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

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

final routes = [
  GoRoute(
    path: '/',
    builder: (context, state) => const Page(
      number: "1",
    ),
  ),
  GoRoute(
    path: '/:page',
    builder: (context, state) => Page(number: state.params["page"] ?? "1"),
  ),
];

class MyApp extends StatelessWidget {
  final _router = GoRouter(
      routes: routes,
      navigatorBuilder: (
        BuildContext context,
        GoRouterState state,
        Widget child,
      ) {
        print(state.location); // -> /2
        print(state.params); // -> null :( expected: { 'page': '2' }
        return child;
      });

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      routeInformationProvider: _router.routeInformationProvider,
      routeInformationParser: _router.routeInformationParser,
      routerDelegate: _router.routerDelegate,
    );
  }
}

class Page extends StatelessWidget {
  const Page({Key? key, required this.number}) : super(key: key);
  final String number;

  @override
  Widget build(BuildContext context) {
    return Center(
        child: Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Text("Page $number"),
        ElevatedButton(
            onPressed: () {
              final next = (int.tryParse(number) ?? 1) + 1;
              context.go("/$next");
            },
            child: Text("Next"))
      ],
    ));
  }
}