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

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

final routerConfig = GoRouter(
  restorationScopeId: 'go_router_scope_id',
  initialLocation: '/',
  routes: [
    ShellRoute(
      restorationScopeId: 'go_router_scope_id_for_shell_route',
      routes: [
        GoRoute(
          path: '/',
          builder: (context, state) => const MyHomePage(),
        ),
      ],
      builder: (context, state, child) {
        return RestorationScope(
          restorationId: 'custom_restoration_scope',
          child: child,
        );
      },
    ),
  ],
);

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      restorationScopeId: 'app_scope',
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
      ),
      routerConfig: routerConfig,
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> with RestorationMixin {
  final RestorableCounterState _counter = RestorableCounterState();

  @override
  String? get restorationId => 'home_page';

  @override
  void restoreState(RestorationBucket? oldBucket, bool initialRestore) {
    registerForRestoration(_counter, 'counter_state');
  }

  void _incrementCounter() {
    _counter.value.counter = CounterDto(
      _counter.value.counter.counter + 1,
      _counter.value.counter.counterName,
    );
  }

  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider.value(
      value: _counter.value,
      child: Scaffold(
        appBar: AppBar(title: const Text('Title')),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Padding(
                padding: const EdgeInsets.all(16),
                child: TextFormField(
                  decoration: const InputDecoration(
                    labelText: 'Counter name',
                  ),
                  onChanged: (value) {
                    _counter.value.counter = CounterDto(
                      _counter.value.counter.counter,
                      value,
                    );
                  },
                ),
              ),
              const Text('You have pushed the button this many times:'),
              Consumer<CounterState>(
                builder: (context, state, _) {
                  return Text(
                    '${state.counter.counter}',
                    style: Theme.of(context).textTheme.headlineMedium,
                  );
                },
              ),
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: _incrementCounter,
          child: const Icon(Icons.add),
        ),
      ),
    );
  }
}

class RestorableCounterState extends RestorableChangeNotifier<CounterState> {
  @override
  CounterState createDefaultValue() {
    print('RestorableCounterState -> Creating default value');
    return CounterState();
  }

  @override
  CounterState fromPrimitives(Object? data) {
    print('RestorableCounterState -> Restoring $data');
    final map = data as Map;
    final json = map.cast<String, dynamic>();
    return CounterState.fromValue(CounterDto.fromJson(json));
  }

  @override
  Object? toPrimitives() {
    print('RestorableCounterState -> Serializing ${value.counter}');
    return value.counter.toJson();
  }
}

class CounterState extends ChangeNotifier {
  CounterState();
  CounterState.fromValue(this._counter);

  CounterDto _counter = CounterDto(0, 'N/A');

  CounterDto get counter => _counter;

  set counter(CounterDto value) {
    _counter = value;
    notifyListeners();
  }
}

class CounterDto {
  final int counter;
  final String counterName;

  CounterDto(this.counter, this.counterName);

  @override
  String toString() => 'counter: $counter; name: $counterName';

  factory CounterDto.fromJson(Map<String, dynamic> json) => CounterDto(
    json['counter'],
    json['counterName'],
  );

  Map<String, dynamic> toJson() => {
    'counter': counter,
    'counterName': counterName,
  };
}