feat(gui): Allow discovery of sellers via connecting to rendezvous point (#83)

We,
- add a new list_sellers Tauri IPC command
- we rename the Seller struct to AliceAddress to name clash

src-gui/src/renderer/api.ts

@@ -1,3 +1,9 @@
+// This file is responsible for making HTTP requests to the Unstoppable API and to the CoinGecko API.
+// The APIs are used to:
+// - fetch provider status from the public registry
+// - fetch alerts to be displayed to the user
+// - and to submit feedback
+// - fetch currency rates from CoinGecko
 import { Alert, ExtendedProviderStatus } from "models/apiModel";
 
 const API_BASE_URL = "https://api.unstoppableswap.net";

src-gui/src/renderer/components/modal/listSellers/ListSellersDialog.tsx

@@ -11,11 +11,15 @@ import {
   TextField,
   Theme,
 } from "@material-ui/core";
-import { Multiaddr } from "multiaddr";
+import { ListSellersResponse } from "models/tauriModel";
 import { useSnackbar } from "notistack";
 import { ChangeEvent, useState } from "react";
 import TruncatedText from "renderer/components/other/TruncatedText";
 import PromiseInvokeButton from "renderer/components/PromiseInvokeButton";
+import { listSellersAtRendezvousPoint } from "renderer/rpc";
+import { discoveredProvidersByRendezvous } from "store/features/providersSlice";
+import { useAppDispatch } from "store/hooks";
+import { isValidMultiAddressWithPeerId } from "utils/parseUtils";
 
 const PRESET_RENDEZVOUS_POINTS = [
   "/dns4/discover.unstoppableswap.net/tcp/8888/p2p/12D3KooWA6cnqJpVnreBVnoro8midDL9Lpzmg8oJPoAGi7YYaamE",
@@ -42,27 +46,23 @@ export default function ListSellersDialog({
   const classes = useStyles();
   const [rendezvousAddress, setRendezvousAddress] = useState("");
   const { enqueueSnackbar } = useSnackbar();
+  const dispatch = useAppDispatch();
 
   function handleMultiAddrChange(event: ChangeEvent<HTMLInputElement>) {
     setRendezvousAddress(event.target.value);
   }
 
   function getMultiAddressError(): string | null {
-    try {
-      const multiAddress = new Multiaddr(rendezvousAddress);
-      if (!multiAddress.protoNames().includes("p2p")) {
-        return "The multi address must contain the peer id (/p2p/)";
-      }
-      return null;
-    } catch {
-      return "Not a valid multi address";
-    }
+    return isValidMultiAddressWithPeerId(rendezvousAddress) ? null : "Address is invalid or missing peer ID";
   }
 
-  function handleSuccess(amountOfSellers: number) {
+  function handleSuccess({ sellers }: ListSellersResponse) {
+    dispatch(discoveredProvidersByRendezvous(sellers));
+
+    const discoveredSellersCount = sellers.length;
     let message: string;
 
-    switch (amountOfSellers) {
+    switch (discoveredSellersCount) {
       case 0:
         message = `No providers were discovered at the rendezvous point`;
         break;
@@ -70,7 +70,7 @@ export default function ListSellersDialog({
         message = `Discovered one provider at the rendezvous point`;
         break;
       default:
-        message = `Discovered ${amountOfSellers} providers at the rendezvous point`;
+        message = `Discovered ${discoveredSellersCount} providers at the rendezvous point`;
     }
 
     enqueueSnackbar(message, {
@@ -119,12 +119,13 @@ export default function ListSellersDialog({
         <Button onClick={onClose}>Cancel</Button>
         <PromiseInvokeButton
           variant="contained"
-          disabled={!(rendezvousAddress && !getMultiAddressError())}
+          disabled={
+            // We disable the button if the multiaddress is invalid
+            getMultiAddressError() !== null
+          }
           color="primary"
           onSuccess={handleSuccess}
-          onInvoke={() => {
-            throw new Error("Not implemented");
-          }}
+          onInvoke={() => listSellersAtRendezvousPoint(rendezvousAddress)}
         >
           Connect
         </PromiseInvokeButton>

