workouttest_app/lib/main.dart

import 'package:aitrainer_app/model/auth.dart';
import 'package:aitrainer_app/service/api.dart';
import 'package:aitrainer_app/service/customer_service.dart';
import 'package:aitrainer_app/view/customer_modify_page.dart';
import 'package:aitrainer_app/view/customer_new_page.dart';
import 'package:aitrainer_app/view/login.dart';
import 'package:aitrainer_app/view/exercise_new_page.dart';
import 'package:aitrainer_app/view/exercise_type_modify_page.dart';
import 'package:aitrainer_app/view/exercise_type_new_page.dart';
import 'package:aitrainer_app/view/registration.dart';
import 'package:aitrainer_app/viewmodel/exercise_changing_view_model.dart';
import 'package:flutter/material.dart';
import 'package:aitrainer_app/view/customer_list_page.dart';
import 'package:aitrainer_app/view/exercise_type_list_page.dart';
import 'package:aitrainer_app/widgets/nav_drawer.dart';
import 'package:flutter/widgets.dart';
import 'package:provider/provider.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:shared_preferences/shared_preferences.dart';

void main() {
  runApp(
    MultiProvider(
        // Initialize the model in the builder. That way, Provider
        // can own Models's lifecycle, making sure to call `dispose`
        // when not needed anymore.
        providers: [
          ChangeNotifierProvider(create: (context) => ExerciseChangingViewModel(null)),
        ],
        child: AitrainerApp(),
      ),
  );
}

class AitrainerApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      localizationsDelegates: [
        // ... app-specific localization delegate[s] here
        GlobalMaterialLocalizations.delegate,
        GlobalWidgetsLocalizations.delegate,
        GlobalCupertinoLocalizations.delegate,
      ],
      supportedLocales: [
        const Locale('en'), // English
        const Locale('hu'), // Hungarian
        // ... other locales the app supports
      ],
      routes: {
        'home': (context) => AitrainerHome(),
        'customersPage': (context) => CustomerListPage(),
        'customerNewPage': (context) => CustomerNewPage(),
        'customerModifyPage': (context) => CustomerModifyPage(),
        'exerciseTypeListPage': (context) => ExerciseTypeListPage(),
        'exerciseTypeNewPage': (context) => ExerciseTypeNewPage(),
        'exerciseTypeModifyPage': (context) => ExerciseTypeModifyPage(),
        'exerciseNewPage': (context) => ExerciseNewPage(),
        'login': (context) => LoginPage(),
        'registration': (context) => RegistrationPage(),
      },
      initialRoute: 'home',
      title: 'Aitrainer Demo',
      theme: ThemeData(
        primarySwatch: Colors.green,
      ),
      home: AitrainerHome(),
    );
  }
}

class AitrainerHome extends StatefulWidget {
  static final String routeName = 'home';


  @override
  State<StatefulWidget> createState() {
    return new _HomePageState();
  }
}

class _HomePageState extends State<AitrainerHome> {
  GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();
  Future<SharedPreferences> _prefs = SharedPreferences.getInstance();
  Auth _auth = Auth();
  SharedPreferences _sharedPreferences;
  var _authToken;


  @override
  void initState() {
    super.initState();
    _fetchSessionAndNavigate();
  }

  _fetchSessionAndNavigate() async {
    _sharedPreferences = await _prefs;
    String authToken = Auth.getToken(_sharedPreferences);
    var customerId = _sharedPreferences.getInt(Auth.customerIdKey);

    if ( _auth.firstLoad ) {
      _fetchToken(_sharedPreferences);
    }

  }

  /*
    Auth flow of the user, see auth.dart
   */
  _fetchToken(SharedPreferences prefs) async {
    var responseJson = await APIClient.authenticateUser(
        Auth.username,
        Auth.password
    );

    if(responseJson['error'] != null) {
      showSnackBar(_scaffoldKey, responseJson['error']);
      print("************** Here big error - no authentication");
    } else if (responseJson['token'] != null) {
      prefs.setString(Auth.authTokenKey,  responseJson['token']);
      Auth auth = Auth();
      auth.authToken = responseJson['token'];
      if ( prefs.get(Auth.customerIdKey) == null  ) {
        print("************** Registration");
        // registration
        Navigator.of(context).pushNamed('registration');
        prefs.setBool(Auth.isRegisteredKey, true);
      } else {
        DateTime now = DateTime.now();
        DateTime lastStoreDate = DateTime.parse( prefs.get(Auth.lastStoreDateKey) );
        DateTime minStoreDate = now.add(Duration(days: -10));

        if ( lastStoreDate == null ||
              lastStoreDate.difference(minStoreDate) > Duration(days: 10) ||
              prefs.get(Auth.isLoggedInKey) == null ||
              prefs.get(Auth.isLoggedInKey) == false ) {
          print("*************  Login");
          Navigator.of(context).pushNamed('login');

