/**
* Copyright 2013 IBM Corp.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
**/
var util = require("util");
var mqtt = require("mqtt");
var events = require("events");
//var inspect = require("sys").inspect;
//var Client = module.exports.Client = function(
var port = 1883;
var host = "localhost";
function MQTTClient(port,host) {
this.port = port||1883;
this.host = host||"localhost";
this.messageId = 1;
this.pendingSubscriptions = {};
this.inboundMessages = {};
this.lastOutbound = (new Date()).getTime();
this.lastInbound = (new Date()).getTime();
this.connected = false;
this._nextMessageId = function() {
this.messageId += 1;
if (this.messageId > 0xFFFF) {
this.messageId = 1;
}
return this.messageId;
}
events.EventEmitter.call(this);
}
util.inherits(MQTTClient, events.EventEmitter);
MQTTClient.prototype.connect = function(options) {
if (!this.connected) {
var self = this;
options = options||{};
self.options = options;
self.options.keepalive = options.keepalive||15;
self.options.clean = self.options.clean||true;
self.options.protocolId = 'MQIsdp';
self.options.protocolVersion = 3;
self.client = mqtt.createConnection(this.port,this.host,function(err,client) {
if (err) {
self.connected = false;
clearInterval(self.watchdog);
self.connectionError = true;
//util.log('[mqtt] ['+self.uid+'] connection error 1 : '+inspect(err));
self.emit('connectionlost',err);
return;
}
client.on('close',function(e) {
//util.log('[mqtt] ['+self.uid+'] on close');
clearInterval(self.watchdog);
if (!self.connectionError) {
if (self.connected) {
self.connected = false;
self.emit('connectionlost',e);
} else {
self.emit('disconnect');
}
}
});
client.on('error',function(e) {
//util.log('[mqtt] ['+self.uid+'] on error : '+inspect(e));
clearInterval(self.watchdog);
if (self.connected) {
self.connected = false;
self.emit('connectionlost',e);
}
});
client.on('connack',function(packet) {
if (packet.returnCode == 0) {
self.watchdog = setInterval(function(self) {
var now = (new Date()).getTime();
//util.log('[mqtt] ['+self.uid+'] watchdog '+inspect({connected:self.connected,connectionError:self.connectionError,pingOutstanding:self.pingOutstanding,now:now,lastOutbound:self.lastOutbound,lastInbound:self.lastInbound}));
if (now - self.lastOutbound > self.options.keepalive*500 || now - self.lastInbound > self.options.keepalive*500) {
if (self.pingOutstanding) {
//util.log('[mqtt] ['+self.uid+'] watchdog pingOustanding - disconnect');
try {
self.client.disconnect();
} catch (err) {
}
} else {
//util.log('[mqtt] ['+self.uid+'] watchdog pinging');
self.lastOutbound = (new Date()).getTime();
self.lastInbound = (new Date()).getTime();
self.pingOutstanding = true;
self.client.pingreq();
}
}
},self.options.keepalive*500,self);
self.pingOutstanding = false;
self.lastInbound = (new Date()).getTime()
self.lastOutbound = (new Date()).getTime()
self.connected = true;
self.connectionError = false;
self.emit('connect');
} else {
self.connected = false;
self.emit('connectionlost');
}
});
client.on('suback',function(packet) {
self.lastInbound = (new Date()).getTime()
var topic = self.pendingSubscriptions[packet.messageId];
self.emit('subscribe',topic,packet.granted[0]);
delete self.pendingSubscriptions[packet.messageId];
});
client.on('unsuback',function(packet) {
self.lastInbound = (new Date()).getTime()
var topic = self.pendingSubscriptions[packet.messageId];
self.emit('unsubscribe',topic,packet.granted[0]);
delete self.pendingSubscriptions[packet.messageId];
});
client.on('publish',function(packet) {
self.lastInbound = (new Date()).getTime()
if (packet.qos < 2) {
var p = packet;
self.emit('message',p.topic,p.payload,p.qos,p.retain);
} else {
self.inboundMessages[packet.messageId] = packet;
this.lastOutbound = (new Date()).getTime()
self.client.pubrec(packet);
}
if (packet.qos == 1) {
this.lastOutbound = (new Date()).getTime()
self.client.puback(packet);
}
});
client.on('pubrel',function(packet) {
self.lastInbound = (new Date()).getTime()
var p = self.inboundMessages[packet.messageId];
if (p) {
self.emit('message',p.topic,p.payload,p.qos,p.retain);
delete self.inboundMessages[packet.messageId];
}
self.lastOutbound = (new Date()).getTime()
self.client.pubcomp(packet);
});
client.on('puback',function(packet) {
self.lastInbound = (new Date()).getTime()
// outbound qos-1 complete
});
client.on('pubrec',function(packet) {
self.lastInbound = (new Date()).getTime()
self.lastOutbound = (new Date()).getTime()
self.client.pubrel(packet);
});
client.on('pubcomp',function(packet) {
self.lastInbound = (new Date()).getTime()
// outbound qos-2 complete
});
client.on('pingresp',function(packet) {
//util.log('[mqtt] ['+self.uid+'] received pingresp');
self.lastInbound = (new Date()).getTime()
self.pingOutstanding = false;
});
this.lastOutbound = (new Date()).getTime()
this.connectionError = false;
client.connect(self.options);
});
}
}
MQTTClient.prototype.subscribe = function(topic,qos) {
var self = this;
if (self.connected) {
var options = {
subscriptions:[{topic:topic,qos:qos}],
messageId: self._nextMessageId()
};
this.pendingSubscriptions[options.messageId] = topic;
this.lastOutbound = (new Date()).getTime()
self.client.subscribe(options);
}
}
MQTTClient.prototype.unsubscribe = function(topic) {
var self = this;
if (self.connected) {
var options = {
topic:topic,
messageId: self._nextMessageId()
};
this.pendingSubscriptions[options.messageId] = topic;
this.lastOutbound = (new Date()).getTime()
self.client.unsubscribe(options);
}
}
MQTTClient.prototype.publish = function(topic,payload,qos,retain) {
var self = this;
if (self.connected) {
if (!Buffer.isBuffer(payload)) {
if (typeof payload === "object") {
payload = JSON.stringify(payload);
} else if (typeof payload !== "string") {
payload = ""+payload;
}
}
var options = {
topic: topic,
payload: payload,
qos: qos||0,
retain:retain||false
};
if (options.qos != 0) {
options.messageId = self._nextMessageId();
}
this.lastOutbound = (new Date()).getTime()
self.client.publish(options);
}
}
MQTTClient.prototype.disconnect = function() {
var self = this;
if (this.connected) {
this.connected = false;
try {
this.client.disconnect();
} catch(err) {
}
}
}
MQTTClient.prototype.isConnected = function() {
return this.connected;
}
module.exports.createClient = function(port,host) {
var mqtt_client = new MQTTClient(port,host);
return mqtt_client;
}