Display LN Address on "Receive via Lightning Address" page

lib/app/view/app.dart

@@ -52,8 +52,14 @@ class App extends StatelessWidget {
           lazy: false,
           create: (BuildContext context) => WebhookCubit(
             injector.breezSdkLiquid,
-            injector.breezPreferences,
-            injector.notifications,
+            WebhookService(
+              injector.breezSdkLiquid,
+              injector.notifications,
+            ),
+            LnUrlPayService(
+              injector.breezSdkLiquid,
+              injector.breezPreferences,
+            ),
           ),
         ),
         BlocProvider<CurrencyCubit>(

lib/cubit/webhook/lnurl_pay_service.dart

@@ -0,0 +1,159 @@
+import 'dart:convert';
+
+import 'package:breez_preferences/breez_preferences.dart';
+import 'package:breez_sdk_liquid/breez_sdk_liquid.dart';
+import 'package:flutter_breez_liquid/flutter_breez_liquid.dart';
+import 'package:http/http.dart' as http;
+import 'package:l_breez/cubit/webhook/webhook_state.dart';
+import 'package:logging/logging.dart';
+
+final Logger _logger = Logger('LnUrlPayService');
+
+class LnUrlPayService {
+  static const String lnurlServiceURL = 'https://breez.fun';
+
+  final BreezSDKLiquid _breezSdkLiquid;
+  final BreezPreferences _breezPreferences;
+
+  LnUrlPayService(this._breezSdkLiquid, this._breezPreferences);
+
+  Future<Map<String, String>> registerLnurlpay(
+    WalletInfo walletInfo,
+    String webhookUrl, {
+    String? username,
+  }) async {
+    final String pubKey = walletInfo.pubkey;
+
+    await _invalidatePreviousWebhookIfNeeded(pubKey, webhookUrl);
+
+    final int currentTime = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+
+    // TODO(erdemyerebasmaz): Utilize user's username(only when user has created a new wallet)
+    // TODO(erdemyerebasmaz): Handle multiple device setup cases
+    final String? lnAddressUsername =
+        (username ?? await _breezPreferences.getProfileName())?.replaceAll(' ', '');
+
+    final SignMessageResponse? signMessageRes = await _generateSignature(
+      webhookUrl: webhookUrl,
+      currentTime: currentTime,
+      lnAddressUsername: lnAddressUsername,
+    );
+
+    if (signMessageRes == null) {
+      throw Exception('Missing signature');
+    }
+
+    final Map<String, String> response = await _postWebhookRegistrationRequest(
+      pubKey: pubKey,
+      webhookUrl: webhookUrl,
+      currentTime: currentTime,
+      lnAddressUsername: lnAddressUsername,
+      signature: signMessageRes.signature,
+    );
+
+    await setLnUrlPayKey(webhookUrl: webhookUrl);
+    return response;
+  }
+
+  Future<void> _invalidatePreviousWebhookIfNeeded(String pubKey, String webhookUrl) async {
+    final String? lastUsedLnurlPay = await getLnUrlPayKey();
+    if (lastUsedLnurlPay != null && lastUsedLnurlPay != webhookUrl) {
+      await _invalidateLnurlPay(pubKey, lastUsedLnurlPay);
+    }
+  }
+
+  Future<SignMessageResponse?> _generateSignature({
+    required String webhookUrl,
+    required int currentTime,
+    String? lnAddressUsername,
+  }) async {
+    final String username = lnAddressUsername?.isNotEmpty == true ? '-$lnAddressUsername' : '';
+    final String message = '$currentTime-$webhookUrl$username';
+
+    final SignMessageRequest req = SignMessageRequest(message: message);
