@aws-amplify/pubsub/src/vendor/paho-mqtt.js

/*******************************************************************************
 * Copyright (c) 2013 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 *
 * The Eclipse Public License is available at
 *    http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Andrew Banks - initial API and implementation and initial documentation
 *******************************************************************************/

// Only expose a single object name in the global namespace.
// Everything must go through this module. Global Paho module
// only has a single public function, client, which returns
// a Paho client object given connection details.

/**
 * Send and receive messages using web browsers.
 * <p>
 * This programming interface lets a JavaScript client application use the MQTT V3.1 or
 * V3.1.1 protocol to connect to an MQTT-supporting messaging server.
 *
 * The function supported includes:
 * <ol>
 * <li>Connecting to and disconnecting from a server. The server is identified by its host name and port number.
 * <li>Specifying options that relate to the communications link with the server,
 * for example the frequency of keep-alive heartbeats, and whether SSL/TLS is required.
 * <li>Subscribing to and receiving messages from MQTT Topics.
 * <li>Publishing messages to MQTT Topics.
 * </ol>
 * <p>
 * The API consists of two main objects:
 * <dl>
 * <dt><b>{@link Paho.Client}</b></dt>
 * <dd>This contains methods that provide the functionality of the API,
 * including provision of callbacks that notify the application when a message
 * arrives from or is delivered to the messaging server,
 * or when the status of its connection to the messaging server changes.</dd>
 * <dt><b>{@link Paho.Message}</b></dt>
 * <dd>This encapsulates the payload of the message along with various attributes
 * associated with its delivery, in particular the destination to which it has
 * been (or is about to be) sent.</dd>
 * </dl>
 * <p>
 * The programming interface validates parameters passed to it, and will throw
 * an Error containing an error message intended for developer use, if it detects
 * an error with any parameter.
 * <p>
 * Example:
 *
 * <code><pre>
var client = new Paho.MQTT.Client(location.hostname, Number(location.port), "clientId");
client.onConnectionLost = onConnectionLost;
client.onMessageArrived = onMessageArrived;
client.connect({onSuccess:onConnect});

function onConnect() {
  // Once a connection has been made, make a subscription and send a message.
  console.log("onConnect");
  client.subscribe("/World");
  var message = new Paho.MQTT.Message("Hello");
  message.destinationName = "/World";
  client.send(message);
};
function onConnectionLost(responseObject) {
  if (responseObject.errorCode !== 0)
	console.log("onConnectionLost:"+responseObject.errorMessage);
};
function onMessageArrived(message) {
  console.log("onMessageArrived:"+message.payloadString);
  client.disconnect();
};
 * </pre></code>
 * @namespace Paho
 */

/* jshint shadow:true */
(function ExportLibrary(root, factory) {
	if (typeof exports === 'object' && typeof module === 'object') {
		module.exports = factory();
	} else if (typeof define === 'function' && define.amd) {
		define(factory);
	} else if (typeof exports === 'object') {
		exports = factory();
	} else {
		//if (typeof root.Paho === "undefined"){
		//	root.Paho = {};
		//}
		root.Paho = factory();
	}
})(this, function LibraryFactory() {
	var PahoMQTT = (function (global) {
		// Private variables below, these are only visible inside the function closure
		// which is used to define the module.
		var version = '@VERSION@-@BUILDLEVEL@';

		// 2023-01-05: AWS Amplify change to incorporate upstream pull request:
		// https://github.com/eclipse/paho.mqtt.javascript/pull/247

		/**
		 * @private
		 */
		var localStorage = (function () {
			try {
				// When third-party cookies are disabled accessing localStorage will cause an error
				if (global.localStorage) return global.localStorage;
			} catch (e) {
				var data = {};

				return {
					setItem: function (key, item) {
						data[key] = item;
					},
					getItem: function (key) {
						return data[key];
					},
					removeItem: function (key) {
						delete data[key];
					},
				};
			}
		})();

		// End of AWS Amplify change

		/**
		 * Unique message type identifiers, with associated
		 * associated integer values.
		 * @private
		 */
		var MESSAGE_TYPE = {
			CONNECT: 1,
			CONNACK: 2,
			PUBLISH: 3,
			PUBACK: 4,
			PUBREC: 5,
			PUBREL: 6,
			PUBCOMP: 7,
			SUBSCRIBE: 8,
			SUBACK: 9,
			UNSUBSCRIBE: 10,
			UNSUBACK: 11,
			PINGREQ: 12,
			PINGRESP: 13,
			DISCONNECT: 14,
		};

		// Collection of utility methods used to simplify module code
		// and promote the DRY pattern.

		/**
		 * Validate an object's parameter names to ensure they
		 * match a list of expected variables name for this option
		 * type. Used to ensure option object passed into the API don't
		 * contain erroneous parameters.
		 * @param {Object} obj - User options object
		 * @param {Object} keys - valid keys and types that may exist in obj.
		 * @throws {Error} Invalid option parameter found.
		 * @private
		 */
		var validate = function (obj, keys) {
			for (var key in obj) {
				if (obj.hasOwnProperty(key)) {
					if (keys.hasOwnProperty(key)) {
						if (typeof obj[key] !== keys[key])
							throw new Error(
								format(ERROR.INVALID_TYPE, [typeof obj[key], key])
							);
					} else {
						var errorStr =
							'Unknown property, ' + key + '. Valid properties are:';
						for (var validKey in keys)
							if (keys.hasOwnProperty(validKey))
								errorStr = errorStr + ' ' + validKey;
						throw new Error(errorStr);
					}
				}
			}
		};

		/**
		 * Return a new function which runs the user function bound
		 * to a fixed scope.
		 * @param {function} User function
		 * @param {object} Function scope
		 * @return {function} User function bound to another scope
		 * @private
		 */
		var scope = function (f, scope) {
			return function () {
				return f.apply(scope, arguments);
			};
		};

		/**
		 * Unique message type identifiers, with associated
		 * associated integer values.
		 * @private
		 */
		var ERROR = {
			OK: { code: 0, text: 'AMQJSC0000I OK.' },
			CONNECT_TIMEOUT: { code: 1, text: 'AMQJSC0001E Connect timed out.' },
			SUBSCRIBE_TIMEOUT: { code: 2, text: 'AMQJS0002E Subscribe timed out.' },
			UNSUBSCRIBE_TIMEOUT: {
				code: 3,
				text: 'AMQJS0003E Unsubscribe timed out.',
			},
			PING_TIMEOUT: { code: 4, text: 'AMQJS0004E Ping timed out.' },
			INTERNAL_ERROR: {
				code: 5,
				text: 'AMQJS0005E Internal error. Error Message: {0}, Stack trace: {1}',
			},
			CONNACK_RETURNCODE: {
				code: 6,
				text: 'AMQJS0006E Bad Connack return code:{0} {1}.',
			},
			SOCKET_ERROR: { code: 7, text: 'AMQJS0007E Socket error:{0}.' },
			SOCKET_CLOSE: { code: 8, text: 'AMQJS0008I Socket closed.' },
			MALFORMED_UTF: {
				code: 9,
				text: 'AMQJS0009E Malformed UTF data:{0} {1} {2}.',
			},
			UNSUPPORTED: {
				code: 10,
				text: 'AMQJS0010E {0} is not supported by this browser.',
			},
			INVALID_STATE: { code: 11, text: 'AMQJS0011E Invalid state {0}.' },
			INVALID_TYPE: { code: 12, text: 'AMQJS0012E Invalid type {0} for {1}.' },
			INVALID_ARGUMENT: {
				code: 13,
				text: 'AMQJS0013E Invalid argument {0} for {1}.',
			},
			UNSUPPORTED_OPERATION: {
				code: 14,
				text: 'AMQJS0014E Unsupported operation.',
			},
			INVALID_STORED_DATA: {
				code: 15,
				text: 'AMQJS0015E Invalid data in local storage key={0} value={1}.',
			},
			INVALID_MQTT_MESSAGE_TYPE: {
				code: 16,
				text: 'AMQJS0016E Invalid MQTT message type {0}.',
			},
			MALFORMED_UNICODE: {
				code: 17,
				text: 'AMQJS0017E Malformed Unicode string:{0} {1}.',
			},
			BUFFER_FULL: {
				code: 18,
				text: 'AMQJS0018E Message buffer is full, maximum buffer size: {0}.',
			},
		};

		/** CONNACK RC Meaning. */
		var CONNACK_RC = {
			0: 'Connection Accepted',
			1: 'Connection Refused: unacceptable protocol version',
			2: 'Connection Refused: identifier rejected',
			3: 'Connection Refused: server unavailable',
			4: 'Connection Refused: bad user name or password',
			5: 'Connection Refused: not authorized',
		};

		/**
		 * Format an error message text.
		 * @private
		 * @param {error} ERROR value above.
		 * @param {substitutions} [array] substituted into the text.
		 * @return the text with the substitutions made.
		 */
		var format = function (error, substitutions) {
			var text = error.text;
			if (substitutions) {
				var field, start;
				for (var i = 0; i < substitutions.length; i++) {
					field = '{' + i + '}';
					start = text.indexOf(field);
					if (start > 0) {
						var part1 = text.substring(0, start);
						var part2 = text.substring(start + field.length);
						text = part1 + substitutions[i] + part2;
					}
				}
			}
			return text;
		};

		//MQTT protocol and version          6    M    Q    I    s    d    p    3
		var MqttProtoIdentifierv3 = [
			0x00, 0x06, 0x4d, 0x51, 0x49, 0x73, 0x64, 0x70, 0x03,
		];
		//MQTT proto/version for 311         4    M    Q    T    T    4
		var MqttProtoIdentifierv4 = [0x00, 0x04, 0x4d, 0x51, 0x54, 0x54, 0x04];

		/**
		 * Construct an MQTT wire protocol message.
		 * @param type MQTT packet type.
		 * @param options optional wire message attributes.
		 *
		 * Optional properties
		 *
		 * messageIdentifier: message ID in the range [0..65535]
		 * payloadMessage:	Application Message - PUBLISH only
		 * connectStrings:	array of 0 or more Strings to be put into the CONNECT payload
		 * topics:			array of strings (SUBSCRIBE, UNSUBSCRIBE)
		 * requestQoS:		array of QoS values [0..2]
		 *
		 * "Flag" properties
		 * cleanSession:	true if present / false if absent (CONNECT)
		 * willMessage:  	true if present / false if absent (CONNECT)
		 * isRetained:		true if present / false if absent (CONNECT)
		 * userName:		true if present / false if absent (CONNECT)
		 * password:		true if present / false if absent (CONNECT)
		 * keepAliveInterval:	integer [0..65535]  (CONNECT)
		 *
		 * @private
		 * @ignore
		 */
		var WireMessage = function (type, options) {
			this.type = type;
			for (var name in options) {
				if (options.hasOwnProperty(name)) {
					this[name] = options[name];
				}
			}
		};

		WireMessage.prototype.encode = function () {
			// Compute the first byte of the fixed header
			var first = (this.type & 0x0f) << 4;

			/*
			 * Now calculate the length of the variable header + payload by adding up the lengths
			 * of all the component parts
			 */

			var remLength = 0;
			var topicStrLength = [];
			var destinationNameLength = 0;
			var willMessagePayloadBytes;

