Add Liquid SDK Event & Log stream handlers to example app (#305)

Update example app
* Use defaultConfig on ConnectRequest
* Update feesSat as non-null
* Use payment & walletInfo streams from BreezLiquidSDK

packages/flutter/example/lib/main.dart

@@ -5,21 +5,23 @@ import 'package:flutter_breez_liquid_example/routes/home/home_page.dart';
 import 'package:flutter_breez_liquid_example/services/credentials_manager.dart';
 import 'package:flutter_breez_liquid_example/services/keychain.dart';
 import 'package:flutter_breez_liquid_example/utils/config.dart';
-import 'package:path_provider/path_provider.dart';
+
+import 'services/breez_liquid_sdk.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   await initialize();
+  final BreezLiquidSDK liquidSDK = BreezLiquidSDK();
   final credentialsManager = CredentialsManager(keyChain: KeyChain());
   final mnemonic = await credentialsManager.restoreMnemonic();
-  BindingLiquidSdk? liquidSDK;
   if (mnemonic.isNotEmpty) {
-    liquidSDK = await reconnect(mnemonic: mnemonic);
+    reconnect(liquidSDK: liquidSDK, mnemonic: mnemonic);
   }
   runApp(App(credentialsManager: credentialsManager, liquidSDK: liquidSDK));
 }
 
 Future<BindingLiquidSdk> reconnect({
+  required BreezLiquidSDK liquidSDK,
   required String mnemonic,
   Network network = Network.mainnet,
 }) async {
@@ -28,13 +30,13 @@ Future<BindingLiquidSdk> reconnect({
     config: config,
     mnemonic: mnemonic,
   );
-  return await connect(req: req);
+  return await liquidSDK.connect(req: req);
 }
 
 class App extends StatefulWidget {
   final CredentialsManager credentialsManager;
-  final BindingLiquidSdk? liquidSDK;
-  const App({super.key, required this.credentialsManager, this.liquidSDK});
+  final BreezLiquidSDK liquidSDK;
+  const App({super.key, required this.credentialsManager, required this.liquidSDK});
 
   static const title = 'Breez Liquid SDK Demo';
 
@@ -48,9 +50,15 @@ class _AppState extends State<App> {
     return MaterialApp(
       title: App.title,
       theme: ThemeData.from(colorScheme: ColorScheme.fromSeed(seedColor: Colors.white), useMaterial3: true),
-      home: widget.liquidSDK == null
-          ? ConnectPage(credentialsManager: widget.credentialsManager)
-          : HomePage(credentialsManager: widget.credentialsManager, liquidSDK: widget.liquidSDK!),
+      home: widget.liquidSDK.wallet == null
+          ? ConnectPage(
+              liquidSDK: widget.liquidSDK,
+              credentialsManager: widget.credentialsManager,
+            )
+          : HomePage(
+              credentialsManager: widget.credentialsManager,
+              liquidSDK: widget.liquidSDK,
+            ),
     );
   }
 }

packages/flutter/example/lib/routes/connect/connect_page.dart

@@ -3,13 +3,14 @@ import 'package:flutter/material.dart';
 import 'package:flutter_breez_liquid/flutter_breez_liquid.dart';
 import 'package:flutter_breez_liquid_example/routes/connect/restore_page.dart';
 import 'package:flutter_breez_liquid_example/routes/home/home_page.dart';
+import 'package:flutter_breez_liquid_example/services/breez_liquid_sdk.dart';
 import 'package:flutter_breez_liquid_example/services/credentials_manager.dart';
 import 'package:flutter_breez_liquid_example/utils/config.dart';
-import 'package:path_provider/path_provider.dart';
 
 class ConnectPage extends StatefulWidget {
+  final BreezLiquidSDK liquidSDK;
   final CredentialsManager credentialsManager;
-  const ConnectPage({super.key, required this.credentialsManager});
+  const ConnectPage({super.key, required this.liquidSDK, required this.credentialsManager});
 
