(function (global, factory) {
            typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
            typeof define === 'function' && define.amd ? define(['exports'], factory) :
            (global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.strophe = {}));
})(this, (function (exports) { 'use strict';

            var global$1 = typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {};

            /*
             * This module provides uniform
             * Shims APIs and globals that are not present in all JS environments,
             * the most common example for Strophe being browser APIs like WebSocket
             * and DOM that don't exist under nodejs.
             *
             * Usually these will be supplied in nodejs by conditionally requiring a
             * NPM module that provides a compatible implementation.
             */

            /* global global */

            /**
             * WHATWG WebSockets API
             * https://www.w3.org/TR/websockets/
             *
             * Interface to use the web socket protocol
             *
             * Used implementations:
             * - supported browsers: built-in in WebSocket global
             *   https://developer.mozilla.org/en-US/docs/Web/API/WebSocket#Browser_compatibility
             * - nodejs: use standard-compliant 'ws' module
             *   https://www.npmjs.com/package/ws
             */
            function getWebSocketImplementation() {
              let WebSocketImplementation = global$1.WebSocket;

              if (typeof WebSocketImplementation === 'undefined') {
                try {
                  WebSocketImplementation = require('ws');
                } catch (err) {
                  throw new Error('You must install the "ws" package to use Strophe in nodejs.');
                }
              }

              return WebSocketImplementation;
            }

            const WebSocket = getWebSocketImplementation();
            /**
             * DOMParser
             * https://w3c.github.io/DOM-Parsing/#the-domparser-interface
             *
             * Interface to parse XML strings into Document objects
             *
             * Used implementations:
             * - supported browsers: built-in in DOMParser global
             *   https://developer.mozilla.org/en-US/docs/Web/API/DOMParser#Browser_compatibility
             * - nodejs: use '@xmldom/xmldom' module
             *   https://www.npmjs.com/package/@xmldom/xmldom
             */

            function getDOMParserImplementation() {
              let DOMParserImplementation = global$1.DOMParser;

              if (typeof DOMParserImplementation === 'undefined') {
                try {
                  DOMParserImplementation = require('@xmldom/xmldom').DOMParser;
                } catch (err) {
                  throw new Error('You must install the "@xmldom/xmldom" package to use Strophe in nodejs.');
                }
              }

              return DOMParserImplementation;
            }

            const DOMParser = getDOMParserImplementation();
            /**
             *  Gets IE xml doc object. Used by getDummyXMLDocument shim.
             *
             *  Returns:
             *    A Microsoft XML DOM Object
             *  See Also:
             *    http://msdn.microsoft.com/en-us/library/ms757837%28VS.85%29.aspx
             */

            function _getIEXmlDom() {
              const docStrings = ["Msxml2.DOMDocument.6.0", "Msxml2.DOMDocument.5.0", "Msxml2.DOMDocument.4.0", "MSXML2.DOMDocument.3.0", "MSXML2.DOMDocument", "MSXML.DOMDocument", "Microsoft.XMLDOM"];

              for (let d = 0; d < docStrings.length; d++) {
                try {
                  // eslint-disable-next-line no-undef
                  const doc = new ActiveXObject(docStrings[d]);
                  return doc;
                } catch (e) {// Try next one
                }
              }
            }
            /**
             * Creates a dummy XML DOM document to serve as an element and text node generator.
             *
             * Used implementations:
             *  - IE < 10: avoid using createDocument() due to a memory leak, use ie-specific
             *    workaround
             *  - other supported browsers: use document's createDocument
             *  - nodejs: use '@xmldom/xmldom'
             */


            function getDummyXMLDOMDocument() {
              // nodejs
              if (typeof document === 'undefined') {
                try {
                  const DOMImplementation = require('@xmldom/xmldom').DOMImplementation;

                  return new DOMImplementation().createDocument('jabber:client', 'strophe', null);
                } catch (err) {
                  throw new Error('You must install the "@xmldom/xmldom" package to use Strophe in nodejs.');
                }
              } // IE < 10


              if (document.implementation.createDocument === undefined || document.implementation.createDocument && document.documentMode && document.documentMode < 10) {
                const doc = _getIEXmlDom();

                doc.appendChild(doc.createElement('strophe'));
                return doc;
              } // All other supported browsers


              return document.implementation.createDocument('jabber:client', 'strophe', null);
            }

            /*
             * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
             * Digest Algorithm, as defined in RFC 1321.
             * Version 2.1 Copyright (C) Paul Johnston 1999 - 2002.
             * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
             * Distributed under the BSD License
             * See http://pajhome.org.uk/crypt/md5 for more info.
             */

            /*
             * Everything that isn't used by Strophe has been stripped here!
             */

            /*
             * Add integers, wrapping at 2^32. This uses 16-bit operations internally
             * to work around bugs in some JS interpreters.
             */
            const safe_add$1 = function (x, y) {
              const lsw = (x & 0xFFFF) + (y & 0xFFFF);
              const msw = (x >> 16) + (y >> 16) + (lsw >> 16);
              return msw << 16 | lsw & 0xFFFF;
            };
            /*
             * Bitwise rotate a 32-bit number to the left.
             */


            const bit_rol = function (num, cnt) {
              return num << cnt | num >>> 32 - cnt;
            };
            /*
             * Convert a string to an array of little-endian words
             */


            const str2binl = function (str) {
              if (typeof str !== "string") {
                throw new Error("str2binl was passed a non-string");
              }

              const bin = [];

              for (let i = 0; i < str.length * 8; i += 8) {
                bin[i >> 5] |= (str.charCodeAt(i / 8) & 255) << i % 32;
              }

              return bin;
            };
            /*
             * Convert an array of little-endian words to a string
             */


            const binl2str = function (bin) {
              let str = "";

              for (let i = 0; i < bin.length * 32; i += 8) {
                str += String.fromCharCode(bin[i >> 5] >>> i % 32 & 255);
              }

              return str;
            };
            /*
             * Convert an array of little-endian words to a hex string.
             */


            const binl2hex = function (binarray) {
              const hex_tab = "0123456789abcdef";
              let str = "";

              for (let i = 0; i < binarray.length * 4; i++) {
                str += hex_tab.charAt(binarray[i >> 2] >> i % 4 * 8 + 4 & 0xF) + hex_tab.charAt(binarray[i >> 2] >> i % 4 * 8 & 0xF);
              }

              return str;
            };
            /*
             * These functions implement the four basic operations the algorithm uses.
             */


            const md5_cmn = function (q, a, b, x, s, t) {
              return safe_add$1(bit_rol(safe_add$1(safe_add$1(a, q), safe_add$1(x, t)), s), b);
            };

            const md5_ff = function (a, b, c, d, x, s, t) {
              return md5_cmn(b & c | ~b & d, a, b, x, s, t);
            };

            const md5_gg = function (a, b, c, d, x, s, t) {
              return md5_cmn(b & d | c & ~d, a, b, x, s, t);
            };

            const md5_hh = function (a, b, c, d, x, s, t) {
              return md5_cmn(b ^ c ^ d, a, b, x, s, t);
            };

            const md5_ii = function (a, b, c, d, x, s, t) {
              return md5_cmn(c ^ (b | ~d), a, b, x, s, t);
            };
            /*
             * Calculate the MD5 of an array of little-endian words, and a bit length
             */


            const core_md5 = function (x, len) {
              /* append padding */
              x[len >> 5] |= 0x80 << len % 32;
              x[(len + 64 >>> 9 << 4) + 14] = len;
              let a = 1732584193;
              let b = -271733879;
              let c = -1732584194;
              let d = 271733878;
              let olda, oldb, oldc, oldd;

