mqtt/lib/client.js

'use strict'

/**
 * Module dependencies
 */
var events = require('events')
var Store = require('./store')
var mqttPacket = require('mqtt-packet')
var Writable = require('readable-stream').Writable
var inherits = require('inherits')
var reInterval = require('reinterval')
var validations = require('./validations')
var xtend = require('xtend')
var setImmediate = global.setImmediate || function (callback) {
  // works in node v0.8
  process.nextTick(callback)
}
var defaultConnectOptions = {
  keepalive: 60,
  reschedulePings: true,
  protocolId: 'MQTT',
  protocolVersion: 4,
  reconnectPeriod: 1000,
  connectTimeout: 30 * 1000,
  clean: true,
  resubscribe: true
}
var errors = {
  0: '',
  1: 'Unacceptable protocol version',
  2: 'Identifier rejected',
  3: 'Server unavailable',
  4: 'Bad username or password',
  5: 'Not authorized',
  16: 'No matching subscribers',
  17: 'No subscription existed',
  128: 'Unspecified error',
  129: 'Malformed Packet',
  130: 'Protocol Error',
  131: 'Implementation specific error',
  132: 'Unsupported Protocol Version',
  133: 'Client Identifier not valid',
  134: 'Bad User Name or Password',
  135: 'Not authorized',
  136: 'Server unavailable',
  137: 'Server busy',
  138: 'Banned',
  139: 'Server shutting down',
  140: 'Bad authentication method',
  141: 'Keep Alive timeout',
  142: 'Session taken over',
  143: 'Topic Filter invalid',
  144: 'Topic Name invalid',
  145: 'Packet identifier in use',
  146: 'Packet Identifier not found',
  147: 'Receive Maximum exceeded',
  148: 'Topic Alias invalid',
  149: 'Packet too large',
  150: 'Message rate too high',
  151: 'Quota exceeded',
  152: 'Administrative action',
  153: 'Payload format invalid',
  154: 'Retain not supported',
  155: 'QoS not supported',
  156: 'Use another server',
  157: 'Server moved',
  158: 'Shared Subscriptions not supported',
  159: 'Connection rate exceeded',
  160: 'Maximum connect time',
  161: 'Subscription Identifiers not supported',
  162: 'Wildcard Subscriptions not supported'
}

function defaultId () {
  return 'mqttjs_' + Math.random().toString(16).substr(2, 8)
}

function sendPacket (client, packet, cb) {
  client.emit('packetsend', packet)

  var result = mqttPacket.writeToStream(packet, client.stream, client.options)

  if (!result && cb) {
    client.stream.once('drain', cb)
  } else if (cb) {
    cb()
  }
}

function flush (queue) {
  if (queue) {
    Object.keys(queue).forEach(function (messageId) {
      if (typeof queue[messageId].cb === 'function') {
        queue[messageId].cb(new Error('Connection closed'))
        delete queue[messageId]
      }
    })
  }
}

function flushVolatile (queue) {
  if (queue) {
    Object.keys(queue).forEach(function (messageId) {
      if (queue[messageId].volatile && typeof queue[messageId].cb === 'function') {
        queue[messageId].cb(new Error('Connection closed'))
        delete queue[messageId]
      }
    })
  }
}

function storeAndSend (client, packet, cb, cbStorePut) {
  client.outgoingStore.put(packet, function storedPacket (err) {
    if (err) {
      return cb && cb(err)
    }
    cbStorePut()
    sendPacket(client, packet, cb)
  })
}

function nop () {}

/**
 * MqttClient constructor
 *
 * @param {Stream} stream - stream
 * @param {Object} [options] - connection options
 * (see Connection#connect)
 */
function MqttClient (streamBuilder, options) {
  var k
  var that = this

  if (!(this instanceof MqttClient)) {
    return new MqttClient(streamBuilder, options)
  }

  this.options = options || {}

  // Defaults
  for (k in defaultConnectOptions) {
    if (typeof this.options[k] === 'undefined') {
      this.options[k] = defaultConnectOptions[k]
    } else {
      this.options[k] = options[k]
    }
  }

  this.options.clientId = (typeof options.clientId === 'string') ? options.clientId : defaultId()

  this.options.customHandleAcks = (options.protocolVersion === 5 && options.customHandleAcks) ? options.customHandleAcks : function () { arguments[3](0) }

  this.streamBuilder = streamBuilder

  // Inflight message storages
  this.outgoingStore = options.outgoingStore || new Store()
  this.incomingStore = options.incomingStore || new Store()

  // Should QoS zero messages be queued when the connection is broken?
  this.queueQoSZero = options.queueQoSZero === undefined ? true : options.queueQoSZero

  // map of subscribed topics to support reconnection
  this._resubscribeTopics = {}

