feat: add Baileys WhatsApp session with reconnect logic

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/worker/package.json

@@ -8,6 +8,7 @@
     "test": "jest"
   },
   "dependencies": {
+    "@hapi/boom": "^10.0.1",
     "@tower/config": "workspace:*",
     "@tower/logger": "workspace:*",
     "@tower/types": "workspace:*",

apps/worker/src/whatsapp/session.ts

@@ -0,0 +1,58 @@
+import makeWASocket, {
+  useMultiFileAuthState,
+  fetchLatestBaileysVersion,
+  DisconnectReason,
+  WASocket,
+  proto,
+  GroupMetadata,
+} from '@whiskeysockets/baileys';
+import { Boom } from '@hapi/boom';
+import { createLogger } from '@tower/logger';
+
+const logger = createLogger('whatsapp-session');
+
+export type OnMessageCallback = (msg: proto.IWebMessageInfo) => void;
+export type OnGroupsCallback = (groups: Record<string, GroupMetadata>) => void;
+
+export async function createWhatsAppSession(
+  sessionPath: string,
+  onMessage: OnMessageCallback,
+  onGroups: OnGroupsCallback,
+): Promise<WASocket> {
+  const { state, saveCreds } = await useMultiFileAuthState(sessionPath);
+  const { version } = await fetchLatestBaileysVersion();
+
+  const sock = makeWASocket({
+    version,
+    auth: state,
+    printQRInTerminal: true,
+    logger: logger as any,
+  });
+
+  sock.ev.on('creds.update', saveCreds);
+
+  sock.ev.on('connection.update', async ({ connection, lastDisconnect }) => {
+    if (connection === 'close') {
+      const reason = (lastDisconnect?.error as Boom)?.output?.statusCode;
+      const shouldReconnect = reason !== DisconnectReason.loggedOut;
+      logger.info({ reason, shouldReconnect }, 'Connection closed');
+      if (shouldReconnect) {
+        logger.info('Reconnecting in 5s...');
+        setTimeout(() => createWhatsAppSession(sessionPath, onMessage, onGroups), 5000);
+      }
+    } else if (connection === 'open') {
+      logger.info('WhatsApp connected');
+      const groups = await sock.groupFetchAllParticipating();
+      onGroups(groups);
+    }
+  });
+
+  sock.ev.on('messages.upsert', ({ messages, type }) => {
+    if (type !== 'notify') return;
+    for (const msg of messages) {
+      onMessage(msg);
+    }
+  });
+
+  return sock;
+}