              for (let i = 0; i < x.length; i += 16) {
                olda = a;
                oldb = b;
                oldc = c;
                oldd = d;
                a = md5_ff(a, b, c, d, x[i + 0], 7, -680876936);
                d = md5_ff(d, a, b, c, x[i + 1], 12, -389564586);
                c = md5_ff(c, d, a, b, x[i + 2], 17, 606105819);
                b = md5_ff(b, c, d, a, x[i + 3], 22, -1044525330);
                a = md5_ff(a, b, c, d, x[i + 4], 7, -176418897);
                d = md5_ff(d, a, b, c, x[i + 5], 12, 1200080426);
                c = md5_ff(c, d, a, b, x[i + 6], 17, -1473231341);
                b = md5_ff(b, c, d, a, x[i + 7], 22, -45705983);
                a = md5_ff(a, b, c, d, x[i + 8], 7, 1770035416);
                d = md5_ff(d, a, b, c, x[i + 9], 12, -1958414417);
                c = md5_ff(c, d, a, b, x[i + 10], 17, -42063);
                b = md5_ff(b, c, d, a, x[i + 11], 22, -1990404162);
                a = md5_ff(a, b, c, d, x[i + 12], 7, 1804603682);
                d = md5_ff(d, a, b, c, x[i + 13], 12, -40341101);
                c = md5_ff(c, d, a, b, x[i + 14], 17, -1502002290);
                b = md5_ff(b, c, d, a, x[i + 15], 22, 1236535329);
                a = md5_gg(a, b, c, d, x[i + 1], 5, -165796510);
                d = md5_gg(d, a, b, c, x[i + 6], 9, -1069501632);
                c = md5_gg(c, d, a, b, x[i + 11], 14, 643717713);
                b = md5_gg(b, c, d, a, x[i + 0], 20, -373897302);
                a = md5_gg(a, b, c, d, x[i + 5], 5, -701558691);
                d = md5_gg(d, a, b, c, x[i + 10], 9, 38016083);
                c = md5_gg(c, d, a, b, x[i + 15], 14, -660478335);
                b = md5_gg(b, c, d, a, x[i + 4], 20, -405537848);
                a = md5_gg(a, b, c, d, x[i + 9], 5, 568446438);
                d = md5_gg(d, a, b, c, x[i + 14], 9, -1019803690);
                c = md5_gg(c, d, a, b, x[i + 3], 14, -187363961);
                b = md5_gg(b, c, d, a, x[i + 8], 20, 1163531501);
                a = md5_gg(a, b, c, d, x[i + 13], 5, -1444681467);
                d = md5_gg(d, a, b, c, x[i + 2], 9, -51403784);
                c = md5_gg(c, d, a, b, x[i + 7], 14, 1735328473);
                b = md5_gg(b, c, d, a, x[i + 12], 20, -1926607734);
                a = md5_hh(a, b, c, d, x[i + 5], 4, -378558);
                d = md5_hh(d, a, b, c, x[i + 8], 11, -2022574463);
                c = md5_hh(c, d, a, b, x[i + 11], 16, 1839030562);
                b = md5_hh(b, c, d, a, x[i + 14], 23, -35309556);
                a = md5_hh(a, b, c, d, x[i + 1], 4, -1530992060);
                d = md5_hh(d, a, b, c, x[i + 4], 11, 1272893353);
                c = md5_hh(c, d, a, b, x[i + 7], 16, -155497632);
                b = md5_hh(b, c, d, a, x[i + 10], 23, -1094730640);
                a = md5_hh(a, b, c, d, x[i + 13], 4, 681279174);
                d = md5_hh(d, a, b, c, x[i + 0], 11, -358537222);
                c = md5_hh(c, d, a, b, x[i + 3], 16, -722521979);
                b = md5_hh(b, c, d, a, x[i + 6], 23, 76029189);
                a = md5_hh(a, b, c, d, x[i + 9], 4, -640364487);
                d = md5_hh(d, a, b, c, x[i + 12], 11, -421815835);
                c = md5_hh(c, d, a, b, x[i + 15], 16, 530742520);
                b = md5_hh(b, c, d, a, x[i + 2], 23, -995338651);
                a = md5_ii(a, b, c, d, x[i + 0], 6, -198630844);
                d = md5_ii(d, a, b, c, x[i + 7], 10, 1126891415);
                c = md5_ii(c, d, a, b, x[i + 14], 15, -1416354905);
                b = md5_ii(b, c, d, a, x[i + 5], 21, -57434055);
                a = md5_ii(a, b, c, d, x[i + 12], 6, 1700485571);
                d = md5_ii(d, a, b, c, x[i + 3], 10, -1894986606);
                c = md5_ii(c, d, a, b, x[i + 10], 15, -1051523);
                b = md5_ii(b, c, d, a, x[i + 1], 21, -2054922799);
                a = md5_ii(a, b, c, d, x[i + 8], 6, 1873313359);
                d = md5_ii(d, a, b, c, x[i + 15], 10, -30611744);
                c = md5_ii(c, d, a, b, x[i + 6], 15, -1560198380);
                b = md5_ii(b, c, d, a, x[i + 13], 21, 1309151649);
                a = md5_ii(a, b, c, d, x[i + 4], 6, -145523070);
                d = md5_ii(d, a, b, c, x[i + 11], 10, -1120210379);
                c = md5_ii(c, d, a, b, x[i + 2], 15, 718787259);
                b = md5_ii(b, c, d, a, x[i + 9], 21, -343485551);
                a = safe_add$1(a, olda);
                b = safe_add$1(b, oldb);
                c = safe_add$1(c, oldc);
                d = safe_add$1(d, oldd);
              }

              return [a, b, c, d];
            };
            /*
             * These are the functions you'll usually want to call.
             * They take string arguments and return either hex or base-64 encoded
             * strings.
             */


            const MD5 = {
              hexdigest: function (s) {
                return binl2hex(core_md5(str2binl(s), s.length * 8));
              },
              hash: function (s) {
                return binl2str(core_md5(str2binl(s), s.length * 8));
              }
            };

            /** Class: Strophe.SASLMechanism
             *
             *  Encapsulates an SASL authentication mechanism.
             *
             *  User code may override the priority for each mechanism or disable it completely.
             *  See <priority> for information about changing priority and <test> for informatian on
             *  how to disable a mechanism.
             *
             *  By default, all mechanisms are enabled and the priorities are
             *
             *      SCRAM-SHA-1 - 60
             *      PLAIN       - 50
             *      OAUTHBEARER - 40
             *      X-OAUTH2    - 30
             *      ANONYMOUS   - 20
             *      EXTERNAL    - 10
             *
             *  See: Strophe.Connection.addSupportedSASLMechanisms
             */
            class SASLMechanism {
              /**
               * PrivateConstructor: Strophe.SASLMechanism
               * SASL auth mechanism abstraction.
               *
               *  Parameters:
               *    (String) name - SASL Mechanism name.
               *    (Boolean) isClientFirst - If client should send response first without challenge.
               *    (Number) priority - Priority.
               *
               *  Returns:
               *    A new Strophe.SASLMechanism object.
               */
              constructor(name, isClientFirst, priority) {
                /** PrivateVariable: mechname
                 *  Mechanism name.
                 */
                this.mechname = name;
                /** PrivateVariable: isClientFirst
                 *  If client sends response without initial server challenge.
                 */

                this.isClientFirst = isClientFirst;
                /** Variable: priority
                 *  Determines which <SASLMechanism> is chosen for authentication (Higher is better).
                 *  Users may override this to prioritize mechanisms differently.
                 *
                 *  Example: (This will cause Strophe to choose the mechanism that the server sent first)
                 *
                 *  > Strophe.SASLPlain.priority = Strophe.SASLSHA1.priority;
                 *
                 *  See <SASL mechanisms> for a list of available mechanisms.
                 *
                 */

                this.priority = priority;
              }
              /**
               *  Function: test
               *  Checks if mechanism able to run.
               *  To disable a mechanism, make this return false;
               *
               *  To disable plain authentication run
               *  > Strophe.SASLPlain.test = function() {
               *  >   return false;
               *  > }
               *
               *  See <SASL mechanisms> for a list of available mechanisms.
               *
               *  Parameters:
               *    (Strophe.Connection) connection - Target Connection.
               *
               *  Returns:
               *    (Boolean) If mechanism was able to run.
               */


              test() {
                // eslint-disable-line class-methods-use-this
                return true;
              }
              /** PrivateFunction: onStart
               *  Called before starting mechanism on some connection.
               *
               *  Parameters:
               *    (Strophe.Connection) connection - Target Connection.
               */


              onStart(connection) {
                this._connection = connection;
              }
              /** PrivateFunction: onChallenge
               *  Called by protocol implementation on incoming challenge.
               *
               *  By deafult, if the client is expected to send data first (isClientFirst === true),
               *  this method is called with `challenge` as null on the first call,
               *  unless `clientChallenge` is overridden in the relevant subclass.
               *
               *  Parameters:
               *    (Strophe.Connection) connection - Target Connection.
               *    (String) challenge - current challenge to handle.
               *
               *  Returns:
               *    (String) Mechanism response.
               */


              onChallenge(connection, challenge) {
                // eslint-disable-line
                throw new Error("You should implement challenge handling!");
              }
              /** PrivateFunction: clientChallenge
               *  Called by the protocol implementation if the client is expected to send
               *  data first in the authentication exchange (i.e. isClientFirst === true).
               *
               *  Parameters:
               *    (Strophe.Connection) connection - Target Connection.
               *
               *  Returns:
               *    (String) Mechanism response.
               */


              clientChallenge(connection) {
                if (!this.isClientFirst) {
                  throw new Error("clientChallenge should not be called if isClientFirst is false!");
                }

                return this.onChallenge(connection);
              }
              /** PrivateFunction: onFailure
               *  Protocol informs mechanism implementation about SASL failure.
               */


              onFailure() {
                this._connection = null;
              }
              /** PrivateFunction: onSuccess
               *  Protocol informs mechanism implementation about SASL success.
               */


              onSuccess() {
                this._connection = null;
              }

            }

            class SASLAnonymous extends SASLMechanism {
              /** PrivateConstructor: SASLAnonymous
               *  SASL ANONYMOUS authentication.
               */
              constructor() {
                let mechname = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 'ANONYMOUS';
                let isClientFirst = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : false;
                let priority = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 20;
                super(mechname, isClientFirst, priority);
              }

              test(connection) {
                // eslint-disable-line class-methods-use-this
                return connection.authcid === null;
              }

            }

            class SASLExternal extends SASLMechanism {
              /** PrivateConstructor: SASLExternal
               *  SASL EXTERNAL authentication.
               *
               *  The EXTERNAL mechanism allows a client to request the server to use
               *  credentials established by means external to the mechanism to
               *  authenticate the client. The external means may be, for instance,
               *  TLS services.
               */
              constructor() {
                let mechname = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 'EXTERNAL';
                let isClientFirst = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : true;
                let priority = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 10;
                super(mechname, isClientFirst, priority);
              }

              onChallenge(connection) {
                // eslint-disable-line class-methods-use-this