  // map of a subscribe messageId and a topic
  this.messageIdToTopic = {}

  // Ping timer, setup in _setupPingTimer
  this.pingTimer = null
  // Is the client connected?
  this.connected = false
  // Are we disconnecting?
  this.disconnecting = false
  // Packet queue
  this.queue = []
  // connack timer
  this.connackTimer = null
  // Reconnect timer
  this.reconnectTimer = null
  // Is processing store?
  this._storeProcessing = false
  // Packet Ids are put into the store during store processing
  this._packetIdsDuringStoreProcessing = {}
  /**
   * MessageIDs starting with 1
   * ensure that nextId is min. 1, see https://github.com/mqttjs/MQTT.js/issues/810
   */
  this.nextId = Math.max(1, Math.floor(Math.random() * 65535))

  // Inflight callbacks
  this.outgoing = {}

  // True if connection is first time.
  this._firstConnection = true

  // Mark disconnected on stream close
  this.on('close', function () {
    this.connected = false
    clearTimeout(this.connackTimer)
  })

  // Send queued packets
  this.on('connect', function () {
    var queue = this.queue

    function deliver () {
      var entry = queue.shift()
      var packet = null

      if (!entry) {
        return
      }

      packet = entry.packet

      that._sendPacket(
        packet,
        function (err) {
          if (entry.cb) {
            entry.cb(err)
          }
          deliver()
        }
      )
    }

    deliver()
  })

  // Clear ping timer
  this.on('close', function () {
    if (that.pingTimer !== null) {
      that.pingTimer.clear()
      that.pingTimer = null
    }
  })

  // Setup reconnect timer on disconnect
  this.on('close', this._setupReconnect)

  events.EventEmitter.call(this)

  this._setupStream()
}
inherits(MqttClient, events.EventEmitter)

/**
 * setup the event handlers in the inner stream.
 *
 * @api private
 */
MqttClient.prototype._setupStream = function () {
  var connectPacket
  var that = this
  var writable = new Writable()
  var parser = mqttPacket.parser(this.options)
  var completeParse = null
  var packets = []

  this._clearReconnect()

  this.stream = this.streamBuilder(this)

  parser.on('packet', function (packet) {
    packets.push(packet)
  })

  function nextTickWork () {
    if (packets.length) {
      process.nextTick(work)
    } else {
      var done = completeParse
      completeParse = null
      done()
    }
  }

  function work () {
    var packet = packets.shift()

    if (packet) {
      that._handlePacket(packet, nextTickWork)
    } else {
      var done = completeParse
      completeParse = null
      if (done) done()
    }
  }

  writable._write = function (buf, enc, done) {
    completeParse = done
    parser.parse(buf)
    work()
  }

  this.stream.pipe(writable)

  // Suppress connection errors
  this.stream.on('error', nop)

  // Echo stream close
  this.stream.on('close', function () {
    flushVolatile(that.outgoing)
    that.emit('close')
  })

  // Send a connect packet
  connectPacket = Object.create(this.options)
  connectPacket.cmd = 'connect'
  // avoid message queue
  sendPacket(this, connectPacket)

  // Echo connection errors
  parser.on('error', this.emit.bind(this, 'error'))

  // auth
  if (this.options.properties) {
    if (!this.options.properties.authenticationMethod && this.options.properties.authenticationData) {
      this.emit('error', new Error('Packet has no Authentication Method'))
      return this
    }
    if (this.options.properties.authenticationMethod && this.options.authPacket && typeof this.options.authPacket === 'object') {
      var authPacket = xtend({cmd: 'auth', reasonCode: 0}, this.options.authPacket)
      sendPacket(this, authPacket)
    }
  }

  // many drain listeners are needed for qos 1 callbacks if the connection is intermittent
  this.stream.setMaxListeners(1000)

  clearTimeout(this.connackTimer)
  this.connackTimer = setTimeout(function () {
    that._cleanUp(true)
  }, this.options.connectTimeout)
}

MqttClient.prototype._handlePacket = function (packet, done) {
  var options = this.options

  if (options.protocolVersion === 5 && options.properties && options.properties.maximumPacketSize && options.properties.maximumPacketSize < packet.length) {
    this.emit('error', new Error('exceeding packets size ' + packet.cmd))
    this.end({reasonCode: 149, properties: { reasonString: 'Maximum packet size was exceeded' }})
    return this
  }

  this.emit('packetreceive', packet)

  switch (packet.cmd) {
    case 'publish':
      this._handlePublish(packet, done)
      break
    case 'puback':
    case 'pubrec':
    case 'pubcomp':
    case 'suback':
    case 'unsuback':
      this._handleAck(packet)
      done()
      break
    case 'pubrel':
      this._handlePubrel(packet, done)
      break
    case 'connack':
      this._handleConnack(packet)
      done()
      break
    case 'pingresp':
      this._handlePingresp(packet)
      done()
      break
    case 'disconnect':
      this._handleDisconnect(packet)
      done()
      break
    default:
      // do nothing
      // maybe we should do an error handling
      // or just log it
      break
  }
}