			// if the message contains a messageIdentifier then we need two bytes for that
			if (this.messageIdentifier !== undefined) remLength += 2;

			switch (this.type) {
				// If this a Connect then we need to include 12 bytes for its header
				case MESSAGE_TYPE.CONNECT:
					switch (this.mqttVersion) {
						case 3:
							remLength += MqttProtoIdentifierv3.length + 3;
							break;
						case 4:
							remLength += MqttProtoIdentifierv4.length + 3;
							break;
					}

					remLength += UTF8Length(this.clientId) + 2;
					if (this.willMessage !== undefined) {
						remLength += UTF8Length(this.willMessage.destinationName) + 2;
						// Will message is always a string, sent as UTF-8 characters with a preceding length.
						willMessagePayloadBytes = this.willMessage.payloadBytes;
						if (!(willMessagePayloadBytes instanceof Uint8Array))
							willMessagePayloadBytes = new Uint8Array(payloadBytes);
						remLength += willMessagePayloadBytes.byteLength + 2;
					}
					if (this.userName !== undefined)
						remLength += UTF8Length(this.userName) + 2;
					if (this.password !== undefined)
						remLength += UTF8Length(this.password) + 2;
					break;

				// Subscribe, Unsubscribe can both contain topic strings
				case MESSAGE_TYPE.SUBSCRIBE:
					first |= 0x02; // Qos = 1;
					for (var i = 0; i < this.topics.length; i++) {
						topicStrLength[i] = UTF8Length(this.topics[i]);
						remLength += topicStrLength[i] + 2;
					}
					remLength += this.requestedQos.length; // 1 byte for each topic's Qos
					// QoS on Subscribe only
					break;

				case MESSAGE_TYPE.UNSUBSCRIBE:
					first |= 0x02; // Qos = 1;
					for (var i = 0; i < this.topics.length; i++) {
						topicStrLength[i] = UTF8Length(this.topics[i]);
						remLength += topicStrLength[i] + 2;
					}
					break;

				case MESSAGE_TYPE.PUBREL:
					first |= 0x02; // Qos = 1;
					break;

				case MESSAGE_TYPE.PUBLISH:
					if (this.payloadMessage.duplicate) first |= 0x08;
					first = first |= this.payloadMessage.qos << 1;
					if (this.payloadMessage.retained) first |= 0x01;
					destinationNameLength = UTF8Length(
						this.payloadMessage.destinationName
					);
					remLength += destinationNameLength + 2;
					var payloadBytes = this.payloadMessage.payloadBytes;
					remLength += payloadBytes.byteLength;
					if (payloadBytes instanceof ArrayBuffer)
						payloadBytes = new Uint8Array(payloadBytes);
					else if (!(payloadBytes instanceof Uint8Array))
						payloadBytes = new Uint8Array(payloadBytes.buffer);
					break;

				case MESSAGE_TYPE.DISCONNECT:
					break;

				default:
					break;
			}

			// Now we can allocate a buffer for the message

			var mbi = encodeMBI(remLength); // Convert the length to MQTT MBI format
			var pos = mbi.length + 1; // Offset of start of variable header
			var buffer = new ArrayBuffer(remLength + pos);
			var byteStream = new Uint8Array(buffer); // view it as a sequence of bytes

			//Write the fixed header into the buffer
			byteStream[0] = first;
			byteStream.set(mbi, 1);

			// If this is a PUBLISH then the variable header starts with a topic
			if (this.type == MESSAGE_TYPE.PUBLISH)
				pos = writeString(
					this.payloadMessage.destinationName,
					destinationNameLength,
					byteStream,
					pos
				);
			// If this is a CONNECT then the variable header contains the protocol name/version, flags and keepalive time
			else if (this.type == MESSAGE_TYPE.CONNECT) {
				switch (this.mqttVersion) {
					case 3:
						byteStream.set(MqttProtoIdentifierv3, pos);
						pos += MqttProtoIdentifierv3.length;
						break;
					case 4:
						byteStream.set(MqttProtoIdentifierv4, pos);
						pos += MqttProtoIdentifierv4.length;
						break;
				}
				var connectFlags = 0;
				if (this.cleanSession) connectFlags = 0x02;
				if (this.willMessage !== undefined) {
					connectFlags |= 0x04;
					connectFlags |= this.willMessage.qos << 3;
					if (this.willMessage.retained) {
						connectFlags |= 0x20;
					}
				}
				if (this.userName !== undefined) connectFlags |= 0x80;
				if (this.password !== undefined) connectFlags |= 0x40;
				byteStream[pos++] = connectFlags;
				pos = writeUint16(this.keepAliveInterval, byteStream, pos);
			}

			// Output the messageIdentifier - if there is one
			if (this.messageIdentifier !== undefined)
				pos = writeUint16(this.messageIdentifier, byteStream, pos);

			switch (this.type) {
				case MESSAGE_TYPE.CONNECT:
					pos = writeString(
						this.clientId,
						UTF8Length(this.clientId),
						byteStream,
						pos
					);
					if (this.willMessage !== undefined) {
						pos = writeString(
							this.willMessage.destinationName,
							UTF8Length(this.willMessage.destinationName),
							byteStream,
							pos
						);
						pos = writeUint16(
							willMessagePayloadBytes.byteLength,
							byteStream,
							pos
						);
						byteStream.set(willMessagePayloadBytes, pos);
						pos += willMessagePayloadBytes.byteLength;
					}
					if (this.userName !== undefined)
						pos = writeString(
							this.userName,
							UTF8Length(this.userName),
							byteStream,
							pos
						);
					if (this.password !== undefined)
						pos = writeString(
							this.password,
							UTF8Length(this.password),
							byteStream,
							pos
						);
					break;

				case MESSAGE_TYPE.PUBLISH:
					// PUBLISH has a text or binary payload, if text do not add a 2 byte length field, just the UTF characters.
					byteStream.set(payloadBytes, pos);

					break;

				//    	    case MESSAGE_TYPE.PUBREC:
				//    	    case MESSAGE_TYPE.PUBREL:
				//    	    case MESSAGE_TYPE.PUBCOMP:
				//    	    	break;

				case MESSAGE_TYPE.SUBSCRIBE:
					// SUBSCRIBE has a list of topic strings and request QoS
					for (var i = 0; i < this.topics.length; i++) {
						pos = writeString(
							this.topics[i],
							topicStrLength[i],
							byteStream,
							pos
						);
						byteStream[pos++] = this.requestedQos[i];
					}
					break;

				case MESSAGE_TYPE.UNSUBSCRIBE:
					// UNSUBSCRIBE has a list of topic strings
					for (var i = 0; i < this.topics.length; i++)
						pos = writeString(
							this.topics[i],
							topicStrLength[i],
							byteStream,
							pos
						);
					break;

				default:
				// Do nothing.
			}

			return buffer;
		};

		function decodeMessage(input, pos) {
			var startingPos = pos;
			var first = input[pos];
			var type = first >> 4;
			var messageInfo = (first &= 0x0f);
			pos += 1;

			// Decode the remaining length (MBI format)

			var digit;
			var remLength = 0;
			var multiplier = 1;
			do {
				if (pos == input.length) {
					return [null, startingPos];
				}
				digit = input[pos++];
				remLength += (digit & 0x7f) * multiplier;
				multiplier *= 128;
			} while ((digit & 0x80) !== 0);

			var endPos = pos + remLength;
			if (endPos > input.length) {
				return [null, startingPos];
			}

			var wireMessage = new WireMessage(type);
			switch (type) {
				case MESSAGE_TYPE.CONNACK:
					var connectAcknowledgeFlags = input[pos++];
					if (connectAcknowledgeFlags & 0x01) wireMessage.sessionPresent = true;
					wireMessage.returnCode = input[pos++];
					break;

				case MESSAGE_TYPE.PUBLISH:
					var qos = (messageInfo >> 1) & 0x03;

					var len = readUint16(input, pos);
					pos += 2;
					var topicName = parseUTF8(input, pos, len);
					pos += len;
					// If QoS 1 or 2 there will be a messageIdentifier
					if (qos > 0) {
						wireMessage.messageIdentifier = readUint16(input, pos);
						pos += 2;
					}

					var message = new Message(input.subarray(pos, endPos));
					if ((messageInfo & 0x01) == 0x01) message.retained = true;
					if ((messageInfo & 0x08) == 0x08) message.duplicate = true;
					message.qos = qos;
					message.destinationName = topicName;
					wireMessage.payloadMessage = message;
					break;

				case MESSAGE_TYPE.PUBACK:
				case MESSAGE_TYPE.PUBREC:
				case MESSAGE_TYPE.PUBREL:
				case MESSAGE_TYPE.PUBCOMP:
				case MESSAGE_TYPE.UNSUBACK:
					wireMessage.messageIdentifier = readUint16(input, pos);
					break;

				case MESSAGE_TYPE.SUBACK:
					wireMessage.messageIdentifier = readUint16(input, pos);
					pos += 2;
					wireMessage.returnCode = input.subarray(pos, endPos);
					break;

				default:
					break;
			}

			return [wireMessage, endPos];
		}

		function writeUint16(input, buffer, offset) {
			buffer[offset++] = input >> 8; //MSB
			buffer[offset++] = input % 256; //LSB
			return offset;
		}

		function writeString(input, utf8Length, buffer, offset) {
			offset = writeUint16(utf8Length, buffer, offset);
			stringToUTF8(input, buffer, offset);
			return offset + utf8Length;
		}

		function readUint16(buffer, offset) {
			return 256 * buffer[offset] + buffer[offset + 1];
		}

		/**
		 * Encodes an MQTT Multi-Byte Integer
		 * @private
		 */
		function encodeMBI(number) {
			var output = new Array(1);
			var numBytes = 0;

			do {
				var digit = number % 128;
				number = number >> 7;
				if (number > 0) {
					digit |= 0x80;
				}
				output[numBytes++] = digit;
			} while (number > 0 && numBytes < 4);

			return output;
		}

		/**
		 * Takes a String and calculates its length in bytes when encoded in UTF8.
		 * @private
		 */
		function UTF8Length(input) {
			var output = 0;
			for (var i = 0; i < input.length; i++) {
				var charCode = input.charCodeAt(i);
				if (charCode > 0x7ff) {
					// Surrogate pair means its a 4 byte character
					if (0xd800 <= charCode && charCode <= 0xdbff) {
						i++;
						output++;
					}
					output += 3;
				} else if (charCode > 0x7f) output += 2;
				else output++;
			}
			return output;
		}

		/**
		 * Takes a String and writes it into an array as UTF8 encoded bytes.
		 * @private
		 */
		function stringToUTF8(input, output, start) {
			var pos = start;
			for (var i = 0; i < input.length; i++) {
				var charCode = input.charCodeAt(i);