   @override
   State<ConnectPage> createState() => _ConnectPageState();
@@ -84,7 +85,7 @@ class _ConnectPageState extends State<ConnectPage> {
             context,
             MaterialPageRoute(
               builder: (BuildContext context) => HomePage(
-                liquidSDK: liquidSDK,
+                liquidSDK: widget.liquidSDK,
                 credentialsManager: widget.credentialsManager,
               ),
             ),
@@ -103,6 +104,6 @@ class _ConnectPageState extends State<ConnectPage> {
       config: config,
       mnemonic: mnemonic,
     );
-    return await connect(req: req);
+    return await widget.liquidSDK.connect(req: req);
   }
 }

packages/flutter/example/lib/routes/home/home_page.dart

@@ -1,17 +1,17 @@
 import 'dart:async';
 
 import 'package:flutter/material.dart';
-import 'package:flutter_breez_liquid/flutter_breez_liquid.dart';
 import 'package:flutter_breez_liquid_example/routes/home/widgets/balance.dart';
 import 'package:flutter_breez_liquid_example/routes/home/widgets/bottom_app_bar.dart';
 import 'package:flutter_breez_liquid_example/routes/home/widgets/drawer.dart';
 import 'package:flutter_breez_liquid_example/routes/home/widgets/payment_list/payment_list.dart';
 import 'package:flutter_breez_liquid_example/routes/home/widgets/qr_scan_action_button.dart';
+import 'package:flutter_breez_liquid_example/services/breez_liquid_sdk.dart';
 import 'package:flutter_breez_liquid_example/services/credentials_manager.dart';
 
 class HomePage extends StatefulWidget {
   final CredentialsManager credentialsManager;
-  final BindingLiquidSdk liquidSDK;
+  final BreezLiquidSDK liquidSDK;
 
   const HomePage({super.key, required this.credentialsManager, required this.liquidSDK});
 
@@ -20,26 +20,6 @@ class HomePage extends StatefulWidget {
 }
 
 class _HomePageState extends State<HomePage> {
-  Stream<GetInfoResponse> walletInfoStream() async* {
-    debugPrint("Initialized walletInfoStream");
-    yield await widget.liquidSDK.getInfo();
-    while (true) {
-      await Future.delayed(const Duration(seconds: 10));
-      yield await widget.liquidSDK.getInfo();
-      debugPrint("Refreshed wallet info");
-    }
-  }
-
-  Stream<List<Payment>> paymentsStream() async* {
-    debugPrint("Initialized paymentsStream");
-    yield await widget.liquidSDK.listPayments();
-    while (true) {
-      await Future.delayed(const Duration(seconds: 10));
-      yield await widget.liquidSDK.listPayments();
-      debugPrint("Refreshed payments");
-    }
-  }
-
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -70,13 +50,13 @@ class _HomePageState extends State<HomePage> {
                 Container(
                   height: constraints.maxHeight * 0.3,
                   color: Colors.white,
-                  child: Balance(walletInfoStream: walletInfoStream().asBroadcastStream()),
+                  child: Balance(walletInfoStream: widget.liquidSDK.walletInfoStream),
                 ),
                 Container(
                   height: constraints.maxHeight * 0.7,
                   color: Colors.white,
                   child: PaymentList(
-                    paymentsStream: paymentsStream().asBroadcastStream(),
+                    paymentsStream: widget.liquidSDK.paymentsStream,
                     onRefresh: () async => await _sync(),
                   ),
                 ),
@@ -84,12 +64,13 @@ class _HomePageState extends State<HomePage> {
             );
           },
         ),
-        drawer: HomePageDrawer(liquidSDK: widget.liquidSDK, credentialsManager: widget.credentialsManager),
-        floatingActionButton: QrActionButton(liquidSDK: widget.liquidSDK),
+        drawer: HomePageDrawer(
+            liquidSDK: widget.liquidSDK.wallet!, credentialsManager: widget.credentialsManager),
+        floatingActionButton: QrActionButton(liquidSDK: widget.liquidSDK.wallet!),
         floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
         bottomNavigationBar: HomePageBottomAppBar(
-          liquidSDK: widget.liquidSDK,
-          paymentsStream: paymentsStream().asBroadcastStream(),
+          liquidSDK: widget.liquidSDK.wallet!,
+          paymentsStream: widget.liquidSDK.paymentsStream,
         ),
       ),
     );
@@ -98,7 +79,7 @@ class _HomePageState extends State<HomePage> {
   Future<void> _sync() async {
     try {
       debugPrint("Syncing wallet.");
-      await widget.liquidSDK.sync();
+      await widget.liquidSDK.wallet!.sync();
       debugPrint("Wallet synced!");
     } on Exception catch (e) {
       final errMsg = "Failed to sync wallet. $e";