                /** According to XEP-178, an authzid SHOULD NOT be presented when the
                 * authcid contained or implied in the client certificate is the JID (i.e.
                 * authzid) with which the user wants to log in as.
                 *
                 * To NOT send the authzid, the user should therefore set the authcid equal
                 * to the JID when instantiating a new Strophe.Connection object.
                 */
                return connection.authcid === connection.authzid ? '' : connection.authzid;
              }

            }

            const utils = {
              utf16to8: function (str) {
                var i, c;
                var out = "";
                var len = str.length;

                for (i = 0; i < len; i++) {
                  c = str.charCodeAt(i);

                  if (c >= 0x0000 && c <= 0x007F) {
                    out += str.charAt(i);
                  } else if (c > 0x07FF) {
                    out += String.fromCharCode(0xE0 | c >> 12 & 0x0F);
                    out += String.fromCharCode(0x80 | c >> 6 & 0x3F);
                    out += String.fromCharCode(0x80 | c >> 0 & 0x3F);
                  } else {
                    out += String.fromCharCode(0xC0 | c >> 6 & 0x1F);
                    out += String.fromCharCode(0x80 | c >> 0 & 0x3F);
                  }
                }

                return out;
              },
              addCookies: function (cookies) {
                /* Parameters:
                 *  (Object) cookies - either a map of cookie names
                 *    to string values or to maps of cookie values.
                 *
                 * For example:
                 * { "myCookie": "1234" }
                 *
                 * or:
                 * { "myCookie": {
                 *      "value": "1234",
                 *      "domain": ".example.org",
                 *      "path": "/",
                 *      "expires": expirationDate
                 *      }
                 *  }
                 *
                 *  These values get passed to Strophe.Connection via
                 *   options.cookies
                 */
                cookies = cookies || {};

                for (const cookieName in cookies) {
                  if (Object.prototype.hasOwnProperty.call(cookies, cookieName)) {
                    let expires = '';
                    let domain = '';
                    let path = '';
                    const cookieObj = cookies[cookieName];
                    const isObj = typeof cookieObj === "object";
                    const cookieValue = escape(unescape(isObj ? cookieObj.value : cookieObj));

                    if (isObj) {
                      expires = cookieObj.expires ? ";expires=" + cookieObj.expires : '';
                      domain = cookieObj.domain ? ";domain=" + cookieObj.domain : '';
                      path = cookieObj.path ? ";path=" + cookieObj.path : '';
                    }

                    document.cookie = cookieName + '=' + cookieValue + expires + domain + path;
                  }
                }
              }
            };

            class SASLOAuthBearer extends SASLMechanism {
              /** PrivateConstructor: SASLOAuthBearer
               *  SASL OAuth Bearer authentication.
               */
              constructor() {
                let mechname = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 'OAUTHBEARER';
                let isClientFirst = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : true;
                let priority = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 40;
                super(mechname, isClientFirst, priority);
              }

              test(connection) {
                // eslint-disable-line class-methods-use-this
                return connection.pass !== null;
              }

              onChallenge(connection) {
                // eslint-disable-line class-methods-use-this
                let auth_str = 'n,';

                if (connection.authcid !== null) {
                  auth_str = auth_str + 'a=' + connection.authzid;
                }

                auth_str = auth_str + ',';
                auth_str = auth_str + "\u0001";
                auth_str = auth_str + 'auth=Bearer ';
                auth_str = auth_str + connection.pass;
                auth_str = auth_str + "\u0001";
                auth_str = auth_str + "\u0001";
                return utils.utf16to8(auth_str);
              }

            }

            class SASLPlain extends SASLMechanism {
              /** PrivateConstructor: SASLPlain
               *  SASL PLAIN authentication.
               */
              constructor() {
                let mechname = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 'PLAIN';
                let isClientFirst = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : true;
                let priority = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 50;
                super(mechname, isClientFirst, priority);
              }

              test(connection) {
                // eslint-disable-line class-methods-use-this
                return connection.authcid !== null;
              }

              onChallenge(connection) {
                // eslint-disable-line class-methods-use-this
                const {
                  authcid,
                  authzid,
                  domain,
                  pass
                } = connection;

                if (!domain) {
                  throw new Error("SASLPlain onChallenge: domain is not defined!");
                } // Only include authzid if it differs from authcid.
                // See: https://tools.ietf.org/html/rfc6120#section-6.3.8


                let auth_str = authzid !== `${authcid}@${domain}` ? authzid : '';
                auth_str = auth_str + "\u0000";
                auth_str = auth_str + authcid;
                auth_str = auth_str + "\u0000";
                auth_str = auth_str + pass;
                return utils.utf16to8(auth_str);
              }

            }

            /*
             * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
             * in FIPS PUB 180-1
             * Version 2.1a Copyright Paul Johnston 2000 - 2002.
             * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
             * Distributed under the BSD License
             * See http://pajhome.org.uk/crypt/md5 for details.
             */

            /* global define */

            /* Some functions and variables have been stripped for use with Strophe */

            /*
             * Calculate the SHA-1 of an array of big-endian words, and a bit length
             */
            function core_sha1(x, len) {
              /* append padding */
              x[len >> 5] |= 0x80 << 24 - len % 32;
              x[(len + 64 >> 9 << 4) + 15] = len;
              var w = new Array(80);
              var a = 1732584193;
              var b = -271733879;
              var c = -1732584194;
              var d = 271733878;
              var e = -1009589776;
              var i, j, t, olda, oldb, oldc, oldd, olde;

              for (i = 0; i < x.length; i += 16) {
                olda = a;
                oldb = b;
                oldc = c;
                oldd = d;
                olde = e;

                for (j = 0; j < 80; j++) {
                  if (j < 16) {
                    w[j] = x[i + j];
                  } else {
                    w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);
                  }

                  t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)), safe_add(safe_add(e, w[j]), sha1_kt(j)));
                  e = d;
                  d = c;
                  c = rol(b, 30);
                  b = a;
                  a = t;
                }

                a = safe_add(a, olda);
                b = safe_add(b, oldb);
                c = safe_add(c, oldc);
                d = safe_add(d, oldd);
                e = safe_add(e, olde);
              }

              return [a, b, c, d, e];
            }
            /*
             * Perform the appropriate triplet combination function for the current
             * iteration
             */


            function sha1_ft(t, b, c, d) {
              if (t < 20) {
                return b & c | ~b & d;
              }

              if (t < 40) {
                return b ^ c ^ d;
              }

              if (t < 60) {
                return b & c | b & d | c & d;
              }

              return b ^ c ^ d;
            }
            /*
             * Determine the appropriate additive constant for the current iteration
             */


            function sha1_kt(t) {
              return t < 20 ? 1518500249 : t < 40 ? 1859775393 : t < 60 ? -1894007588 : -899497514;
            }
            /*
             * Calculate the HMAC-SHA1 of a key and some data
             */


            function core_hmac_sha1(key, data) {
              var bkey = str2binb(key);

              if (bkey.length > 16) {
                bkey = core_sha1(bkey, key.length * 8);
              }

              var ipad = new Array(16),
                  opad = new Array(16);

              for (var i = 0; i < 16; i++) {
                ipad[i] = bkey[i] ^ 0x36363636;
                opad[i] = bkey[i] ^ 0x5C5C5C5C;
              }

              var hash = core_sha1(ipad.concat(str2binb(data)), 512 + data.length * 8);
              return core_sha1(opad.concat(hash), 512 + 160);
            }
            /*
             * Add integers, wrapping at 2^32. This uses 16-bit operations internally
             * to work around bugs in some JS interpreters.
             */


            function safe_add(x, y) {
              var lsw = (x & 0xFFFF) + (y & 0xFFFF);
              var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
              return msw << 16 | lsw & 0xFFFF;
            }
            /*
             * Bitwise rotate a 32-bit number to the left.
             */


            function rol(num, cnt) {
              return num << cnt | num >>> 32 - cnt;
            }
            /*
             * Convert an 8-bit or 16-bit string to an array of big-endian words
             * In 8-bit function, characters >255 have their hi-byte silently ignored.
             */


            function str2binb(str) {
              var bin = [];
              var mask = 255;

              for (var i = 0; i < str.length * 8; i += 8) {
                bin[i >> 5] |= (str.charCodeAt(i / 8) & mask) << 24 - i % 32;
              }

              return bin;
            }
            /*
             * Convert an array of big-endian words to a base-64 string
             */


            function binb2b64(binarray) {
              var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
              var str = "";
              var triplet, j;

              for (var i = 0; i < binarray.length * 4; i += 3) {
                triplet = (binarray[i >> 2] >> 8 * (3 - i % 4) & 0xFF) << 16 | (binarray[i + 1 >> 2] >> 8 * (3 - (i + 1) % 4) & 0xFF) << 8 | binarray[i + 2 >> 2] >> 8 * (3 - (i + 2) % 4) & 0xFF;

                for (j = 0; j < 4; j++) {
                  if (i * 8 + j * 6 > binarray.length * 32) {
                    str += "=";
                  } else {
                    str += tab.charAt(triplet >> 6 * (3 - j) & 0x3F);
                  }
                }
              }