				// Check for a surrogate pair.
				if (0xd800 <= charCode && charCode <= 0xdbff) {
					var lowCharCode = input.charCodeAt(++i);
					if (isNaN(lowCharCode)) {
						throw new Error(
							format(ERROR.MALFORMED_UNICODE, [charCode, lowCharCode])
						);
					}
					charCode =
						((charCode - 0xd800) << 10) + (lowCharCode - 0xdc00) + 0x10000;
				}

				if (charCode <= 0x7f) {
					output[pos++] = charCode;
				} else if (charCode <= 0x7ff) {
					output[pos++] = ((charCode >> 6) & 0x1f) | 0xc0;
					output[pos++] = (charCode & 0x3f) | 0x80;
				} else if (charCode <= 0xffff) {
					output[pos++] = ((charCode >> 12) & 0x0f) | 0xe0;
					output[pos++] = ((charCode >> 6) & 0x3f) | 0x80;
					output[pos++] = (charCode & 0x3f) | 0x80;
				} else {
					output[pos++] = ((charCode >> 18) & 0x07) | 0xf0;
					output[pos++] = ((charCode >> 12) & 0x3f) | 0x80;
					output[pos++] = ((charCode >> 6) & 0x3f) | 0x80;
					output[pos++] = (charCode & 0x3f) | 0x80;
				}
			}
			return output;
		}

		function parseUTF8(input, offset, length) {
			var output = '';
			var utf16;
			var pos = offset;

			while (pos < offset + length) {
				var byte1 = input[pos++];
				if (byte1 < 128) utf16 = byte1;
				else {
					var byte2 = input[pos++] - 128;
					if (byte2 < 0)
						throw new Error(
							format(ERROR.MALFORMED_UTF, [
								byte1.toString(16),
								byte2.toString(16),
								'',
							])
						);
					if (byte1 < 0xe0)
						// 2 byte character
						utf16 = 64 * (byte1 - 0xc0) + byte2;
					else {
						var byte3 = input[pos++] - 128;
						if (byte3 < 0)
							throw new Error(
								format(ERROR.MALFORMED_UTF, [
									byte1.toString(16),
									byte2.toString(16),
									byte3.toString(16),
								])
							);
						if (byte1 < 0xf0)
							// 3 byte character
							utf16 = 4096 * (byte1 - 0xe0) + 64 * byte2 + byte3;
						else {
							var byte4 = input[pos++] - 128;
							if (byte4 < 0)
								throw new Error(
									format(ERROR.MALFORMED_UTF, [
										byte1.toString(16),
										byte2.toString(16),
										byte3.toString(16),
										byte4.toString(16),
									])
								);
							if (byte1 < 0xf8)
								// 4 byte character
								utf16 =
									262144 * (byte1 - 0xf0) + 4096 * byte2 + 64 * byte3 + byte4;
							// longer encodings are not supported
							else
								throw new Error(
									format(ERROR.MALFORMED_UTF, [
										byte1.toString(16),
										byte2.toString(16),
										byte3.toString(16),
										byte4.toString(16),
									])
								);
						}
					}
				}

				if (utf16 > 0xffff) {
					// 4 byte character - express as a surrogate pair
					utf16 -= 0x10000;
					output += String.fromCharCode(0xd800 + (utf16 >> 10)); // lead character
					utf16 = 0xdc00 + (utf16 & 0x3ff); // trail character
				}
				output += String.fromCharCode(utf16);
			}
			return output;
		}

		/**
		 * Repeat keepalive requests, monitor responses.
		 * @ignore
		 */
		var Pinger = function (client, keepAliveInterval) {
			this._client = client;
			this._keepAliveInterval = keepAliveInterval * 1000;
			this.isReset = false;

			var pingReq = new WireMessage(MESSAGE_TYPE.PINGREQ).encode();

			var doTimeout = function (pinger) {
				return function () {
					return doPing.apply(pinger);
				};
			};

			/** @ignore */
			var doPing = function () {
				if (!this.isReset) {
					this._client._trace('Pinger.doPing', 'Timed out');
					this._client._disconnected(
						ERROR.PING_TIMEOUT.code,
						format(ERROR.PING_TIMEOUT)
					);
				} else {
					this.isReset = false;
					this._client._trace('Pinger.doPing', 'send PINGREQ');
					this._client.socket.send(pingReq);
					this.timeout = setTimeout(doTimeout(this), this._keepAliveInterval);
				}
			};

			this.reset = function () {
				this.isReset = true;
				clearTimeout(this.timeout);
				if (this._keepAliveInterval > 0)
					this.timeout = setTimeout(doTimeout(this), this._keepAliveInterval);
			};

			this.cancel = function () {
				clearTimeout(this.timeout);
			};
		};

		/**
		 * Monitor request completion.
		 * @ignore
		 */
		var Timeout = function (client, timeoutSeconds, action, args) {
			if (!timeoutSeconds) timeoutSeconds = 30;

			var doTimeout = function (action, client, args) {
				return function () {
					return action.apply(client, args);
				};
			};
			this.timeout = setTimeout(
				doTimeout(action, client, args),
				timeoutSeconds * 1000
			);

			this.cancel = function () {
				clearTimeout(this.timeout);
			};
		};

		/**
		 * Internal implementation of the Websockets MQTT V3.1 client.
		 *
		 * @name Paho.ClientImpl @constructor
		 * @param {String} host the DNS nameof the webSocket host.
		 * @param {Number} port the port number for that host.
		 * @param {String} clientId the MQ client identifier.
		 */
		var ClientImpl = function (uri, host, port, path, clientId) {
			// Check dependencies are satisfied in this browser.
			if (!('WebSocket' in global && global.WebSocket !== null)) {
				throw new Error(format(ERROR.UNSUPPORTED, ['WebSocket']));
			}
			if (!('ArrayBuffer' in global && global.ArrayBuffer !== null)) {
				throw new Error(format(ERROR.UNSUPPORTED, ['ArrayBuffer']));
			}
			this._trace('Paho.Client', uri, host, port, path, clientId);

			this.host = host;
			this.port = port;
			this.path = path;
			this.uri = uri;
			this.clientId = clientId;
			this._wsuri = null;

			// Local storagekeys are qualified with the following string.
			// The conditional inclusion of path in the key is for backward
			// compatibility to when the path was not configurable and assumed to
			// be /mqtt
			this._localKey =
				host +
				':' +
				port +
				(path != '/mqtt' ? ':' + path : '') +
				':' +
				clientId +
				':';

			// Create private instance-only message queue
			// Internal queue of messages to be sent, in sending order.
			this._msg_queue = [];
			this._buffered_msg_queue = [];

			// Messages we have sent and are expecting a response for, indexed by their respective message ids.
			this._sentMessages = {};

			// Messages we have received and acknowleged and are expecting a confirm message for
			// indexed by their respective message ids.
			this._receivedMessages = {};

			// Internal list of callbacks to be executed when messages
			// have been successfully sent over web socket, e.g. disconnect
			// when it doesn't have to wait for ACK, just message is dispatched.
			this._notify_msg_sent = {};

			// Unique identifier for SEND messages, incrementing
			// counter as messages are sent.
			this._message_identifier = 1;

			// Used to determine the transmission sequence of stored sent messages.
			this._sequence = 0;

			// Load the local state, if any, from the saved version, only restore state relevant to this client.
			for (var key in localStorage)
				if (
					key.indexOf('Sent:' + this._localKey) === 0 ||
					key.indexOf('Received:' + this._localKey) === 0
				)
					this.restore(key);
		};

		// Messaging Client public instance members.
		ClientImpl.prototype.host = null;
		ClientImpl.prototype.port = null;
		ClientImpl.prototype.path = null;
		ClientImpl.prototype.uri = null;
		ClientImpl.prototype.clientId = null;

		// Messaging Client private instance members.
		ClientImpl.prototype.socket = null;
		/* true once we have received an acknowledgement to a CONNECT packet. */
		ClientImpl.prototype.connected = false;
		/* The largest message identifier allowed, may not be larger than 2**16 but
		 * if set smaller reduces the maximum number of outbound messages allowed.
		 */
		ClientImpl.prototype.maxMessageIdentifier = 65536;
		ClientImpl.prototype.connectOptions = null;
		ClientImpl.prototype.hostIndex = null;
		ClientImpl.prototype.onConnected = null;
		ClientImpl.prototype.onConnectionLost = null;
		ClientImpl.prototype.onMessageDelivered = null;
		ClientImpl.prototype.onMessageArrived = null;
		ClientImpl.prototype.traceFunction = null;
		ClientImpl.prototype._msg_queue = null;
		ClientImpl.prototype._buffered_msg_queue = null;
		ClientImpl.prototype._connectTimeout = null;
		/* The sendPinger monitors how long we allow before we send data to prove to the server that we are alive. */
		ClientImpl.prototype.sendPinger = null;
		/* The receivePinger monitors how long we allow before we require evidence that the server is alive. */
		ClientImpl.prototype.receivePinger = null;
		ClientImpl.prototype._reconnectInterval = 1; // Reconnect Delay, starts at 1 second
		ClientImpl.prototype._reconnecting = false;
		ClientImpl.prototype._reconnectTimeout = null;
		ClientImpl.prototype.disconnectedPublishing = false;
		ClientImpl.prototype.disconnectedBufferSize = 5000;

		ClientImpl.prototype.receiveBuffer = null;

		ClientImpl.prototype._traceBuffer = null;
		ClientImpl.prototype._MAX_TRACE_ENTRIES = 100;

		ClientImpl.prototype.connect = function (connectOptions) {
			var connectOptionsMasked = this._traceMask(connectOptions, 'password');
			this._trace(
				'Client.connect',
				connectOptionsMasked,
				this.socket,
				this.connected
			);

			if (this.connected)
				throw new Error(format(ERROR.INVALID_STATE, ['already connected']));
			if (this.socket)
				throw new Error(format(ERROR.INVALID_STATE, ['already connected']));

			if (this._reconnecting) {
				// connect() function is called while reconnect is in progress.
				// Terminate the auto reconnect process to use new connect options.
				this._reconnectTimeout.cancel();
				this._reconnectTimeout = null;
				this._reconnecting = false;
			}

			this.connectOptions = connectOptions;
			this._reconnectInterval = 1;
			this._reconnecting = false;
			if (connectOptions.uris) {
				this.hostIndex = 0;
				this._doConnect(connectOptions.uris[0]);
			} else {
				this._doConnect(this.uri);
			}
		};

		ClientImpl.prototype.subscribe = function (filter, subscribeOptions) {
			this._trace('Client.subscribe', filter, subscribeOptions);

			if (!this.connected)
				throw new Error(format(ERROR.INVALID_STATE, ['not connected']));

			var wireMessage = new WireMessage(MESSAGE_TYPE.SUBSCRIBE);
			wireMessage.topics = filter.constructor === Array ? filter : [filter];
			if (subscribeOptions.qos === undefined) subscribeOptions.qos = 0;
			wireMessage.requestedQos = [];
			for (var i = 0; i < wireMessage.topics.length; i++)
				wireMessage.requestedQos[i] = subscribeOptions.qos;

			if (subscribeOptions.onSuccess) {
				wireMessage.onSuccess = function (grantedQos) {
					subscribeOptions.onSuccess({
						invocationContext: subscribeOptions.invocationContext,
						grantedQos: grantedQos,
					});
				};
			}

			if (subscribeOptions.onFailure) {
				wireMessage.onFailure = function (errorCode) {
					subscribeOptions.onFailure({
						invocationContext: subscribeOptions.invocationContext,
						errorCode: errorCode,
						errorMessage: format(errorCode),
					});
				};
			}

			if (subscribeOptions.timeout) {
				wireMessage.timeOut = new Timeout(
					this,
					subscribeOptions.timeout,
					subscribeOptions.onFailure,
					[
						{
							invocationContext: subscribeOptions.invocationContext,
							errorCode: ERROR.SUBSCRIBE_TIMEOUT.code,
							errorMessage: format(ERROR.SUBSCRIBE_TIMEOUT),
						},
					]
				);
			}

			// All subscriptions return a SUBACK.
			this._requires_ack(wireMessage);
			this._schedule_message(wireMessage);
		};

		/** @ignore */
		ClientImpl.prototype.unsubscribe = function (filter, unsubscribeOptions) {
			this._trace('Client.unsubscribe', filter, unsubscribeOptions);

			if (!this.connected)
				throw new Error(format(ERROR.INVALID_STATE, ['not connected']));

			var wireMessage = new WireMessage(MESSAGE_TYPE.UNSUBSCRIBE);
			wireMessage.topics = filter.constructor === Array ? filter : [filter];

			if (unsubscribeOptions.onSuccess) {
				wireMessage.callback = function () {
					unsubscribeOptions.onSuccess({
						invocationContext: unsubscribeOptions.invocationContext,
					});
				};
			}
			if (unsubscribeOptions.timeout) {
				wireMessage.timeOut = new Timeout(
					this,
					unsubscribeOptions.timeout,
					unsubscribeOptions.onFailure,
					[
						{
							invocationContext: unsubscribeOptions.invocationContext,
							errorCode: ERROR.UNSUBSCRIBE_TIMEOUT.code,
							errorMessage: format(ERROR.UNSUBSCRIBE_TIMEOUT),
						},
					]
				);
			}

