import { MongoClient } from "mongodb";
import { getConfig, getMongoUri, hasMongoConfig } from "./config.js";

const DEFAULT_DB_NAME = "arena_picker";

let mongoClient;
let mongoClientPromise;

export { hasMongoConfig };

export async function getMongoClient() {
  if (mongoClient) {
    return mongoClient;
  }

  if (!mongoClientPromise) {
    const appConfig = getConfig();
    const client = new MongoClient(getMongoUri(), {
      maxPoolSize: appConfig.MONGODB_MAX_POOL_SIZE,
      serverSelectionTimeoutMS: appConfig.MONGODB_SERVER_SELECTION_TIMEOUT_MS,
    });

    mongoClientPromise = client
      .connect()
      .then((connectedClient) => {
        mongoClient = connectedClient;
        return connectedClient;
      })
      .catch((error) => {
        mongoClientPromise = undefined;
        throw error;
      });
  }

  return mongoClientPromise;
}

export async function getDb() {
  const client = await getMongoClient();
  return client.db(getConfig().MONGODB_DB || DEFAULT_DB_NAME);
}

export async function closeMongoConnection() {
  if (!mongoClient && !mongoClientPromise) {
    return;
  }

  const client = mongoClient || (await mongoClientPromise);
  mongoClient = undefined;
  mongoClientPromise = undefined;
  await client.close();
}