feat(desktop): add native reply notifications

desktop/src/main.ts

@@ -19,6 +19,10 @@ import {
 import type { IpcMainInvokeEvent, WebContents } from "electron";
 
 import { UnixWebSocketClient } from "./unixWebSocket.js";
+import {
+  clearDesktopNotificationBadge,
+  handleDesktopNotificationFrame,
+} from "./notifications.js";
 
 type EngineStatus = "starting" | "ready" | "restarting" | "stopped" | "crashed";
 
@@ -547,6 +551,7 @@ function createWindow(): BrowserWindow {
   });
 
   win.once("ready-to-show", () => win.show());
+  win.on("focus", clearDesktopNotificationBadge);
   win.webContents.setWindowOpenHandler(({ url }) => {
     openExternalIfSafe(url);
     return { action: "deny" };
@@ -622,7 +627,10 @@ function registerIpcHandlers(): void {
     const id = randomBytes(12).toString("hex");
     const client = new UnixWebSocketClient(runtime.socketPath, url, {
       onOpen: () => sendToRenderer(event.sender, "nanobot:ws-event", { id, type: "open" }),
-      onMessage: (data) => sendToRenderer(event.sender, "nanobot:ws-event", { id, type: "message", data }),
+      onMessage: (data) => {
+        handleDesktopNotificationFrame(data, { getWindow: () => mainWindow });
+        sendToRenderer(event.sender, "nanobot:ws-event", { id, type: "message", data });
+      },
       onError: (message) => sendToRenderer(event.sender, "nanobot:ws-event", { id, type: "error", message }),
       onClose: (code, reason) => {
         hostSockets.delete(id);

desktop/src/notifications.ts

@@ -0,0 +1,123 @@
+import {
+  app,
+  BrowserWindow,
+  Notification,
+} from "electron";
+
+type NotificationSource = {
+  kind?: unknown;
+  label?: unknown;
+};
+
+type WsMessageFrame = {
+  chat_id?: unknown;
+  event?: unknown;
+  kind?: unknown;
+  source?: NotificationSource;
+  text?: unknown;
+};
+
+interface DesktopNotifierOptions {
+  getWindow: () => BrowserWindow | null;
+}
+
+const MAX_NOTIFICATION_BODY_LENGTH = 180;
+const MAX_NOTIFICATION_TITLE_LENGTH = 80;
+
+let unreadNotificationCount = 0;
+
+export function handleDesktopNotificationFrame(
+  data: string,
+  options: DesktopNotifierOptions,
+): void {
+  const frame = parseWsMessageFrame(data);
+  if (!frame || !isAssistantNotificationFrame(frame)) return;
+  if (!shouldNotify(options.getWindow())) return;
+  showDesktopNotification(frame, options);
+}
+
+export function clearDesktopNotificationBadge(): void {
+  unreadNotificationCount = 0;
+  app.setBadgeCount(0);
+}
+
+function parseWsMessageFrame(data: string): WsMessageFrame | null {
+  try {
+    const parsed = JSON.parse(data) as unknown;
+    return parsed && typeof parsed === "object"
+      ? parsed as WsMessageFrame
+      : null;
+  } catch {
+    return null;
+  }
+}
+
+function isAssistantNotificationFrame(frame: WsMessageFrame): frame is WsMessageFrame & {
+  chat_id: string;
+  text: string;
+} {
+  return (
+    frame.event === "message" &&
+    typeof frame.chat_id === "string" &&
+    typeof frame.text === "string" &&
+    frame.text.trim().length > 0 &&
+    frame.kind !== "tool_hint" &&
+    frame.kind !== "progress" &&
+    frame.kind !== "reasoning"
+  );
+}
+
+function shouldNotify(win: BrowserWindow | null): boolean {
+  if (!Notification.isSupported()) return false;
+  if (!win || win.isDestroyed()) return false;
+  return !win.isFocused();
+}
+
+function showDesktopNotification(
+  frame: WsMessageFrame & { chat_id: string; text: string },
+  options: DesktopNotifierOptions,
+): void {
+  const notification = new Notification({
+    title: notificationTitle(frame.source),
+    body: notificationBody(frame.text),
+    subtitle: "nanobot",
+  });
+  notification.on("click", () => openChatFromNotification(frame.chat_id, options));
+  notification.show();
+  unreadNotificationCount += 1;
+  app.setBadgeCount(unreadNotificationCount);
+}
+
+function notificationTitle(source: NotificationSource | undefined): string {
+  if (source?.kind === "cron" && typeof source.label === "string") {
+    const label = source.label.trim();
+    if (label) return truncateText(label, MAX_NOTIFICATION_TITLE_LENGTH);
+  }
+  return "nanobot";
+}
+
+function notificationBody(text: string): string {
+  const compact = text.replace(/\s+/g, " ").trim();
+  return truncateText(compact, MAX_NOTIFICATION_BODY_LENGTH);
+}
+
+function truncateText(text: string, maxLength: number): string {
+  if (text.length <= maxLength) return text;
+  return `${text.slice(0, maxLength - 3)}...`;
+}
+
+function openChatFromNotification(chatId: string, options: DesktopNotifierOptions): void {
+  const win = options.getWindow();
+  if (!win || win.isDestroyed()) return;
+  if (win.isMinimized()) win.restore();
+  if (!win.isVisible()) win.show();
+  win.focus();
+  clearDesktopNotificationBadge();
+
+  const sessionKey = `websocket:${chatId}`;
+  const hash = `#/chat/${encodeURIComponent(sessionKey)}`;
+  void win.webContents.executeJavaScript(
+    `window.location.hash = ${JSON.stringify(hash)}`,
+    true,
+  ).catch(() => {});
+}