+    return _breezSdkLiquid.instance?.signMessage(req: req);
+  }
+
+  Future<Map<String, String>> _postWebhookRegistrationRequest({
+    required String pubKey,
+    required String webhookUrl,
+    required int currentTime,
+    required String signature,
+    String? lnAddressUsername,
+  }) async {
+    final String lnurlWebhookUrl = '$lnurlServiceURL/lnurlpay/$pubKey';
+    final Uri uri = Uri.parse(lnurlWebhookUrl);
+
+    final http.Response jsonResponse = await http.post(
+      uri,
+      body: jsonEncode(
+        AddWebhookRequest(
+          time: currentTime,
+          webhookUrl: webhookUrl,
+          username: lnAddressUsername,
+          signature: signature,
+        ).toJson(),
+      ),
+    );
+
+    if (jsonResponse.statusCode == 200) {
+      final Map<String, dynamic> data = jsonDecode(jsonResponse.body);
+      final String lnurl = data['lnurl'];
+      final String lnAddress = data.containsKey('lightning_address') ? data['lightning_address'] : '';
+      _logger.info('Registered LnUrl Webhook: $webhookUrl, lnurl = $lnurl, lnAddress = $lnAddress');
+      return <String, String>{
+        'lnurl': lnurl,
+        'lnAddress': lnAddress,
+      };
+    } else {
+      // TODO(erdemyerebasmaz): Handle username conflicts(only when user has created a new wallet)
+      // Add a random four-digit identifier, a discriminator, as a suffix if user's username is taken(~1/600 probability of conflict)
+      // Add a retry & randomizer logic until first registration succeeds
+      // TODO(erdemyerebasmaz): Handle custom username conflicts
+      throw Exception('Failed to register LnUrl Webhook: ${jsonResponse.body}');
+    }
+  }
+
+  Future<Map<String, String>> updateLnAddressUsername(WalletInfo walletInfo, String username) async {
+    final String? webhookUrl = await getLnUrlPayKey();
+    if (webhookUrl == null) {
+      throw Exception('Failed to retrieve registered webhook.');
+    }
+    return await registerLnurlpay(walletInfo, webhookUrl, username: username);
+  }
+
+  Future<void> _invalidateLnurlPay(String pubKey, String toInvalidate) async {
+    final String lnurlWebhookUrl = '$lnurlServiceURL/lnurlpay/$pubKey';
+    final int currentTime = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+    final SignMessageRequest req = SignMessageRequest(message: '$currentTime-$toInvalidate');
+    final SignMessageResponse? signMessageRes = _breezSdkLiquid.instance?.signMessage(req: req);
+    if (signMessageRes == null) {
+      throw Exception('Missing signature');
+    }
+    final Uri uri = Uri.parse(lnurlWebhookUrl);
+    final http.Response response = await http.delete(
+      uri,
+      body: jsonEncode(
+        RemoveWebhookRequest(
+          time: currentTime,
+          webhookUrl: toInvalidate,
+          signature: signMessageRes.signature,
+        ).toJson(),
+      ),
+    );
+    _logger.info('invalidate lnurl pay response: ${response.statusCode}');
+    await resetLnUrlPayKey();
+  }
+
+  Future<void> setLnUrlPayKey({required String webhookUrl}) async {
+    return await _breezPreferences.setLnUrlPayKey(webhookUrl);
+  }
+
+  Future<String?> getLnUrlPayKey() async {
+    return await _breezPreferences.getLnUrlPayKey();
+  }
+
+  Future<void> resetLnUrlPayKey() async {
+    return await _breezPreferences.resetLnUrlPayKey();
+  }
+}