			// All unsubscribes return a SUBACK.
			this._requires_ack(wireMessage);
			this._schedule_message(wireMessage);
		};

		ClientImpl.prototype.send = function (message) {
			this._trace('Client.send', message);

			var wireMessage = new WireMessage(MESSAGE_TYPE.PUBLISH);
			wireMessage.payloadMessage = message;

			if (this.connected) {
				// Mark qos 1 & 2 message as "ACK required"
				// For qos 0 message, invoke onMessageDelivered callback if there is one.
				// Then schedule the message.
				if (message.qos > 0) {
					this._requires_ack(wireMessage);
				} else if (this.onMessageDelivered) {
					this._notify_msg_sent[wireMessage] = this.onMessageDelivered(
						wireMessage.payloadMessage
					);
				}
				this._schedule_message(wireMessage);
			} else {
				// Currently disconnected, will not schedule this message
				// Check if reconnecting is in progress and disconnected publish is enabled.
				if (this._reconnecting && this.disconnectedPublishing) {
					// Check the limit which include the "required ACK" messages
					var messageCount =
						Object.keys(this._sentMessages).length +
						this._buffered_msg_queue.length;
					if (messageCount > this.disconnectedBufferSize) {
						throw new Error(
							format(ERROR.BUFFER_FULL, [this.disconnectedBufferSize])
						);
					} else {
						if (message.qos > 0) {
							// Mark this message as "ACK required"
							this._requires_ack(wireMessage);
						} else {
							wireMessage.sequence = ++this._sequence;
							// Add messages in fifo order to array, by adding to start
							this._buffered_msg_queue.unshift(wireMessage);
						}
					}
				} else {
					throw new Error(format(ERROR.INVALID_STATE, ['not connected']));
				}
			}
		};

		ClientImpl.prototype.disconnect = function () {
			this._trace('Client.disconnect');

			if (this._reconnecting) {
				// disconnect() function is called while reconnect is in progress.
				// Terminate the auto reconnect process.
				this._reconnectTimeout.cancel();
				this._reconnectTimeout = null;
				this._reconnecting = false;
			}

			if (!this.socket)
				throw new Error(
					format(ERROR.INVALID_STATE, ['not connecting or connected'])
				);

			var wireMessage = new WireMessage(MESSAGE_TYPE.DISCONNECT);

			// Run the disconnected call back as soon as the message has been sent,
			// in case of a failure later on in the disconnect processing.
			// as a consequence, the _disconected call back may be run several times.
			this._notify_msg_sent[wireMessage] = scope(this._disconnected, this);

			this._schedule_message(wireMessage);
		};

		ClientImpl.prototype.getTraceLog = function () {
			if (this._traceBuffer !== null) {
				this._trace('Client.getTraceLog', new Date());
				this._trace(
					'Client.getTraceLog in flight messages',
					this._sentMessages.length
				);
				for (var key in this._sentMessages)
					this._trace('_sentMessages ', key, this._sentMessages[key]);
				for (var key in this._receivedMessages)
					this._trace('_receivedMessages ', key, this._receivedMessages[key]);

				return this._traceBuffer;
			}
		};

		ClientImpl.prototype.startTrace = function () {
			if (this._traceBuffer === null) {
				this._traceBuffer = [];
			}
			this._trace('Client.startTrace', new Date(), version);
		};

		ClientImpl.prototype.stopTrace = function () {
			delete this._traceBuffer;
		};

		ClientImpl.prototype._doConnect = function (wsurl) {
			// When the socket is open, this client will send the CONNECT WireMessage using the saved parameters.
			if (this.connectOptions.useSSL) {
				var uriParts = wsurl.split(':');
				uriParts[0] = 'wss';
				wsurl = uriParts.join(':');
			}
			this._wsuri = wsurl;
			this.connected = false;

			if (this.connectOptions.mqttVersion < 4) {
				this.socket = new WebSocket(wsurl, ['mqttv3.1']);
			} else {
				this.socket = new WebSocket(wsurl, ['mqtt']);
			}
			this.socket.binaryType = 'arraybuffer';
			this.socket.onopen = scope(this._on_socket_open, this);
			this.socket.onmessage = scope(this._on_socket_message, this);
			this.socket.onerror = scope(this._on_socket_error, this);
			this.socket.onclose = scope(this._on_socket_close, this);

			this.sendPinger = new Pinger(this, this.connectOptions.keepAliveInterval);
			this.receivePinger = new Pinger(
				this,
				this.connectOptions.keepAliveInterval
			);
			if (this._connectTimeout) {
				this._connectTimeout.cancel();
				this._connectTimeout = null;
			}
			this._connectTimeout = new Timeout(
				this,
				this.connectOptions.timeout,
				this._disconnected,
				[ERROR.CONNECT_TIMEOUT.code, format(ERROR.CONNECT_TIMEOUT)]
			);
		};

		// Schedule a new message to be sent over the WebSockets
		// connection. CONNECT messages cause WebSocket connection
		// to be started. All other messages are queued internally
		// until this has happened. When WS connection starts, process
		// all outstanding messages.
		ClientImpl.prototype._schedule_message = function (message) {
			// Add messages in fifo order to array, by adding to start
			this._msg_queue.unshift(message);
			// Process outstanding messages in the queue if we have an  open socket, and have received CONNACK.
			if (this.connected) {
				this._process_queue();
			}
		};

		ClientImpl.prototype.store = function (prefix, wireMessage) {
			var storedMessage = {
				type: wireMessage.type,
				messageIdentifier: wireMessage.messageIdentifier,
				version: 1,
			};

			switch (wireMessage.type) {
				case MESSAGE_TYPE.PUBLISH:
					if (wireMessage.pubRecReceived) storedMessage.pubRecReceived = true;

					// Convert the payload to a hex string.
					storedMessage.payloadMessage = {};
					var hex = '';
					var messageBytes = wireMessage.payloadMessage.payloadBytes;
					for (var i = 0; i < messageBytes.length; i++) {
						if (messageBytes[i] <= 0xf)
							hex = hex + '0' + messageBytes[i].toString(16);
						else hex = hex + messageBytes[i].toString(16);
					}
					storedMessage.payloadMessage.payloadHex = hex;

					storedMessage.payloadMessage.qos = wireMessage.payloadMessage.qos;
					storedMessage.payloadMessage.destinationName =
						wireMessage.payloadMessage.destinationName;
					if (wireMessage.payloadMessage.duplicate)
						storedMessage.payloadMessage.duplicate = true;
					if (wireMessage.payloadMessage.retained)
						storedMessage.payloadMessage.retained = true;

					// Add a sequence number to sent messages.
					if (prefix.indexOf('Sent:') === 0) {
						if (wireMessage.sequence === undefined)
							wireMessage.sequence = ++this._sequence;
						storedMessage.sequence = wireMessage.sequence;
					}
					break;

				default:
					throw Error(
						format(ERROR.INVALID_STORED_DATA, [
							prefix + this._localKey + wireMessage.messageIdentifier,
							storedMessage,
						])
					);
			}
			localStorage.setItem(
				prefix + this._localKey + wireMessage.messageIdentifier,
				JSON.stringify(storedMessage)
			);
		};

		ClientImpl.prototype.restore = function (key) {
			var value = localStorage.getItem(key);
			var storedMessage = JSON.parse(value);

			var wireMessage = new WireMessage(storedMessage.type, storedMessage);

			switch (storedMessage.type) {
				case MESSAGE_TYPE.PUBLISH:
					// Replace the payload message with a Message object.
					var hex = storedMessage.payloadMessage.payloadHex;
					var buffer = new ArrayBuffer(hex.length / 2);
					var byteStream = new Uint8Array(buffer);
					var i = 0;
					while (hex.length >= 2) {
						var x = parseInt(hex.substring(0, 2), 16);
						hex = hex.substring(2, hex.length);
						byteStream[i++] = x;
					}
					var payloadMessage = new Message(byteStream);

					payloadMessage.qos = storedMessage.payloadMessage.qos;
					payloadMessage.destinationName =
						storedMessage.payloadMessage.destinationName;
					if (storedMessage.payloadMessage.duplicate)
						payloadMessage.duplicate = true;
					if (storedMessage.payloadMessage.retained)
						payloadMessage.retained = true;
					wireMessage.payloadMessage = payloadMessage;

					break;

				default:
					throw Error(format(ERROR.INVALID_STORED_DATA, [key, value]));
			}

			if (key.indexOf('Sent:' + this._localKey) === 0) {
				wireMessage.payloadMessage.duplicate = true;
				this._sentMessages[wireMessage.messageIdentifier] = wireMessage;
			} else if (key.indexOf('Received:' + this._localKey) === 0) {
				this._receivedMessages[wireMessage.messageIdentifier] = wireMessage;
			}
		};

		ClientImpl.prototype._process_queue = function () {
			var message = null;

			// Send all queued messages down socket connection
			while ((message = this._msg_queue.pop())) {
				this._socket_send(message);
				// Notify listeners that message was successfully sent
				if (this._notify_msg_sent[message]) {
					this._notify_msg_sent[message]();
					delete this._notify_msg_sent[message];
				}
			}
		};

		/**
		 * Expect an ACK response for this message. Add message to the set of in progress
		 * messages and set an unused identifier in this message.
		 * @ignore
		 */
		ClientImpl.prototype._requires_ack = function (wireMessage) {
			var messageCount = Object.keys(this._sentMessages).length;
			if (messageCount > this.maxMessageIdentifier)
				throw Error('Too many messages:' + messageCount);

			while (this._sentMessages[this._message_identifier] !== undefined) {
				this._message_identifier++;
			}
			wireMessage.messageIdentifier = this._message_identifier;
			this._sentMessages[wireMessage.messageIdentifier] = wireMessage;
			if (wireMessage.type === MESSAGE_TYPE.PUBLISH) {
				this.store('Sent:', wireMessage);
			}
			if (this._message_identifier === this.maxMessageIdentifier) {
				this._message_identifier = 1;
			}
		};

		/**
		 * Called when the underlying websocket has been opened.
		 * @ignore
		 */
		ClientImpl.prototype._on_socket_open = function () {
			// Create the CONNECT message object.
			var wireMessage = new WireMessage(
				MESSAGE_TYPE.CONNECT,
				this.connectOptions
			);
			wireMessage.clientId = this.clientId;
			this._socket_send(wireMessage);
		};

		/**
		 * Called when the underlying websocket has received a complete packet.
		 * @ignore
		 */
		ClientImpl.prototype._on_socket_message = function (event) {
			this._trace('Client._on_socket_message', event.data);
			var messages = this._deframeMessages(event.data);
			for (var i = 0; i < messages.length; i += 1) {
				this._handleMessage(messages[i]);
			}
		};

		ClientImpl.prototype._deframeMessages = function (data) {
			var byteArray = new Uint8Array(data);
			var messages = [];
			if (this.receiveBuffer) {
				var newData = new Uint8Array(
					this.receiveBuffer.length + byteArray.length
				);
				newData.set(this.receiveBuffer);
				newData.set(byteArray, this.receiveBuffer.length);
				byteArray = newData;
				delete this.receiveBuffer;
			}
			try {
				var offset = 0;
				while (offset < byteArray.length) {
					var result = decodeMessage(byteArray, offset);
					var wireMessage = result[0];
					offset = result[1];
					if (wireMessage !== null) {
						messages.push(wireMessage);
					} else {
						break;
					}
				}
				if (offset < byteArray.length) {
					this.receiveBuffer = byteArray.subarray(offset);
				}
			} catch (error) {
				var errorStack =
					error.hasOwnProperty('stack') == 'undefined'
						? error.stack.toString()
						: 'No Error Stack Available';
				this._disconnected(
					ERROR.INTERNAL_ERROR.code,
					format(ERROR.INTERNAL_ERROR, [error.message, errorStack])
				);
				return;
			}
			return messages;
		};

