import { initializeApp, getApps, FirebaseApp } from 'firebase/app';
import { getAuth, Auth } from 'firebase/auth';
import { getFirestore, Firestore } from 'firebase/firestore';
import { getStorage, FirebaseStorage } from 'firebase/storage';

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,
};

// Only initialize if we have the API key (skip during build and if no config)
let _app: FirebaseApp | undefined;
let _auth: Auth | undefined;
let _db: Firestore | undefined;
let _storage: FirebaseStorage | undefined;

// Check if Firebase is properly configured
const isFirebaseConfigured = firebaseConfig.apiKey && 
                              firebaseConfig.authDomain && 
                              firebaseConfig.projectId;

if (isFirebaseConfigured && (typeof window !== 'undefined' || firebaseConfig.apiKey)) {
  try {
    // Initialize Firebase (client-side only, safe for browser)
    _app = getApps().length === 0 ? initializeApp(firebaseConfig) : getApps()[0];
    _auth = getAuth(_app);
    _db = getFirestore(_app);
    _storage = getStorage(_app);
  } catch (error) {
    console.warn('Firebase initialization skipped - no credentials configured');
  }
} else {
  console.warn('Firebase not configured - using PostgreSQL backend');
}

// Export with type assertions - these will be defined at runtime in the browser
// During build, they may be undefined, but won't be accessed
export const auth = _auth as Auth;
export const db = _db as Firestore;
export const storage = _storage as FirebaseStorage;
export default _app;