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

void main() {
  runApp(
    MyApp(),
  );
}

class MyRouter {
  static final GlobalKey<NavigatorState> _rootNavigator =
      GlobalKey<NavigatorState>(debugLabel: 'root');

  static String agentRouteName = '/agent';
  static String homeRouteName = '/home';
  static String profileRouteName = '/profile';

  static GoRouter router = GoRouter(
      navigatorKey: _rootNavigator,
      debugLogDiagnostics: kDebugMode,
      initialLocation: '/agent',
      routes: [
        GoRoute(
          name: agentRouteName,
          path: '/agent',
          builder: (context, state) {
            return AgentPage();
          },
        ),
        StatefulShellRoute.indexedStack(
          builder: (context, state, navigationShell) {
            return NavPage(navigationShell: navigationShell);
          },
          branches: [
            StatefulShellBranch(
              routes: [
                GoRoute(
                  name: homeRouteName,
                  path: '/home',
                  pageBuilder: (context, state) {
                    return NoTransitionPage(child: HomePage());
                  },
                ),
              ],
            ),
            StatefulShellBranch(
              routes: [
                GoRoute(
                  name: profileRouteName,
                  path: '/profile',
                  pageBuilder: (context, state) {
                    return NoTransitionPage(child: ProfilePage());
                  },
                ),
              ],
            ),
          ],
        ),
      ]);
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      title: 'Reproducible code',
      debugShowCheckedModeBanner: false,
      routerConfig: MyRouter.router,
    );
  }
}

class AgentPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Agent page')),
      body: Center(
        child: ElevatedButton(
          onPressed: () => context.pushNamed(MyRouter.homeRouteName),
          child: Text('Go to home page'),
        ),
      ),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Home page')),
      body: Text('Home Page'),
    );
  }
}

class ProfilePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Profile page')),
      body: Text('Profile Page'),
    );
  }
}

class NavPage extends StatelessWidget {
  final StatefulNavigationShell navigationShell;
  const NavPage({
    required this.navigationShell,
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: navigationShell,
      bottomNavigationBar: NavigationBar(
        selectedIndex: navigationShell.currentIndex,
        destinations: const [
          NavigationDestination(label: 'Home Page', icon: Icon(Icons.home)),
          NavigationDestination(
              label: 'Profile Page', icon: Icon(Icons.person)),
        ],
        onDestinationSelected: _goBranch,
      ),
    );
  }

  void _goBranch(int index) {
    navigationShell.goBranch(index);
  }
}