packages/flutter/example/lib/routes/home/widgets/bottom_app_bar.dart

@@ -49,7 +49,7 @@ class HomePageBottomAppBar extends StatelessWidget {
                   context: context,
                   builder: (context) => ReceivePaymentDialog(
                     liquidSDK: liquidSDK,
-                    paymentsStream: paymentsStream.asBroadcastStream(),
+                    paymentsStream: paymentsStream,
                   ),
                 );
               },

packages/flutter/example/lib/routes/home/widgets/payment_list/widgets/payment_item.dart

@@ -62,7 +62,7 @@ class PaymentItem extends StatelessWidget {
             "${item.paymentType == PaymentType.send ? "-" : "+"}${item.amountSat} sats",
             style: Theme.of(context).textTheme.bodyLarge,
           ),
-          if (item.feesSat != null) ...[
+          if (item.feesSat != BigInt.zero) ...[
             Text("FEE: ${item.paymentType == PaymentType.receive ? "-" : ""}${item.feesSat} sats"),
           ]
         ],

packages/flutter/example/lib/services/breez_liquid_sdk.dart

@@ -0,0 +1,149 @@
+import 'dart:async';
+
+import 'package:flutter_breez_liquid/flutter_breez_liquid.dart' as liquid_sdk;
+import 'package:rxdart/rxdart.dart';
+
+class BreezLiquidSDK {
+  liquid_sdk.BindingLiquidSdk? wallet;
+
+  Future<liquid_sdk.BindingLiquidSdk> connect({
+    required liquid_sdk.ConnectRequest req,
+  }) async {
+    wallet = await liquid_sdk.connect(req: req);
+    _initializeEventsStream(wallet!);
+    _subscribeToSdkStreams(wallet!);
+    await _fetchWalletData(wallet!);
+    return wallet!;
+  }
+
+  void disconnect(liquid_sdk.BindingLiquidSdk sdk) {
+    sdk.disconnect();
+    _unsubscribeFromSdkStreams();
+  }
+
+  Future _fetchWalletData(liquid_sdk.BindingLiquidSdk sdk) async {
+    await _getInfo(sdk);
+    await _listPayments(sdk);
+  }
+
+  Future<liquid_sdk.GetInfoResponse> _getInfo(liquid_sdk.BindingLiquidSdk sdk) async {
+    final walletInfo = await sdk.getInfo(req: const liquid_sdk.GetInfoRequest(withScan: false));
+    _walletInfoController.add(walletInfo);
+    return walletInfo;
+  }
+
+  Future<List<liquid_sdk.Payment>> _listPayments(liquid_sdk.BindingLiquidSdk sdk) async {
+    final paymentsList = await sdk.listPayments();
+    _paymentsController.add(paymentsList);
+    return paymentsList;
+  }
+
+  StreamSubscription<liquid_sdk.LogEntry>? _breezLogSubscription;
+
+  Stream<liquid_sdk.LogEntry>? _breezLogStream;
+
+  /// Initializes SDK log stream.
+  ///
+  /// Call once on your Dart entrypoint file, e.g.; `lib/main.dart`.
+  void initializeLogStream() {
+    _breezLogStream ??= liquid_sdk.breezLogStream().asBroadcastStream();
+  }
+
+  StreamSubscription<liquid_sdk.LiquidSdkEvent>? _breezEventsSubscription;
+
+  Stream<liquid_sdk.LiquidSdkEvent>? _breezEventsStream;
+
+  void _initializeEventsStream(liquid_sdk.BindingLiquidSdk sdk) {
+    _breezEventsStream ??= sdk.addEventListener().asBroadcastStream();
+  }
+
+  /// Subscribes to SDK's event & log streams.
+  void _subscribeToSdkStreams(liquid_sdk.BindingLiquidSdk sdk) {
+    _subscribeToEventsStream(sdk);
+    _subscribeToLogStream();
+  }
+
+  final StreamController<liquid_sdk.GetInfoResponse> _walletInfoController =
+      BehaviorSubject<liquid_sdk.GetInfoResponse>();
+
+  Stream<liquid_sdk.GetInfoResponse> get walletInfoStream => _walletInfoController.stream;
+
+  final StreamController<liquid_sdk.Payment> _paymentResultStream = StreamController.broadcast();