src-gui/src/renderer/components/modal/provider/ProviderInfo.tsx

@@ -39,7 +39,7 @@ export default function ProviderInfo({
         {provider.multiAddr}
       </Typography>
       <Typography color="textSecondary" gutterBottom>
-        <TruncatedText limit={12}>{provider.peerId}</TruncatedText>
+        <TruncatedText>{provider.peerId}</TruncatedText>
       </Typography>
       <Typography variant="caption">
         Exchange rate:{" "}

src-gui/src/renderer/components/pages/swap/SwapWidget.tsx

@@ -177,7 +177,7 @@ function HasNoProvidersSwapWidget() {
   const forceShowDialog = useAppSelector((state) => state.swap.state !== null);
   const isPublicRegistryDown = useAppSelector((state) =>
     isRegistryDown(
-      state.providers.registry.failedReconnectAttemptsSinceLastSuccess,
+      state.providers.registry.connectionFailsCount,
     ),
   );
   const classes = useStyles();
@@ -255,7 +255,7 @@ export default function SwapWidget() {
     (state) =>
       state.providers.registry.providers === null &&
       !isRegistryDown(
-        state.providers.registry.failedReconnectAttemptsSinceLastSuccess,
+        state.providers.registry.connectionFailsCount,
       ),
   );
 

src-gui/src/renderer/index.tsx

@@ -2,7 +2,10 @@ import { createRoot } from "react-dom/client";
 import { Provider } from "react-redux";
 import { PersistGate } from "redux-persist/integration/react";
 import { setAlerts } from "store/features/alertsSlice";
-import { setRegistryProviders } from "store/features/providersSlice";
+import {
+  registryConnectionFailed,
+  setRegistryProviders,
+} from "store/features/providersSlice";
 import { setBtcPrice, setXmrPrice } from "store/features/ratesSlice";
 import logger from "../utils/logger";
 import {
@@ -12,18 +15,9 @@ import {
   fetchXmrPrice,
 } from "./api";
 import App from "./components/App";
-import {
-  checkBitcoinBalance,
-  getAllSwapInfos,
-  initEventListeners,
-} from "./rpc";
+import { initEventListeners } from "./rpc";
 import { persistor, store } from "./store/storeRenderer";
 
-setInterval(() => {
-  checkBitcoinBalance();
-  getAllSwapInfos();
-}, 30 * 1000);
-
 const container = document.getElementById("root");
 const root = createRoot(container!);
 root.render(
@@ -44,6 +38,7 @@ async function fetchInitialData() {
       "Fetched providers via UnstoppableSwap HTTP API",
     );
   } catch (e) {
+    store.dispatch(registryConnectionFailed());
     logger.error(e, "Failed to fetch providers via UnstoppableSwap HTTP API");
   }
 

src-gui/src/renderer/rpc.ts

@@ -8,6 +8,7 @@ import {
   GetLogsArgs,
   GetLogsResponse,
   GetSwapInfoResponse,
+  ListSellersArgs,
   MoneroRecoveryArgs,
   ResumeSwapArgs,
   ResumeSwapResponse,
@@ -27,6 +28,7 @@ import { store } from "./store/storeRenderer";
 import { Provider } from "models/apiModel";
 import { providerToConcatenatedMultiAddr } from "utils/multiAddrUtils";
 import { MoneroRecoveryResponse } from "models/rpcModel";
+import { ListSellersResponse } from "../models/tauriModel";
 
 export async function initEventListeners() {
   // This operation is in-expensive
@@ -144,3 +146,11 @@ export async function getLogsOfSwap(
     redact,
   });
 }
+
+export async function listSellersAtRendezvousPoint(
+  rendezvousPointAddress: string,
+): Promise<ListSellersResponse> {
+  return await invoke<ListSellersArgs, ListSellersResponse>("list_sellers", {
+    rendezvous_point: rendezvousPointAddress,
+  });
+}

src-gui/src/store/features/providersSlice.ts

@@ -1,6 +1,8 @@
 import { createSlice, PayloadAction } from "@reduxjs/toolkit";
 import { ExtendedProviderStatus, ProviderStatus } from "models/apiModel";
+import { Seller } from "models/tauriModel";
 import { getStubTestnetProvider } from "store/config";
+import { rendezvousSellerToProviderStatus } from "utils/conversionUtils";
 import { isProviderCompatible } from "utils/multiAddrUtils";
 import { sortProviderList } from "utils/sortUtils";
 