MqttClient.prototype._checkDisconnecting = function (callback) {
  if (this.disconnecting) {
    if (callback) {
      callback(new Error('client disconnecting'))
    } else {
      this.emit('error', new Error('client disconnecting'))
    }
  }
  return this.disconnecting
}

/**
 * publish - publish <message> to <topic>
 *
 * @param {String} topic - topic to publish to
 * @param {String, Buffer} message - message to publish
 * @param {Object} [opts] - publish options, includes:
 *    {Number} qos - qos level to publish on
 *    {Boolean} retain - whether or not to retain the message
 *    {Boolean} dup - whether or not mark a message as duplicate
 *    {Function} cbStorePut - function(){} called when message is put into `outgoingStore`
 * @param {Function} [callback] - function(err){}
 *    called when publish succeeds or fails
 * @returns {MqttClient} this - for chaining
 * @api public
 *
 * @example client.publish('topic', 'message');
 * @example
 *     client.publish('topic', 'message', {qos: 1, retain: true, dup: true});
 * @example client.publish('topic', 'message', console.log);
 */
MqttClient.prototype.publish = function (topic, message, opts, callback) {
  var packet
  var options = this.options

  // .publish(topic, payload, cb);
  if (typeof opts === 'function') {
    callback = opts
    opts = null
  }

  // default opts
  var defaultOpts = {qos: 0, retain: false, dup: false}
  opts = xtend(defaultOpts, opts)

  if (this._checkDisconnecting(callback)) {
    return this
  }

  packet = {
    cmd: 'publish',
    topic: topic,
    payload: message,
    qos: opts.qos,
    retain: opts.retain,
    messageId: this._nextId(),
    dup: opts.dup
  }

  if (options.protocolVersion === 5) {
    packet.properties = opts.properties
    if ((!options.properties && packet.properties && packet.properties.topicAlias) || ((opts.properties && options.properties) &&
      ((opts.properties.topicAlias && options.properties.topicAliasMaximum && opts.properties.topicAlias > options.properties.topicAliasMaximum) ||
        (!options.properties.topicAliasMaximum && opts.properties.topicAlias)))) {
      /*
      if we are don`t setup topic alias or
      topic alias maximum less than topic alias or
      server don`t give topic alias maximum,
      we are removing topic alias from packet
      */
      delete packet.properties.topicAlias
    }
  }

  switch (opts.qos) {
    case 1:
    case 2:
      // Add to callbacks
      this.outgoing[packet.messageId] = {
        volatile: false,
        cb: callback || nop
      }
      if (this._storeProcessing) {
        this._packetIdsDuringStoreProcessing[packet.messageId] = false
        this._storePacket(packet, undefined, opts.cbStorePut)
      } else {
        this._sendPacket(packet, undefined, opts.cbStorePut)
      }
      break
    default:
      if (this._storeProcessing) {
        this._storePacket(packet, callback, opts.cbStorePut)
      } else {
        this._sendPacket(packet, callback, opts.cbStorePut)
      }
      break
  }

  return this
}

/**
 * subscribe - subscribe to <topic>
 *
 * @param {String, Array, Object} topic - topic(s) to subscribe to, supports objects in the form {'topic': qos}
 * @param {Object} [opts] - optional subscription options, includes:
 *    {Number} qos - subscribe qos level
 * @param {Function} [callback] - function(err, granted){} where:
 *    {Error} err - subscription error (none at the moment!)
 *    {Array} granted - array of {topic: 't', qos: 0}
 * @returns {MqttClient} this - for chaining
 * @api public
 * @example client.subscribe('topic');
 * @example client.subscribe('topic', {qos: 1});
 * @example client.subscribe({'topic': {qos: 0}, 'topic2': {qos: 1}}, console.log);
 * @example client.subscribe('topic', console.log);
 */
MqttClient.prototype.subscribe = function () {
  var packet
  var args = new Array(arguments.length)
  for (var i = 0; i < arguments.length; i++) {
    args[i] = arguments[i]
  }
  var subs = []
  var obj = args.shift()
  var resubscribe = obj.resubscribe
  var callback = args.pop() || nop
  var opts = args.pop()
  var invalidTopic
  var that = this
  var version = this.options.protocolVersion

  delete obj.resubscribe

  if (typeof obj === 'string') {
    obj = [obj]
  }

  if (typeof callback !== 'function') {
    opts = callback
    callback = nop
  }

  invalidTopic = validations.validateTopics(obj)
  if (invalidTopic !== null) {
    setImmediate(callback, new Error('Invalid topic ' + invalidTopic))
    return this
  }

