feat: Watch for lightning invoice payment

This will submit the order once a hodl invoice is paid.

In the next step we have to extend the post order api to revail the pre image so that the coordinator can claim the payment and open a single sided channel.

coordinator/src/node/invoice.rs

@@ -1,39 +1,48 @@
+use bitcoin::Amount;
 use futures_util::TryStreamExt;
 use lnd_bridge::InvoiceState;
 use lnd_bridge::LndBridge;
+use tokio::sync::broadcast;
 use xxi_node::commons;
+use xxi_node::commons::Message;
 
 /// Watches a hodl invoice with the given r_hash
-pub fn spawn_invoice_watch(lnd_bridge: LndBridge, invoice_params: commons::HodlInvoiceParams) {
+pub fn spawn_invoice_watch(
+    trader_sender: broadcast::Sender<Message>,
+    lnd_bridge: LndBridge,
+    invoice_params: commons::HodlInvoiceParams,
+) {
     tokio::spawn(async move {
         let trader_pubkey = invoice_params.trader_pubkey;
         let r_hash = invoice_params.r_hash;
         let mut stream = lnd_bridge.subscribe_to_invoice(r_hash.clone());
 
         'watch_invoice: loop {
             match stream.try_next().await {
-                Ok(Some(invoice)) => {
-                    match invoice.state {
-                        InvoiceState::Open => {
-                            tracing::debug!(%trader_pubkey, r_hash, "Watching hodl invoice.");
-                            continue 'watch_invoice;
-                        }
-                        InvoiceState::Settled => {
-                            tracing::info!(%trader_pubkey, r_hash, "Accepted hodl invoice has been settled.");
-                            break 'watch_invoice;
-                        }
-                        InvoiceState::Canceled => {
-                            tracing::warn!(%trader_pubkey, r_hash, "Pending hodl invoice has been canceled.");
-                            break 'watch_invoice;
-                        }
-                        InvoiceState::Accepted => {
-                            tracing::info!(%trader_pubkey, r_hash, "Pending hodl invoice has been accepted.");
-                            // TODO(holzeis): Notify the client about the accepted invoice.
-                            // wait for the invoice to get settled.
-                            continue 'watch_invoice;
+                Ok(Some(invoice)) => match invoice.state {
+                    InvoiceState::Open => {
+                        tracing::debug!(%trader_pubkey, invoice.r_hash, "Watching hodl invoice.");
+                        continue 'watch_invoice;
+                    }
+                    InvoiceState::Settled => {
+                        tracing::info!(%trader_pubkey, invoice.r_hash, "Accepted hodl invoice has been settled.");
+                        break 'watch_invoice;
+                    }
+                    InvoiceState::Canceled => {
+                        tracing::warn!(%trader_pubkey, invoice.r_hash, "Pending hodl invoice has been canceled.");
+                        break 'watch_invoice;
+                    }
+                    InvoiceState::Accepted => {
+                        tracing::info!(%trader_pubkey, invoice.r_hash, "Pending hodl invoice has been accepted.");
+                        if let Err(e) = trader_sender.send(Message::PaymentReceived {
+                            r_hash: invoice.r_hash.clone(),
+                            amount: Amount::from_sat(invoice.amt_paid_sat),
+                        }) {
+                            tracing::error!(%trader_pubkey, r_hash = invoice.r_hash, "Failed to send payment received event to app. Error: {e:#}")
                         }
+                        continue 'watch_invoice;
                     }
-                }
+                },
                 Ok(None) => {
                     tracing::error!(%trader_pubkey, r_hash, "Websocket sender died.");
                     break 'watch_invoice;

coordinator/src/routes.rs

@@ -552,6 +552,7 @@ fn parse_offset_datetime(date_str: String) -> Result<Option<OffsetDateTime>> {
     Ok(Some(date_time))
 }
 
+#[instrument(skip_all, err(Debug))]
 pub async fn get_leaderboard(
     State(state): State<Arc<AppState>>,
     params: Query<LeaderBoardQueryParams>,
@@ -593,6 +594,7 @@ pub async fn get_leaderboard(
     }))
 }
 
+#[instrument(skip_all, err(Debug))]
 async fn post_error(
     State(state): State<Arc<AppState>>,
     app_error: Json<ReportedError>,
@@ -608,6 +610,7 @@ async fn post_error(
     Ok(())
 }
 
+#[instrument(skip_all, err(Debug))]
 async fn create_invoice(
     State(state): State<Arc<AppState>>,
     Json(invoice_params): Json<SignedValue<commons::HodlInvoiceParams>>,
@@ -630,7 +633,11 @@ async fn create_invoice(
         .map_err(|e| AppError::InternalServerError(format!("{e:#}")))?;
 
