const { MongoClient, ObjectId } = require('mongodb');
const { config } = require('../config');

const USER = encodeURIComponent(config.dbUser);
const PASSWORD = encodeURIComponent(config.dbPassword);
const DB_NAME = config.dbName;
const HOST = config.dbHost;
const PORT = config.dbPort;

// const MONGO_URI = `mongodb+srv://${USER}:${PASSWORD}@${HOST}/${DB_NAME}?retryWrites=true&w=majority`
const MONGO_URI = `mongodb://127.0.0.1:27017/${DB_NAME}`

class MongoLib {
  constructor() {
    this.client = new MongoClient(MONGO_URI, { useNewUrlParser: true });
    this.dbName = DB_NAME;
  }

  connect() {
    if (MongoLib.connection) return MongoLib.connection;
    MongoLib.connection = new Promise((resolve, reject) => {
      this.client.connect(err => {
        if (err) {
          reject(err);
        }
        console.log('MongoDB connected');
        resolve(this.client.db(this.dbName))
      });
    });
    return MongoLib.connection;
  }

  getAll(collection, query) {
    return this.connect().then(db => {
      return db.collection(collection).find(query).toArray();
    });
  }

  get(collection, id) {
    return this.connect().then(db => {
      return db.collection(collection).findOne({_id: ObjectId(id)});
    });

  }

  create(collection, data) {
    return this.connect()
      .then(db => {
        return db.collection(collection).insertOne(data);
      })
      .then(result => result.insertedId);
  }

  update(collection, id, data) {
    return this.connect()
      .then(db => {
        return db.collection(collection).updateOne({_id: ObjectId(id) }, { $set: data });
      })
      .then(result => result.upsertedId || id);
  }

  delete(collection, id) {
    return this.connect()
      .then(db => {
        return db.collection(collection).deleteOne({_id: ObjectId(id)});
      })
      .then(() => id);
  }
}

module.exports = MongoLib;