  if (this._checkDisconnecting(callback)) {
    return this
  }

  var defaultOpts = {
    qos: 0
  }
  if (version === 5) {
    defaultOpts.nl = false
    defaultOpts.rap = false
    defaultOpts.rh = 0
  }
  opts = xtend(defaultOpts, opts)

  if (Array.isArray(obj)) {
    obj.forEach(function (topic) {
      if (!that._resubscribeTopics.hasOwnProperty(topic) ||
        that._resubscribeTopics[topic].qos < opts.qos ||
          resubscribe) {
        var currentOpts = {
          topic: topic,
          qos: opts.qos
        }
        if (version === 5) {
          currentOpts.nl = opts.nl
          currentOpts.rap = opts.rap
          currentOpts.rh = opts.rh
          currentOpts.properties = opts.properties
        }
        subs.push(currentOpts)
      }
    })
  } else {
    Object
      .keys(obj)
      .forEach(function (k) {
        if (!that._resubscribeTopics.hasOwnProperty(k) ||
          that._resubscribeTopics[k].qos < obj[k].qos ||
            resubscribe) {
          var currentOpts = {
            topic: k,
            qos: obj[k].qos
          }
          if (version === 5) {
            currentOpts.nl = obj[k].nl
            currentOpts.rap = obj[k].rap
            currentOpts.rh = obj[k].rh
            currentOpts.properties = opts.properties
          }
          subs.push(currentOpts)
        }
      })
  }

  packet = {
    cmd: 'subscribe',
    subscriptions: subs,
    qos: 1,
    retain: false,
    dup: false,
    messageId: this._nextId()
  }

  if (opts.properties) {
    packet.properties = opts.properties
  }

  if (!subs.length) {
    callback(null, [])
    return
  }

  // subscriptions to resubscribe to in case of disconnect
  if (this.options.resubscribe) {
    var topics = []
    subs.forEach(function (sub) {
      if (that.options.reconnectPeriod > 0) {
        var topic = { qos: sub.qos }
        if (version === 5) {
          topic.nl = sub.nl || false
          topic.rap = sub.rap || false
          topic.rh = sub.rh || 0
          topic.properties = sub.properties
        }
        that._resubscribeTopics[sub.topic] = topic
        topics.push(sub.topic)
      }
    })
    that.messageIdToTopic[packet.messageId] = topics
  }

  this.outgoing[packet.messageId] = {
    volatile: true,
    cb: function (err, packet) {
      if (!err) {
        var granted = packet.granted
        for (var i = 0; i < granted.length; i += 1) {
          subs[i].qos = granted[i]
        }
      }

      callback(err, subs)
    }
  }

  this._sendPacket(packet)

  return this
}

/**
 * unsubscribe - unsubscribe from topic(s)
 *
 * @param {String, Array} topic - topics to unsubscribe from
 * @param {Object} [opts] - optional subscription options, includes:
 *    {Object} properties - properties of unsubscribe packet
 * @param {Function} [callback] - callback fired on unsuback
 * @returns {MqttClient} this - for chaining
 * @api public
 * @example client.unsubscribe('topic');
 * @example client.unsubscribe('topic', console.log);
 */
MqttClient.prototype.unsubscribe = function () {
  var packet = {
    cmd: 'unsubscribe',
    qos: 1,
    messageId: this._nextId()
  }
  var that = this
  var args = new Array(arguments.length)
  for (var i = 0; i < arguments.length; i++) {
    args[i] = arguments[i]
  }
  var topic = args.shift()
  var callback = args.pop() || nop
  var opts = args.pop()

  if (typeof topic === 'string') {
    topic = [topic]
  }

  if (typeof callback !== 'function') {
    opts = callback
    callback = nop
  }

  if (this._checkDisconnecting(callback)) {
    return this
  }

  if (typeof topic === 'string') {
    packet.unsubscriptions = [topic]
  } else if (typeof topic === 'object' && topic.length) {
    packet.unsubscriptions = topic
  }

  if (this.options.resubscribe) {
    packet.unsubscriptions.forEach(function (topic) {
      delete that._resubscribeTopics[topic]
    })
  }

  if (typeof opts === 'object' && opts.properties) {
    packet.properties = opts.properties
  }

  this.outgoing[packet.messageId] = {
    volatile: true,
    cb: callback
  }

  this._sendPacket(packet)

  return this
}

/**
 * end - close connection
 *
 * @returns {MqttClient} this - for chaining
 * @param {Boolean} force - do not wait for all in-flight messages to be acked
 * @param {Function} cb - called when the client has been closed
 *
 * @api public
 */
MqttClient.prototype.end = function () {
  var that = this