     // watch for the created hodl invoice
-    invoice::spawn_invoice_watch(state.lnd_bridge.clone(), invoice_params);
+    invoice::spawn_invoice_watch(
+        state.tx_orderbook_feed.clone(),
+        state.lnd_bridge.clone(),
+        invoice_params,
+    );
 
     Ok(Json(response.payment_request))
 }

crates/tests-e2e/src/test_subscriber.rs

@@ -194,6 +194,9 @@ impl Senders {
             native::event::EventInternal::FundingChannelNotification(_) => {
                 // ignored
             }
+            native::event::EventInternal::PaymentReceived => {
+                // ignored
+            }
         }
         Ok(())
     }

crates/xxi-node/Cargo.toml

@@ -10,6 +10,7 @@ description = "A common library for the 10101 node"
 anyhow = { version = "1", features = ["backtrace"] }
 async-trait = "0.1.71"
 axum = { version = "0.6", features = ["ws"], optional = true }
+base64 = "0.22.1"
 bdk = { version = "1.0.0-alpha.6", features = ["std"] }
 bdk_coin_select = "0.2.0"
 bdk_esplora = { version = "0.8.0" }

crates/xxi-node/src/commons/message.rs

@@ -41,6 +41,11 @@ pub enum Message {
         order_id: Uuid,
         error: TradingError,
     },
+    PaymentReceived {
+        r_hash: String,
+        #[serde(with = "bitcoin::amount::serde::as_sat")]
+        amount: Amount,
+    },
     RolloverError {
         error: TradingError,
     },
@@ -123,6 +128,9 @@ impl Display for Message {
             Message::RolloverError { .. } => {
                 write!(f, "RolloverError")
             }
+            Message::PaymentReceived { .. } => {
+                write!(f, "PaymentReceived")
+            }
         }
     }
 }

crates/xxi-node/src/commons/pre_image.rs

@@ -1,3 +1,5 @@
+use base64::engine::general_purpose;
+use base64::Engine;
 use rand::Rng;
 use sha256::digest;
 
@@ -6,6 +8,12 @@ pub struct PreImage {
     pub hash: String,
 }
 
+impl PreImage {
+    pub fn get_base64_encoded_pre_image(&self) -> String {
+        general_purpose::URL_SAFE.encode(self.pre_image)
+    }
+}
+
 pub fn create_pre_image() -> PreImage {
     let pre_image = inner_create_pre_image();
     let hash = inner_hash_pre_image(&pre_image);

mobile/lib/common/routes.dart

@@ -1,31 +1,32 @@
 import 'package:flutter/material.dart';
+import 'package:get_10101/common/background_task_dialog_screen.dart';
 import 'package:get_10101/common/global_keys.dart';
+import 'package:get_10101/common/scaffold_with_nav_bar.dart';
+import 'package:get_10101/common/settings/app_info_screen.dart';
 import 'package:get_10101/common/settings/channel_screen.dart';
+import 'package:get_10101/common/settings/collab_close_screen.dart';
 import 'package:get_10101/common/settings/emergency_kit_screen.dart';
+import 'package:get_10101/common/settings/force_close_screen.dart';
+import 'package:get_10101/common/settings/seed_screen.dart';
+import 'package:get_10101/common/settings/settings_screen.dart';
+import 'package:get_10101/common/settings/share_logs_screen.dart';
 import 'package:get_10101/common/settings/user_screen.dart';
 import 'package:get_10101/common/settings/wallet_settings.dart';
 import 'package:get_10101/common/status_screen.dart';
-import 'package:get_10101/common/background_task_dialog_screen.dart';
+import 'package:get_10101/features/trade/application/order_service.dart';
 import 'package:get_10101/features/trade/channel_creation_flow/channel_configuration_screen.dart';
 import 'package:get_10101/features/trade/channel_creation_flow/channel_funding_screen.dart';
+import 'package:get_10101/features/trade/trade_screen.dart';
 import 'package:get_10101/features/wallet/domain/destination.dart';
+import 'package:get_10101/features/wallet/domain/wallet_type.dart';
+import 'package:get_10101/features/wallet/receive_screen.dart';
+import 'package:get_10101/features/wallet/scanner_screen.dart';
 import 'package:get_10101/features/wallet/send/send_onchain_screen.dart';
+import 'package:get_10101/features/wallet/wallet_screen.dart';
 import 'package:get_10101/features/welcome/error_screen.dart';
 import 'package:get_10101/features/welcome/loading_screen.dart';
-import 'package:get_10101/common/scaffold_with_nav_bar.dart';
-import 'package:get_10101/common/settings/app_info_screen.dart';
-import 'package:get_10101/common/settings/collab_close_screen.dart';
-import 'package:get_10101/common/settings/force_close_screen.dart';
-import 'package:get_10101/common/settings/settings_screen.dart';
-import 'package:get_10101/common/settings/share_logs_screen.dart';
 import 'package:get_10101/features/welcome/onboarding.dart';
-import 'package:get_10101/features/trade/trade_screen.dart';
-import 'package:get_10101/features/wallet/domain/wallet_type.dart';
-import 'package:get_10101/features/wallet/receive_screen.dart';
-import 'package:get_10101/features/wallet/scanner_screen.dart';
 import 'package:get_10101/features/welcome/seed_import_screen.dart';
-import 'package:get_10101/common/settings/seed_screen.dart';
-import 'package:get_10101/features/wallet/wallet_screen.dart';
 import 'package:get_10101/features/welcome/welcome_screen.dart';
 import 'package:go_router/go_router.dart';
 
