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

src/services/settings.ts

@@ -0,0 +1,194 @@
+import { existsSync, readFileSync, writeFileSync } from "node:fs";
+
+import { EventEmitter } from "../utils/event-emitter.js";
+import { getSettingsPath } from "../utils/paths.js";
+
+/**
+ * Supported persisted settings keys.
+ */
+export type SettingsData = {
+  "default-mnemonic"?: string;
+  currency: string;
+};
+
+/**
+ * Event payloads emitted by {@link SettingsService}.
+ */
+export type SettingsServiceEventMap = {
+  "settings-updated": {
+    key: keyof SettingsData;
+    value: string | undefined;
+    settings: SettingsData;
+  };
+};
+
+/**
+ * Runtime defaults for settings that should always exist in memory.
+ */
+const DEFAULT_SETTINGS: SettingsData = {
+  currency: "USD",
+};
+
+/**
+ * Handles loading, migrating, and persisting wallet settings.
+ *
+ * The backing file is `~/.config/xo-cli/.wallet`. Historically it stored a raw
+ * mnemonic reference string. This service migrates that legacy format to JSON:
+ * `{ "default-mnemonic": "<value>", "currency": "USD" }`.
+ */
+export class SettingsService extends EventEmitter<SettingsServiceEventMap> {
+  private readonly settingsPath: string;
+  private settings: SettingsData;
+
+  /**
+   * Creates a new settings service instance.
+   *
+   * @param settingsPath - Optional custom settings file path (useful for tests)
+   */
+  constructor(settingsPath: string = getSettingsPath()) {
+    super();
+    this.settingsPath = settingsPath;
+    this.settings = this.loadSettings();
+  }
+
+  /**
+   * Returns the current settings snapshot.
+   */
+  public getSettings(): SettingsData {
+    return { ...this.settings };
+  }
+
+  /**
+   * Returns the currently selected default mnemonic reference.
+   */
+  public getDefaultMnemonic(): string | undefined {
+    return this.settings["default-mnemonic"];
+  }
+
+  /**
+   * Updates the default mnemonic reference and persists it to disk.
+   */
+  public setDefaultMnemonic(mnemonicRef: string): void {
+    const normalizedMnemonicRef = mnemonicRef.trim();
+    if (normalizedMnemonicRef.length === 0) {
+      throw new Error("default-mnemonic cannot be empty");
+    }
+
+    this.settings["default-mnemonic"] = normalizedMnemonicRef;
+    this.persistSettings();
+
+    this.emit("settings-updated", {
+      key: "default-mnemonic",
+      value: normalizedMnemonicRef,
+      settings: this.getSettings(),
+    });
+  }
+
+  /**
+   * Returns the selected fiat currency code (ISO-like uppercase).
+   */
+  public getCurrency(): string {
+    return this.settings.currency;
+  }
+
+  /**
+   * Updates the selected fiat currency and persists it to disk.
+   */
+  public setCurrency(currencyCode: string): void {
+    const normalizedCurrency = this.normalizeCurrency(currencyCode);
+    if (this.settings.currency === normalizedCurrency) {
+      return;
+    }
+
+    this.settings.currency = normalizedCurrency;
+    this.persistSettings();
+
+    this.emit("settings-updated", {
+      key: "currency",
+      value: normalizedCurrency,
+      settings: this.getSettings(),
+    });
+  }
+
+  /**
+   * Reads and normalizes the settings file from disk.
+   *
+   * If the file contains the old legacy format (raw mnemonic string), the
+   * migrated JSON shape is written back immediately.
+   */
+  private loadSettings(): SettingsData {
+    if (!existsSync(this.settingsPath)) {
+      return { ...DEFAULT_SETTINGS };
+    }
+
+    const rawContents = readFileSync(this.settingsPath, "utf8").trim();
+    if (rawContents.length === 0) {
+      return { ...DEFAULT_SETTINGS };
+    }
+
+    try {
+      const parsed = JSON.parse(rawContents);
+      const normalized = this.normalizeSettings(parsed);
+      return normalized;
+    } catch {
+      const migrated = this.normalizeSettings({
+        "default-mnemonic": rawContents,
+      });
+      this.persistSettings(migrated);
+      return migrated;
+    }
+  }
+
+  /**
+   * Writes the given settings object to disk as pretty JSON.
+   *
+   * @param nextSettings - Optional explicit value, defaults to in-memory state
+   */
+  private persistSettings(nextSettings?: SettingsData): void {
+    if (nextSettings) {
+      this.settings = nextSettings;
+    }
+
+    writeFileSync(
+      this.settingsPath,
+      `${JSON.stringify(this.settings, null, 2)}\n`,
+      "utf8",
+    );
+  }
+
+  /**
+   * Coerces unknown input into a safe settings object.
+   */
+  private normalizeSettings(input: unknown): SettingsData {
+    const normalized: SettingsData = {
+      ...DEFAULT_SETTINGS,
+    };
+
+    if (!input || typeof input !== "object") {
+      return normalized;
+    }
+
+    const maybeMnemonic = (input as Record<string, unknown>)["default-mnemonic"];
+    if (typeof maybeMnemonic === "string" && maybeMnemonic.trim().length > 0) {
+      normalized["default-mnemonic"] = maybeMnemonic.trim();
+    }
+
+    const maybeCurrency = (input as Record<string, unknown>).currency;
+    if (typeof maybeCurrency === "string" && maybeCurrency.trim().length > 0) {
+      normalized.currency = this.normalizeCurrency(maybeCurrency);
+    }
+
+    return normalized;
+  }
+
+  /**
+   * Ensures currency values stay uppercase and non-empty.
+   */
+  private normalizeCurrency(currencyCode: string): string {
+    const normalizedCurrency = currencyCode.trim().toUpperCase();
+    if (normalizedCurrency.length === 0) {
+      throw new Error("currency cannot be empty");
+    }
+    return normalizedCurrency;
+  }
+}