  var force = arguments[0]
  var opts = arguments[1]
  var cb = arguments[2]

  if (force == null || typeof force !== 'boolean') {
    cb = opts || nop
    opts = force
    force = false
    if (typeof opts !== 'object') {
      cb = opts
      opts = null
      if (typeof cb !== 'function') {
        cb = nop
      }
    }
  }

  if (typeof opts !== 'object') {
    cb = opts
    opts = null
  }

  cb = cb || nop

  function closeStores () {
    that.disconnected = true
    that.incomingStore.close(function () {
      that.outgoingStore.close(function () {
        if (cb) {
          cb.apply(null, arguments)
        }
        that.emit('end')
      })
    })
    if (that._deferredReconnect) {
      that._deferredReconnect()
    }
  }

  function finish () {
    // defer closesStores of an I/O cycle,
    // just to make sure things are
    // ok for websockets
    that._cleanUp(force, setImmediate.bind(null, closeStores), opts)
  }

  if (this.disconnecting) {
    return this
  }

  this._clearReconnect()

  this.disconnecting = true

  if (!force && Object.keys(this.outgoing).length > 0) {
    // wait 10ms, just to be sure we received all of it
    this.once('outgoingEmpty', setTimeout.bind(null, finish, 10))
  } else {
    finish()
  }

  return this
}

/**
 * removeOutgoingMessage - remove a message in outgoing store
 * the outgoing callback will be called withe Error('Message removed') if the message is removed
 *
 * @param {Number} mid - messageId to remove message
 * @returns {MqttClient} this - for chaining
 * @api public
 *
 * @example client.removeOutgoingMessage(client.getLastMessageId());
 */
MqttClient.prototype.removeOutgoingMessage = function (mid) {
  var cb = this.outgoing[mid] ? this.outgoing[mid].cb : null
  delete this.outgoing[mid]
  this.outgoingStore.del({messageId: mid}, function () {
    cb(new Error('Message removed'))
  })
  return this
}

/**
 * reconnect - connect again using the same options as connect()
 *
 * @param {Object} [opts] - optional reconnect options, includes:
 *    {Store} incomingStore - a store for the incoming packets
 *    {Store} outgoingStore - a store for the outgoing packets
 *    if opts is not given, current stores are used
 * @returns {MqttClient} this - for chaining
 *
 * @api public
 */
MqttClient.prototype.reconnect = function (opts) {
  var that = this
  var f = function () {
    if (opts) {
      that.options.incomingStore = opts.incomingStore
      that.options.outgoingStore = opts.outgoingStore
    } else {
      that.options.incomingStore = null
      that.options.outgoingStore = null
    }
    that.incomingStore = that.options.incomingStore || new Store()
    that.outgoingStore = that.options.outgoingStore || new Store()
    that.disconnecting = false
    that.disconnected = false
    that._deferredReconnect = null
    that._reconnect()
  }

  if (this.disconnecting && !this.disconnected) {
    this._deferredReconnect = f
  } else {
    f()
  }
  return this
}

/**
 * _reconnect - implement reconnection
 * @api privateish
 */
MqttClient.prototype._reconnect = function () {
  this.emit('reconnect')
  this._setupStream()
}

/**
 * _setupReconnect - setup reconnect timer
 */
MqttClient.prototype._setupReconnect = function () {
  var that = this

  if (!that.disconnecting && !that.reconnectTimer && (that.options.reconnectPeriod > 0)) {
    if (!this.reconnecting) {
      this.emit('offline')
      this.reconnecting = true
    }
    that.reconnectTimer = setInterval(function () {
      that._reconnect()
    }, that.options.reconnectPeriod)
  }
}

/**
 * _clearReconnect - clear the reconnect timer
 */
MqttClient.prototype._clearReconnect = function () {
  if (this.reconnectTimer) {
    clearInterval(this.reconnectTimer)
    this.reconnectTimer = null
  }
}

/**
 * _cleanUp - clean up on connection end
 * @api private
 */
MqttClient.prototype._cleanUp = function (forced, done) {
  var opts = arguments[2]
  if (done) {
    this.stream.on('close', done)
  }

  if (forced) {
    if ((this.options.reconnectPeriod === 0) && this.options.clean) {
      flush(this.outgoing)
    }
    this.stream.destroy()
  } else {
    var packet = xtend({ cmd: 'disconnect' }, opts)
    this._sendPacket(
      packet,
      setImmediate.bind(
        null,
        this.stream.end.bind(this.stream)
      )
    )
  }

  if (!this.disconnecting) {
    this._clearReconnect()
    this._setupReconnect()
  }

  if (this.pingTimer !== null) {
    this.pingTimer.clear()
    this.pingTimer = null
  }

  if (done && !this.connected) {
    this.stream.removeListener('close', done)
    done()
  }
}