              return str;
            }
            /*
             * Convert an array of big-endian words to a string
             */


            function binb2str(bin) {
              var str = "";
              var mask = 255;

              for (var i = 0; i < bin.length * 32; i += 8) {
                str += String.fromCharCode(bin[i >> 5] >>> 24 - i % 32 & mask);
              }

              return str;
            }
            /*
             * These are the functions you'll usually want to call
             * They take string arguments and return either hex or base-64 encoded strings
             */


            const SHA1 = {
              b64_hmac_sha1: function (key, data) {
                return binb2b64(core_hmac_sha1(key, data));
              },
              b64_sha1: function (s) {
                return binb2b64(core_sha1(str2binb(s), s.length * 8));
              },
              binb2str: binb2str,
              core_hmac_sha1: core_hmac_sha1,
              str_hmac_sha1: function (key, data) {
                return binb2str(core_hmac_sha1(key, data));
              },
              str_sha1: function (s) {
                return binb2str(core_sha1(str2binb(s), s.length * 8));
              }
            };

            class SASLSHA1 extends SASLMechanism {
              /** PrivateConstructor: SASLSHA1
               *  SASL SCRAM SHA 1 authentication.
               */
              constructor() {
                let mechname = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 'SCRAM-SHA-1';
                let isClientFirst = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : true;
                let priority = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 60;
                super(mechname, isClientFirst, priority);
              }

              test(connection) {
                // eslint-disable-line class-methods-use-this
                return connection.authcid !== null;
              }

              onChallenge(connection, challenge) {
                // eslint-disable-line class-methods-use-this
                let nonce, salt, iter, Hi, U, U_old, i, k;
                let responseText = "c=biws,";
                let authMessage = `${connection._sasl_data["client-first-message-bare"]},${challenge},`;
                const cnonce = connection._sasl_data.cnonce;
                const attribMatch = /([a-z]+)=([^,]+)(,|$)/;

                while (challenge.match(attribMatch)) {
                  const matches = challenge.match(attribMatch);
                  challenge = challenge.replace(matches[0], "");

                  switch (matches[1]) {
                    case "r":
                      nonce = matches[2];
                      break;

                    case "s":
                      salt = matches[2];
                      break;

                    case "i":
                      iter = matches[2];
                      break;
                  }
                }

                if (nonce.slice(0, cnonce.length) !== cnonce) {
                  connection._sasl_data = {};
                  return connection._sasl_failure_cb();
                }

                responseText += "r=" + nonce;
                authMessage += responseText;
                salt = atob(salt);
                salt += "\x00\x00\x00\x01";
                const pass = utils.utf16to8(connection.pass);
                Hi = U_old = SHA1.core_hmac_sha1(pass, salt);

                for (i = 1; i < iter; i++) {
                  U = SHA1.core_hmac_sha1(pass, SHA1.binb2str(U_old));

                  for (k = 0; k < 5; k++) {
                    Hi[k] ^= U[k];
                  }

                  U_old = U;
                }

                Hi = SHA1.binb2str(Hi);
                const clientKey = SHA1.core_hmac_sha1(Hi, "Client Key");
                const serverKey = SHA1.str_hmac_sha1(Hi, "Server Key");
                const clientSignature = SHA1.core_hmac_sha1(SHA1.str_sha1(SHA1.binb2str(clientKey)), authMessage);
                connection._sasl_data["server-signature"] = SHA1.b64_hmac_sha1(serverKey, authMessage);

                for (k = 0; k < 5; k++) {
                  clientKey[k] ^= clientSignature[k];
                }

                responseText += ",p=" + btoa(SHA1.binb2str(clientKey));
                return responseText;
              }

              clientChallenge(connection, test_cnonce) {
                // eslint-disable-line class-methods-use-this
                const cnonce = test_cnonce || MD5.hexdigest("" + Math.random() * 1234567890);
                let auth_str = "n=" + utils.utf16to8(connection.authcid);
                auth_str += ",r=";
                auth_str += cnonce;
                connection._sasl_data.cnonce = cnonce;
                connection._sasl_data["client-first-message-bare"] = auth_str;
                auth_str = "n,," + auth_str;
                return auth_str;
              }

            }

            class SASLXOAuth2 extends SASLMechanism {
              /** PrivateConstructor: SASLXOAuth2
               *  SASL X-OAuth2 authentication.
               */
              constructor() {
                let mechname = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 'X-OAUTH2';
                let isClientFirst = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : true;
                let priority = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 30;
                super(mechname, isClientFirst, priority);
              }

              test(connection) {
                // eslint-disable-line class-methods-use-this
                return connection.pass !== null;
              }

              onChallenge(connection) {
                // eslint-disable-line class-methods-use-this
                let auth_str = '\u0000';

                if (connection.authcid !== null) {
                  auth_str = auth_str + connection.authzid;
                }

                auth_str = auth_str + "\u0000";
                auth_str = auth_str + connection.pass;
                return utils.utf16to8(auth_str);
              }

            }

            /**
             * Implementation of atob() according to the HTML and Infra specs, except that
             * instead of throwing INVALID_CHARACTER_ERR we return null.
             */

            function atob$2(data) {
              if (arguments.length === 0) {
                throw new TypeError("1 argument required, but only 0 present.");
              } // Web IDL requires DOMStrings to just be converted using ECMAScript
              // ToString, which in our case amounts to using a template literal.


              data = `${data}`; // "Remove all ASCII whitespace from data."

              data = data.replace(/[ \t\n\f\r]/g, ""); // "If data's length divides by 4 leaving no remainder, then: if data ends
              // with one or two U+003D (=) code points, then remove them from data."

              if (data.length % 4 === 0) {
                data = data.replace(/==?$/, "");
              } // "If data's length divides by 4 leaving a remainder of 1, then return
              // failure."
              //
              // "If data contains a code point that is not one of
              //
              // U+002B (+)
              // U+002F (/)
              // ASCII alphanumeric
              //
              // then return failure."


              if (data.length % 4 === 1 || /[^+/0-9A-Za-z]/.test(data)) {
                return null;
              } // "Let output be an empty byte sequence."


              let output = ""; // "Let buffer be an empty buffer that can have bits appended to it."
              //
              // We append bits via left-shift and or.  accumulatedBits is used to track
              // when we've gotten to 24 bits.

              let buffer = 0;
              let accumulatedBits = 0; // "Let position be a position variable for data, initially pointing at the
              // start of data."
              //
              // "While position does not point past the end of data:"

              for (let i = 0; i < data.length; i++) {
                // "Find the code point pointed to by position in the second column of
                // Table 1: The Base 64 Alphabet of RFC 4648. Let n be the number given in
                // the first cell of the same row.
                //
                // "Append to buffer the six bits corresponding to n, most significant bit
                // first."
                //
                // atobLookup() implements the table from RFC 4648.
                buffer <<= 6;
                buffer |= atobLookup(data[i]);
                accumulatedBits += 6; // "If buffer has accumulated 24 bits, interpret them as three 8-bit
                // big-endian numbers. Append three bytes with values equal to those
                // numbers to output, in the same order, and then empty buffer."

                if (accumulatedBits === 24) {
                  output += String.fromCharCode((buffer & 0xff0000) >> 16);
                  output += String.fromCharCode((buffer & 0xff00) >> 8);
                  output += String.fromCharCode(buffer & 0xff);
                  buffer = accumulatedBits = 0;
                } // "Advance position by 1."

              } // "If buffer is not empty, it contains either 12 or 18 bits. If it contains
              // 12 bits, then discard the last four and interpret the remaining eight as
              // an 8-bit big-endian number. If it contains 18 bits, then discard the last
              // two and interpret the remaining 16 as two 8-bit big-endian numbers. Append
              // the one or two bytes with values equal to those one or two numbers to
              // output, in the same order."


              if (accumulatedBits === 12) {
                buffer >>= 4;
                output += String.fromCharCode(buffer);
              } else if (accumulatedBits === 18) {
                buffer >>= 2;
                output += String.fromCharCode((buffer & 0xff00) >> 8);
                output += String.fromCharCode(buffer & 0xff);
              } // "Return output."


              return output;
            }
            /**
             * A lookup table for atob(), which converts an ASCII character to the
             * corresponding six-bit number.
             */


            const keystr$1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

            function atobLookup(chr) {
              const index = keystr$1.indexOf(chr); // Throw exception if character is not in the lookup string; should not be hit in tests

              return index < 0 ? undefined : index;
            }

            var atob_1 = atob$2;

            /**
             * btoa() as defined by the HTML and Infra specs, which mostly just references
             * RFC 4648.
             */

            function btoa$2(s) {
              if (arguments.length === 0) {
                throw new TypeError("1 argument required, but only 0 present.");
              }

              let i; // String conversion as required by Web IDL.

              s = `${s}`; // "The btoa() method must throw an "InvalidCharacterError" DOMException if
              // data contains any character whose code point is greater than U+00FF."

