import { MongoClient, type Db } from "mongodb";

let client: MongoClient | null = null;
let db: Db | null = null;

export async function getDb(): Promise<Db> {
  if (db) return db;

  const uri = useRuntimeConfig().db;
  if (!uri) throw new Error("NUXT_DB is not configured");

  client = new MongoClient(uri);
  await client.connect();
  db = client.db("vat-api");

  // Create indexes for the requests collection
  const requests = db.collection("requests");
  await requests.createIndex({ timestamp: -1 });
  await requests.createIndex({ ip: 1, timestamp: -1 });

  return db;
}

export async function closeDb(): Promise<void> {
  if (client) {
    await client.close();
    client = null;
    db = null;
  }
}