import 'package:flutter/material.dart';
import 'package:package_info_plus/package_info_plus.dart';
import 'package:provider/provider.dart';

import 'auth/auth_screen.dart';
import 'auth/session_store.dart';
import 'camera/camera_screen.dart';
import 'container.dart';
import 'home/home_screen.dart';
import 'legal/terms_screen.dart';
import 'payment/paywall_screen.dart';
import 'update/update_checker.dart';
import 'update/update_screen.dart';

class ObserverApp extends StatelessWidget {
  final AppContainer container;

  const ObserverApp({super.key, required this.container});

  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        Provider.value(value: container),
        Provider.value(value: container.sessionStore),
        ChangeNotifierProvider.value(value: container.authViewModel),
        ChangeNotifierProvider.value(value: container.homeViewModel),
        ChangeNotifierProvider.value(value: container.paywallViewModel),
      ],
      child: MaterialApp(
        title: '视野',
        theme: ThemeData(
          colorScheme: ColorScheme.fromSeed(seedColor: Colors.green),
        ),
        initialRoute: '/gate',
        routes: {
          '/gate': (_) => const StartupGate(),
          '/terms': (_) => const TermsScreen(),
          '/login': (_) => const AuthScreen(),
          '/home': (_) => const HomeScreen(),
          '/paywall': (_) => const PaywallScreen(),
          '/camera': (_) => const CameraScreen(),
        },
      ),
    );
  }
}

/// 启动门卫：无登录 token → 登录页；已登录 → 主界面（到期状态由主界面展示）
class StartupGate extends StatefulWidget {
  const StartupGate({super.key});

  @override
  State<StartupGate> createState() => _StartupGateState();
}

class _StartupGateState extends State<StartupGate> {
  @override
  void initState() {
    super.initState();
    _check();
  }

  Future<void> _check() async {
    // 首次启动强制协议；同意后不再展示（拒绝则退出应用）
    final accepted = await TermsScreen.readAccepted();
    if (!mounted) return;
    if (accepted != '1') {
      Navigator.of(context).pushReplacementNamed('/terms');
      return;
    }
    // 版本更新检查（公开接口，无需登录态；仅 Android）：服务器版本高于
    // 「已装版本与已确认接受版本」中的较大者即强制更新，弹全屏阻塞页。
    // APK 版本号不递增时，点过「立即更新」的 accepted 版本参与比较，
    // 更新完成后再次启动不反复提示。
    final info = await UpdateChecker().fetch();
    final current = await PackageInfo.fromPlatform();
    if (!mounted) return;
    final session = context.read<SessionStore>();
    final acceptedUpdate = await session.readAcceptedUpdateVersion();
    if (!mounted) return;
    if (UpdateChecker.needsUpdate(info.version, current.version, acceptedUpdate)) {
      Navigator.of(context).pushReplacement(MaterialPageRoute(
        builder: (_) => UpdateScreen(
          version: info.version,
          url: UpdateChecker.downloadUrl(),
          notes: info.notes,
          onUpdateAccepted: () =>
              session.saveAcceptedUpdateVersion(info.version),
        ),
      ));
      return;
    }
    final token = await session.readToken();
    if (!mounted) return;
    Navigator.of(context)
        .pushReplacementNamed(token == null ? '/login' : '/home');
  }

  @override
  Widget build(BuildContext context) {
    return const Scaffold(
      body: Center(child: CircularProgressIndicator()),
    );
  }
}