const util = require('util');
const Transform = require('stream').Transform;
const intercomDrinks = require('intercom-drinks').default;

function Stream(latitude, longitude, radius) {
  if (!(this instanceof Stream)) {
    return new Stream();
  }
  Transform.call(this, {
    readableObjectMode: true,
    writableObjectMode: true
  });

  this._latitude = latitude;
  this._longitude = longitude;
  this._radius = radius;
}

util.inherits(Stream, Transform);

Stream.prototype._transform = function (customer, encoding, done) {
  // 5. calculate distance and filter
  if (intercomDrinks.isNearbyCustomer(this._latitude, this._longitude, this._radius, customer)) {
    this.push(customer);
  }
  done();
};

module.exports = Stream;