		ClientImpl.prototype._handleMessage = function (wireMessage) {
			this._trace('Client._handleMessage', wireMessage);

			try {
				switch (wireMessage.type) {
					case MESSAGE_TYPE.CONNACK:
						this._connectTimeout.cancel();
						if (this._reconnectTimeout) this._reconnectTimeout.cancel();

						// If we have started using clean session then clear up the local state.
						if (this.connectOptions.cleanSession) {
							for (var key in this._sentMessages) {
								var sentMessage = this._sentMessages[key];
								localStorage.removeItem(
									'Sent:' + this._localKey + sentMessage.messageIdentifier
								);
							}
							this._sentMessages = {};

							for (var key in this._receivedMessages) {
								var receivedMessage = this._receivedMessages[key];
								localStorage.removeItem(
									'Received:' +
										this._localKey +
										receivedMessage.messageIdentifier
								);
							}
							this._receivedMessages = {};
						}
						// Client connected and ready for business.
						if (wireMessage.returnCode === 0) {
							this.connected = true;
							// Jump to the end of the list of uris and stop looking for a good host.

							if (this.connectOptions.uris)
								this.hostIndex = this.connectOptions.uris.length;
						} else {
							this._disconnected(
								ERROR.CONNACK_RETURNCODE.code,
								format(ERROR.CONNACK_RETURNCODE, [
									wireMessage.returnCode,
									CONNACK_RC[wireMessage.returnCode],
								])
							);
							break;
						}

						// Resend messages.
						var sequencedMessages = [];
						for (var msgId in this._sentMessages) {
							if (this._sentMessages.hasOwnProperty(msgId))
								sequencedMessages.push(this._sentMessages[msgId]);
						}

						// Also schedule qos 0 buffered messages if any
						if (this._buffered_msg_queue.length > 0) {
							var msg = null;
							while ((msg = this._buffered_msg_queue.pop())) {
								sequencedMessages.push(msg);
								if (this.onMessageDelivered)
									this._notify_msg_sent[msg] = this.onMessageDelivered(
										msg.payloadMessage
									);
							}
						}

						// Sort sentMessages into the original sent order.
						var sequencedMessages = sequencedMessages.sort(function (a, b) {
							return a.sequence - b.sequence;
						});
						for (var i = 0, len = sequencedMessages.length; i < len; i++) {
							var sentMessage = sequencedMessages[i];
							if (
								sentMessage.type == MESSAGE_TYPE.PUBLISH &&
								sentMessage.pubRecReceived
							) {
								var pubRelMessage = new WireMessage(MESSAGE_TYPE.PUBREL, {
									messageIdentifier: sentMessage.messageIdentifier,
								});
								this._schedule_message(pubRelMessage);
							} else {
								this._schedule_message(sentMessage);
							}
						}

						// Execute the connectOptions.onSuccess callback if there is one.
						// Will also now return if this connection was the result of an automatic
						// reconnect and which URI was successfully connected to.
						if (this.connectOptions.onSuccess) {
							this.connectOptions.onSuccess({
								invocationContext: this.connectOptions.invocationContext,
							});
						}

						var reconnected = false;
						if (this._reconnecting) {
							reconnected = true;
							this._reconnectInterval = 1;
							this._reconnecting = false;
						}

						// Execute the onConnected callback if there is one.
						this._connected(reconnected, this._wsuri);

						// Process all queued messages now that the connection is established.
						this._process_queue();
						break;

					case MESSAGE_TYPE.PUBLISH:
						this._receivePublish(wireMessage);
						break;

					case MESSAGE_TYPE.PUBACK:
						var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
						// If this is a re flow of a PUBACK after we have restarted receivedMessage will not exist.
						if (sentMessage) {
							delete this._sentMessages[wireMessage.messageIdentifier];
							localStorage.removeItem(
								'Sent:' + this._localKey + wireMessage.messageIdentifier
							);
							if (this.onMessageDelivered)
								this.onMessageDelivered(sentMessage.payloadMessage);
						}
						break;

					case MESSAGE_TYPE.PUBREC:
						var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
						// If this is a re flow of a PUBREC after we have restarted receivedMessage will not exist.
						if (sentMessage) {
							sentMessage.pubRecReceived = true;
							var pubRelMessage = new WireMessage(MESSAGE_TYPE.PUBREL, {
								messageIdentifier: wireMessage.messageIdentifier,
							});
							this.store('Sent:', sentMessage);
							this._schedule_message(pubRelMessage);
						}
						break;

					case MESSAGE_TYPE.PUBREL:
						var receivedMessage =
							this._receivedMessages[wireMessage.messageIdentifier];
						localStorage.removeItem(
							'Received:' + this._localKey + wireMessage.messageIdentifier
						);
						// If this is a re flow of a PUBREL after we have restarted receivedMessage will not exist.
						if (receivedMessage) {
							this._receiveMessage(receivedMessage);
							delete this._receivedMessages[wireMessage.messageIdentifier];
						}
						// Always flow PubComp, we may have previously flowed PubComp but the server lost it and restarted.
						var pubCompMessage = new WireMessage(MESSAGE_TYPE.PUBCOMP, {
							messageIdentifier: wireMessage.messageIdentifier,
						});
						this._schedule_message(pubCompMessage);

						break;

					case MESSAGE_TYPE.PUBCOMP:
						var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
						delete this._sentMessages[wireMessage.messageIdentifier];
						localStorage.removeItem(
							'Sent:' + this._localKey + wireMessage.messageIdentifier
						);
						if (this.onMessageDelivered)
							this.onMessageDelivered(sentMessage.payloadMessage);
						break;

					case MESSAGE_TYPE.SUBACK:
						var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
						if (sentMessage) {
							if (sentMessage.timeOut) sentMessage.timeOut.cancel();
							// This will need to be fixed when we add multiple topic support
							if (wireMessage.returnCode[0] === 0x80) {
								if (sentMessage.onFailure) {
									sentMessage.onFailure(wireMessage.returnCode);
								}
							} else if (sentMessage.onSuccess) {
								sentMessage.onSuccess(wireMessage.returnCode);
							}
							delete this._sentMessages[wireMessage.messageIdentifier];
						}
						break;

					case MESSAGE_TYPE.UNSUBACK:
						var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
						if (sentMessage) {
							if (sentMessage.timeOut) sentMessage.timeOut.cancel();
							if (sentMessage.callback) {
								sentMessage.callback();
							}
							delete this._sentMessages[wireMessage.messageIdentifier];
						}

						break;

					case MESSAGE_TYPE.PINGRESP:
						/* The sendPinger or receivePinger may have sent a ping, the receivePinger has already been reset. */
						this.sendPinger.reset();
						break;

					case MESSAGE_TYPE.DISCONNECT:
						// Clients do not expect to receive disconnect packets.
						this._disconnected(
							ERROR.INVALID_MQTT_MESSAGE_TYPE.code,
							format(ERROR.INVALID_MQTT_MESSAGE_TYPE, [wireMessage.type])
						);
						break;

					default:
						this._disconnected(
							ERROR.INVALID_MQTT_MESSAGE_TYPE.code,
							format(ERROR.INVALID_MQTT_MESSAGE_TYPE, [wireMessage.type])
						);
				}
			} catch (error) {
				var errorStack =
					error.hasOwnProperty('stack') == 'undefined'
						? error.stack.toString()
						: 'No Error Stack Available';
				this._disconnected(
					ERROR.INTERNAL_ERROR.code,
					format(ERROR.INTERNAL_ERROR, [error.message, errorStack])
				);
				return;
			}
		};

		/** @ignore */
		ClientImpl.prototype._on_socket_error = function (error) {
			if (!this._reconnecting) {
				this._disconnected(
					ERROR.SOCKET_ERROR.code,
					format(ERROR.SOCKET_ERROR, [error.data])
				);
			}
		};

		/** @ignore */
		ClientImpl.prototype._on_socket_close = function () {
			if (!this._reconnecting) {
				this._disconnected(ERROR.SOCKET_CLOSE.code, format(ERROR.SOCKET_CLOSE));
			}
		};

		/** @ignore */
		ClientImpl.prototype._socket_send = function (wireMessage) {
			if (wireMessage.type == 1) {
				var wireMessageMasked = this._traceMask(wireMessage, 'password');
				this._trace('Client._socket_send', wireMessageMasked);
			} else this._trace('Client._socket_send', wireMessage);

			this.socket.send(wireMessage.encode());
			/* We have proved to the server we are alive. */
			this.sendPinger.reset();
		};

		/** @ignore */
		ClientImpl.prototype._receivePublish = function (wireMessage) {
			switch (wireMessage.payloadMessage.qos) {
				case 'undefined':
				case 0:
					this._receiveMessage(wireMessage);
					break;

				case 1:
					var pubAckMessage = new WireMessage(MESSAGE_TYPE.PUBACK, {
						messageIdentifier: wireMessage.messageIdentifier,
					});
					this._schedule_message(pubAckMessage);
					this._receiveMessage(wireMessage);
					break;

				case 2:
					this._receivedMessages[wireMessage.messageIdentifier] = wireMessage;
					this.store('Received:', wireMessage);
					var pubRecMessage = new WireMessage(MESSAGE_TYPE.PUBREC, {
						messageIdentifier: wireMessage.messageIdentifier,
					});
					this._schedule_message(pubRecMessage);

					break;

				default:
					throw Error('Invaild qos=' + wireMessage.payloadMessage.qos);
			}
		};

		/** @ignore */
		ClientImpl.prototype._receiveMessage = function (wireMessage) {
			if (this.onMessageArrived) {
				this.onMessageArrived(wireMessage.payloadMessage);
			}
		};

		/**
		 * Client has connected.
		 * @param {reconnect} [boolean] indicate if this was a result of reconnect operation.
		 * @param {uri} [string] fully qualified WebSocket URI of the server.
		 */
		ClientImpl.prototype._connected = function (reconnect, uri) {
			// Execute the onConnected callback if there is one.
			if (this.onConnected) this.onConnected(reconnect, uri);
		};

		/**
		 * Attempts to reconnect the client to the server.
		 * For each reconnect attempt, will double the reconnect interval
		 * up to 128 seconds.
		 */
		ClientImpl.prototype._reconnect = function () {
			this._trace('Client._reconnect');
			if (!this.connected) {
				this._reconnecting = true;
				this.sendPinger.cancel();
				this.receivePinger.cancel();
				if (this._reconnectInterval < 128)
					this._reconnectInterval = this._reconnectInterval * 2;
				if (this.connectOptions.uris) {
					this.hostIndex = 0;
					this._doConnect(this.connectOptions.uris[0]);
				} else {
					this._doConnect(this.uri);
				}
			}
		};

		/**
		 * Client has disconnected either at its own request or because the server
		 * or network disconnected it. Remove all non-durable state.
		 * @param {errorCode} [number] the error number.
		 * @param {errorText} [string] the error text.
		 * @ignore
		 */
		ClientImpl.prototype._disconnected = function (errorCode, errorText) {
			this._trace('Client._disconnected', errorCode, errorText);

			if (errorCode !== undefined && this._reconnecting) {
				//Continue automatic reconnect process
				this._reconnectTimeout = new Timeout(
					this,
					this._reconnectInterval,
					this._reconnect
				);
				return;
			}

			this.sendPinger.cancel();
			this.receivePinger.cancel();
			if (this._connectTimeout) {
				this._connectTimeout.cancel();
				this._connectTimeout = null;
			}

