import { Db, MongoClient } from 'mongodb';
import { AddPayload, DeletePayload, UpdatePayload } from '../websockets/interfaces';

export class MongoConnector {
  private _URL = 'mongodb://localhost:27017/';
  private _DBNAME = 'mongorx';
  private _db: Db;
  private _is_initialized: boolean;

  constructor() {
    this._is_initialized = false;
    this.initialize();
  }

  async initialize(): Promise<MongoConnector> {
    const client = await MongoClient.connect(
      this._URL,
      { useNewUrlParser: true }
    );
    this._db = client.db(this._DBNAME);
    this._is_initialized = true;
    return this;
  }

  add(bucket_id: string, payload: AddPayload): AddPayload {
    this._check_init();
    this._db.collection(bucket_id).insertMany(payload.items);
    return payload;
  }
  update(bucket_id: string, payload: UpdatePayload): UpdatePayload {
    this._check_init();
    payload.updates.forEach(update => {
      this._db.collection(bucket_id).update({ id: update.id }, update);
    });
    return payload;
  }
  delete(bucket_id: string, payload: DeletePayload): DeletePayload {
    this._check_init();
    payload.ids.forEach(id => {
      this._db.collection(bucket_id).deleteOne({ id });
    });
    return payload;
  }

  private _check_init() {
    if (!this._is_initialized) {
      throw new Error('Not initialized.');
    }
  }
}