App> createState() => _AppState();
}

class _AppState extends State<App> {
  late final AppState appState;
  late final SessionManager sessionManager;
  late final AuthRepository authRepository;
  late final SessionTracker _sessionTracker;
  late final AnalyticsService _analytics;
  late final PageViewTracker _pageViewTracker;
  late final AnalyticsRouteObserver _routeObserver;

  @override
  void initState() {
    super.initState();
    appState = AppState()..load();
    sessionManager =
        widget.sessionManager ??
        SessionManager(store: const SecureTokenStore());

    _sessionTracker = SessionTracker(
      onLeaveForeground: () => _analytics.flushNow(),
    );
    WidgetsBinding.instance.addObserver(_sessionTracker);

    _analytics = AnalyticsService(
      apiBaseUrl: patbondUserApiBaseUrl,
      getAccessToken: () => sessionManager.accessToken,
      getSessionId: () => _sessionTracker.sessionId,
    );
    _initAppVersion();
    // 冷启动恢复持久化埋点队列并冲刷离线积压（后台任务，不阻塞渲染）。
    _analytics.restore();

    _pageViewTracker = PageViewTracker(_analytics.trackEvent);
    _routeObserver = AnalyticsRouteObserver(
      tracker: _pageViewTracker,
      resolveRootPage: _resolveRootPage,
    );

    authRepository = widget.authRepository ?? _buildRepository();

    // 认证状态切换补点（根路由 AnimatedSwitcher 无路由事件）
    sessionManager.addListener(_reportAuthStateChange);
  }

  /// 异步读取 appVersion 并注入 analytics（启动后台任务，不阻塞渲染）。
  Future<void> _initAppVersion() async {
    try {
      final info = await PackageInfo.fromPlatform();
      _analytics.setAppVersion('${info.version}+${info.buildNumber}');
    } catch (error) {
      // 读取失败回退 'unknown'（AnalyticsService 构造默认值已兜底）。
    }
  }

  AuthRepository _buildRepository() {
    final dio = buildPatbondDio(session: sessionManager);
    final refresher = TokenRefresher(dio: dio, session: sessionManager);
    final api = ApiClient(
      dio: dio,
      session: sessionManager,
      refresher: refresher,
    );
    return ApiAuthRepository(
      api: api,
      session: sessionManager,
      refresher: refresher,
      analytics: _analytics,
    );
  }

  AnalyticsPageName? _resolveRootPage() {
    // 回栈到无名根路由时解析当前认证状态页/主壳 Tab
    return switch (sessionManager.status) {
      AuthStatus.unknown => null,
      AuthStatus.unauthenticated => AnalyticsPageName.login,
      AuthStatus.authenticated => _pageViewTracker.currentTab,
    };
  }

  void _reportAuthStateChange() {
    // 认证状态机切页补点（03 §3.2 非路由曝光 1/2）
    final page = switch (sessionManager.status) {
      AuthStatus.unauthenticated => AnalyticsPageName.login,
      AuthStatus.authenticated => _pageViewTracker.currentTab,
      AuthStatus.unknown => null,
    };
    if (page != null) _pageViewTracker.report(page);
  }

  @override
  void dispose() {
    sessionManager.removeListener(_reportAuthStateChange);
    WidgetsBinding.instance.removeObserver(_sessionTracker);
    appState.dispose();
    if (widget.sessionManager == null) sessionManager.dispose();
    super.dispose();
  }

  Widget _homeForStatus() {
    switch (sessionManager.status) {
      case AuthStatus.unknown:
        return SplashPage(
          key: const ValueKey('splash'),
          authRepository: authRepository,
          sessionManager: sessionManager,
        );
      case AuthStatus.unauthenticated:
        return LoginPage(
          key: const ValueKey('login'),
          authRepository: authRepository,
        );
      case AuthStatus.authenticated:
        return MainShellPage(
          key: const ValueKey('shell'),
          appState: appState,
          pageViewTracker: _pageViewTracker,
          onLogout: authRepository.logout,
        );
    }
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Patbond',
      debugShowCheckedModeBanner: false,
      theme: buildAppTheme(),
      navigatorObservers: [_routeObserver],
      home: ListenableBuilder(
        listenable: sessionManager,
        builder: (context, _) {
          // 认证状态切换统一 300ms 淡入淡出（Splash ↔ 登录 ↔ 主壳，
          // BrandMark 同构保证品牌区过渡对位，组装稿 §7）。
          return AnimatedSwitcher(
            duration: const Duration(milliseconds: 300),
            child: _homeForStatus(),
          );
        },
      ),
    );
  }
}