+
+  final StreamController<List<liquid_sdk.Payment>> _paymentsController =
+      BehaviorSubject<List<liquid_sdk.Payment>>();
+
+  Stream<List<liquid_sdk.Payment>> get paymentsStream => _paymentsController.stream;
+
+  Stream<liquid_sdk.Payment> get paymentResultStream => _paymentResultStream.stream;
+
+  /* TODO: Liquid - Log statements are added for debugging purposes, should be removed after early development stage is complete & events are behaving as expected.*/
+  /// Subscribes to LiquidSdkEvent's stream
+  void _subscribeToEventsStream(liquid_sdk.BindingLiquidSdk sdk) {
+    _breezEventsSubscription = _breezEventsStream?.listen(
+      (event) async {
+        if (event is liquid_sdk.LiquidSdkEvent_PaymentFailed) {
+          _logStreamController
+              .add(liquid_sdk.LogEntry(line: "Payment Failed. ${event.details.swapId}", level: "WARN"));
+          _paymentResultStream.addError(PaymentException(event.details));
+        }
+        if (event is liquid_sdk.LiquidSdkEvent_PaymentPending) {
+          _logStreamController
+              .add(liquid_sdk.LogEntry(line: "Payment Pending. ${event.details.swapId}", level: "INFO"));
+          _paymentResultStream.add(event.details);
+        }
+        if (event is liquid_sdk.LiquidSdkEvent_PaymentRefunded) {
+          _logStreamController
+              .add(liquid_sdk.LogEntry(line: "Payment Refunded. ${event.details.swapId}", level: "INFO"));
+          _paymentResultStream.add(event.details);
+        }
+        if (event is liquid_sdk.LiquidSdkEvent_PaymentRefundPending) {
+          _logStreamController.add(
+              liquid_sdk.LogEntry(line: "Pending Payment Refund. ${event.details.swapId}", level: "INFO"));
+          _paymentResultStream.add(event.details);
+        }
+        if (event is liquid_sdk.LiquidSdkEvent_PaymentSucceeded) {
+          _logStreamController
+              .add(liquid_sdk.LogEntry(line: "Payment Succeeded. ${event.details.swapId}", level: "INFO"));
+          _paymentResultStream.add(event.details);
+          await _fetchWalletData(sdk);
+        }
+        if (event is liquid_sdk.LiquidSdkEvent_PaymentWaitingConfirmation) {
+          _logStreamController.add(liquid_sdk.LogEntry(
+              line: "Payment Waiting Confirmation. ${event.details.swapId}", level: "INFO"));
+          _paymentResultStream.add(event.details);
+        }
+        if (event is liquid_sdk.LiquidSdkEvent_Synced) {
+          _logStreamController.add(const liquid_sdk.LogEntry(line: "Received Synced event.", level: "INFO"));
+          await _fetchWalletData(sdk);
+        }
+      },
+    );
+  }
+
+  final _logStreamController = StreamController<liquid_sdk.LogEntry>.broadcast();
+
+  Stream<liquid_sdk.LogEntry> get logStream => _logStreamController.stream;
+
+  /// Subscribes to SDK's logs stream
+  void _subscribeToLogStream() {
+    _breezLogSubscription = _breezLogStream?.listen((logEntry) {
+      _logStreamController.add(logEntry);
+    }, onError: (e) {
+      _logStreamController.addError(e);
+    });
+  }
+
+  /// Unsubscribes from SDK's event & log streams.
+  void _unsubscribeFromSdkStreams() {
+    _breezEventsSubscription?.cancel();
+    _breezLogSubscription?.cancel();
+  }
+}
+
+// TODO: Liquid - Return this exception from the SDK directly
+class PaymentException {
+  final liquid_sdk.Payment details;
+
+  const PaymentException(this.details);
+}