Add currency settings, Settings service, and dialog to select fiat currency. Add support for non Official currencies like DOGE when using rates.

src/services/rates.ts

@@ -3,6 +3,7 @@ import {
   type RatesEventMap,
 } from '../utils/rates/base-rates.js';
 import { RatesOracle } from '../utils/rates/rates-oracles.js';
+import { SettingsService } from './settings.js';
 
 /**
  * Event map emitted by {@link RatesService}.
@@ -52,13 +53,15 @@ export interface RatesAdapter {
  */
 export class RatesService extends EventEmitter<RatesServiceEventMap> {
   private readonly adapter: RatesAdapter;
+  private readonly settings: SettingsService;
   private readonly ratesByPair = new Map<string, CachedRate>();
   private unsubscribeFromAdapter: (() => void) | null = null;
   private started = false;
 
-  constructor(adapter: RatesAdapter) {
+  constructor(adapter: RatesAdapter, settings: SettingsService) {
     super();
     this.adapter = adapter;
+    this.settings = settings;
   }
 
   /**
@@ -66,9 +69,12 @@ export class RatesService extends EventEmitter<RatesServiceEventMap> {
    *
    * If no adapter is passed, this defaults to the Oracle-backed adapter.
    */
-  public static async create(adapter?: RatesAdapter): Promise<RatesService> {
-    const resolvedAdapter = adapter ?? (await RatesOracle.from());
-    return new RatesService(resolvedAdapter);
+  public static async create(
+    settings: SettingsService,
+    adapter?: RatesAdapter,
+  ): Promise<RatesService> {
+    const resolvedAdapter = adapter ?? (await RatesOracle.from(undefined, settings));
+    return new RatesService(resolvedAdapter, settings);
   }
 
   /**
@@ -162,6 +168,20 @@ export class RatesService extends EventEmitter<RatesServiceEventMap> {
     return this.adapter.formatCurrency(amount, currencyCode.toUpperCase());
   }
 
+  /**
+   * Lists available market pairs in NUMERATOR/DENOMINATOR format.
+   */
+  public async listPairs(): Promise<Set<string>> {
+    return this.adapter.listPairs();
+  }
+
+  /**
+   * Returns the fiat currency currently configured in settings.
+   */
+  public getConfiguredCurrency(): string {
+    return this.settings.getCurrency();
+  }
+
   /**
    * Handles normalized updates from the underlying adapter.
    */