/**
 * _sendPacket - send or queue a packet
 * @param {String} type - packet type (see `protocol`)
 * @param {Object} packet - packet options
 * @param {Function} cb - callback when the packet is sent
 * @param {Function} cbStorePut - called when message is put into outgoingStore
 * @api private
 */
MqttClient.prototype._sendPacket = function (packet, cb, cbStorePut) {
  cbStorePut = cbStorePut || nop

  if (!this.connected) {
    this._storePacket(packet, cb, cbStorePut)
    return
  }

  // When sending a packet, reschedule the ping timer
  this._shiftPingInterval()

  switch (packet.cmd) {
    case 'publish':
      break
    case 'pubrel':
      storeAndSend(this, packet, cb, cbStorePut)
      return
    default:
      sendPacket(this, packet, cb)
      return
  }

  switch (packet.qos) {
    case 2:
    case 1:
      storeAndSend(this, packet, cb, cbStorePut)
      break
    /**
     * no need of case here since it will be caught by default
     * and jshint comply that before default it must be a break
     * anyway it will result in -1 evaluation
     */
    case 0:
      /* falls through */
    default:
      sendPacket(this, packet, cb)
      break
  }
}

/**
 * _storePacket - queue a packet
 * @param {String} type - packet type (see `protocol`)
 * @param {Object} packet - packet options
 * @param {Function} cb - callback when the packet is sent
 * @param {Function} cbStorePut - called when message is put into outgoingStore
 * @api private
 */
MqttClient.prototype._storePacket = function (packet, cb, cbStorePut) {
  cbStorePut = cbStorePut || nop

  if (((packet.qos || 0) === 0 && this.queueQoSZero) || packet.cmd !== 'publish') {
    this.queue.push({ packet: packet, cb: cb })
  } else if (packet.qos > 0) {
    cb = this.outgoing[packet.messageId] ? this.outgoing[packet.messageId].cb : null
    this.outgoingStore.put(packet, function (err) {
      if (err) {
        return cb && cb(err)
      }
      cbStorePut()
    })
  } else if (cb) {
    cb(new Error('No connection to broker'))
  }
}

/**
 * _setupPingTimer - setup the ping timer
 *
 * @api private
 */
MqttClient.prototype._setupPingTimer = function () {
  var that = this

  if (!this.pingTimer && this.options.keepalive) {
    this.pingResp = true
    this.pingTimer = reInterval(function () {
      that._checkPing()
    }, this.options.keepalive * 1000)
  }
}

/**
 * _shiftPingInterval - reschedule the ping interval
 *
 * @api private
 */
MqttClient.prototype._shiftPingInterval = function () {
  if (this.pingTimer && this.options.keepalive && this.options.reschedulePings) {
    this.pingTimer.reschedule(this.options.keepalive * 1000)
  }
}
/**
 * _checkPing - check if a pingresp has come back, and ping the server again
 *
 * @api private
 */
MqttClient.prototype._checkPing = function () {
  if (this.pingResp) {
    this.pingResp = false
    this._sendPacket({ cmd: 'pingreq' })
  } else {
    // do a forced cleanup since socket will be in bad shape
    this._cleanUp(true)
  }
}

/**
 * _handlePingresp - handle a pingresp
 *
 * @api private
 */
MqttClient.prototype._handlePingresp = function () {
  this.pingResp = true
}

/**
 * _handleConnack
 *
 * @param {Object} packet
 * @api private
 */

MqttClient.prototype._handleConnack = function (packet) {
  var options = this.options
  var version = options.protocolVersion
  var rc = version === 5 ? packet.reasonCode : packet.returnCode

  clearTimeout(this.connackTimer)

  if (packet.properties) {
    if (packet.properties.topicAliasMaximum) {
      if (!options.properties) { options.properties = {} }
      options.properties.topicAliasMaximum = packet.properties.topicAliasMaximum
    }
    if (packet.properties.serverKeepAlive && options.keepalive) {
      options.keepalive = packet.properties.serverKeepAlive
      this._shiftPingInterval()
    }
    if (packet.properties.maximumPacketSize) {
      if (!options.properties) { options.properties = {} }
      options.properties.maximumPacketSize = packet.properties.maximumPacketSize
    }
  }

  if (rc === 0) {
    this.reconnecting = false
    this._onConnect(packet)
  } else if (rc > 0) {
    var err = new Error('Connection refused: ' + errors[rc])
    err.code = rc
    this.emit('error', err)
  }
}

