nj/app/lib/core/routing/app_router.dart

// 暖记路由表 — go_router 20 页面 + 认证守卫
//
// 路由守卫逻辑：
// - 未认证用户访问受保护路由 → 重定向到 /login
// - 已认证用户访问 /login → 重定向到 /home
// - 需要角色选择 → 重定向到 /role-selection
// - 需要班级码 → 重定向到 /class-code

export '../../widgets/responsive_scaffold.dart';

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';

import '../../widgets/responsive_scaffold.dart';

import '../../features/home/views/home_page.dart';
import '../../features/calendar/views/calendar_page.dart';
import '../../features/mood/views/mood_page.dart';
import '../../features/search/views/search_page.dart';
import '../../features/profile/views/profile_page.dart';
import '../../features/editor/views/editor_page.dart';
import '../../features/auth/views/login_page.dart';
import '../../features/auth/views/role_selection_page.dart';
import '../../features/auth/views/class_code_join_page.dart';
import '../../features/class_/views/class_page.dart';
import '../../features/teacher/views/teacher_page.dart';
import '../../features/parent/views/parent_page.dart';
import '../../features/achievement/views/achievement_page.dart';
import '../../features/stickers/views/sticker_library_page.dart';
import '../../features/templates/views/template_gallery_page.dart';
import '../../features/settings/views/settings_page.dart';
import '../../features/auth/bloc/auth_bloc.dart';

// Shell 分支键
final _rootNavigatorKey = GlobalKey<NavigatorState>();
final _shellNavigatorKey = GlobalKey<NavigatorState>();

/// 不需要认证的白名单路径
const _publicPaths = ['/login', '/role-selection', '/class-code'];

/// 创建路由配置 — 需要注入 AuthBloc
GoRouter createAppRouter(AuthBloc authBloc) {
  return GoRouter(
    navigatorKey: _rootNavigatorKey,
    initialLocation: '/home',
    debugLogDiagnostics: true,

    // ===== 认证路由守卫 =====
    redirect: (context, state) {
      final authState = authBloc.state;
      final currentPath = state.uri.path;

      // 加载中 → 不做重定向
      if (authState is AuthInitial || authState is AuthLoading) {
        return null;
      }

      final isAuthenticated = authState is Authenticated;
      final isPublicPath = _publicPaths.contains(currentPath);

      // 已认证 + 访问公开页面 → 根据状态重定向
      if (isAuthenticated && isPublicPath) {
        if (authState.needsRoleSelection) return '/role-selection';
        if (authState.needsClassCode) return '/class-code';
        return '/home';
      }

      // 已认证 + 访问受保护页面 → 检查是否需要额外步骤
      if (isAuthenticated) {
        if (authState.needsRoleSelection && currentPath != '/role-selection') {
          return '/role-selection';
        }
        if (authState.needsClassCode &&
            currentPath != '/class-code' &&
            currentPath != '/role-selection') {
          return '/class-code';
        }
        return null;
      }

      // 未认证 + 访问公开页面 → 放行
      if (isPublicPath) return null;

      // 未认证 + 访问受保护页面 → 重定向到登录
      return '/login';
    },

    // 监听认证状态变化，自动触发重定向
    refreshListenable: _AuthListenable(authBloc),

    routes: [
      // 认证路由（无 Shell）
      GoRoute(
        path: '/login',
        name: 'login',
        builder: (context, state) => const LoginPage(),
      ),
      GoRoute(
        path: '/role-selection',
        name: 'roleSelection',
        builder: (context, state) => const RoleSelectionPage(),
      ),
      GoRoute(
        path: '/class-code',
        name: 'classCode',
        builder: (context, state) => const ClassCodeJoinPage(),
      ),

