/// example/lib/main.dart

import 'package:example/src/view.dart';

void main() => runApp(MyApp(key: const Key('MyApp')));

/// example/src/app/view/my_app.dart

import 'package:example/src/view.dart';

import 'package:example/src/controller.dart';

class MyApp extends AppStatefulWidgetMVC {
  const MyApp({Key? key}) : super(key: key);

  /// This is the App's State object
  @override
  AppStateMVC createState() => _MyAppState();
}

class _MyAppState extends AppStateMVC<MyApp> {
  factory _MyAppState() => _this ??= _MyAppState._();
  static _MyAppState? _this;

  @override
  Widget buildApp(BuildContext context) => MaterialApp(
        home: FutureBuilder<bool>(
            future: initAsync(),
            builder: (context, snapshot) {
              //
              if (snapshot.hasData) {
                //
                if (snapshot.data!) {
                  /// Key identifies the widget. New key? New widget!
                  /// Demonstrates how to explicitly 're-create' a State object
                  return MyHomePage(key: UniqueKey());
                } else {
                  //
                  return const Text('Failed to startup');
                }
              } else if (snapshot.hasError) {
                //
                return Text('${snapshot.error}');
              }
              // By default, show a loading spinner.
              return const Center(child: CircularProgressIndicator());
            }),
      );
}

/// example/src/app/controller/app_controller.dart

import 'package:example/src/view.dart';

class AppController extends StateXController with AppControllerMVC {
  factory AppController() => _this ??= AppController._();
  AppController._();
  static AppController? _this;

  /// Initialize any 'time-consuming' operations at the beginning.
  /// Initialize asynchronous items essential to the Mobile Applications.
  /// Typically called within a FutureBuilder() widget.
  @override
  Future<bool> initAsync() async {
    // Simply wait for 10 seconds at startup.
    /// In production, this is where databases are opened, logins attempted, etc.
    return Future.delayed(const Duration(seconds: 10), () {
      return true;
    });
  }

  /// Supply an 'error handler' routine if something goes wrong
  /// in the corresponding initAsync() routine.
  /// Returns true if the error was properly handled.
  @override
  bool onAsyncError(FlutterErrorDetails details) {
    return false;
  }
}

/// example/src/home/view/my_home_page.dart

import 'package:example/src/view.dart';

import 'package:example/src/controller.dart';

/// The Home page
class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, this.title = 'Flutter Demo'}) : super(key: key);

  // Fields in a StatefulWidget should always be "final".
  final String title;

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

/// This 'MVC version' is a subclass of the State class.
/// This version is linked to the App's lifecycle using [WidgetsBindingObserver]
class _MyHomePageState extends StateX<MyHomePage> {
  /// Let the 'business logic' run in a Controller
  _MyHomePageState() : super(Controller()) {
    /// Acquire a reference to the passed Controller.
    con = controller as Controller;
  }
  late Controller con;

  @override
  void initState() {
    /// Look inside the parent function and see it calls
    /// all it's Controllers if any.
    super.initState();

    /// Retrieve the 'app level' State object
    appState = rootState!;

    /// You're able to retrieve the Controller(s) from other State objects.
    var con = appState.controller;

    con = appState.controllerByType<AppController>();

    con = appState.controllerById(con?.keyId);
  }

  late AppStateMVC appState;

  /// This is 'the View'; the interface of the home page.
  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              /// Display the App's data object if it has something to display
              if (con.dataObject != null && con.dataObject is String)
                Padding(
                  padding: const EdgeInsets.all(30),
                  child: Text(
                    con.dataObject as String,
                    key: const Key('greetings'),
                    style: TextStyle(
                      color: Colors.red,
                      fontSize: Theme.of(context).textTheme.headline4!.fontSize,
                    ),
                  ),
                ),
              Text(
                'You have pushed the button this many times:',
                style: Theme.of(context).textTheme.bodyText2,
              ),
              // Text(
              //   '${con.count}',
              //   style: Theme.of(context).textTheme.headline4,
              // ),
              SetState(
                builder: (context, dataObject) => Text(
                  '${con.count}',
                  style: Theme.of(context).textTheme.headline4,
                ),
              ),
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          key: const Key('+'),

          /// Refresh only the Text widget containing the counter.
          onPressed: () => con.incrementCounter(),

          /// The traditional approach calling the State object's setState() function.
          // onPressed: () {
          //   setState(con.incrementCounter);
          // },
          /// You can have the Controller called the interface (the View).
//          onPressed: con.onPressed,
          child: const Icon(Icons.add),
        ),
      );

  /// Supply an error handler for Unit Testing.
  @override
  void onError(FlutterErrorDetails details) {
    /// Error is now handled.
    super.onError(details);
  }
}

/// example/src/home/controller/controller.dart

import 'package:example/src/view.dart';

import 'package:example/src/model.dart';

class Controller extends StateXController {
  factory Controller([StateX? state]) => _this ??= Controller._(state);
  Controller._(StateX? state)
      : _model = Model(),
        super(state);
  static Controller? _this;

  final Model _model;

  /// Note, the count comes from a separate class, _Model.
  int get count => _model.counter;

  // The Controller knows how to 'talk to' the Model and to the View (interface).
  void incrementCounter() {
    //
    _model.incrementCounter();

    /// Only calls only 'SetState' widgets
    /// or widgets that called the inheritWidget(context) function
    inheritBuild();

    /// Retrieve a particular State object.
    final homeState = stateOf<MyHomePage>();

    /// If working with a particular State object and if divisible by 5
    if (homeState != null && _model.counter % 5 == 0) {
      //
      dataObject = _model.sayHello();
      setState(() {});
    }
  }

  /// Call the State object's setState() function to reflect the change.
  void onPressed() => setState(() => _model.incrementCounter());
}

/// example/src/view.dart

export 'package:flutter/material.dart' hide StateSetter;

export 'package:mvc_pattern/mvc_pattern.dart';

export 'package:example/src/app/view/my_app.dart';

export 'package:example/src/home/view/my_home_page.dart';

export 'package:example/src/home/view/page_01.dart';

export 'package:example/src/home/view/page_02.dart';

export 'package:example/src/home/view/page_03.dart';

export 'package:example/src/home/view/common/build_page.dart';

/// example/src/controller.dart

export 'package:example/src/app/controller/app_controller.dart';

export 'package:example/src/home/controller/controller.dart';

export 'package:example/src/home/controller/another_controller.dart';

export 'package:example/src/home/controller/yet_another_controller.dart';

/// example/src/model.dart

export 'package:example/src/home/model/data_source.dart';