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

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

final router = GoRouter(
  initialLocation: '/',
  routes: [
    GoRoute(
      path: '/',
      builder: (_, __) => ScreenOne(),
      routes: [
        GoRoute(
          path: 'two',
          builder: (_, __) => ScreenTwo(),
          routes: [
            GoRoute(
              path: 'three',
              builder: (_, __) => ScreenThree(),
            ),
          ],
        ),
      ],
    ),
  ],
);

class RootScreen extends StatelessWidget {
  const RootScreen({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      routerConfig: router,
    );
  }
}

class ScreenOne extends StatelessWidget {
  const ScreenOne({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final router = GoRouter.of(context);

    return Scaffold(
      appBar: AppBar(
        title: Text(router.location),
      ),
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            context.go('/two');
          },
          child: Text('Go'),
        ),
      ),
    );
  }
}

class ScreenTwo extends StatelessWidget {
  const ScreenTwo({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(router.location),
      ),
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            context.go('/two/three');
          },
          child: Text('Go'),
        ),
      ),
    );
  }
}

class ScreenThree extends StatelessWidget {
  const ScreenThree({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(router.location),
      ),
      body: Center(
        child: Text('three'),
      ),
    );
  }
}