@@ -242,7 +243,7 @@ GoRouter createRoutes() {
                       final data = state.extra! as Map<String, dynamic>;
                       return ChannelFundingScreen(
                         amount: data["amount"],
-                        address: data["address"],
+                        funding: data["funding"] as ExternalFunding,
                       );
                     },
                     routes: const [],

mobile/lib/features/trade/application/order_service.dart

@@ -5,6 +5,18 @@ import 'package:get_10101/features/trade/domain/leverage.dart';
 import 'package:get_10101/features/trade/domain/order.dart';
 import 'package:get_10101/ffi.dart' as rust;
 
+class ExternalFunding {
+  final String bitcoinAddress;
+  final String paymentRequest;
+
+  const ExternalFunding({required this.bitcoinAddress, required this.paymentRequest});
+
+  static ExternalFunding fromApi(rust.ExternalFunding funding) {
+    return ExternalFunding(
+        bitcoinAddress: funding.bitcoinAddress, paymentRequest: funding.paymentRequest);
+  }
+}
+
 class OrderService {
   Future<String> submitMarketOrder(Leverage leverage, Usd quantity, ContractSymbol contractSymbol,
       Direction direction, bool stable) async {
@@ -43,7 +55,7 @@ class OrderService {
 
   // starts a process to watch for funding an address before creating the order
   // returns the address to watch for
-  Future<String> submitUnfundedChannelOpeningMarketOrder(
+  Future<ExternalFunding> submitUnfundedChannelOpeningMarketOrder(
       Leverage leverage,
       Usd quantity,
       ContractSymbol contractSymbol,
@@ -60,15 +72,13 @@ class OrderService {
         orderType: const rust.OrderType.market(),
         stable: stable);
 
-    var address = await rust.api.getNewAddress();
-
-    await rust.api.submitUnfundedChannelOpeningOrder(
-        fundingAddress: address,
+    final funding = await rust.api.submitUnfundedChannelOpeningOrder(
         order: order,
         coordinatorReserve: coordinatorReserve.sats,
         traderReserve: traderReserve.sats,
         estimatedMargin: margin.sats);
-    return address;
+
+    return ExternalFunding.fromApi(funding);
   }
 
   Future<List<Order>> fetchOrders() async {

mobile/lib/features/trade/channel_creation_flow/channel_configuration_screen.dart

@@ -9,6 +9,7 @@ import 'package:get_10101/common/dlc_channel_service.dart';
 import 'package:get_10101/common/domain/model.dart';
 import 'package:get_10101/common/snack_bar.dart';
 import 'package:get_10101/common/value_data_row.dart';
+import 'package:get_10101/features/trade/application/order_service.dart';
 import 'package:get_10101/features/trade/channel_creation_flow/channel_funding_screen.dart';
 import 'package:get_10101/features/trade/channel_creation_flow/custom_framed_container.dart';
 import 'package:get_10101/features/trade/channel_creation_flow/fee_expansion_widget.dart';
@@ -419,9 +420,9 @@ class _ChannelConfiguration extends State<ChannelConfiguration> {
                                             ChannelOpeningParams(
                                                 coordinatorReserve: counterpartyCollateral,
                                                 traderReserve: ownTotalCollateral))
-                                        .then((address) {
+                                        .then((ExternalFunding funding) {
                                       GoRouter.of(context).push(ChannelFundingScreen.route, extra: {
-                                        "address": address,
+                                        "funding": funding,
                                         "amount": totalAmountToBeFunded
                                       });
                                     }).onError((error, stackTrace) {