@@ -12,7 +14,8 @@ export interface ProvidersSlice {
   };
   registry: {
     providers: ExtendedProviderStatus[] | null;
-    failedReconnectAttemptsSinceLastSuccess: number;
+    // This counts how many failed connections attempts we have counted since the last successful connection
+    connectionFailsCount: number;
   };
   selectedProvider: ExtendedProviderStatus | null;
 }
@@ -23,7 +26,7 @@ const initialState: ProvidersSlice = {
   },
   registry: {
     providers: stubTestnetProvider ? [stubTestnetProvider] : null,
-    failedReconnectAttemptsSinceLastSuccess: 0,
+    connectionFailsCount: 0,
   },
   selectedProvider: null,
 };
@@ -47,35 +50,42 @@ export const providersSlice = createSlice({
   name: "providers",
   initialState,
   reducers: {
-    discoveredProvidersByRendezvous(
-      slice,
-      action: PayloadAction<ProviderStatus[]>,
-    ) {
-      action.payload.forEach((discoveredProvider) => {
+    discoveredProvidersByRendezvous(slice, action: PayloadAction<Seller[]>) {
+      action.payload.forEach((discoveredSeller) => {
+        const discoveredProviderStatus =
+          rendezvousSellerToProviderStatus(discoveredSeller);
+
+        // If the seller has a status of "Unreachable" the provider is not added to the list
+        if (discoveredProviderStatus === null) {
+          return;
+        }
+
+        // If the provider was already discovered via the public registry, don't add it again
         if (
           !slice.registry.providers?.some(
             (prov) =>
-              prov.peerId === discoveredProvider.peerId &&
-              prov.multiAddr === discoveredProvider.multiAddr,
+              prov.peerId === discoveredProviderStatus.peerId &&
+              prov.multiAddr === discoveredProviderStatus.multiAddr,
           )
         ) {
           const indexOfExistingProvider = slice.rendezvous.providers.findIndex(
             (prov) =>
-              prov.peerId === discoveredProvider.peerId &&
-              prov.multiAddr === discoveredProvider.multiAddr,
+              prov.peerId === discoveredProviderStatus.peerId &&
+              prov.multiAddr === discoveredProviderStatus.multiAddr,
           );
 
-          // Avoid duplicates, replace instead
+          // Avoid duplicate entries, replace them instead
           if (indexOfExistingProvider !== -1) {
             slice.rendezvous.providers[indexOfExistingProvider] =
-              discoveredProvider;
+              discoveredProviderStatus;
           } else {
-            slice.rendezvous.providers.push(discoveredProvider);
+            slice.rendezvous.providers.push(discoveredProviderStatus);
           }
         }
       });
 
       slice.rendezvous.providers = sortProviderList(slice.rendezvous.providers);
+      slice.selectedProvider = selectNewSelectedProvider(slice);
     },
     setRegistryProviders(
       slice,
@@ -90,8 +100,8 @@ export const providersSlice = createSlice({
       );
       slice.selectedProvider = selectNewSelectedProvider(slice);
     },
-    increaseFailedRegistryReconnectAttemptsSinceLastSuccess(slice) {
-      slice.registry.failedReconnectAttemptsSinceLastSuccess += 1;
+    registryConnectionFailed(slice) {
+      slice.registry.connectionFailsCount += 1;
     },
     setSelectedProvider(
       slice,
@@ -110,7 +120,7 @@ export const providersSlice = createSlice({
 export const {
   discoveredProvidersByRendezvous,
   setRegistryProviders,
-  increaseFailedRegistryReconnectAttemptsSinceLastSuccess,
+  registryConnectionFailed,
   setSelectedProvider,
 } = providersSlice.actions;
 

