Example of repository

booking.repository.js

'use strict'
const repository = (container) => {
  // we get the db object via the container
  const {db} = container.resolve('database')

  const makeBooking = (user, booking) => {
    return new Promise((resolve, reject) => {
      // payload to be insterted to the booking collection 
      const payload = {
        city: booking.city,
        cinema: booking.cinema,
        book: {
          userType: (user.membership) ? 'loyal' : 'normal',
          movie: {
            title: booking.movie.title,
            format: booking.movie.format,
            schedule: booking.schedule
          }
        }
      }

      db.collection('booking').insertOne(payload, (err, booked) => {
        if (err) {
          reject(new Error('An error occuered registring a user booking, err:' + err))
        }
        resolve(booked)
      })
    })
  }

  const generateTicket = (paid, booking) => {
    return new Promise((resolve, reject) => {
      // payload of ticket
      const payload = Object.assign({}, {booking, orderId: paid._id})
      db.collection('tickets').insertOne(payload, (err, ticket) => {
        if (err) {
          reject(new Error('an error occured registring a ticket, err:' + err))
        }
        resolve(ticket)
      })
    })
  }

  const getOrderById = (orderId) => {
    return new Promise((resolve, reject) => {
      const ObjectID = container.resolve('ObjectID')
      const query = {_id: new ObjectID(orderId)}
      const response = (err, order) => {
        if (err) {
          reject(new Error('An error occuered retrieving a order, err: ' + err))
        }
        resolve(order)
      }
      db.collection('booking').findOne(query, {}, response)
    })
  }

  const disconnect = () => {
    db.close()
  }

  return Object.create({
    makeBooking,
    getOrderById,
    generateTicket,
    disconnect
  })
}

const connect = (container) => {
  return new Promise((resolve, reject) => {
    if (!container.resolve('database')) {
      reject(new Error('connection db not supplied!'))
    }
    resolve(repository(container))
  })
}

module.exports = Object.assign({}, {connect})