Base arch structure

backend/.gitignore

@@ -0,0 +1 @@
+.venv/

mobile/.gitignore

@@ -8,6 +8,7 @@
 .buildlog/
 .history
 .svn/
+.vscode/    
 
 # IntelliJ related
 *.iml

mobile/lib/main.dart

@@ -1,117 +1,7 @@
 import 'package:flutter/material.dart';
 
-void main() {
-  runApp(MyApp());
-}
-
-class MyApp extends StatelessWidget {
-  // This widget is the root of your application.
-  @override
-  Widget build(BuildContext context) {
-    return MaterialApp(
-      title: 'Flutter Demo',
-      theme: ThemeData(
-        // This is the theme of your application.
-        //
-        // Try running your application with "flutter run". You'll see the
-        // application has a blue toolbar. Then, without quitting the app, try
-        // changing the primarySwatch below to Colors.green and then invoke
-        // "hot reload" (press "r" in the console where you ran "flutter run",
-        // or simply save your changes to "hot reload" in a Flutter IDE).
-        // Notice that the counter didn't reset back to zero; the application
-        // is not restarted.
-        primarySwatch: Colors.blue,
-        // This makes the visual density adapt to the platform that you run
-        // the app on. For desktop platforms, the controls will be smaller and
-        // closer together (more dense) than on mobile platforms.
-        visualDensity: VisualDensity.adaptivePlatformDensity,
-      ),
-      home: MyHomePage(title: 'Flutter Demo Home Page'),
-    );
-  }
-}
-
-class MyHomePage extends StatefulWidget {
-  MyHomePage({Key key, this.title}) : super(key: key);
-
-  // This widget is the home page of your application. It is stateful, meaning
-  // that it has a State object (defined below) that contains fields that affect
-  // how it looks.
-
-  // This class is the configuration for the state. It holds the values (in this
-  // case the title) provided by the parent (in this case the App widget) and
-  // used by the build method of the State. Fields in a Widget subclass are
-  // always marked "final".
+import 'src/app.dart';
 
-  final String title;
-
-  @override
-  _MyHomePageState createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    setState(() {
-      // This call to setState tells the Flutter framework that something has
-      // changed in this State, which causes it to rerun the build method below
-      // so that the display can reflect the updated values. If we changed
-      // _counter without calling setState(), then the build method would not be
-      // called again, and so nothing would appear to happen.
-      _counter++;
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    // This method is rerun every time setState is called, for instance as done
-    // by the _incrementCounter method above.
-    //
-    // The Flutter framework has been optimized to make rerunning build methods
-    // fast, so that you can just rebuild anything that needs updating rather
-    // than having to individually change instances of widgets.
-    return Scaffold(
-      appBar: AppBar(
-        // Here we take the value from the MyHomePage object that was created by
-        // the App.build method, and use it to set our appbar title.
-        title: Text(widget.title),
-      ),
-      body: Center(
-        // Center is a layout widget. It takes a single child and positions it
-        // in the middle of the parent.
-        child: Column(
-          // Column is also a layout widget. It takes a list of children and
-          // arranges them vertically. By default, it sizes itself to fit its
-          // children horizontally, and tries to be as tall as its parent.
-          //
-          // Invoke "debug painting" (press "p" in the console, choose the
-          // "Toggle Debug Paint" action from the Flutter Inspector in Android
-          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
-          // to see the wireframe for each widget.
-          //
-          // Column has various properties to control how it sizes itself and
-          // how it positions its children. Here we use mainAxisAlignment to
-          // center the children vertically; the main axis here is the vertical
-          // axis because Columns are vertical (the cross axis would be
-          // horizontal).
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            Text(
-              'You have pushed the button this many times:',
-            ),
-            Text(
-              '$_counter',
-              style: Theme.of(context).textTheme.headline4,
-            ),
-          ],
-        ),
-      ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: Icon(Icons.add),
-      ), // This trailing comma makes auto-formatting nicer for build methods.
-    );
-  }
+void main() {
+  runApp(App());
 }

mobile/lib/src/app.dart

@@ -0,0 +1,29 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+import 'presentation/wallets/wallets_route.dart';
+import 'locator.dart';
+import 'theme.dart';
+
+class App extends StatelessWidget {
+  App() {
+    registerServices();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    /// Cubits are provided globally down all of the context tree
+    return MultiBlocProvider(
+      providers: createBlocProviders(),
+      child: MaterialApp(
+        title: 'PolyDodo',
+        theme: theme,
+        home: WalletsRoute(),
+        initialRoute: WalletsRoute.name,
+        routes: {
+          WalletsRoute.name: (context) => WalletsRoute(),
+        },
+      ),
+    );
+  }
+}