              for (i = 0; i < s.length; i++) {
                if (s.charCodeAt(i) > 255) {
                  return null;
                }
              }

              let out = "";

              for (i = 0; i < s.length; i += 3) {
                const groupsOfSix = [undefined, undefined, undefined, undefined];
                groupsOfSix[0] = s.charCodeAt(i) >> 2;
                groupsOfSix[1] = (s.charCodeAt(i) & 0x03) << 4;

                if (s.length > i + 1) {
                  groupsOfSix[1] |= s.charCodeAt(i + 1) >> 4;
                  groupsOfSix[2] = (s.charCodeAt(i + 1) & 0x0f) << 2;
                }

                if (s.length > i + 2) {
                  groupsOfSix[2] |= s.charCodeAt(i + 2) >> 6;
                  groupsOfSix[3] = s.charCodeAt(i + 2) & 0x3f;
                }

                for (let j = 0; j < groupsOfSix.length; j++) {
                  if (typeof groupsOfSix[j] === "undefined") {
                    out += "=";
                  } else {
                    out += btoaLookup(groupsOfSix[j]);
                  }
                }
              }

              return out;
            }
            /**
             * Lookup table for btoa(), which converts a six-bit number into the
             * corresponding ASCII character.
             */


            const keystr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

            function btoaLookup(index) {
              if (index >= 0 && index < 64) {
                return keystr[index];
              } // Throw INVALID_CHARACTER_ERR exception here -- won't be hit in the tests.


              return undefined;
            }

            var btoa_1 = btoa$2;

            const atob$1 = atob_1;

            const btoa$1 = btoa_1;

            var abab = {
              atob: atob$1,
              btoa: btoa$1
            };

            /*
                This program is distributed under the terms of the MIT license.
                Please see the LICENSE file for details.

                Copyright 2006-2018, OGG, LLC
            */
            /** Function: $build
             *  Create a Strophe.Builder.
             *  This is an alias for 'new Strophe.Builder(name, attrs)'.
             *
             *  Parameters:
             *    (String) name - The root element name.
             *    (Object) attrs - The attributes for the root element in object notation.
             *
             *  Returns:
             *    A new Strophe.Builder object.
             */

            function $build(name, attrs) {
              return new Strophe.Builder(name, attrs);
            }
            /** Function: $msg
             *  Create a Strophe.Builder with a <message/> element as the root.
             *
             *  Parameters:
             *    (Object) attrs - The <message/> element attributes in object notation.
             *
             *  Returns:
             *    A new Strophe.Builder object.
             */

            function $msg(attrs) {
              return new Strophe.Builder("message", attrs);
            }
            /** Function: $iq
             *  Create a Strophe.Builder with an <iq/> element as the root.
             *
             *  Parameters:
             *    (Object) attrs - The <iq/> element attributes in object notation.
             *
             *  Returns:
             *    A new Strophe.Builder object.
             */

            function $iq(attrs) {
              return new Strophe.Builder("iq", attrs);
            }
            /** Function: $pres
             *  Create a Strophe.Builder with a <presence/> element as the root.
             *
             *  Parameters:
             *    (Object) attrs - The <presence/> element attributes in object notation.
             *
             *  Returns:
             *    A new Strophe.Builder object.
             */

            function $pres(attrs) {
              return new Strophe.Builder("presence", attrs);
            }
            /** Class: Strophe
             *  An object container for all Strophe library functions.
             *
             *  This class is just a container for all the objects and constants
             *  used in the library.  It is not meant to be instantiated, but to
             *  provide a namespace for library objects, constants, and functions.
             */

            const Strophe = {
              /** Constant: VERSION */
              VERSION: "1.5.0",

              /** Constants: XMPP Namespace Constants
               *  Common namespace constants from the XMPP RFCs and XEPs.
               *
               *  NS.HTTPBIND - HTTP BIND namespace from XEP 124.
               *  NS.BOSH - BOSH namespace from XEP 206.
               *  NS.CLIENT - Main XMPP client namespace.
               *  NS.AUTH - Legacy authentication namespace.
               *  NS.ROSTER - Roster operations namespace.
               *  NS.PROFILE - Profile namespace.
               *  NS.DISCO_INFO - Service discovery info namespace from XEP 30.
               *  NS.DISCO_ITEMS - Service discovery items namespace from XEP 30.
               *  NS.MUC - Multi-User Chat namespace from XEP 45.
               *  NS.SASL - XMPP SASL namespace from RFC 3920.
               *  NS.STREAM - XMPP Streams namespace from RFC 3920.
               *  NS.BIND - XMPP Binding namespace from RFC 3920 and RFC 6120.
               *  NS.SESSION - XMPP Session namespace from RFC 3920.
               *  NS.XHTML_IM - XHTML-IM namespace from XEP 71.
               *  NS.XHTML - XHTML body namespace from XEP 71.
               */
              NS: {
                HTTPBIND: "http://jabber.org/protocol/httpbind",
                BOSH: "urn:xmpp:xbosh",
                CLIENT: "jabber:client",
                AUTH: "jabber:iq:auth",
                ROSTER: "jabber:iq:roster",
                PROFILE: "jabber:iq:profile",
                DISCO_INFO: "http://jabber.org/protocol/disco#info",
                DISCO_ITEMS: "http://jabber.org/protocol/disco#items",
                MUC: "http://jabber.org/protocol/muc",
                SASL: "urn:ietf:params:xml:ns:xmpp-sasl",
                STREAM: "http://etherx.jabber.org/streams",
                FRAMING: "urn:ietf:params:xml:ns:xmpp-framing",
                BIND: "urn:ietf:params:xml:ns:xmpp-bind",
                SESSION: "urn:ietf:params:xml:ns:xmpp-session",
                VERSION: "jabber:iq:version",
                STANZAS: "urn:ietf:params:xml:ns:xmpp-stanzas",
                XHTML_IM: "http://jabber.org/protocol/xhtml-im",
                XHTML: "http://www.w3.org/1999/xhtml"
              },

              /** Constants: XHTML_IM Namespace
               *  contains allowed tags, tag attributes, and css properties.
               *  Used in the createHtml function to filter incoming html into the allowed XHTML-IM subset.
               *  See http://xmpp.org/extensions/xep-0071.html#profile-summary for the list of recommended
               *  allowed tags and their attributes.
               */
              XHTML: {
                tags: ['a', 'blockquote', 'br', 'cite', 'em', 'img', 'li', 'ol', 'p', 'span', 'strong', 'ul', 'body'],
                attributes: {
                  'a': ['href'],
                  'blockquote': ['style'],
                  'br': [],
                  'cite': ['style'],
                  'em': [],
                  'img': ['src', 'alt', 'style', 'height', 'width'],
                  'li': ['style'],
                  'ol': ['style'],
                  'p': ['style'],
                  'span': ['style'],
                  'strong': [],
                  'ul': ['style'],
                  'body': []
                },
                css: ['background-color', 'color', 'font-family', 'font-size', 'font-style', 'font-weight', 'margin-left', 'margin-right', 'text-align', 'text-decoration'],

                /** Function: XHTML.validTag
                 *
                 * Utility method to determine whether a tag is allowed
                 * in the XHTML_IM namespace.
                 *
                 * XHTML tag names are case sensitive and must be lower case.
                 */
                validTag(tag) {
                  for (let i = 0; i < Strophe.XHTML.tags.length; i++) {
                    if (tag === Strophe.XHTML.tags[i]) {
                      return true;
                    }
                  }

                  return false;
                },

                /** Function: XHTML.validAttribute
                 *
                 * Utility method to determine whether an attribute is allowed
                 * as recommended per XEP-0071
                 *
                 * XHTML attribute names are case sensitive and must be lower case.
                 */
                validAttribute(tag, attribute) {
                  if (typeof Strophe.XHTML.attributes[tag] !== 'undefined' && Strophe.XHTML.attributes[tag].length > 0) {
                    for (let i = 0; i < Strophe.XHTML.attributes[tag].length; i++) {
                      if (attribute === Strophe.XHTML.attributes[tag][i]) {
                        return true;
                      }
                    }
                  }

                  return false;
                },

                validCSS(style) {
                  for (let i = 0; i < Strophe.XHTML.css.length; i++) {
                    if (style === Strophe.XHTML.css[i]) {
                      return true;
                    }
                  }

                  return false;
                }

              },

              /** Constants: Connection Status Constants
               *  Connection status constants for use by the connection handler
               *  callback.
               *
               *  Status.ERROR - An error has occurred
               *  Status.CONNECTING - The connection is currently being made
               *  Status.CONNFAIL - The connection attempt failed
               *  Status.AUTHENTICATING - The connection is authenticating
               *  Status.AUTHFAIL - The authentication attempt failed
               *  Status.CONNECTED - The connection has succeeded
               *  Status.DISCONNECTED - The connection has been terminated
               *  Status.DISCONNECTING - The connection is currently being terminated
               *  Status.ATTACHED - The connection has been attached
               *  Status.REDIRECT - The connection has been redirected
               *  Status.CONNTIMEOUT - The connection has timed out
               */
              Status: {
                ERROR: 0,
                CONNECTING: 1,
                CONNFAIL: 2,
                AUTHENTICATING: 3,
                AUTHFAIL: 4,
                CONNECTED: 5,
                DISCONNECTED: 6,
                DISCONNECTING: 7,
                ATTACHED: 8,
                REDIRECT: 9,
                CONNTIMEOUT: 10,
                BINDREQUIRED: 11,
                ATTACHFAIL: 12
              },
              ErrorCondition: {
                BAD_FORMAT: "bad-format",
                CONFLICT: "conflict",
                MISSING_JID_NODE: "x-strophe-bad-non-anon-jid",
                NO_AUTH_MECH: "no-auth-mech",
                UNKNOWN_REASON: "unknown"
              },

