lifx-lan-client/src/lifx/packets/stateZone.js

Node.js implementation of the LIFX LAN protocol

'use strict';

const {constants} = require('../../lifx');

const Packet = {
  size: 10
};

/**
 * Converts packet specific data from a buffer to an object
 * @param  {Buffer} buf Buffer containing only packet specific data no header
 * @return {Object}     Information contained in packet
 */
Packet.toObject = function(buf) {
  const obj = {};
  let offset = 0;

  if (buf.length !== this.size) {
    throw new Error('Invalid length given for stateZone LIFX packet');
  }

  obj.count = buf.readUInt8(offset);
  offset += 1;

  obj.index = buf.readUInt8(offset);
  offset += 1;

  obj.color = {};
  obj.color.hue = buf.readUInt16LE(offset);
  offset += 2;
  obj.color.saturation = buf.readUInt16LE(offset);
  offset += 2;
  obj.color.brightness = buf.readUInt16LE(offset);
  offset += 2;
  obj.color.kelvin = buf.readUInt16LE(offset);
  offset += 2;

  return obj;
};

/**
 * Converts the given packet specific object into a packet
 * @param  {Object} obj object with configuration data
 * @param  {Number} obj.count between 0 and 255
 * @param  {Number} obj.index between 0 and 255
 * @param  {Object} obj.color an object with colors to set
 * @param  {Number} obj.color.hue between 0 and 65535
 * @param  {Number} obj.color.saturation between 0 and 65535
 * @param  {Number} obj.color.brightness between 0 and 65535
 * @param  {Number} obj.color.kelvin between 2500 and 9000
 * @return {Buffer} packet
 */
Packet.toBuffer = function(obj) {
  const buf = Buffer.alloc(this.size);
  buf.fill(0);
  let offset = 0;

  if (typeof obj.count !== 'number' && obj.count < 0 || obj.count > 255) {
    throw new RangeError('Invalid count value given for stateZone LIFX packet, must be a number between 0 and 255');
  }
  buf.writeUInt8(obj.count, offset);
  offset += 1;

  if (typeof obj.index !== 'number' && obj.index < 0 || obj.index > 255) {
    throw new RangeError('Invalid index value given for stateZone LIFX packet, must be a number between 0 and 255');
  }
  buf.writeUInt8(obj.index, offset);
  offset += 1;

  if (typeof obj.hue !== 'number' && obj.hue < 0 || obj.hue > 65535) {
    throw new RangeError('Invalid color hue given for stateZone LIFX packet, must be a number between 0 and 65535');
  }
  buf.writeUInt16LE(obj.hue, offset);
  offset += 2;

  if (typeof obj.saturation !== 'number' && obj.saturation < 0 || obj.saturation > 65535) {
    throw new RangeError('Invalid color saturation given for stateZone LIFX packet, must be a number between 0 and 65535');
  }
  buf.writeUInt16LE(obj.saturation, offset);
  offset += 2;

  if (typeof obj.brightness !== 'number' && obj.brightness < 0 || obj.brightness > 65535) {
    throw new RangeError('Invalid color brightness given for stateZone LIFX packet, must be a number between 0 and 65535');
  }
  buf.writeUInt16LE(obj.brightness, offset);
  offset += 2;

  if (obj.kelvin === undefined) {
    obj.kelvin = constants.HSBK_DEFAULT_KELVIN;
  }
  if (typeof obj.kelvin !== 'number' && obj.kelvin < 2500 || obj.kelvin > 9000) {
    throw new RangeError('Invalid color kelvin given for stateZone LIFX packet, must be a number between 2500 and 9000');
  }
  buf.writeUInt16LE(obj.kelvin, offset);
  offset += 2;

  return buf;
};

module.exports = Packet;