/**
 * _handlePublish
 *
 * @param {Object} packet
 * @api private
 */
/*
those late 2 case should be rewrite to comply with coding style:

case 1:
case 0:
  // do not wait sending a puback
  // no callback passed
  if (1 === qos) {
    this._sendPacket({
      cmd: 'puback',
      messageId: mid
    });
  }
  // emit the message event for both qos 1 and 0
  this.emit('message', topic, message, packet);
  this.handleMessage(packet, done);
  break;
default:
  // do nothing but every switch mus have a default
  // log or throw an error about unknown qos
  break;

for now i just suppressed the warnings
*/
MqttClient.prototype._handlePublish = function (packet, done) {
  done = typeof done !== 'undefined' ? done : nop
  var topic = packet.topic.toString()
  var message = packet.payload
  var qos = packet.qos
  var mid = packet.messageId
  var that = this
  var options = this.options
  var validReasonCodes = [0, 16, 128, 131, 135, 144, 145, 151, 153]

  switch (qos) {
    case 2: {
      options.customHandleAcks(topic, message, packet, function (error, code) {
        if (!(error instanceof Error)) {
          code = error
          error = null
        }
        if (error) { return that.emit('error', error) }
        if (validReasonCodes.indexOf(code) === -1) { return that.emit('error', new Error('Wrong reason code for pubrec')) }
        if (code) {
          that._sendPacket({cmd: 'pubrec', messageId: mid, reasonCode: code}, done)
        } else {
          that.incomingStore.put(packet, function () {
            that._sendPacket({cmd: 'pubrec', messageId: mid}, done)
          })
        }
      })
      break
    }
    case 1: {
      // emit the message event
      options.customHandleAcks(topic, message, packet, function (error, code) {
        if (!(error instanceof Error)) {
          code = error
          error = null
        }
        if (error) { return that.emit('error', error) }
        if (validReasonCodes.indexOf(code) === -1) { return that.emit('error', new Error('Wrong reason code for puback')) }
        if (!code) { that.emit('message', topic, message, packet) }
        that.handleMessage(packet, function (err) {
          if (err) {
            return done && done(err)
          }
          that._sendPacket({cmd: 'puback', messageId: mid, reasonCode: code}, done)
        })
      })
      break
    }
    case 0:
      // emit the message event
      this.emit('message', topic, message, packet)
      this.handleMessage(packet, done)
      break
    default:
      // do nothing
      // log or throw an error about unknown qos
      break
  }
}

/**
 * Handle messages with backpressure support, one at a time.
 * Override at will.
 *
 * @param Packet packet the packet
 * @param Function callback call when finished
 * @api public
 */
MqttClient.prototype.handleMessage = function (packet, callback) {
  callback()
}

/**
 * _handleAck
 *
 * @param {Object} packet
 * @api private
 */

MqttClient.prototype._handleAck = function (packet) {
  /* eslint no-fallthrough: "off" */
  var mid = packet.messageId
  var type = packet.cmd
  var response = null
  var cb = this.outgoing[mid] ? this.outgoing[mid].cb : null
  var that = this
  var err

  if (!cb) {
    // Server sent an ack in error, ignore it.
    return
  }

  // Process
  switch (type) {
    case 'pubcomp':
      // same thing as puback for QoS 2
    case 'puback':
      var pubackRC = packet.reasonCode
      // Callback - we're done
      if (pubackRC && pubackRC > 0 && pubackRC !== 16) {
        err = new Error('Publish error: ' + errors[pubackRC])
        err.code = pubackRC
        cb(err, packet)
      }
      delete this.outgoing[mid]
      this.outgoingStore.del(packet, cb)
      break
    case 'pubrec':
      response = {
        cmd: 'pubrel',
        qos: 2,
        messageId: mid
      }
      var pubrecRC = packet.reasonCode

      if (pubrecRC && pubrecRC > 0 && pubrecRC !== 16) {
        err = new Error('Publish error: ' + errors[pubrecRC])
        err.code = pubrecRC
        cb(err, packet)
      } else {
        this._sendPacket(response)
      }
      break
    case 'suback':
      delete this.outgoing[mid]
      for (var grantedI = 0; grantedI < packet.granted.length; grantedI++) {
        if ((packet.granted[grantedI] & 0x80) !== 0) {
          // suback with Failure status
          var topics = this.messageIdToTopic[mid]
          if (topics) {
            topics.forEach(function (topic) {
              delete that._resubscribeTopics[topic]
            })
          }
        }
      }
      cb(null, packet)
      break
    case 'unsuback':
      delete this.outgoing[mid]
      cb(null)
      break
    default:
      that.emit('error', new Error('unrecognized packet type'))
  }

  if (this.disconnecting &&
      Object.keys(this.outgoing).length === 0) {
    this.emit('outgoingEmpty')
  }
}

