feat: implement Firebase Admin SDK push notification logic in server.js with fallback support

whatsapp_bridge/server.js

@@ -16,6 +16,72 @@ const app = express();
 const server = http.createServer(app);
 const wss = new WebSocketServer({ server });
 
+// ─── Firebase Admin SDK Configuration (Optional Background Pushes) ─────────
+const admin = require('firebase-admin');
+const path = require('path');
+const fs = require('fs');
+
+let firebaseApp = null;
+const serviceAccountPath = path.join(__dirname, 'serviceAccountKey.json');
+
+if (fs.existsSync(serviceAccountPath)) {
+  try {
+    const serviceAccount = require(serviceAccountPath);
+    firebaseApp = admin.initializeApp({
+      credential: admin.credential.cert(serviceAccount)
+    });
+    console.log('[FCM] Firebase Admin SDK initialized successfully using serviceAccountKey.json');
+  } catch (err) {
+    console.error('[FCM ERROR] Failed to initialize Firebase Admin SDK:', err.message);
+  }
+} else {
+  console.warn('[FCM WARNING] serviceAccountKey.json not found in server directory. Background push notifications will be disabled.');
+}
+
+async function sendPushNotification(chatId, senderName, body) {
+  if (!firebaseApp) {
+    console.log('[FCM] Push skipped: Firebase Admin SDK not initialized.');
+    return;
+  }
+
+  const tokenPath = path.join(__dirname, 'fcm_token.json');
+  if (!fs.existsSync(tokenPath)) {
+    console.log('[FCM] Push skipped: No registered FCM device token found.');
+    return;
+  }
+
+  try {
+    const tokenData = JSON.parse(fs.readFileSync(tokenPath));
+    const token = tokenData.token;
+    if (!token) return;
+
+    const message = {
+      token: token,
+      notification: {
+        title: senderName || 'WhatsApp Message',
+        body: body || 'New Message'
+      },
+      data: {
+        chatId: chatId,
+        name: senderName || 'WhatsApp'
+      },
+      apns: {
+        payload: {
+          aps: {
+            sound: 'default',
+            badge: 1
+          }
+        }
+      }
+    };
+
+    const response = await admin.messaging().send(message);
+    console.log('[FCM] Push notification sent successfully, messageId:', response);
+  } catch (err) {
+    console.error('[FCM SEND ERROR] Failed to send push notification:', err.message);
+  }
+}
+
 // ─── State ─────────────────────────────────────────────────────────────────
 let waClient = null;
 let clientReady = false;
@@ -216,6 +282,21 @@ function initWhatsApp() {
     try {
       const formatted = formatMessage(msg);
       broadcast({ type: 'new_message', chatId: msg.from, data: formatted });
+
+      // Trigger background push notification if not sent by me
+      if (!msg.fromMe) {
+        try {
+          const contact = await msg.getContact();
+          const senderName = contact.name || contact.pushname || msg.from.split('@')[0];
+          let body = msg.body || '';
+          if (!body && msg.hasMedia) {
+            body = '📷 Media/Attachment';
+          }
+          await sendPushNotification(msg.from, senderName, body);
+        } catch (fcmErr) {
+          console.error('[FCM PUSH ERROR] Failed to send background push:', fcmErr.message);
+        }
+      }
     } catch (err) {
       console.error('[WA] Error formatting new message event:', err.message);
     }