			// Clear message buffers.
			this._msg_queue = [];
			this._buffered_msg_queue = [];
			this._notify_msg_sent = {};

			if (this.socket) {
				// Cancel all socket callbacks so that they cannot be driven again by this socket.
				this.socket.onopen = null;
				this.socket.onmessage = null;
				this.socket.onerror = null;
				this.socket.onclose = null;
				if (this.socket.readyState === 1) this.socket.close();
				delete this.socket;
			}

			if (
				this.connectOptions.uris &&
				this.hostIndex < this.connectOptions.uris.length - 1
			) {
				// Try the next host.
				this.hostIndex++;
				this._doConnect(this.connectOptions.uris[this.hostIndex]);
			} else {
				if (errorCode === undefined) {
					errorCode = ERROR.OK.code;
					errorText = format(ERROR.OK);
				}

				// Run any application callbacks last as they may attempt to reconnect and hence create a new socket.
				if (this.connected) {
					this.connected = false;
					// Execute the connectionLostCallback if there is one, and we were connected.
					if (this.onConnectionLost) {
						this.onConnectionLost({
							errorCode: errorCode,
							errorMessage: errorText,
							reconnect: this.connectOptions.reconnect,
							uri: this._wsuri,
						});
					}
					if (errorCode !== ERROR.OK.code && this.connectOptions.reconnect) {
						// Start automatic reconnect process for the very first time since last successful connect.
						this._reconnectInterval = 1;
						this._reconnect();
						return;
					}
				} else {
					// Otherwise we never had a connection, so indicate that the connect has failed.
					if (
						this.connectOptions.mqttVersion === 4 &&
						this.connectOptions.mqttVersionExplicit === false
					) {
						this._trace('Failed to connect V4, dropping back to V3');
						this.connectOptions.mqttVersion = 3;
						if (this.connectOptions.uris) {
							this.hostIndex = 0;
							this._doConnect(this.connectOptions.uris[0]);
						} else {
							this._doConnect(this.uri);
						}
					} else if (this.connectOptions.onFailure) {
						this.connectOptions.onFailure({
							invocationContext: this.connectOptions.invocationContext,
							errorCode: errorCode,
							errorMessage: errorText,
						});
					}
				}
			}
		};

		/** @ignore */
		ClientImpl.prototype._trace = function () {
			// Pass trace message back to client's callback function
			if (this.traceFunction) {
				var args = Array.prototype.slice.call(arguments);
				for (var i in args) {
					if (typeof args[i] !== 'undefined')
						args.splice(i, 1, JSON.stringify(args[i]));
				}
				var record = args.join('');
				this.traceFunction({ severity: 'Debug', message: record });
			}

			//buffer style trace
			if (this._traceBuffer !== null) {
				for (var i = 0, max = arguments.length; i < max; i++) {
					if (this._traceBuffer.length == this._MAX_TRACE_ENTRIES) {
						this._traceBuffer.shift();
					}
					if (i === 0) this._traceBuffer.push(arguments[i]);
					else if (typeof arguments[i] === 'undefined')
						this._traceBuffer.push(arguments[i]);
					else this._traceBuffer.push('  ' + JSON.stringify(arguments[i]));
				}
			}
		};

		/** @ignore */
		ClientImpl.prototype._traceMask = function (traceObject, masked) {
			var traceObjectMasked = {};
			for (var attr in traceObject) {
				if (traceObject.hasOwnProperty(attr)) {
					if (attr == masked) traceObjectMasked[attr] = '******';
					else traceObjectMasked[attr] = traceObject[attr];
				}
			}
			return traceObjectMasked;
		};

		// ------------------------------------------------------------------------
		// Public Programming interface.
		// ------------------------------------------------------------------------

		/**
		 * The JavaScript application communicates to the server using a {@link Paho.Client} object.
		 * <p>
		 * Most applications will create just one Client object and then call its connect() method,
		 * however applications can create more than one Client object if they wish.
		 * In this case the combination of host, port and clientId attributes must be different for each Client object.
		 * <p>
		 * The send, subscribe and unsubscribe methods are implemented as asynchronous JavaScript methods
		 * (even though the underlying protocol exchange might be synchronous in nature).
		 * This means they signal their completion by calling back to the application,
		 * via Success or Failure callback functions provided by the application on the method in question.
		 * Such callbacks are called at most once per method invocation and do not persist beyond the lifetime
		 * of the script that made the invocation.
		 * <p>
		 * In contrast there are some callback functions, most notably <i>onMessageArrived</i>,
		 * that are defined on the {@link Paho.Client} object.
		 * These may get called multiple times, and aren't directly related to specific method invocations made by the client.
		 *
		 * @name Paho.Client
		 *
		 * @constructor
		 *
		 * @param {string} host - the address of the messaging server, as a fully qualified WebSocket URI, as a DNS name or dotted decimal IP address.
		 * @param {number} port - the port number to connect to - only required if host is not a URI
		 * @param {string} path - the path on the host to connect to - only used if host is not a URI. Default: '/mqtt'.
		 * @param {string} clientId - the Messaging client identifier, between 1 and 23 characters in length.
		 *
		 * @property {string} host - <i>read only</i> the server's DNS hostname or dotted decimal IP address.
		 * @property {number} port - <i>read only</i> the server's port.
		 * @property {string} path - <i>read only</i> the server's path.
		 * @property {string} clientId - <i>read only</i> used when connecting to the server.
		 * @property {function} onConnectionLost - called when a connection has been lost.
		 *                            after a connect() method has succeeded.
		 *                            Establish the call back used when a connection has been lost. The connection may be
		 *                            lost because the client initiates a disconnect or because the server or network
		 *                            cause the client to be disconnected. The disconnect call back may be called without
		 *                            the connectionComplete call back being invoked if, for example the client fails to
		 *                            connect.
		 *                            A single response object parameter is passed to the onConnectionLost callback containing the following fields:
		 *                            <ol>
		 *                            <li>errorCode
		 *                            <li>errorMessage
		 *                            </ol>
		 * @property {function} onMessageDelivered - called when a message has been delivered.
		 *                            All processing that this Client will ever do has been completed. So, for example,
		 *                            in the case of a Qos=2 message sent by this client, the PubComp flow has been received from the server
		 *                            and the message has been removed from persistent storage before this callback is invoked.
		 *                            Parameters passed to the onMessageDelivered callback are:
		 *                            <ol>
		 *                            <li>{@link Paho.Message} that was delivered.
		 *                            </ol>
		 * @property {function} onMessageArrived - called when a message has arrived in this Paho.client.
		 *                            Parameters passed to the onMessageArrived callback are:
		 *                            <ol>
		 *                            <li>{@link Paho.Message} that has arrived.
		 *                            </ol>
		 * @property {function} onConnected - called when a connection is successfully made to the server.
		 *                                  after a connect() method.
		 *                                  Parameters passed to the onConnected callback are:
		 *                                  <ol>
		 *                                  <li>reconnect (boolean) - If true, the connection was the result of a reconnect.</li>
		 *                                  <li>URI (string) - The URI used to connect to the server.</li>
		 *                                  </ol>
		 * @property {boolean} disconnectedPublishing - if set, will enable disconnected publishing in
		 *                                            in the event that the connection to the server is lost.
		 * @property {number} disconnectedBufferSize - Used to set the maximum number of messages that the disconnected
		 *                                             buffer will hold before rejecting new messages. Default size: 5000 messages
		 * @property {function} trace - called whenever trace is called. TODO
		 */
		var Client = function (host, port, path, clientId) {
			var uri;

			if (typeof host !== 'string')
				throw new Error(format(ERROR.INVALID_TYPE, [typeof host, 'host']));

			if (arguments.length == 2) {
				// host: must be full ws:// uri
				// port: clientId
				clientId = port;
				uri = host;
				var match = uri.match(
					/^(wss?):\/\/((\[(.+)\])|([^\/]+?))(:(\d+))?(\/.*)$/
				);
				if (match) {
					host = match[4] || match[2];
					port = parseInt(match[7]);
					path = match[8];
				} else {
					throw new Error(format(ERROR.INVALID_ARGUMENT, [host, 'host']));
				}
			} else {
				if (arguments.length == 3) {
					clientId = path;
					path = '/mqtt';
				}
				if (typeof port !== 'number' || port < 0)
					throw new Error(format(ERROR.INVALID_TYPE, [typeof port, 'port']));
				if (typeof path !== 'string')
					throw new Error(format(ERROR.INVALID_TYPE, [typeof path, 'path']));

				var ipv6AddSBracket =
					host.indexOf(':') !== -1 &&
					host.slice(0, 1) !== '[' &&
					host.slice(-1) !== ']';
				uri =
					'ws://' +
					(ipv6AddSBracket ? '[' + host + ']' : host) +
					':' +
					port +
					path;
			}

			var clientIdLength = 0;
			for (var i = 0; i < clientId.length; i++) {
				var charCode = clientId.charCodeAt(i);
				if (0xd800 <= charCode && charCode <= 0xdbff) {
					i++; // Surrogate pair.
				}
				clientIdLength++;
			}
			if (typeof clientId !== 'string' || clientIdLength > 65535)
				throw new Error(format(ERROR.INVALID_ARGUMENT, [clientId, 'clientId']));

			var client = new ClientImpl(uri, host, port, path, clientId);

			//Public Properties
			Object.defineProperties(this, {
				host: {
					get: function () {
						return host;
					},
					set: function () {
						throw new Error(format(ERROR.UNSUPPORTED_OPERATION));
					},
				},
				port: {
					get: function () {
						return port;
					},
					set: function () {
						throw new Error(format(ERROR.UNSUPPORTED_OPERATION));
					},
				},
				path: {
					get: function () {
						return path;
					},
					set: function () {
						throw new Error(format(ERROR.UNSUPPORTED_OPERATION));
					},
				},
				uri: {
					get: function () {
						return uri;
					},
					set: function () {
						throw new Error(format(ERROR.UNSUPPORTED_OPERATION));
					},
				},
				clientId: {
					get: function () {
						return client.clientId;
					},
					set: function () {
						throw new Error(format(ERROR.UNSUPPORTED_OPERATION));
					},
				},
				onConnected: {
					get: function () {
						return client.onConnected;
					},
					set: function (newOnConnected) {
						if (typeof newOnConnected === 'function')
							client.onConnected = newOnConnected;
						else
							throw new Error(
								format(ERROR.INVALID_TYPE, [
									typeof newOnConnected,
									'onConnected',
								])
							);
					},
				},
				disconnectedPublishing: {
					get: function () {
						return client.disconnectedPublishing;
					},
					set: function (newDisconnectedPublishing) {
						client.disconnectedPublishing = newDisconnectedPublishing;
					},
				},
				disconnectedBufferSize: {
					get: function () {
						return client.disconnectedBufferSize;
					},
					set: function (newDisconnectedBufferSize) {
						client.disconnectedBufferSize = newDisconnectedBufferSize;
					},
				},
				onConnectionLost: {
					get: function () {
						return client.onConnectionLost;
					},
					set: function (newOnConnectionLost) {
						if (typeof newOnConnectionLost === 'function')
							client.onConnectionLost = newOnConnectionLost;
						else
							throw new Error(
								format(ERROR.INVALID_TYPE, [
									typeof newOnConnectionLost,
									'onConnectionLost',
								])
							);
					},
				},
				onMessageDelivered: {
					get: function () {
						return client.onMessageDelivered;
					},
					set: function (newOnMessageDelivered) {
						if (typeof newOnMessageDelivered === 'function')
							client.onMessageDelivered = newOnMessageDelivered;
						else
							throw new Error(
								format(ERROR.INVALID_TYPE, [
									typeof newOnMessageDelivered,
									'onMessageDelivered',
								])
							);
					},
				},
				onMessageArrived: {
					get: function () {
						return client.onMessageArrived;
					},
					set: function (newOnMessageArrived) {
						if (typeof newOnMessageArrived === 'function')
							client.onMessageArrived = newOnMessageArrived;
						else
							throw new Error(
								format(ERROR.INVALID_TYPE, [
									typeof newOnMessageArrived,
									'onMessageArrived',
								])
							);
					},
				},
				trace: {
					get: function () {
						return client.traceFunction;
					},
					set: function (trace) {
						if (typeof trace === 'function') {
							client.traceFunction = trace;
						} else {
							throw new Error(
								format(ERROR.INVALID_TYPE, [typeof trace, 'onTrace'])
							);
						}
					},
				},
			});