lib/cubit/webhook/webhook_cubit.dart

@@ -1,153 +1,91 @@
-import 'dart:convert';
-
-import 'package:breez_preferences/breez_preferences.dart';
 import 'package:breez_sdk_liquid/breez_sdk_liquid.dart';
-import 'package:firebase_notifications_client/firebase_notifications_client.dart';
-import 'package:flutter/foundation.dart';
 import 'package:flutter_breez_liquid/flutter_breez_liquid.dart';
-import 'package:http/http.dart' as http;
 import 'package:hydrated_bloc/hydrated_bloc.dart';
 import 'package:l_breez/cubit/cubit.dart';
 import 'package:logging/logging.dart';
 
+export 'lnurl_pay_service.dart';
+export 'webhook_service.dart';
 export 'webhook_state.dart';
 
 final Logger _logger = Logger('WebhookCubit');
 
 class WebhookCubit extends Cubit<WebhookState> {
-  static const String notifierServiceURL = 'https://notifier.breez.technology';
-  static const String lnurlServiceURL = 'https://breez.fun';
-
   final BreezSDKLiquid _breezSdkLiquid;
-  final BreezPreferences _breezPreferences;
-  final NotificationsClient _notifications;
+  final WebhookService _webhookService;
+  final LnUrlPayService _lnUrlPayService;
 
-  WebhookCubit(
-    this._breezSdkLiquid,
-    this._breezPreferences,
-    this._notifications,
-  ) : super(WebhookState()) {
+  WebhookCubit(this._breezSdkLiquid, this._webhookService, this._lnUrlPayService) : super(WebhookState()) {
     _breezSdkLiquid.walletInfoStream.first.then(
       (GetInfoResponse getInfoResponse) => refreshWebhooks(walletInfo: getInfoResponse.walletInfo),
     );
   }
 
-  Future<void> refreshWebhooks({WalletInfo? walletInfo}) async {
-    _logger.info('Refreshing webhooks');
+  Future<void> refreshWebhooks({WalletInfo? walletInfo, String? username}) async {
+    _logger.info('Refreshing Webhooks');
     emit(WebhookState(isLoading: true));
     try {
       walletInfo = walletInfo ?? (await _breezSdkLiquid.instance?.getInfo())?.walletInfo;
-      if (walletInfo != null) {
-        await _registerWebhooks(walletInfo);
-      } else {
-        throw Exception('Unable to retrieve wallet information.');
+      if (walletInfo == null) {
+        throw Exception('Failed to retrieve wallet info.');
       }
-    } catch (err) {
-      _logger.warning('Failed to refresh lnurlpay: $err');
+      final String webhookUrl = await _webhookService.generateWebhookURL();
+      await _webhookService.registerWebhook(webhookUrl);
+      final Map<String, String> lnUrlData = await _lnUrlPayService.registerLnurlpay(
+        walletInfo,
+        webhookUrl,
+        username: username ?? state.lnAddressUsername,
+      );
       emit(
-        state.copyWith(
-          lnurlPayErrorTitle: 'Failed to refresh Lightning Address:',
-          lnurlPayError: err.toString(),
+        WebhookState(
+          lnurlPayUrl: lnUrlData['lnurl'],
+          lnAddress: lnUrlData['lnAddress'],
         ),
       );
-    } finally {
-      emit(state.copyWith(isLoading: false));
-    }
-  }
-
-  Future<void> _registerWebhooks(WalletInfo walletInfo) async {
-    try {
-      final String webhookUrl = await _generateWebhookURL();
-      await _breezSdkLiquid.instance?.registerWebhook(webhookUrl: webhookUrl);
-      _logger.info('SDK webhook registered: $webhookUrl');
-      final String lnurl = await _registerLnurlpay(walletInfo, webhookUrl);
-      emit(WebhookState(lnurlPayUrl: lnurl));
     } catch (err) {
-      _logger.warning('Failed to register webhooks: $err');
-      emit(state.copyWith(lnurlPayErrorTitle: 'Failed to register webhooks:', lnurlPayError: err.toString()));
-      rethrow;
-    }
-  }
-
-  Future<String> _registerLnurlpay(
-    WalletInfo walletInfo,
-    String webhookUrl,
-  ) async {
-    final String? lastUsedLnurlPay = await _breezPreferences.getLnUrlPayKey();
-    if (lastUsedLnurlPay != null && lastUsedLnurlPay != webhookUrl) {
-      await _invalidateLnurlPay(walletInfo, lastUsedLnurlPay);
-    }
-    String? username = await _breezPreferences.getProfileName();
-    username = username?.replaceAll(' ', '');
-    final int currentTime = DateTime.now().millisecondsSinceEpoch ~/ 1000;
-    final String optionalUsernameKey = username != null ? '-$username' : '';
-    final SignMessageRequest req =
-        SignMessageRequest(message: '$currentTime-$webhookUrl$optionalUsernameKey');
-    final SignMessageResponse? signMessageRes = _breezSdkLiquid.instance?.signMessage(req: req);
-    if (signMessageRes == null) {
-      throw Exception('Missing signature');
-    }
-    final String lnurlWebhookUrl = '$lnurlServiceURL/lnurlpay/${walletInfo.pubkey}';
-    final Uri uri = Uri.parse(lnurlWebhookUrl);
-    final http.Response jsonResponse = await http.post(
-      uri,
-      body: jsonEncode(
-        AddWebhookRequest(
-          time: currentTime,
-          webhookUrl: webhookUrl,
-          username: username,
-          signature: signMessageRes.signature,
-        ).toJson(),
-      ),
-    );
-    if (jsonResponse.statusCode == 200) {
-      final Map<String, dynamic> data = jsonDecode(jsonResponse.body);
-      final String lnurl = data.containsKey('lightning_address') ? data['lightning_address'] : data['lnurl'];
-      _logger.info('lnurlpay webhook registered: $webhookUrl, lnurl = $lnurl');
-      await _breezPreferences.setLnUrlPayKey(webhookUrl);
-      return lnurl;
-    } else {
-      throw jsonResponse.body;
+      _logger.warning('Failed to refresh webhooks: $err');
+      emit(
+        WebhookState(
+          webhookError: err.toString(),
+          webhookErrorTitle: 'Failed to refresh Lightning Address:',
+        ),
+      );
     }
   }
 