              /** Constants: Log Level Constants
               *  Logging level indicators.
               *
               *  LogLevel.DEBUG - Debug output
               *  LogLevel.INFO - Informational output
               *  LogLevel.WARN - Warnings
               *  LogLevel.ERROR - Errors
               *  LogLevel.FATAL - Fatal errors
               */
              LogLevel: {
                DEBUG: 0,
                INFO: 1,
                WARN: 2,
                ERROR: 3,
                FATAL: 4
              },

              /** PrivateConstants: DOM Element Type Constants
               *  DOM element types.
               *
               *  ElementType.NORMAL - Normal element.
               *  ElementType.TEXT - Text data element.
               *  ElementType.FRAGMENT - XHTML fragment element.
               */
              ElementType: {
                NORMAL: 1,
                TEXT: 3,
                CDATA: 4,
                FRAGMENT: 11
              },

              /** PrivateConstants: Timeout Values
               *  Timeout values for error states.  These values are in seconds.
               *  These should not be changed unless you know exactly what you are
               *  doing.
               *
               *  TIMEOUT - Timeout multiplier. A waiting request will be considered
               *      failed after Math.floor(TIMEOUT * wait) seconds have elapsed.
               *      This defaults to 1.1, and with default wait, 66 seconds.
               *  SECONDARY_TIMEOUT - Secondary timeout multiplier. In cases where
               *      Strophe can detect early failure, it will consider the request
               *      failed if it doesn't return after
               *      Math.floor(SECONDARY_TIMEOUT * wait) seconds have elapsed.
               *      This defaults to 0.1, and with default wait, 6 seconds.
               */
              TIMEOUT: 1.1,
              SECONDARY_TIMEOUT: 0.1,

              /** Function: addNamespace
               *  This function is used to extend the current namespaces in
               *  Strophe.NS.  It takes a key and a value with the key being the
               *  name of the new namespace, with its actual value.
               *  For example:
               *  Strophe.addNamespace('PUBSUB', "http://jabber.org/protocol/pubsub");
               *
               *  Parameters:
               *    (String) name - The name under which the namespace will be
               *      referenced under Strophe.NS
               *    (String) value - The actual namespace.
               */
              addNamespace(name, value) {
                Strophe.NS[name] = value;
              },

              /** Function: forEachChild
               *  Map a function over some or all child elements of a given element.
               *
               *  This is a small convenience function for mapping a function over
               *  some or all of the children of an element.  If elemName is null, all
               *  children will be passed to the function, otherwise only children
               *  whose tag names match elemName will be passed.
               *
               *  Parameters:
               *    (XMLElement) elem - The element to operate on.
               *    (String) elemName - The child element tag name filter.
               *    (Function) func - The function to apply to each child.  This
               *      function should take a single argument, a DOM element.
               */
              forEachChild(elem, elemName, func) {
                for (let i = 0; i < elem.childNodes.length; i++) {
                  const childNode = elem.childNodes[i];

                  if (childNode.nodeType === Strophe.ElementType.NORMAL && (!elemName || this.isTagEqual(childNode, elemName))) {
                    func(childNode);
                  }
                }
              },

              /** Function: isTagEqual
               *  Compare an element's tag name with a string.
               *
               *  This function is case sensitive.
               *
               *  Parameters:
               *    (XMLElement) el - A DOM element.
               *    (String) name - The element name.
               *
               *  Returns:
               *    true if the element's tag name matches _el_, and false
               *    otherwise.
               */
              isTagEqual(el, name) {
                return el.tagName === name;
              },

              /** PrivateVariable: _xmlGenerator
               *  _Private_ variable that caches a DOM document to
               *  generate elements.
               */
              _xmlGenerator: null,

              /** Function: xmlGenerator
               *  Get the DOM document to generate elements.
               *
               *  Returns:
               *    The currently used DOM document.
               */
              xmlGenerator() {
                if (!Strophe._xmlGenerator) {
                  Strophe._xmlGenerator = getDummyXMLDOMDocument();
                }

                return Strophe._xmlGenerator;
              },

              /** Function: xmlElement
               *  Create an XML DOM element.
               *
               *  This function creates an XML DOM element correctly across all
               *  implementations. Note that these are not HTML DOM elements, which
               *  aren't appropriate for XMPP stanzas.
               *
               *  Parameters:
               *    (String) name - The name for the element.
               *    (Array|Object) attrs - An optional array or object containing
               *      key/value pairs to use as element attributes. The object should
               *      be in the format {'key': 'value'} or {key: 'value'}. The array
               *      should have the format [['key1', 'value1'], ['key2', 'value2']].
               *    (String) text - The text child data for the element.
               *
               *  Returns:
               *    A new XML DOM element.
               */
              xmlElement(name) {
                if (!name) {
                  return null;
                }

                const node = Strophe.xmlGenerator().createElement(name); // FIXME: this should throw errors if args are the wrong type or
                // there are more than two optional args

                for (let a = 1; a < arguments.length; a++) {
                  const arg = arguments[a];

                  if (!arg) {
                    continue;
                  }

                  if (typeof arg === "string" || typeof arg === "number") {
                    node.appendChild(Strophe.xmlTextNode(arg));
                  } else if (typeof arg === "object" && typeof arg.sort === "function") {
                    for (let i = 0; i < arg.length; i++) {
                      const attr = arg[i];

                      if (typeof attr === "object" && typeof attr.sort === "function" && attr[1] !== undefined && attr[1] !== null) {
                        node.setAttribute(attr[0], attr[1]);
                      }
                    }
                  } else if (typeof arg === "object") {
                    for (const k in arg) {
                      if (Object.prototype.hasOwnProperty.call(arg, k) && arg[k] !== undefined && arg[k] !== null) {
                        node.setAttribute(k, arg[k]);
                      }
                    }
                  }
                }

                return node;
              },

              /*  Function: xmlescape
               *  Excapes invalid xml characters.
               *
               *  Parameters:
               *     (String) text - text to escape.
               *
               *  Returns:
               *      Escaped text.
               */
              xmlescape(text) {
                text = text.replace(/\&/g, "&amp;");
                text = text.replace(/</g, "&lt;");
                text = text.replace(/>/g, "&gt;");
                text = text.replace(/'/g, "&apos;");
                text = text.replace(/"/g, "&quot;");
                return text;
              },

              /*  Function: xmlunescape
              *  Unexcapes invalid xml characters.
              *
              *  Parameters:
              *     (String) text - text to unescape.
              *
              *  Returns:
              *      Unescaped text.
              */
              xmlunescape(text) {
                text = text.replace(/\&amp;/g, "&");
                text = text.replace(/&lt;/g, "<");
                text = text.replace(/&gt;/g, ">");
                text = text.replace(/&apos;/g, "'");
                text = text.replace(/&quot;/g, "\"");
                return text;
              },

              /** Function: xmlTextNode
               *  Creates an XML DOM text node.
               *
               *  Provides a cross implementation version of document.createTextNode.
               *
               *  Parameters:
               *    (String) text - The content of the text node.
               *
               *  Returns:
               *    A new XML DOM text node.
               */
              xmlTextNode(text) {
                return Strophe.xmlGenerator().createTextNode(text);
              },

              /** Function: xmlHtmlNode
               *  Creates an XML DOM html node.
               *
               *  Parameters:
               *    (String) html - The content of the html node.
               *
               *  Returns:
               *    A new XML DOM text node.
               */
              xmlHtmlNode(html) {
                let node; //ensure text is escaped

                if (DOMParser) {
                  const parser = new DOMParser();
                  node = parser.parseFromString(html, "text/xml");
                } else {
                  node = new ActiveXObject("Microsoft.XMLDOM");
                  node.async = "false";
                  node.loadXML(html);
                }

                return node;
              },

              /** Function: getText
               *  Get the concatenation of all text children of an element.
               *
               *  Parameters:
               *    (XMLElement) elem - A DOM element.
               *
               *  Returns:
               *    A String with the concatenated text of all text element children.
               */
              getText(elem) {
                if (!elem) {
                  return null;
                }

                let str = "";

                if (elem.childNodes.length === 0 && elem.nodeType === Strophe.ElementType.TEXT) {
                  str += elem.nodeValue;
                }

                for (let i = 0; i < elem.childNodes.length; i++) {
                  if (elem.childNodes[i].nodeType === Strophe.ElementType.TEXT) {
                    str += elem.childNodes[i].nodeValue;
                  }
                }

                return Strophe.xmlescape(str);
              },

              /** Function: copyElement
               *  Copy an XML DOM element.
               *
               *  This function copies a DOM element and all its descendants and returns
               *  the new copy.
               *
               *  Parameters:
               *    (XMLElement) elem - A DOM element.
               *
               *  Returns:
               *    A new, copied DOM element tree.
               */
              copyElement(elem) {
                let el;

                if (elem.nodeType === Strophe.ElementType.NORMAL) {
                  el = Strophe.xmlElement(elem.tagName);

                  for (let i = 0; i < elem.attributes.length; i++) {
                    el.setAttribute(elem.attributes[i].nodeName, elem.attributes[i].value);
                  }

                  for (let i = 0; i < elem.childNodes.length; i++) {
                    el.appendChild(Strophe.copyElement(elem.childNodes[i]));
                  }
                } else if (elem.nodeType === Strophe.ElementType.TEXT) {
                  el = Strophe.xmlGenerator().createTextNode(elem.nodeValue);
                }

                return el;
              },

              /** Function: createHtml
               *  Copy an HTML DOM element into an XML DOM.
               *
               *  This function copies a DOM element and all its descendants and returns
               *  the new copy.
               *
               *  Parameters:
               *    (HTMLElement) elem - A DOM element.
               *
               *  Returns:
               *    A new, copied DOM element tree.
               */
              createHtml(elem) {
                let el;

                if (elem.nodeType === Strophe.ElementType.NORMAL) {
                  const tag = elem.nodeName.toLowerCase(); // XHTML tags must be lower case.