			/**
			 * Connect this Messaging client to its server.
			 *
			 * @name Paho.Client#connect
			 * @function
			 * @param {object} connectOptions - Attributes used with the connection.
			 * @param {number} connectOptions.timeout - If the connect has not succeeded within this
			 *                    number of seconds, it is deemed to have failed.
			 *                    The default is 30 seconds.
			 * @param {string} connectOptions.userName - Authentication username for this connection.
			 * @param {string} connectOptions.password - Authentication password for this connection.
			 * @param {Paho.Message} connectOptions.willMessage - sent by the server when the client
			 *                    disconnects abnormally.
			 * @param {number} connectOptions.keepAliveInterval - the server disconnects this client if
			 *                    there is no activity for this number of seconds.
			 *                    The default value of 60 seconds is assumed if not set.
			 * @param {boolean} connectOptions.cleanSession - if true(default) the client and server
			 *                    persistent state is deleted on successful connect.
			 * @param {boolean} connectOptions.useSSL - if present and true, use an SSL Websocket connection.
			 * @param {object} connectOptions.invocationContext - passed to the onSuccess callback or onFailure callback.
			 * @param {function} connectOptions.onSuccess - called when the connect acknowledgement
			 *                    has been received from the server.
			 * A single response object parameter is passed to the onSuccess callback containing the following fields:
			 * <ol>
			 * <li>invocationContext as passed in to the onSuccess method in the connectOptions.
			 * </ol>
			 * @param {function} connectOptions.onFailure - called when the connect request has failed or timed out.
			 * A single response object parameter is passed to the onFailure callback containing the following fields:
			 * <ol>
			 * <li>invocationContext as passed in to the onFailure method in the connectOptions.
			 * <li>errorCode a number indicating the nature of the error.
			 * <li>errorMessage text describing the error.
			 * </ol>
			 * @param {array} connectOptions.hosts - If present this contains either a set of hostnames or fully qualified
			 * WebSocket URIs (ws://iot.eclipse.org:80/ws), that are tried in order in place
			 * of the host and port paramater on the construtor. The hosts are tried one at at time in order until
			 * one of then succeeds.
			 * @param {array} connectOptions.ports - If present the set of ports matching the hosts. If hosts contains URIs, this property
			 * is not used.
			 * @param {boolean} connectOptions.reconnect - Sets whether the client will automatically attempt to reconnect
			 * to the server if the connection is lost.
			 *<ul>
			 *<li>If set to false, the client will not attempt to automatically reconnect to the server in the event that the
			 * connection is lost.</li>
			 *<li>If set to true, in the event that the connection is lost, the client will attempt to reconnect to the server.
			 * It will initially wait 1 second before it attempts to reconnect, for every failed reconnect attempt, the delay
			 * will double until it is at 2 minutes at which point the delay will stay at 2 minutes.</li>
			 *</ul>
			 * @param {number} connectOptions.mqttVersion - The version of MQTT to use to connect to the MQTT Broker.
			 *<ul>
			 *<li>3 - MQTT V3.1</li>
			 *<li>4 - MQTT V3.1.1</li>
			 *</ul>
			 * @param {boolean} connectOptions.mqttVersionExplicit - If set to true, will force the connection to use the
			 * selected MQTT Version or will fail to connect.
			 * @param {array} connectOptions.uris - If present, should contain a list of fully qualified WebSocket uris
			 * (e.g. ws://iot.eclipse.org:80/ws), that are tried in order in place of the host and port parameter of the construtor.
			 * The uris are tried one at a time in order until one of them succeeds. Do not use this in conjunction with hosts as
			 * the hosts array will be converted to uris and will overwrite this property.
			 * @throws {InvalidState} If the client is not in disconnected state. The client must have received connectionLost
			 * or disconnected before calling connect for a second or subsequent time.
			 */
			this.connect = function (connectOptions) {
				connectOptions = connectOptions || {};
				validate(connectOptions, {
					timeout: 'number',
					userName: 'string',
					password: 'string',
					willMessage: 'object',
					keepAliveInterval: 'number',
					cleanSession: 'boolean',
					useSSL: 'boolean',
					invocationContext: 'object',
					onSuccess: 'function',
					onFailure: 'function',
					hosts: 'object',
					ports: 'object',
					reconnect: 'boolean',
					mqttVersion: 'number',
					mqttVersionExplicit: 'boolean',
					uris: 'object',
				});

				// If no keep alive interval is set, assume 60 seconds.
				if (connectOptions.keepAliveInterval === undefined)
					connectOptions.keepAliveInterval = 60;

				if (connectOptions.mqttVersion > 4 || connectOptions.mqttVersion < 3) {
					throw new Error(
						format(ERROR.INVALID_ARGUMENT, [
							connectOptions.mqttVersion,
							'connectOptions.mqttVersion',
						])
					);
				}

				if (connectOptions.mqttVersion === undefined) {
					connectOptions.mqttVersionExplicit = false;
					connectOptions.mqttVersion = 4;
				} else {
					connectOptions.mqttVersionExplicit = true;
				}

				//Check that if password is set, so is username
				if (
					connectOptions.password !== undefined &&
					connectOptions.userName === undefined
				)
					throw new Error(
						format(ERROR.INVALID_ARGUMENT, [
							connectOptions.password,
							'connectOptions.password',
						])
					);

				if (connectOptions.willMessage) {
					if (!(connectOptions.willMessage instanceof Message))
						throw new Error(
							format(ERROR.INVALID_TYPE, [
								connectOptions.willMessage,
								'connectOptions.willMessage',
							])
						);
					// The will message must have a payload that can be represented as a string.
					// Cause the willMessage to throw an exception if this is not the case.
					connectOptions.willMessage.stringPayload = null;

					if (typeof connectOptions.willMessage.destinationName === 'undefined')
						throw new Error(
							format(ERROR.INVALID_TYPE, [
								typeof connectOptions.willMessage.destinationName,
								'connectOptions.willMessage.destinationName',
							])
						);
				}
				if (typeof connectOptions.cleanSession === 'undefined')
					connectOptions.cleanSession = true;
				if (connectOptions.hosts) {
					if (!(connectOptions.hosts instanceof Array))
						throw new Error(
							format(ERROR.INVALID_ARGUMENT, [
								connectOptions.hosts,
								'connectOptions.hosts',
							])
						);
					if (connectOptions.hosts.length < 1)
						throw new Error(
							format(ERROR.INVALID_ARGUMENT, [
								connectOptions.hosts,
								'connectOptions.hosts',
							])
						);

					var usingURIs = false;
					for (var i = 0; i < connectOptions.hosts.length; i++) {
						if (typeof connectOptions.hosts[i] !== 'string')
							throw new Error(
								format(ERROR.INVALID_TYPE, [
									typeof connectOptions.hosts[i],
									'connectOptions.hosts[' + i + ']',
								])
							);
						if (
							/^(wss?):\/\/((\[(.+)\])|([^\/]+?))(:(\d+))?(\/.*)$/.test(
								connectOptions.hosts[i]
							)
						) {
							if (i === 0) {
								usingURIs = true;
							} else if (!usingURIs) {
								throw new Error(
									format(ERROR.INVALID_ARGUMENT, [
										connectOptions.hosts[i],
										'connectOptions.hosts[' + i + ']',
									])
								);
							}
						} else if (usingURIs) {
							throw new Error(
								format(ERROR.INVALID_ARGUMENT, [
									connectOptions.hosts[i],
									'connectOptions.hosts[' + i + ']',
								])
							);
						}
					}

					if (!usingURIs) {
						if (!connectOptions.ports)
							throw new Error(
								format(ERROR.INVALID_ARGUMENT, [
									connectOptions.ports,
									'connectOptions.ports',
								])
							);
						if (!(connectOptions.ports instanceof Array))
							throw new Error(
								format(ERROR.INVALID_ARGUMENT, [
									connectOptions.ports,
									'connectOptions.ports',
								])
							);
						if (connectOptions.hosts.length !== connectOptions.ports.length)
							throw new Error(
								format(ERROR.INVALID_ARGUMENT, [
									connectOptions.ports,
									'connectOptions.ports',
								])
							);

						connectOptions.uris = [];

						for (var i = 0; i < connectOptions.hosts.length; i++) {
							if (
								typeof connectOptions.ports[i] !== 'number' ||
								connectOptions.ports[i] < 0
							)
								throw new Error(
									format(ERROR.INVALID_TYPE, [
										typeof connectOptions.ports[i],
										'connectOptions.ports[' + i + ']',
									])
								);
							var host = connectOptions.hosts[i];
							var port = connectOptions.ports[i];

							var ipv6 = host.indexOf(':') !== -1;
							uri =
								'ws://' + (ipv6 ? '[' + host + ']' : host) + ':' + port + path;
							connectOptions.uris.push(uri);
						}
					} else {
						connectOptions.uris = connectOptions.hosts;
					}
				}

				client.connect(connectOptions);
			};

			/**
			 * Subscribe for messages, request receipt of a copy of messages sent to the destinations described by the filter.
			 *
			 * @name Paho.Client#subscribe
			 * @function
			 * @param {string} filter describing the destinations to receive messages from.
			 * <br>
			 * @param {object} subscribeOptions - used to control the subscription
			 *
			 * @param {number} subscribeOptions.qos - the maximum qos of any publications sent
			 *                                  as a result of making this subscription.
			 * @param {object} subscribeOptions.invocationContext - passed to the onSuccess callback
			 *                                  or onFailure callback.
			 * @param {function} subscribeOptions.onSuccess - called when the subscribe acknowledgement
			 *                                  has been received from the server.
			 *                                  A single response object parameter is passed to the onSuccess callback containing the following fields:
			 *                                  <ol>
			 *                                  <li>invocationContext if set in the subscribeOptions.
			 *                                  </ol>
			 * @param {function} subscribeOptions.onFailure - called when the subscribe request has failed or timed out.
			 *                                  A single response object parameter is passed to the onFailure callback containing the following fields:
			 *                                  <ol>
			 *                                  <li>invocationContext - if set in the subscribeOptions.
			 *                                  <li>errorCode - a number indicating the nature of the error.
			 *                                  <li>errorMessage - text describing the error.
			 *                                  </ol>
			 * @param {number} subscribeOptions.timeout - which, if present, determines the number of
			 *                                  seconds after which the onFailure calback is called.
			 *                                  The presence of a timeout does not prevent the onSuccess
			 *                                  callback from being called when the subscribe completes.
			 * @throws {InvalidState} if the client is not in connected state.
			 */
			this.subscribe = function (filter, subscribeOptions) {
				if (typeof filter !== 'string' && filter.constructor !== Array)
					throw new Error('Invalid argument:' + filter);
				subscribeOptions = subscribeOptions || {};
				validate(subscribeOptions, {
					qos: 'number',
					invocationContext: 'object',
					onSuccess: 'function',
					onFailure: 'function',
					timeout: 'number',
				});
				if (subscribeOptions.timeout && !subscribeOptions.onFailure)
					throw new Error(
						'subscribeOptions.timeout specified with no onFailure callback.'
					);
				if (
					typeof subscribeOptions.qos !== 'undefined' &&
					!(
						subscribeOptions.qos === 0 ||
						subscribeOptions.qos === 1 ||
						subscribeOptions.qos === 2
					)
				)
					throw new Error(
						format(ERROR.INVALID_ARGUMENT, [
							subscribeOptions.qos,
							'subscribeOptions.qos',
						])
					);
				client.subscribe(filter, subscribeOptions);
			};