/**
 * _handlePubrel
 *
 * @param {Object} packet
 * @api private
 */
MqttClient.prototype._handlePubrel = function (packet, callback) {
  callback = typeof callback !== 'undefined' ? callback : nop
  var mid = packet.messageId
  var that = this

  var comp = {cmd: 'pubcomp', messageId: mid}

  that.incomingStore.get(packet, function (err, pub) {
    if (!err) {
      that.emit('message', pub.topic, pub.payload, pub)
      that.handleMessage(pub, function (err) {
        if (err) {
          return callback(err)
        }
        that.incomingStore.del(pub, nop)
        that._sendPacket(comp, callback)
      })
    } else {
      that._sendPacket(comp, callback)
    }
  })
}

/**
 * _handleDisconnect
 *
 * @param {Object} packet
 * @api private
 */
MqttClient.prototype._handleDisconnect = function (packet) {
  this.emit('disconnect', packet)
}

/**
 * _nextId
 * @return unsigned int
 */
MqttClient.prototype._nextId = function () {
  // id becomes current state of this.nextId and increments afterwards
  var id = this.nextId++
  // Ensure 16 bit unsigned int (max 65535, nextId got one higher)
  if (this.nextId === 65536) {
    this.nextId = 1
  }
  return id
}

/**
 * getLastMessageId
 * @return unsigned int
 */
MqttClient.prototype.getLastMessageId = function () {
  return (this.nextId === 1) ? 65535 : (this.nextId - 1)
}

/**
 * _resubscribe
 * @api private
 */
MqttClient.prototype._resubscribe = function (connack) {
  var _resubscribeTopicsKeys = Object.keys(this._resubscribeTopics)
  if (!this._firstConnection &&
      (this.options.clean || (this.options.protocolVersion === 5 && !connack.sessionPresent)) &&
      _resubscribeTopicsKeys.length > 0) {
    if (this.options.resubscribe) {
      if (this.options.protocolVersion === 5) {
        for (var topicI = 0; topicI < _resubscribeTopicsKeys.length; topicI++) {
          var resubscribeTopic = {}
          resubscribeTopic[_resubscribeTopicsKeys[topicI]] = this._resubscribeTopics[_resubscribeTopicsKeys[topicI]]
          resubscribeTopic.resubscribe = true
          this.subscribe(resubscribeTopic, {properties: resubscribeTopic[_resubscribeTopicsKeys[topicI]].properties})
        }
      } else {
        this._resubscribeTopics.resubscribe = true
        this.subscribe(this._resubscribeTopics)
      }
    } else {
      this._resubscribeTopics = {}
    }
  }

  this._firstConnection = false
}

/**
 * _onConnect
 *
 * @api private
 */
MqttClient.prototype._onConnect = function (packet) {
  if (this.disconnected) {
    this.emit('connect', packet)
    return
  }

  var that = this

  this._setupPingTimer()
  this._resubscribe(packet)

  this.connected = true

  function startStreamProcess () {
    var outStore = that.outgoingStore.createStream()

    function clearStoreProcessing () {
      that._storeProcessing = false
      that._packetIdsDuringStoreProcessing = {}
    }

    that.once('close', remove)
    outStore.on('error', function (err) {
      clearStoreProcessing()
      that.removeListener('close', remove)
      that.emit('error', err)
    })

    function remove () {
      outStore.destroy()
      outStore = null
      clearStoreProcessing()
    }

    function storeDeliver () {
      // edge case, we wrapped this twice
      if (!outStore) {
        return
      }
      that._storeProcessing = true

      var packet = outStore.read(1)

      var cb

      if (!packet) {
        // read when data is available in the future
        outStore.once('readable', storeDeliver)
        return
      }

      // Skip already processed store packets
      if (that._packetIdsDuringStoreProcessing[packet.messageId]) {
        storeDeliver()
        return
      }

      // Avoid unnecessary stream read operations when disconnected
      if (!that.disconnecting && !that.reconnectTimer) {
        cb = that.outgoing[packet.messageId] ? that.outgoing[packet.messageId].cb : null
        that.outgoing[packet.messageId] = {
          volatile: false,
          cb: function (err, status) {
            // Ensure that the original callback passed in to publish gets invoked
            if (cb) {
              cb(err, status)
            }

            storeDeliver()
          }
        }
        that._packetIdsDuringStoreProcessing[packet.messageId] = true
        that._sendPacket(packet)
      } else if (outStore.destroy) {
        outStore.destroy()
      }
    }

    outStore.on('end', function () {
      var allProcessed = true
      for (var id in that._packetIdsDuringStoreProcessing) {
        if (!that._packetIdsDuringStoreProcessing[id]) {
          allProcessed = false
          break
        }
      }
      if (allProcessed) {
        clearStoreProcessing()
        that.removeListener('close', remove)
        that.emit('connect', packet)
      } else {
        startStreamProcess()
      }
    })
    storeDeliver()
  }
  // start flowing
  startStreamProcess()
}

module.exports = MqttClient