                  if (Strophe.XHTML.validTag(tag)) {
                    try {
                      el = Strophe.xmlElement(tag);

                      for (let i = 0; i < Strophe.XHTML.attributes[tag].length; i++) {
                        const attribute = Strophe.XHTML.attributes[tag][i];
                        let value = elem.getAttribute(attribute);

                        if (typeof value === 'undefined' || value === null || value === '' || value === false || value === 0) {
                          continue;
                        }

                        if (attribute === 'style' && typeof value === 'object' && typeof value.cssText !== 'undefined') {
                          value = value.cssText; // we're dealing with IE, need to get CSS out
                        } // filter out invalid css styles


                        if (attribute === 'style') {
                          const css = [];
                          const cssAttrs = value.split(';');

                          for (let j = 0; j < cssAttrs.length; j++) {
                            const attr = cssAttrs[j].split(':');
                            const cssName = attr[0].replace(/^\s*/, "").replace(/\s*$/, "").toLowerCase();

                            if (Strophe.XHTML.validCSS(cssName)) {
                              const cssValue = attr[1].replace(/^\s*/, "").replace(/\s*$/, "");
                              css.push(cssName + ': ' + cssValue);
                            }
                          }

                          if (css.length > 0) {
                            value = css.join('; ');
                            el.setAttribute(attribute, value);
                          }
                        } else {
                          el.setAttribute(attribute, value);
                        }
                      }

                      for (let i = 0; i < elem.childNodes.length; i++) {
                        el.appendChild(Strophe.createHtml(elem.childNodes[i]));
                      }
                    } catch (e) {
                      // invalid elements
                      el = Strophe.xmlTextNode('');
                    }
                  } else {
                    el = Strophe.xmlGenerator().createDocumentFragment();

                    for (let i = 0; i < elem.childNodes.length; i++) {
                      el.appendChild(Strophe.createHtml(elem.childNodes[i]));
                    }
                  }
                } else if (elem.nodeType === Strophe.ElementType.FRAGMENT) {
                  el = Strophe.xmlGenerator().createDocumentFragment();

                  for (let i = 0; i < elem.childNodes.length; i++) {
                    el.appendChild(Strophe.createHtml(elem.childNodes[i]));
                  }
                } else if (elem.nodeType === Strophe.ElementType.TEXT) {
                  el = Strophe.xmlTextNode(elem.nodeValue);
                }

                return el;
              },

              /** Function: escapeNode
               *  Escape the node part (also called local part) of a JID.
               *
               *  Parameters:
               *    (String) node - A node (or local part).
               *
               *  Returns:
               *    An escaped node (or local part).
               */
              escapeNode(node) {
                if (typeof node !== "string") {
                  return node;
                }

                return node.replace(/^\s+|\s+$/g, '').replace(/\\/g, "\\5c").replace(/ /g, "\\20").replace(/\"/g, "\\22").replace(/\&/g, "\\26").replace(/\'/g, "\\27").replace(/\//g, "\\2f").replace(/:/g, "\\3a").replace(/</g, "\\3c").replace(/>/g, "\\3e").replace(/@/g, "\\40");
              },

              /** Function: unescapeNode
               *  Unescape a node part (also called local part) of a JID.
               *
               *  Parameters:
               *    (String) node - A node (or local part).
               *
               *  Returns:
               *    An unescaped node (or local part).
               */
              unescapeNode(node) {
                if (typeof node !== "string") {
                  return node;
                }

                return node.replace(/\\20/g, " ").replace(/\\22/g, '"').replace(/\\26/g, "&").replace(/\\27/g, "'").replace(/\\2f/g, "/").replace(/\\3a/g, ":").replace(/\\3c/g, "<").replace(/\\3e/g, ">").replace(/\\40/g, "@").replace(/\\5c/g, "\\");
              },

              /** Function: getNodeFromJid
               *  Get the node portion of a JID String.
               *
               *  Parameters:
               *    (String) jid - A JID.
               *
               *  Returns:
               *    A String containing the node.
               */
              getNodeFromJid(jid) {
                if (jid.indexOf("@") < 0) {
                  return null;
                }

                return jid.split("@")[0];
              },

              /** Function: getDomainFromJid
               *  Get the domain portion of a JID String.
               *
               *  Parameters:
               *    (String) jid - A JID.
               *
               *  Returns:
               *    A String containing the domain.
               */
              getDomainFromJid(jid) {
                const bare = Strophe.getBareJidFromJid(jid);

                if (bare.indexOf("@") < 0) {
                  return bare;
                } else {
                  const parts = bare.split("@");
                  parts.splice(0, 1);
                  return parts.join('@');
                }
              },

              /** Function: getResourceFromJid
               *  Get the resource portion of a JID String.
               *
               *  Parameters:
               *    (String) jid - A JID.
               *
               *  Returns:
               *    A String containing the resource.
               */
              getResourceFromJid(jid) {
                if (!jid) {
                  return null;
                }

                const s = jid.split("/");

                if (s.length < 2) {
                  return null;
                }

                s.splice(0, 1);
                return s.join('/');
              },

              /** Function: getBareJidFromJid
               *  Get the bare JID from a JID String.
               *
               *  Parameters:
               *    (String) jid - A JID.
               *
               *  Returns:
               *    A String containing the bare JID.
               */
              getBareJidFromJid(jid) {
                return jid ? jid.split("/")[0] : null;
              },

              /** PrivateFunction: _handleError
               *  _Private_ function that properly logs an error to the console
               */
              _handleError(e) {
                if (typeof e.stack !== "undefined") {
                  Strophe.fatal(e.stack);
                }

                if (e.sourceURL) {
                  Strophe.fatal("error: " + this.handler + " " + e.sourceURL + ":" + e.line + " - " + e.name + ": " + e.message);
                } else if (e.fileName) {
                  Strophe.fatal("error: " + this.handler + " " + e.fileName + ":" + e.lineNumber + " - " + e.name + ": " + e.message);
                } else {
                  Strophe.fatal("error: " + e.message);
                }
              },

              /** Function: log
               *  User overrideable logging function.
               *
               *  This function is called whenever the Strophe library calls any
               *  of the logging functions.  The default implementation of this
               *  function logs only fatal errors.  If client code wishes to handle the logging
               *  messages, it should override this with
               *  > Strophe.log = function (level, msg) {
               *  >   (user code here)
               *  > };
               *
               *  Please note that data sent and received over the wire is logged
               *  via Strophe.Connection.rawInput() and Strophe.Connection.rawOutput().
               *
               *  The different levels and their meanings are
               *
               *    DEBUG - Messages useful for debugging purposes.
               *    INFO - Informational messages.  This is mostly information like
               *      'disconnect was called' or 'SASL auth succeeded'.
               *    WARN - Warnings about potential problems.  This is mostly used
               *      to report transient connection errors like request timeouts.
               *    ERROR - Some error occurred.
               *    FATAL - A non-recoverable fatal error occurred.
               *
               *  Parameters:
               *    (Integer) level - The log level of the log message.  This will
               *      be one of the values in Strophe.LogLevel.
               *    (String) msg - The log message.
               */
              log(level, msg) {
                if (level === this.LogLevel.FATAL) {
                  var _console;

                  (_console = console) === null || _console === void 0 ? void 0 : _console.error(msg);
                }
              },

              /** Function: debug
               *  Log a message at the Strophe.LogLevel.DEBUG level.
               *
               *  Parameters:
               *    (String) msg - The log message.
               */
              debug(msg) {
                this.log(this.LogLevel.DEBUG, msg);
              },

              /** Function: info
               *  Log a message at the Strophe.LogLevel.INFO level.
               *
               *  Parameters:
               *    (String) msg - The log message.
               */
              info(msg) {
                this.log(this.LogLevel.INFO, msg);
              },

              /** Function: warn
               *  Log a message at the Strophe.LogLevel.WARN level.
               *
               *  Parameters:
               *    (String) msg - The log message.
               */
              warn(msg) {
                this.log(this.LogLevel.WARN, msg);
              },

              /** Function: error
               *  Log a message at the Strophe.LogLevel.ERROR level.
               *
               *  Parameters:
               *    (String) msg - The log message.
               */
              error(msg) {
                this.log(this.LogLevel.ERROR, msg);
              },

              /** Function: fatal
               *  Log a message at the Strophe.LogLevel.FATAL level.
               *
               *  Parameters:
               *    (String) msg - The log message.
               */
              fatal(msg) {
                this.log(this.LogLevel.FATAL, msg);
              },