      // 主 Shell 路由（底部导航 + 侧边导航）
      ShellRoute(
        navigatorKey: _shellNavigatorKey,
        builder: (context, state, child) {
          final index = _selectedIndexFromLocation(state.uri.path);
          return _AppShell(
            selectedIndex: index,
            child: child,
          );
        },
        routes: [
          GoRoute(
            path: '/home',
            name: 'home',
            builder: (context, state) => const HomePage(),
          ),
          GoRoute(
            path: '/calendar',
            name: 'calendar',
            builder: (context, state) => const CalendarPage(),
          ),
          GoRoute(
            path: '/mood',
            name: 'mood',
            builder: (context, state) => const MoodPage(),
          ),
          GoRoute(
            path: '/search',
            name: 'search',
            builder: (context, state) => const SearchPage(),
          ),
          GoRoute(
            path: '/profile',
            name: 'profile',
            builder: (context, state) => const ProfilePage(),
          ),
        ],
      ),

      // 全屏页面（无底部导航）
      GoRoute(
        path: '/editor',
        name: 'editor',
        parentNavigatorKey: _rootNavigatorKey,
        builder: (context, state) {
          final journalId = state.uri.queryParameters['id'];
          return EditorPage(journalId: journalId);
        },
      ),
      GoRoute(
        path: '/class',
        name: 'class',
        parentNavigatorKey: _rootNavigatorKey,
        builder: (context, state) => const ClassPage(),
      ),
      GoRoute(
        path: '/teacher',
        name: 'teacher',
        parentNavigatorKey: _rootNavigatorKey,
        builder: (context, state) => const TeacherPage(),
      ),
      GoRoute(
        path: '/parent',
        name: 'parent',
        parentNavigatorKey: _rootNavigatorKey,
        builder: (context, state) => const ParentPage(),
      ),
      GoRoute(
        path: '/achievements',
        name: 'achievements',
        parentNavigatorKey: _rootNavigatorKey,
        builder: (context, state) => const AchievementPage(),
      ),
      GoRoute(
        path: '/stickers',
        name: 'stickers',
        parentNavigatorKey: _rootNavigatorKey,
        builder: (context, state) => const StickerLibraryPage(),
      ),
      GoRoute(
        path: '/templates',
        name: 'templates',
        parentNavigatorKey: _rootNavigatorKey,
        builder: (context, state) => const TemplateGalleryPage(),
      ),
      GoRoute(
        path: '/settings',
        name: 'settings',
        parentNavigatorKey: _rootNavigatorKey,
        builder: (context, state) => const SettingsPage(),
      ),
    ],
  );
}

/// 路径 → Tab index 映射
int _selectedIndexFromLocation(String location) {
  if (location.startsWith('/calendar')) return 1;
  if (location.startsWith('/mood')) return 2;
  if (location.startsWith('/search')) return 3;
  if (location.startsWith('/profile')) return 4;
  return 0;
}

/// AuthBloc 变化监听器 — 驱动 GoRouter refreshListenable
class _AuthListenable extends ChangeNotifier {
  _AuthListenable(AuthBloc authBloc) {
    _subscription = authBloc.stream.listen((_) {
      notifyListeners();
    });
  }

  late final StreamSubscription<AuthState> _subscription;

  @override
  void dispose() {
    _subscription.cancel();
    super.dispose();
  }
}

/// App Shell — 包裹 ResponsiveScaffold
class _AppShell extends StatelessWidget {
  const _AppShell({
    required this.selectedIndex,
    required this.child,
  });

  final int selectedIndex;
  final Widget child;

  @override
  Widget build(BuildContext context) {
    return ResponsiveScaffold(
      selectedIndex: selectedIndex,
      onDestinationSelected: (index) {
        switch (index) {
          case 0:
            context.go('/home');
          case 1:
            context.go('/calendar');
          case 2:
            context.go('/mood');
          case 3:
            context.go('/search');
          case 4:
            context.go('/profile');
        }
      },
      body: child,
      floatingActionButton: selectedIndex == 0
          ? FloatingActionButton(
              onPressed: () => context.push('/editor'),
              child: const Icon(Icons.edit_rounded),
            )
          : null,
    );
  }
}