server-26/drb-frontend/lib/firebase.ts

import { initializeApp, getApps, getApp } from "firebase/app";
import { getFirestore } from "firebase/firestore";
import { getAuth } from "firebase/auth";

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,
};

const app = getApps().length ? getApp() : initializeApp(firebaseConfig);
const databaseId = process.env.NEXT_PUBLIC_FIRESTORE_DATABASE || "(default)";
export const db = getFirestore(app, databaseId);
export const auth = getAuth(app);
export { app };