mobile/lib/src/application/wallets/wallets_cubit.dart

@@ -0,0 +1,63 @@
+import 'dart:math';
+
+import 'package:bloc/bloc.dart';
+
+import 'package:polydodo/src/application/wallets/wallets_state.dart';
+import 'package:polydodo/src/domain/unique_id.dart';
+import 'package:polydodo/src/domain/wallet/i_wallet_repository.dart';
+import 'package:polydodo/src/domain/wallet/money.dart';
+import 'package:polydodo/src/domain/wallet/owner.dart';
+import 'package:polydodo/src/domain/wallet/wallet.dart';
+
+class WalletsCubit extends Cubit<WalletsState> {
+  final IWalletRepository _walletRepository;
+
+  WalletsCubit(this._walletRepository) : super(WalletsInitial()) {
+    createNewWallets();
+    emit(WalletsLoadInProgress());
+    _walletRepository
+        .watch()
+        .listen((wallets) => emit(WalletsLoadSuccess(wallets)))
+        .onError((e) => emit(WalletsLoadFailure(e)));
+  }
+
+  // Does not yield another state
+  void transfer(Wallet sender, Wallet receiver, Money amount) async {
+    try {
+      sender.transfer(amount, receiver);
+    } catch (e) {
+      emit(WalletsTransferFailure(e));
+    }
+    await Future.wait([
+      _walletRepository.store(sender),
+      _walletRepository.store(receiver),
+    ]).catchError((e) => emit(WalletsTransferFailure(e)));
+  }
+
+  Future<List<void>> createNewWallets() => Future.wait([
+        _walletRepository.store(
+          Wallet(
+            UniqueId(),
+            Owner(
+              id: UniqueId.from('1'),
+              firstName: 'Bob',
+              lastName: 'Skiridovsky',
+              age: 25,
+            ),
+            Money(Random().nextDouble() * 10, Currency.cad),
+          ),
+        ),
+        _walletRepository.store(
+          Wallet(
+            UniqueId(),
+            Owner(
+              id: UniqueId.from('2'),
+              firstName: 'Alice',
+              lastName: 'Pogo',
+              age: 35,
+            ),
+            Money(Random().nextDouble() * 1000, Currency.cad),
+          ),
+        )
+      ]);
+}

mobile/lib/src/application/wallets/wallets_state.dart

@@ -0,0 +1,25 @@
+import 'package:polydodo/src/domain/wallet/wallet.dart';
+
+abstract class WalletsState {}
+
+class WalletsInitial extends WalletsState {}
+
+class WalletsLoadInProgress extends WalletsState {}
+
+class WalletsLoadSuccess extends WalletsState {
+  final List<Wallet> wallets;
+
+  WalletsLoadSuccess(this.wallets);
+}
+
+class WalletsLoadFailure extends WalletsState {
+  final Exception cause;
+
+  WalletsLoadFailure(this.cause);
+}
+
+class WalletsTransferFailure extends WalletsState {
+  final Exception cause;
+
+  WalletsTransferFailure(this.cause);
+}

mobile/lib/src/domain/unique_id.dart

@@ -0,0 +1,20 @@
+import 'package:equatable/equatable.dart';
+import 'package:uuid/uuid.dart';
+
+class UniqueId extends Equatable {
+  final String _id;
+
+  UniqueId() : _id = Uuid().v4();
+
+  UniqueId.from(String unique)
+      : assert(unique != null),
+        _id = unique;
+
+  String get() => _id;
+
+  @override
+  List<Object> get props => [_id];
+
+  @override
+  bool get stringify => true;
+}

mobile/lib/src/domain/wallet/constants.dart

@@ -0,0 +1 @@
+const cadToUsdRate = 1.32;

mobile/lib/src/domain/wallet/i_wallet_repository.dart

@@ -0,0 +1,6 @@
+import 'wallet.dart';
+
+abstract class IWalletRepository {
+  Future<void> store(Wallet wallet);
+  Stream<List<Wallet>> watch();
+}

mobile/lib/src/domain/wallet/money.dart

@@ -0,0 +1,57 @@
+import 'package:equatable/equatable.dart';
+
+import 'constants.dart';
+
+enum Currency { usd, cad }
+
+Map<Currency, String> currencyToString = {
+  Currency.usd: 'USD',
+  Currency.cad: 'CAD',
+};
+
+// Value object usually extends equatable
+class Money extends Equatable {
+  static const _min = 0;
+
+  final double value;
+  final Currency currency;
+
+  Money(this.value, this.currency)
+      : assert(value != null),
+        assert(currency != null) {
+    // Validation that money cannot be in an impossible state
+    if (value <= _min) {
+      Exception('Money amount cannot be inferior to $_min');
+    }
+  }
+
+  double get usd {
+    if (currency == Currency.cad) {
+      return value / cadToUsdRate;
+    }
+    return value;
+  }
+
+  double get cad {
+    if (currency == Currency.usd) {
+      return value * cadToUsdRate;
+    }
+    return value;
+  }
+
+  Money convertTo(Currency currency) {
+    if (currency == Currency.usd) {
+      return Money(usd, currency);
+    }
+    return Money(cad, currency);
+  }
+
+  /// Gives back result into left operand's currency
+  Money operator +(Money other) =>
+      Money(this.usd + other.usd, Currency.usd).convertTo(this.currency);
+  Money operator -(Money other) =>
+      Money(this.usd - other.usd, Currency.usd).convertTo(this.currency);
+
+  @override
+  List<Object> get props => [usd];
+}

mobile/lib/src/domain/wallet/owner.dart

@@ -0,0 +1,32 @@
+import 'package:meta/meta.dart';
+
+import 'package:polydodo/src/domain/unique_id.dart';
+
+class Owner {
+  static const _legalAge = 16;
+
+  final UniqueId id;
+  final String firstName;
+  final String lastName;
+  final int age;
+
+  Owner({
+    @required this.id,
+    @required this.firstName,
+    @required this.lastName,
+    @required this.age,
+  })  : assert(id != null),
+        assert(firstName != null),
+        assert(lastName != null) {
+    if (firstName.length <= 0 || lastName.length <= 0) {
+      throw Exception('First and last name cannot be empty');
+    }
+    if (!_hasLegalAge()) {
+      throw Exception('This owner does not have the legal age');
+    }
+  }
+
+  bool _hasLegalAge() => age >= _legalAge;
+
+  // In a good model entity, we should have behavorial method...
+}