import { initializeApp, getApps, getApp } from "firebase/app";
import { getMessaging, Messaging, getToken, onMessage } from "firebase/messaging";

const firebaseConfig = {
    apiKey: process.env.NEXT_PUBLIC_FIREBASE_API_KEY,
    authDomain: process.env.NEXT_PUBLIC_FIREBASE_AUTH_DOMAIN,
    projectId: process.env.NEXT_PUBLIC_FIREBASE_PROJECT_ID,
    storageBucket: process.env.NEXT_PUBLIC_FIREBASE_STORAGE_BUCKET,
    messagingSenderId: process.env.NEXT_PUBLIC_FIREBASE_MESSAGING_SENDER_ID,
    appId: process.env.NEXT_PUBLIC_FIREBASE_APP_ID,
    measurementId: process.env.NEXT_PUBLIC_FIREBASE_MEASUREMENT_ID,
};

// Initialize Firebase
const app = getApps().length === 0 ? initializeApp(firebaseConfig) : getApp();

let messaging: Messaging | null = null;

if (typeof window !== "undefined") {
    messaging = getMessaging(app);
}

export { app, messaging };

export const requestForToken = async () => {
    if (!messaging) return null;

    try {
        const currentToken = await getToken(messaging, {
            vapidKey: process.env.NEXT_PUBLIC_FIREBASE_VAPID_KEY,
        });
        if (currentToken) {
            return currentToken;
        } else {
            return null;
        }
    } catch (err) {
        console.error("An error occurred while retrieving token:", err);
        return null;
    }
};

export const onMessageListener = (callback: (payload: any) => void) => {
    if (!messaging) return () => { };
    return onMessage(messaging, (payload) => {
        callback(payload);
    });
};