import {MongoClient} from "mongodb";

if (!process.env.MONGODB_URI) {
	throw new Error('Invalid/Missing environment variable: "MONGODB_URI"');
}

const uri = process.env.MONGODB_URI || "";
const options = {};

let client: MongoClient;

if (process.env.NODE_ENV === "development") {
	// In development mode, use a global variable so that the value
	// is preserved across module reloads caused by HMR (Hot Module Replacement).
	let globalWithMongo = global as typeof globalThis & {
		_mongoClient?: MongoClient;
	};

	if (!globalWithMongo._mongoClient) {
		globalWithMongo._mongoClient = new MongoClient(uri, options);
	}
	client = globalWithMongo._mongoClient;
} else {
	// In production mode, it's best to not use a global variable.
	client = new MongoClient(uri, options);
}

// Export a module-scoped MongoClient. By doing this in a
// separate module, the client can be shared across functions.
export default client;