src-gui/src/utils/conversionUtils.ts

@@ -1,3 +1,8 @@
+import { ProviderStatus } from "models/apiModel";
+import { Seller } from "models/tauriModel";
+import { isTestnet } from "store/config";
+import { splitPeerIdFromMultiAddress } from "./parseUtils";
+
 export function satsToBtc(sats: number): number {
   return sats / 100000000;
 }
@@ -40,3 +45,25 @@ export function getMoneroTxExplorerUrl(txid: string, stagenet: boolean) {
 export function secondsToDays(seconds: number): number {
   return seconds / 86400;
 }
+
+// Convert the "Seller" object returned by the list sellers tauri endpoint to a "ProviderStatus" object
+// which we use internally to represent the status of a provider. This provides consistency between
+// the models returned by the public registry and the models used internally.
+export function rendezvousSellerToProviderStatus(
+  seller: Seller,
+): ProviderStatus | null {
+  if (seller.status.type === "Unreachable") {
+    return null;
+  }
+
+  const [multiAddr, peerId] = splitPeerIdFromMultiAddress(seller.multiaddr);
+
+  return {
+    maxSwapAmount: seller.status.content.max_quantity,
+    minSwapAmount: seller.status.content.min_quantity,
+    price: seller.status.content.price,
+    peerId,
+    multiAddr,
+    testnet: isTestnet(),
+  };
+}

src-gui/src/utils/parseUtils.ts

@@ -1,4 +1,5 @@
 import { CliLog } from "models/cliModel";
+import { Multiaddr } from "multiaddr";
 
 /*
 Extract btc amount from string
@@ -72,3 +73,38 @@ export function getLogsFromRawFileString(rawFileData: string): CliLog[] {
 export function logsToRawString(logs: (CliLog | string)[]): string {
   return logs.map((l) => JSON.stringify(l)).join("\n");
 }
+
+// This function checks if a given multi address string is a valid multi address
+// and contains a peer ID component.
+export function isValidMultiAddressWithPeerId(
+  multiAddressStr: string,
+): boolean {
+  try {
+    const multiAddress = new Multiaddr(multiAddressStr);
+    const peerId = multiAddress.getPeerId();
+
+    return peerId !== null;
+  } catch {
+    return false;
+  }
+}
+
+// This function splits a multi address string into the multi address and peer ID components.
+// It throws an error if the multi address string is invalid or does not contain a peer ID component.
+export function splitPeerIdFromMultiAddress(
+  multiAddressStr: string,
+): [multiAddress: string, peerId: string] {
+  const multiAddress = new Multiaddr(multiAddressStr);
+
+  // Extract the peer ID
+  const peerId = multiAddress.getPeerId();
+
+  if (peerId) {
+    // Remove the peer ID component
+    const p2pMultiaddr = new Multiaddr("/p2p/" + peerId);
+    const multiAddressWithoutPeerId = multiAddress.decapsulate(p2pMultiaddr);
+    return [multiAddressWithoutPeerId.toString(), peerId];
+  } else {
+    throw new Error("No peer id encapsulated in multi address");
+  }
+}

src-tauri/src/lib.rs

@@ -4,7 +4,8 @@ use swap::cli::{
     api::{
         request::{
             BalanceArgs, BuyXmrArgs, GetHistoryArgs, GetLogsArgs, GetSwapInfosAllArgs,
-            MoneroRecoveryArgs, ResumeSwapArgs, SuspendCurrentSwapArgs, WithdrawBtcArgs,
+            ListSellersArgs, MoneroRecoveryArgs, ResumeSwapArgs, SuspendCurrentSwapArgs,
+            WithdrawBtcArgs,
         },
         tauri_bindings::{TauriContextStatusEvent, TauriEmitter, TauriHandle},
         Context, ContextBuilder,
@@ -169,6 +170,7 @@ pub fn run() {
             get_history,
             monero_recovery,
             get_logs,
+            list_sellers,
             suspend_current_swap,
             is_context_available,
         ])
@@ -208,6 +210,7 @@ tauri_command!(resume_swap, ResumeSwapArgs);
 tauri_command!(withdraw_btc, WithdrawBtcArgs);
 tauri_command!(monero_recovery, MoneroRecoveryArgs);
 tauri_command!(get_logs, GetLogsArgs);
+tauri_command!(list_sellers, ListSellersArgs);
 
 // These commands require no arguments
 tauri_command!(suspend_current_swap, SuspendCurrentSwapArgs, no_args);

swap/src/cli/api/request.rs

@@ -2,7 +2,7 @@ use super::tauri_bindings::TauriHandle;
 use crate::bitcoin::{CancelTimelock, ExpiredTimelocks, PunishTimelock, TxLock};
 use crate::cli::api::tauri_bindings::{TauriEmitter, TauriSwapProgressEvent};
 use crate::cli::api::Context;
-use crate::cli::{list_sellers as list_sellers_impl, EventLoop, SellerStatus};
+use crate::cli::{list_sellers as list_sellers_impl, EventLoop, Seller, SellerStatus};
 use crate::common::get_logs;
 use crate::libp2p_ext::MultiAddrExt;
 use crate::network::quote::{BidQuote, ZeroQuoteReceived};
@@ -156,8 +156,14 @@ pub struct ListSellersArgs {
     pub rendezvous_point: Multiaddr,
 }
 