        } else {
          print("************** Store SharedPreferences");
          // get API customer
          await CustomerApi().getCustomer( prefs.getInt(Auth.customerIdKey));

        }
      }

      setState(() {
        _auth.firstLoad = false;
        _authToken = auth.authToken;
        _sharedPreferences.setString(Auth.authTokenKey, _authToken);
      });

    }
  }


  static showSnackBar(GlobalKey<ScaffoldState> scaffoldKey, String message) {
    scaffoldKey.currentState.showSnackBar(
        new SnackBar(
          content: new Text(message ?? 'You are offline'),
        )
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
    key: _scaffoldKey,
      drawer: NavDrawer(),
      appBar: AppBar(
        title: Text('Home'),
        backgroundColor: Colors.transparent
      ),
      body: Image.asset('asset/WT01_loading_layers.png',
        fit: BoxFit.fill,
        height: double.infinity,
        width: double.infinity,
        alignment: Alignment.center,
      ),


    );
  }
}

/*
class CustomerScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      drawer: NavDrawer(),
      appBar: AppBar(
        title: Text('Customers'),
      ),
      body: Center(
        child: CustomerListPage(),
      ),
    );
  }
}
*/

/* class AitrainerApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        title: "AITRAINER customers",
        home:
        ChangeNotifierProvider(
          create: (context) => CustomerListViewModel(),
          child: CustomerListPage(),
        )
    );
  }
}

*/

/*
// #docregion MyApp
class MyApp extends StatelessWidget {
  // #docregion build
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Startup Name Generator',
      theme: ThemeData(          // Add the 3 lines from here...
        primaryColor: Colors.white,
      ),
      home: RandomWords(),
    );
  }
// #enddocregion build
}
// #enddocregion MyApp

// #docregion RWS-var
class RandomWordsState extends State<RandomWords> {
  final _suggestions = <WordPair>[];
  final _biggerFont = const TextStyle(fontSize: 18.0);
  final Set<WordPair> _saved = Set<WordPair>();

  // #enddocregion RWS-var

  // #docregion _buildSuggestions
  Widget _buildSuggestions() {
    return ListView.builder(
        padding: const EdgeInsets.all(16.0),
        itemBuilder: /*1*/ (context, i) {
          if (i.isOdd) return Divider(); /*2*/

          final index = i ~/ 2; /*3*/
          if (index >= _suggestions.length) {
            _suggestions.addAll(generateWordPairs().take(10)); /*4*/
          }
          return _buildRow(_suggestions[index]);
        });
  }
  // #enddocregion _buildSuggestions

  // #docregion _buildRow
  Widget _buildRow(WordPair pair) {
    final bool alreadySaved = _saved.contains(pair);
    return ListTile(
      title: Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      trailing: Icon(   // Add the lines from here...
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      onTap: () {      // Add 9 lines from here...
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }
  // #enddocregion _buildRow

  // #docregion RWS-build
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Startup Name Generator'),
        actions: <Widget>[      // Add 3 lines from here...
          IconButton(icon: Icon(Icons.list), onPressed: _pushSaved),
        ],
      ),
      body: _buildSuggestions(),
    );
  }

  void _pushSaved() {
    Navigator.of(context).push(
      MaterialPageRoute<void>(   // Add 20 lines from here...
        builder: (BuildContext context) {
          final Iterable<ListTile> tiles = _saved.map(
                (WordPair pair) {
              return ListTile(
                title: Text(
                  pair.asPascalCase,
                  style: _biggerFont,
                ),
              );
            },
          );
          final List<Widget> divided = ListTile
              .divideTiles(
            context: context,
            tiles: tiles,
          ).toList();
          return Scaffold(         // Add 6 lines from here...
            appBar: AppBar(
              title: Text('Saved Suggestions'),
            ),
            body: ListView(children: divided),
          );
        },

      ),

    );
  }
// #enddocregion RWS-build
// #docregion RWS-var
}
// #enddocregion RWS-var

class RandomWords extends StatefulWidget {
  @override
  RandomWordsState createState() => new RandomWordsState();
}

*/