feat: integrate Firebase Cloud Messaging for push notifications

app/utils/firebase.js

@@ -0,0 +1,63 @@
+import { initializeApp, getApps } from "firebase/app";
+import { getMessaging, getToken, onMessage } from "firebase/messaging";
+
+const firebaseConfig = {
+  apiKey: "AIzaSyBZV7KBLRJSTApahfrO8lBesmIM3zNRSaY",
+  authDomain: "sweet-home-b2766.firebaseapp.com",
+  projectId: "sweet-home-b2766",
+  storageBucket: "sweet-home-b2766.firebasestorage.app",
+  messagingSenderId: "602865114600",
+  appId: "1:602865114600:web:ed9b6754940507a6ab585d",
+  measurementId: "G-M2V95NBJLX",
+};
+
+// Initialize Firebase (avoid duplicate init in SSR)
+const app = getApps().length === 0 ? initializeApp(firebaseConfig) : getApps()[0];
+
+// Get messaging instance (only works in browser)
+let messaging = null;
+if (typeof window !== "undefined" && "serviceWorker" in navigator) {
+  try {
+    messaging = getMessaging(app);
+  } catch (e) {
+    console.warn("[Firebase] Messaging init failed:", e.message);
+  }
+}
+
+// Request notification permission and get FCM token
+export async function requestNotificationPermission() {
+  if (typeof window === "undefined") return null;
+
+  try {
+    const permission = await Notification.requestPermission();
+    if (permission !== "granted") {
+      console.log("[FCM] Notification permission denied");
+      return null;
+    }
+
+    const registration = await navigator.serviceWorker.register("/firebase-messaging-sw.js");
+
+    const token = await getToken(messaging, {
+      vapidKey: "BO0tGzMOqN3xQp8IG2wQEXwJKUJfx7T3eVvLq3HjC2Q", // TODO: Replace with your VAPID key from Firebase Console
+      serviceWorkerRegistration: registration,
+    });
+
+    console.log("[FCM] Token:", token);
+    return token;
+  } catch (err) {
+    console.error("[FCM] Error getting token:", err);
+    return null;
+  }
+}
+
+// Listen for foreground messages
+export function onForegroundMessage(callback) {
+  if (!messaging) return () => {};
+
+  return onMessage(messaging, (payload) => {
+    console.log("[FCM] Foreground message:", payload);
+    callback(payload);
+  });
+}
+
+export { app, messaging };