-  Future<void> _invalidateLnurlPay(
-    WalletInfo walletInfo,
-    String toInvalidate,
-  ) async {
-    final String lnurlWebhookUrl = '$lnurlServiceURL/lnurlpay/${walletInfo.pubkey}';
-    final int currentTime = DateTime.now().millisecondsSinceEpoch ~/ 1000;
-    final SignMessageRequest req = SignMessageRequest(message: '$currentTime-$toInvalidate');
-    final SignMessageResponse? signMessageRes = _breezSdkLiquid.instance?.signMessage(req: req);
-    if (signMessageRes == null) {
-      throw Exception('Missing signature');
-    }
-    final Uri uri = Uri.parse(lnurlWebhookUrl);
-    final http.Response response = await http.delete(
-      uri,
-      body: jsonEncode(
-        RemoveWebhookRequest(
-          time: currentTime,
-          webhookUrl: toInvalidate,
-          signature: signMessageRes.signature,
-        ).toJson(),
+  Future<void> updateLnAddressUsername({required String lnAddressUsername}) async {
+    emit(
+      WebhookState(
+        isLoading: true,
+        lnurlPayUrl: state.lnurlPayUrl,
+        lnAddress: state.lnAddress,
       ),
     );
-    _logger.info('invalidate lnurl pay response: ${response.statusCode}');
-    await _breezPreferences.resetLnUrlPayKey();
-  }
-
-  Future<String> _generateWebhookURL() async {
-    final String? token = await _notifications.getToken();
-    _logger.info('Retrieved token, registering…');
-    final String platform = defaultTargetPlatform == TargetPlatform.iOS
-        ? 'ios'
-        : defaultTargetPlatform == TargetPlatform.android
-            ? 'android'
-            : '';
-    if (platform.isEmpty) {
-      throw Exception('Notifications for platform is not supported');
+    try {
+      final GetInfoResponse? walletInfo = await _breezSdkLiquid.instance?.getInfo();
+      if (walletInfo == null) {
+        throw Exception('Failed to retrieve wallet info.');
+      }
+      final Map<String, String> lnUrlData = await _lnUrlPayService.updateLnAddressUsername(
+        walletInfo.walletInfo,
+        lnAddressUsername,
+      );
+      emit(
+        WebhookState(
+          lnurlPayUrl: lnUrlData['lnurl'],
+          lnAddress: lnUrlData['lnAddress'],
+          lnAddressUsername: lnAddressUsername,
+        ),
+      );
+    } catch (err) {
+      emit(
+        state.copyWith(
+          lnurlPayError: err.toString(),
+          lnurlPayErrorTitle: 'Failed to update Lightning Address username:',
+        ),
+      );
+    } finally {
+      emit(state.copyWith(isLoading: false));
     }
-    return '$notifierServiceURL/api/v1/notify?platform=$platform&token=$token';
   }
 }