+#[typeshare]
+#[derive(Debug, Eq, PartialEq, Serialize)]
+pub struct ListSellersResponse {
+    sellers: Vec<Seller>,
+}
+
 impl Request for ListSellersArgs {
-    type Response = serde_json::Value;
+    type Response = ListSellersResponse;
 
     async fn request(self, ctx: Arc<Context>) -> Result<Self::Response> {
         list_sellers(self, ctx).await
@@ -193,7 +199,7 @@ pub struct GetSwapInfoArgs {
 pub struct GetSwapInfoResponse {
     #[typeshare(serialized_as = "string")]
     pub swap_id: Uuid,
-    pub seller: Seller,
+    pub seller: AliceAddress,
     pub completed: bool,
     pub start_date: String,
     #[typeshare(serialized_as = "string")]
@@ -280,8 +286,8 @@ impl Request for GetHistoryArgs {
 
 // Additional structs
 #[typeshare]
-#[derive(Serialize, Deserialize, Debug)]
-pub struct Seller {
+#[derive(Serialize, Deserialize, Debug, PartialEq, Eq)]
+pub struct AliceAddress {
     #[typeshare(serialized_as = "string")]
     pub peer_id: PeerId,
     pub addresses: Vec<String>,
@@ -507,7 +513,7 @@ pub async fn get_swap_info(
 
     Ok(GetSwapInfoResponse {
         swap_id: args.swap_id,
-        seller: Seller {
+        seller: AliceAddress {
             peer_id,
             addresses: addresses.iter().map(|a| a.to_string()).collect(),
         },
@@ -1016,7 +1022,7 @@ pub async fn get_balance(balance: BalanceArgs, context: Arc<Context>) -> Result<
 pub async fn list_sellers(
     list_sellers: ListSellersArgs,
     context: Arc<Context>,
-) -> Result<serde_json::Value> {
+) -> Result<ListSellersResponse> {
     let ListSellersArgs { rendezvous_point } = list_sellers;
     let rendezvous_node_peer_id = rendezvous_point
         .extract_peer_id()
@@ -1060,7 +1066,7 @@ pub async fn list_sellers(
         }
     }
 
-    Ok(json!({ "sellers": sellers }))
+    Ok(ListSellersResponse { sellers })
 }
 
 #[tracing::instrument(fields(method = "export_bitcoin_wallet"), skip(context))]

swap/src/cli/list_sellers.rs

@@ -14,6 +14,7 @@ use serde_with::{serde_as, DisplayFromStr};
 use std::collections::hash_map::Entry;
 use std::collections::HashMap;
 use std::time::Duration;
+use typeshare::typeshare;
 
 /// Returns sorted list of sellers, with [Online](Status::Online) listed first.
 ///
@@ -60,14 +61,18 @@ pub async fn list_sellers(
 }
 
 #[serde_as]
+#[typeshare]
 #[derive(Debug, Serialize, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct Seller {
     pub status: Status,
     #[serde_as(as = "DisplayFromStr")]
+    #[typeshare(serialized_as = "string")]
     pub multiaddr: Multiaddr,
 }
 
+#[typeshare]
 #[derive(Debug, Serialize, PartialEq, Eq, Hash, Copy, Clone, Ord, PartialOrd)]
+#[serde(tag = "type", content = "content")]
 pub enum Status {
     Online(BidQuote),
     Unreachable,

swap/src/protocol/bob/swap.rs

@@ -398,6 +398,14 @@ async fn next_state(
                 }
                 ExpiredTimelocks::Cancel { .. } => {
                     state.publish_refund_btc(bitcoin_wallet).await?;
+
+                    event_emitter.emit_swap_progress_event(
+                        swap_id,
+                        TauriSwapProgressEvent::BtcRefunded {
+                            btc_refund_txid: state.signed_refund_transaction()?.txid(),
+                        },
+                    );
+
                     BobState::BtcRefunded(state)
                 }
                 ExpiredTimelocks::Punish => {