feat: fallback for timeouts when creating invoices (#398)

lib/BaseClient.ts

@@ -23,7 +23,7 @@ class BaseClient extends EventEmitter {
     return this.status === ClientStatus.OutOfSync;
   }
 
-  protected setClientStatus = (status: ClientStatus): void => {
+  public setClientStatus = (status: ClientStatus): void => {
     this.status = status;
   };
 

lib/PromiseUtils.ts

@@ -0,0 +1,21 @@
+export const racePromise = async <T>(
+  promise: (() => Promise<T>) | Promise<T>,
+  raceHandler: (reason?: any) => void,
+  raceTimeout: number,
+): Promise<T> => {
+  let timeout: NodeJS.Timeout | undefined = undefined;
+
+  const timeoutPromise = new Promise<T>((_, reject) => {
+    timeout = setTimeout(() => raceHandler(reject), raceTimeout);
+  });
+
+  const res = await Promise.race([
+    promise instanceof Promise ? promise : promise(),
+    timeoutPromise,
+  ]);
+
+  if (timeout !== undefined) {
+    clearTimeout(timeout);
+  }
+  return res;
+};

lib/Utils.ts

@@ -516,7 +516,7 @@ export const calculateUtxoTransactionFee = async (
   chainClient: ChainClient,
   transaction: Transaction,
 ): Promise<number> => {
-  let fee = 0;
+  let fee = 0n;
 
   for (const input of transaction.ins) {
     const inputId = transactionHashToId(input.hash);
@@ -525,14 +525,14 @@ export const calculateUtxoTransactionFee = async (
 
     const spentOutput = inputTransaction.outs[input.index];
 
-    fee += spentOutput.value;
+    fee += BigInt(spentOutput.value);
   }
 
   transaction.outs.forEach((output) => {
-    fee -= output.value;
+    fee -= BigInt(output.value);
   });
 
-  return fee;
+  return Number(fee);
 };
 
 export const calculateLiquidTransactionFee = (

lib/lightning/ClnClient.ts

@@ -1,21 +1,21 @@
 import fs from 'fs';
 import bolt11 from 'bolt11';
 import {
-  Metadata,
-  credentials,
   ChannelCredentials,
   ClientReadableStream,
+  credentials,
+  Metadata,
 } from '@grpc/grpc-js';
 import Errors from './Errors';
 import Logger from '../Logger';
 import BaseClient from '../BaseClient';
 import { ClientStatus } from '../consts/Enums';
 import * as noderpc from '../proto/cln/node_pb';
+import { ListfundsOutputs } from '../proto/cln/node_pb';
 import * as holdrpc from '../proto/hold/hold_pb';
 import { grpcOptions, unaryCall } from './GrpcUtils';
 import { NodeClient } from '../proto/cln/node_grpc_pb';
 import { HoldClient } from '../proto/hold/hold_grpc_pb';
-import { ListfundsOutputs } from '../proto/cln/node_pb';
 import * as primitivesrpc from '../proto/cln/primitives_pb';
 import { decodeInvoice, formatError, getHexString } from '../Utils';
 import { WalletBalance } from '../wallet/providers/WalletProviderInterface';
@@ -145,6 +145,8 @@ class ClnClient
         if (startSubscriptions) {
           this.subscribeTrackHoldInvoices();
         }
+
+        this.setClientStatus(ClientStatus.Connected);
       } catch (error) {
         this.setClientStatus(ClientStatus.Disconnected);
 
@@ -318,6 +320,10 @@ class ClnClient
       });
   };
 
+  public stop = (): void => {
+    // Just here for interface compatibility;
+  };
+
   public routingHints = async (node: string): Promise<HopHint[][]> => {
     const req = new holdrpc.RoutingHintsRequest();
     req.setNode(node);

lib/lightning/LightningClient.ts

@@ -1,5 +1,6 @@
 import bolt11 from 'bolt11';
 import * as lndrpc from '../proto/lnd/rpc_pb';
+import { ClientStatus } from '../consts/Enums';
 import { BalancerFetcher } from '../wallet/providers/WalletProviderInterface';
 
 enum InvoiceState {
@@ -111,6 +112,9 @@ interface LightningClient extends BalancerFetcher {
 
   symbol: string;
 