			/**
		 * Unsubscribe for messages, stop receiving messages sent to destinations described by the filter.
		 *
		 * @name Paho.Client#unsubscribe
		 * @function
		 * @param {string} filter - describing the destinations to receive messages from.
		 * @param {object} unsubscribeOptions - used to control the subscription
		 * @param {object} unsubscribeOptions.invocationContext - passed to the onSuccess callback
											  or onFailure callback.
		 * @param {function} unsubscribeOptions.onSuccess - called when the unsubscribe acknowledgement has been received from the server.
		 *                                    A single response object parameter is passed to the
		 *                                    onSuccess callback containing the following fields:
		 *                                    <ol>
		 *                                    <li>invocationContext - if set in the unsubscribeOptions.
		 *                                    </ol>
		 * @param {function} unsubscribeOptions.onFailure called when the unsubscribe request has failed or timed out.
		 *                                    A single response object parameter is passed to the onFailure callback containing the following fields:
		 *                                    <ol>
		 *                                    <li>invocationContext - if set in the unsubscribeOptions.
		 *                                    <li>errorCode - a number indicating the nature of the error.
		 *                                    <li>errorMessage - text describing the error.
		 *                                    </ol>
		 * @param {number} unsubscribeOptions.timeout - which, if present, determines the number of seconds
		 *                                    after which the onFailure callback is called. The presence of
		 *                                    a timeout does not prevent the onSuccess callback from being
		 *                                    called when the unsubscribe completes
		 * @throws {InvalidState} if the client is not in connected state.
		 */
			this.unsubscribe = function (filter, unsubscribeOptions) {
				if (typeof filter !== 'string' && filter.constructor !== Array)
					throw new Error('Invalid argument:' + filter);
				unsubscribeOptions = unsubscribeOptions || {};
				validate(unsubscribeOptions, {
					invocationContext: 'object',
					onSuccess: 'function',
					onFailure: 'function',
					timeout: 'number',
				});
				if (unsubscribeOptions.timeout && !unsubscribeOptions.onFailure)
					throw new Error(
						'unsubscribeOptions.timeout specified with no onFailure callback.'
					);
				client.unsubscribe(filter, unsubscribeOptions);
			};

			/**
			 * Send a message to the consumers of the destination in the Message.
			 *
			 * @name Paho.Client#send
			 * @function
			 * @param {string|Paho.Message} topic - <b>mandatory</b> The name of the destination to which the message is to be sent.
			 * 					   - If it is the only parameter, used as Paho.Message object.
			 * @param {String|ArrayBuffer} payload - The message data to be sent.
			 * @param {number} qos The Quality of Service used to deliver the message.
			 * 		<dl>
			 * 			<dt>0 Best effort (default).
			 *     			<dt>1 At least once.
			 *     			<dt>2 Exactly once.
			 * 		</dl>
			 * @param {Boolean} retained If true, the message is to be retained by the server and delivered
			 *                     to both current and future subscriptions.
			 *                     If false the server only delivers the message to current subscribers, this is the default for new Messages.
			 *                     A received message has the retained boolean set to true if the message was published
			 *                     with the retained boolean set to true
			 *                     and the subscrption was made after the message has been published.
			 * @throws {InvalidState} if the client is not connected.
			 */
			this.send = function (topic, payload, qos, retained) {
				var message;

				if (arguments.length === 0) {
					throw new Error('Invalid argument.' + 'length');
				} else if (arguments.length == 1) {
					if (!(topic instanceof Message) && typeof topic !== 'string')
						throw new Error('Invalid argument:' + typeof topic);

					message = topic;
					if (typeof message.destinationName === 'undefined')
						throw new Error(
							format(ERROR.INVALID_ARGUMENT, [
								message.destinationName,
								'Message.destinationName',
							])
						);
					client.send(message);
				} else {
					//parameter checking in Message object
					message = new Message(payload);
					message.destinationName = topic;
					if (arguments.length >= 3) message.qos = qos;
					if (arguments.length >= 4) message.retained = retained;
					client.send(message);
				}
			};

			/**
			 * Publish a message to the consumers of the destination in the Message.
			 * Synonym for Paho.Mqtt.Client#send
			 *
			 * @name Paho.Client#publish
			 * @function
			 * @param {string|Paho.Message} topic - <b>mandatory</b> The name of the topic to which the message is to be published.
			 * 					   - If it is the only parameter, used as Paho.Message object.
			 * @param {String|ArrayBuffer} payload - The message data to be published.
			 * @param {number} qos The Quality of Service used to deliver the message.
			 * 		<dl>
			 * 			<dt>0 Best effort (default).
			 *     			<dt>1 At least once.
			 *     			<dt>2 Exactly once.
			 * 		</dl>
			 * @param {Boolean} retained If true, the message is to be retained by the server and delivered
			 *                     to both current and future subscriptions.
			 *                     If false the server only delivers the message to current subscribers, this is the default for new Messages.
			 *                     A received message has the retained boolean set to true if the message was published
			 *                     with the retained boolean set to true
			 *                     and the subscrption was made after the message has been published.
			 * @throws {InvalidState} if the client is not connected.
			 */
			this.publish = function (topic, payload, qos, retained) {
				var message;

				if (arguments.length === 0) {
					throw new Error('Invalid argument.' + 'length');
				} else if (arguments.length == 1) {
					if (!(topic instanceof Message) && typeof topic !== 'string')
						throw new Error('Invalid argument:' + typeof topic);

					message = topic;
					if (typeof message.destinationName === 'undefined')
						throw new Error(
							format(ERROR.INVALID_ARGUMENT, [
								message.destinationName,
								'Message.destinationName',
							])
						);
					client.send(message);
				} else {
					//parameter checking in Message object
					message = new Message(payload);
					message.destinationName = topic;
					if (arguments.length >= 3) message.qos = qos;
					if (arguments.length >= 4) message.retained = retained;
					client.send(message);
				}
			};

			/**
			 * Normal disconnect of this Messaging client from its server.
			 *
			 * @name Paho.Client#disconnect
			 * @function
			 * @throws {InvalidState} if the client is already disconnected.
			 */
			this.disconnect = function () {
				client.disconnect();
			};

			/**
			 * Get the contents of the trace log.
			 *
			 * @name Paho.Client#getTraceLog
			 * @function
			 * @return {Object[]} tracebuffer containing the time ordered trace records.
			 */
			this.getTraceLog = function () {
				return client.getTraceLog();
			};

			/**
			 * Start tracing.
			 *
			 * @name Paho.Client#startTrace
			 * @function
			 */
			this.startTrace = function () {
				client.startTrace();
			};

			/**
			 * Stop tracing.
			 *
			 * @name Paho.Client#stopTrace
			 * @function
			 */
			this.stopTrace = function () {
				client.stopTrace();
			};

			this.isConnected = function () {
				return client.connected;
			};
		};

		/**
		 * An application message, sent or received.
		 * <p>
		 * All attributes may be null, which implies the default values.
		 *
		 * @name Paho.Message
		 * @constructor
		 * @param {String|ArrayBuffer} payload The message data to be sent.
		 * <p>
		 * @property {string} payloadString <i>read only</i> The payload as a string if the payload consists of valid UTF-8 characters.
		 * @property {ArrayBuffer} payloadBytes <i>read only</i> The payload as an ArrayBuffer.
		 * <p>
		 * @property {string} destinationName <b>mandatory</b> The name of the destination to which the message is to be sent
		 *                    (for messages about to be sent) or the name of the destination from which the message has been received.
		 *                    (for messages received by the onMessage function).
		 * <p>
		 * @property {number} qos The Quality of Service used to deliver the message.
		 * <dl>
		 *     <dt>0 Best effort (default).
		 *     <dt>1 At least once.
		 *     <dt>2 Exactly once.
		 * </dl>
		 * <p>
		 * @property {Boolean} retained If true, the message is to be retained by the server and delivered
		 *                     to both current and future subscriptions.
		 *                     If false the server only delivers the message to current subscribers, this is the default for new Messages.
		 *                     A received message has the retained boolean set to true if the message was published
		 *                     with the retained boolean set to true
		 *                     and the subscrption was made after the message has been published.
		 * <p>
		 * @property {Boolean} duplicate <i>read only</i> If true, this message might be a duplicate of one which has already been received.
		 *                     This is only set on messages received from the server.
		 *
		 */
		var Message = function (newPayload) {
			var payload;
			if (
				typeof newPayload === 'string' ||
				newPayload instanceof ArrayBuffer ||
				(ArrayBuffer.isView(newPayload) && !(newPayload instanceof DataView))
			) {
				payload = newPayload;
			} else {
				throw format(ERROR.INVALID_ARGUMENT, [newPayload, 'newPayload']);
			}

			var destinationName;
			var qos = 0;
			var retained = false;
			var duplicate = false;

			Object.defineProperties(this, {
				payloadString: {
					enumerable: true,
					get: function () {
						if (typeof payload === 'string') return payload;
						else return parseUTF8(payload, 0, payload.length);
					},
				},
				payloadBytes: {
					enumerable: true,
					get: function () {
						if (typeof payload === 'string') {
							var buffer = new ArrayBuffer(UTF8Length(payload));
							var byteStream = new Uint8Array(buffer);
							stringToUTF8(payload, byteStream, 0);

							return byteStream;
						} else {
							return payload;
						}
					},
				},
				destinationName: {
					enumerable: true,
					get: function () {
						return destinationName;
					},
					set: function (newDestinationName) {
						if (typeof newDestinationName === 'string')
							destinationName = newDestinationName;
						else
							throw new Error(
								format(ERROR.INVALID_ARGUMENT, [
									newDestinationName,
									'newDestinationName',
								])
							);
					},
				},
				qos: {
					enumerable: true,
					get: function () {
						return qos;
					},
					set: function (newQos) {
						if (newQos === 0 || newQos === 1 || newQos === 2) qos = newQos;
						else throw new Error('Invalid argument:' + newQos);
					},
				},
				retained: {
					enumerable: true,
					get: function () {
						return retained;
					},
					set: function (newRetained) {
						if (typeof newRetained === 'boolean') retained = newRetained;
						else
							throw new Error(
								format(ERROR.INVALID_ARGUMENT, [newRetained, 'newRetained'])
							);
					},
				},
				topic: {
					enumerable: true,
					get: function () {
						return destinationName;
					},
					set: function (newTopic) {
						destinationName = newTopic;
					},
				},
				duplicate: {
					enumerable: true,
					get: function () {
						return duplicate;
					},
					set: function (newDuplicate) {
						duplicate = newDuplicate;
					},
				},
			});
		};

		// Module contents.
		return {
			Client: Client,
			Message: Message,
		};
		// eslint-disable-next-line no-nested-ternary
	})(
		typeof global !== 'undefined'
			? global
			: typeof self !== 'undefined'
			? self
			: typeof window !== 'undefined'
			? window
			: {}
	);
	return PahoMQTT;
});