import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:im_app/features/chat/view/chat_db_test_page.dart';

import 'package:im_app/features/app_tab/view/app_tab.dart';
import 'package:im_app/features/chat/view/chat_detail_page.dart';
import 'package:im_app/features/chat/view/chat_page.dart';
import 'package:im_app/features/contact/view/contact_page.dart';
import 'package:im_app/features/login/view/login_page.dart';
import 'package:im_app/features/settings/view/settings_page.dart';
import 'package:im_app/features/settings/view/theme_view.dart';
import 'package:im_app/features/settings/view/edit_profile_page.dart';
import 'package:im_app/features/settings/view/blocklist_page.dart';
import 'package:im_app/features/settings/view/language_page.dart';
import 'package:im_app/features/settings/view/network_diagnostics_page.dart';
import 'package:im_app/features/settings/view/about_page.dart';
import 'package:im_app/app/di/app_providers.dart';
import 'package:im_app/app/router/app_route_name.dart';
import 'package:im_app/app/router/guards/auth_guard.dart';

/// 应用路由 Provider
///
/// 路由结构：
/// ```
/// StatefulShellRoute（底部导航栏持久容器）
///   ├── /chat               ChatPage
///   ├── /contact            ContactPage
///   └── /settings           SettingsPage
///
/// ── 全屏页面（无底部导航栏，parentNavigatorKey = _rootKey）──
/// /chat/detail              ChatDetailPage（extra 传参）
/// /chat/:id                 ChatDetailPage（路径参数）
/// /settings/theme           ThemeView
/// /login                    LoginPage
/// ```
///
/// ## Shell 内 vs Shell 外
///
/// Shell 内路由（Tab 根路由）始终显示底部导航栏。
/// Shell 外路由（详情页 / 子功能页）无底部导航栏，push 进入后有返回按钮。
/// 这与 iOS / Android 主流 IM App 的交互一致（会话详情、设置子页均全屏）。
///
/// ## parentNavigatorKey 的作用
///
/// go_router push 时，路由默认放到"最近的 Navigator 祖先"上。
/// 在 StatefulShellBranch 内 push，最近的 Navigator 是 Branch Navigator，
/// 而不是 Root Navigator，Shell 不会被盖住，TabBar 仍然可见。
///
/// 设置 `parentNavigatorKey: _rootKey` 后，路由强制放到 Root Navigator，
/// 盖住整个 Shell，TabBar 消失，表现为真正的全屏页面。
///
/// ## 登录守卫
///
/// [authGuard] 检查 [AuthNotifier.isLoggedIn]，未登录时重定向到 /login。
/// 登录 / 退出后 [AuthNotifier.notifyListeners] 触发 [refreshListenable]，
/// go_router 自动重新执行 redirect，无需手动跳转。
///
/// ## Tab 状态保持
///
/// [StatefulShellRoute.indexedStack] 为每个 Tab 维护独立的 Navigator 栈，
/// 切换 Tab 时页面状态（滚动位置、输入内容等）不丢失。

// Root Navigator Key：供全屏路由声明 parentNavigatorKey，确保覆盖整个 Shell
final _rootKey = GlobalKey<NavigatorState>();

final routerProvider = Provider<GoRouter>((ref) {
  final authNotifier = ref.read(authNotifierProvider);

  return GoRouter(
    // Root Navigator 的 Key，供全屏路由声明 parentNavigatorKey 使用，
    // 确保 push 时覆盖整个 Shell（包括 TabBar）
    navigatorKey: _rootKey,

    // 冷启动默认落地页；authGuard 会在进入前检查登录状态并按需重定向
    initialLocation: AppRouteName.chat.path,

    // 在控制台打印每次路由变化，方便开发期间调试；上线前设为 false
    debugLogDiagnostics: true,

    // 监听 authNotifier 变化：登录 / 退出时自动触发 redirect 重新执行，
    // 无需在业务代码里手动 context.go，守卫统一负责跳转
    refreshListenable: authNotifier,

    redirect: (context, state) => authGuard(authNotifier, state),
    routes: [
      // ── Shell 内：底部导航栏始终可见 ─────────────────────────────────────
      StatefulShellRoute.indexedStack(
        builder: (context, state, navigationShell) {
          return AppTab(navigationShell: navigationShell);
        },
        branches: [
          StatefulShellBranch(
            routes: [
              GoRoute(
                path: AppRouteName.chat.path,
                builder: (context, state) => const ChatPage(),
              ),
            ],
          ),
          StatefulShellBranch(
            routes: [
              GoRoute(
                path: AppRouteName.contact.path,
                builder: (context, state) => const ContactPage(),
              ),
            ],
          ),
          StatefulShellBranch(
            routes: [
              GoRoute(
                path: AppRouteName.settings.path,
                builder: (context, state) => const SettingsPage(),
              ),
            ],
          ),
        ],
      ),

      // ── Shell 外：全屏页面，无底部导航栏 ─────────────────────────────────
      // parentNavigatorKey: _rootKey 确保路由覆盖 Shell，TabBar 消失
      //
      // extra 传参：接收 ({String conversationId, String title})
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.chatDBTest.path,
        builder: (context, state) {
          return const ChatDbTestPage();
        },
      ),
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.chatDetail.path,
        builder: (context, state) {
          final extra =
              state.extra as ({String conversationId, String title});
          return ChatDetailPage(
            conversationId: extra.conversationId,
            title: extra.title,
          );
        },
      ),
      // 路径参数：id 内嵌在 URL 中（/chat/:id）
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.chatDetailById.path,
        builder: (context, state) {
          final id = state.pathParameters['id']!;
          return ChatDetailPage(
            conversationId: id,
            title: '路径参数详情',
          );
        },
      ),
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.settingsTheme.path,
        builder: (context, state) => const ThemeView(),
      ),
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.settingsEditProfile.path,
        builder: (context, state) => const EditProfilePage(),
      ),
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.settingsBlocklist.path,
        builder: (context, state) => const BlocklistPage(),
      ),
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.settingsLanguage.path,
        builder: (context, state) => const LanguagePage(),
      ),
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.settingsNetworkDiagnostics.path,
        builder: (context, state) => const NetworkDiagnosticsPage(),
      ),
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.settingsAbout.path,
        builder: (context, state) => const AboutPage(),
      ),
      GoRoute(
        parentNavigatorKey: _rootKey,
        path: AppRouteName.login.path,
        builder: (context, state) => const LoginPage(),
      ),
    ],
  );
});