+  isConnected(): boolean;
+  setClientStatus(status: ClientStatus): void;
+
   connect(startSubscriptions?: boolean): Promise<boolean>;
   disconnect(): void;
 
@@ -151,6 +155,7 @@ interface LightningClient extends BalancerFetcher {
 }
 
 interface RoutingHintsProvider {
+  stop(): void;
   routingHints(nodeId: string): Promise<HopHint[][]>;
 }
 

lib/service/TimeoutDeltaProvider.ts

@@ -242,11 +242,11 @@ class TimeoutDeltaProvider {
 
     const decodedInvoice =
       await NodeSwitch.fallback(currency)!.decodeInvoice(invoice);
-    const lightningClient = NodeSwitch.fallback(
+    const lightningClient = this.nodeSwitch.switch(
       currency,
-      this.nodeSwitch.switch(currency, decodedInvoice.value, referralId),
+      decodedInvoice.value,
+      referralId,
     );
-
     const [routeTimeLock, chainInfo] = await Promise.all([
       this.checkRoutability(
         lightningClient,

lib/swap/Errors.ts

@@ -86,4 +86,12 @@ export default {
     message: 'transaction fee is too low',
     code: concatErrorCode(ErrorCodePrefix.Swap, 16),
   }),
+  LIGHTNING_CLIENT_CALL_TIMEOUT: (): Error => ({
+    message: 'lightning client call timeout',
+    code: concatErrorCode(ErrorCodePrefix.Swap, 17),
+  }),
+  NO_AVAILABLE_LIGHTNING_CLIENT: (): Error => ({
+    message: 'no available lightning client',
+    code: concatErrorCode(ErrorCodePrefix.Swap, 18),
+  }),
 };

lib/swap/NodeFallback.ts

@@ -0,0 +1,131 @@
+import Errors from './Errors';
+import Logger from '../Logger';
+import NodeSwitch from './NodeSwitch';
+import { racePromise } from '../PromiseUtils';
+import { ClientStatus } from '../consts/Enums';
+import RoutingHints from './routing/RoutingHints';
+import { Currency } from '../wallet/WalletManager';
+import { NodeType } from '../db/models/ReverseSwap';
+import { HopHint, LightningClient } from '../lightning/LightningClient';
+
+type InvoiceWithRoutingHints = {
+  paymentRequest: string;
+  routingHints: HopHint[][] | undefined;
+};
+
+type HolisticInvoice = InvoiceWithRoutingHints & {
+  nodeType: NodeType;
+  lightningClient: LightningClient;
+};
+
+class NodeFallback {
+  private static readonly addInvoiceTimeout = 10_000;
+
+  constructor(
+    private logger: Logger,
+    private nodeSwitch: NodeSwitch,
+    private routingHints: RoutingHints,
+  ) {}
+
+  public getReverseSwapInvoice = async (
+    id: string,
+    referralId: string | undefined,
+    routingNode: string | undefined,
+    currency: Currency,
+    holdInvoiceAmount: number,
+    preimageHash: Buffer,
+    cltvExpiry?: number,
+    expiry?: number,
+    memo?: string,
+  ): Promise<HolisticInvoice> => {
+    let nodeForSwap = this.nodeSwitch.getNodeForReverseSwap(
+      id,
+      currency,
+      holdInvoiceAmount,
+      referralId,
+    );
+
+    while (nodeForSwap.lightningClient !== undefined) {
+      try {
+        return {
+          ...nodeForSwap,
+          ...(await this.addHoldInvoice(
+            nodeForSwap.nodeType,
+            nodeForSwap.lightningClient,
+            routingNode,
+            currency,
+            holdInvoiceAmount,
+            preimageHash,
+            cltvExpiry,
+            expiry,
+            memo,
+          )),
+        };
+      } catch (e) {
+        if (
+          (e as any).message === Errors.LIGHTNING_CLIENT_CALL_TIMEOUT().message
+        ) {
+          this.logger.warn(
+            `${nodeForSwap.lightningClient.serviceName()} invoice creation timed out after ${
+              NodeFallback.addInvoiceTimeout
+            }ms; trying next node`,
+          );
+          nodeForSwap.lightningClient.setClientStatus(
+            ClientStatus.Disconnected,
+          );
+          nodeForSwap = this.nodeSwitch.getNodeForReverseSwap(
+            id,
+            currency,
+            holdInvoiceAmount,
+            referralId,
+          );
+
+          continue;
+        }
+
+        throw e;
+      }
+    }
+
+    throw Errors.NO_AVAILABLE_LIGHTNING_CLIENT();
+  };
+
+  private addHoldInvoice = async (
+    nodeType: NodeType,
+    lightningClient: LightningClient,
+    routingNode: string | undefined,
+    currency: Currency,
+    holdInvoiceAmount: number,
+    preimageHash: Buffer,
+    cltvExpiry?: number,
+    expiry?: number,
+    memo?: string,
+  ): Promise<InvoiceWithRoutingHints> => {
+    const routingHints =
+      routingNode !== undefined
+        ? await this.routingHints.getRoutingHints(
+            currency.symbol,
+            routingNode,
+            nodeType,
+          )
+        : undefined;
+
+    return racePromise<InvoiceWithRoutingHints>(
+      async (): Promise<InvoiceWithRoutingHints> => ({
+        routingHints,
+        paymentRequest: await lightningClient.addHoldInvoice(
+          holdInvoiceAmount,
+          preimageHash,
+          cltvExpiry,
+          expiry,
+          memo,
+          routingHints,
+        ),
+      }),
+      (reject) => reject(Errors.LIGHTNING_CLIENT_CALL_TIMEOUT()),
+      NodeFallback.addInvoiceTimeout,
+    );
+  };
+}
+
+export default NodeFallback;

lib/swap/NodeSwitch.ts

@@ -1,3 +1,4 @@
+import Errors from './Errors';
 import Logger from '../Logger';
 import { SwapType } from '../db/models/Swap';
 import { Currency } from '../wallet/WalletManager';
@@ -94,24 +95,38 @@ class NodeSwitch {
     currency: Currency,
     amount?: number,
     referralId?: string,
-  ): LightningClient | undefined => {
+  ): LightningClient => {
     if (referralId && this.referralIds.has(referralId)) {
-      return NodeSwitch.switchOnNodeType(
+      return NodeSwitch.fallback(
         currency,
-        this.referralIds.get(referralId)!,
+        NodeSwitch.switchOnNodeType(
+          currency,
+          this.referralIds.get(referralId)!,
+        ),
       );
     }
 
-    return (amount || 0) > this.clnAmountThreshold
-      ? currency.lndClient
-      : currency.clnClient;
+    return NodeSwitch.fallback(
+      currency,
+      (amount || 0) > this.clnAmountThreshold
+        ? currency.lndClient
+        : currency.clnClient,
+    );
   };
 
   public static fallback = (
     currency: Currency,
     client?: LightningClient,
   ): LightningClient => {
-    return (client || currency.lndClient || currency.clnClient)!;
+    const clients = [client, currency.lndClient, currency.clnClient]
+      .filter((client): client is LightningClient => client !== undefined)
+      .filter((client) => client.isConnected());
+
+    if (clients.length === 0) {
+      throw Errors.NO_AVAILABLE_LIGHTNING_CLIENT();
+    }
+
+    return clients[0]!;
   };
 
   private static switchOnNodeType = (