              /** Function: serialize
               *  Render a DOM element and all descendants to a String.
               *
               *  Parameters:
               *    (XMLElement) elem - A DOM element.
               *
               *  Returns:
               *    The serialized element tree as a String.
               */
              serialize(elem) {
                if (!elem) {
                  return null;
                }

                if (typeof elem.tree === "function") {
                  elem = elem.tree();
                }

                const names = [...Array(elem.attributes.length).keys()].map(i => elem.attributes[i].nodeName);
                names.sort();
                let result = names.reduce((a, n) => `${a} ${n}="${Strophe.xmlescape(elem.attributes.getNamedItem(n).value)}"`, `<${elem.nodeName}`);

                if (elem.childNodes.length > 0) {
                  result += ">";

                  for (let i = 0; i < elem.childNodes.length; i++) {
                    const child = elem.childNodes[i];

                    switch (child.nodeType) {
                      case Strophe.ElementType.NORMAL:
                        // normal element, so recurse
                        result += Strophe.serialize(child);
                        break;

                      case Strophe.ElementType.TEXT:
                        // text element to escape values
                        result += Strophe.xmlescape(child.nodeValue);
                        break;

                      case Strophe.ElementType.CDATA:
                        // cdata section so don't escape values
                        result += "<![CDATA[" + child.nodeValue + "]]>";
                    }
                  }

                  result += "</" + elem.nodeName + ">";
                } else {
                  result += "/>";
                }

                return result;
              },

              /** PrivateVariable: _requestId
               *  _Private_ variable that keeps track of the request ids for
               *  connections.
               */
              _requestId: 0,

              /** PrivateVariable: Strophe.connectionPlugins
               *  _Private_ variable Used to store plugin names that need
               *  initialization on Strophe.Connection construction.
               */
              _connectionPlugins: {},

              /** Function: addConnectionPlugin
               *  Extends the Strophe.Connection object with the given plugin.
               *
               *  Parameters:
               *    (String) name - The name of the extension.
               *    (Object) ptype - The plugin's prototype.
               */
              addConnectionPlugin(name, ptype) {
                Strophe._connectionPlugins[name] = ptype;
              }

            };
            /** Class: Strophe.Builder
             *  XML DOM builder.
             *
             *  This object provides an interface similar to JQuery but for building
             *  DOM elements easily and rapidly.  All the functions except for toString()
             *  and tree() return the object, so calls can be chained.  Here's an
             *  example using the $iq() builder helper.
             *  > $iq({to: 'you', from: 'me', type: 'get', id: '1'})
             *  >     .c('query', {xmlns: 'strophe:example'})
             *  >     .c('example')
             *  >     .toString()
             *
             *  The above generates this XML fragment
             *  > <iq to='you' from='me' type='get' id='1'>
             *  >   <query xmlns='strophe:example'>
             *  >     <example/>
             *  >   </query>
             *  > </iq>
             *  The corresponding DOM manipulations to get a similar fragment would be
             *  a lot more tedious and probably involve several helper variables.
             *
             *  Since adding children makes new operations operate on the child, up()
             *  is provided to traverse up the tree.  To add two children, do
             *  > builder.c('child1', ...).up().c('child2', ...)
             *  The next operation on the Builder will be relative to the second child.
             */

            /** Constructor: Strophe.Builder
             *  Create a Strophe.Builder object.
             *
             *  The attributes should be passed in object notation.  For example
             *  > let b = new Builder('message', {to: 'you', from: 'me'});
             *  or
             *  > let b = new Builder('messsage', {'xml:lang': 'en'});
             *
             *  Parameters:
             *    (String) name - The name of the root element.
             *    (Object) attrs - The attributes for the root element in object notation.
             *
             *  Returns:
             *    A new Strophe.Builder.
             */

            Strophe.Builder = class Builder {
              constructor(name, attrs) {
                // Set correct namespace for jabber:client elements
                if (name === "presence" || name === "message" || name === "iq") {
                  if (attrs && !attrs.xmlns) {
                    attrs.xmlns = Strophe.NS.CLIENT;
                  } else if (!attrs) {
                    attrs = {
                      xmlns: Strophe.NS.CLIENT
                    };
                  }
                } // Holds the tree being built.


                this.nodeTree = Strophe.xmlElement(name, attrs); // Points to the current operation node.

                this.node = this.nodeTree;
              }
              /** Function: tree
               *  Return the DOM tree.
               *
               *  This function returns the current DOM tree as an element object.  This
               *  is suitable for passing to functions like Strophe.Connection.send().
               *
               *  Returns:
               *    The DOM tree as a element object.
               */


              tree() {
                return this.nodeTree;
              }
              /** Function: toString
               *  Serialize the DOM tree to a String.
               *
               *  This function returns a string serialization of the current DOM
               *  tree.  It is often used internally to pass data to a
               *  Strophe.Request object.
               *
               *  Returns:
               *    The serialized DOM tree in a String.
               */


              toString() {
                return Strophe.serialize(this.nodeTree);
              }
              /** Function: up
               *  Make the current parent element the new current element.
               *
               *  This function is often used after c() to traverse back up the tree.
               *  For example, to add two children to the same element
               *  > builder.c('child1', {}).up().c('child2', {});
               *
               *  Returns:
               *    The Stophe.Builder object.
               */


              up() {
                this.node = this.node.parentNode;
                return this;
              }
              /** Function: root
               *  Make the root element the new current element.
               *
               *  When at a deeply nested element in the tree, this function can be used
               *  to jump back to the root of the tree, instead of having to repeatedly
               *  call up().
               *
               *  Returns:
               *    The Stophe.Builder object.
               */


              root() {
                this.node = this.nodeTree;
                return this;
              }
              /** Function: attrs
               *  Add or modify attributes of the current element.
               *
               *  The attributes should be passed in object notation.  This function
               *  does not move the current element pointer.
               *
               *  Parameters:
               *    (Object) moreattrs - The attributes to add/modify in object notation.
               *
               *  Returns:
               *    The Strophe.Builder object.
               */


              attrs(moreattrs) {
                for (const k in moreattrs) {
                  if (Object.prototype.hasOwnProperty.call(moreattrs, k)) {
                    if (moreattrs[k] === undefined) {
                      this.node.removeAttribute(k);
                    } else {
                      this.node.setAttribute(k, moreattrs[k]);
                    }
                  }
                }

                return this;
              }
              /** Function: c
               *  Add a child to the current element and make it the new current
               *  element.
               *
               *  This function moves the current element pointer to the child,
               *  unless text is provided.  If you need to add another child, it
               *  is necessary to use up() to go back to the parent in the tree.
               *
               *  Parameters:
               *    (String) name - The name of the child.
               *    (Object) attrs - The attributes of the child in object notation.
               *    (String) text - The text to add to the child.
               *
               *  Returns:
               *    The Strophe.Builder object.
               */


              c(name, attrs, text) {
                const child = Strophe.xmlElement(name, attrs, text);
                this.node.appendChild(child);

                if (typeof text !== "string" && typeof text !== "number") {
                  this.node = child;
                }

                return this;
              }
              /** Function: cnode
               *  Add a child to the current element and make it the new current
               *  element.
               *
               *  This function is the same as c() except that instead of using a
               *  name and an attributes object to create the child it uses an
               *  existing DOM element object.
               *
               *  Parameters:
               *    (XMLElement) elem - A DOM element.
               *
               *  Returns:
               *    The Strophe.Builder object.
               */


              cnode(elem) {
                let impNode;
                const xmlGen = Strophe.xmlGenerator();

                try {
                  impNode = xmlGen.importNode !== undefined;
                } catch (e) {
                  impNode = false;
                }

                const newElem = impNode ? xmlGen.importNode(elem, true) : Strophe.copyElement(elem);
                this.node.appendChild(newElem);
                this.node = newElem;
                return this;
              }
              /** Function: t
               *  Add a child text element.
               *
               *  This *does not* make the child the new current element since there
               *  are no children of text elements.
               *
               *  Parameters:
               *    (String) text - The text data to append to the current element.
               *
               *  Returns:
               *    The Strophe.Builder object.
               */


              t(text) {
                const child = Strophe.xmlTextNode(text);
                this.node.appendChild(child);
                return this;
              }
              /** Function: h
               *  Replace current element contents with the HTML passed in.
               *
               *  This *does not* make the child the new current element
               *
               *  Parameters:
               *    (String) html - The html to insert as contents of current element.
               *
               *  Returns:
               *    The Strophe.Builder object.
               */


              h(html) {
                const fragment = Strophe.xmlGenerator().createElement('body'); // force the browser to try and fix any invalid HTML tags

                fragment.innerHTML = html; // copy cleaned html into an xml dom

                const xhtml = Strophe.createHtml(fragment);

                while (xhtml.childNodes.length > 0) {
                  this.node.appendChild(xhtml.childNodes[0]);
                }

                return this;
              }

            };
            /** PrivateClass: Strophe.Handler
             *  _Private_ helper class for managing stanza handlers.
             *
             *  A Strophe.Handler encapsulates a user provided callback function to be
             *  executed when matching stanzas are received by the connection.
             *  Handlers can be either one-off or persistant depending on their
             *  return value. Returning true will cause a Handler to remain active, and
             *  returning false will remove the Handler.
             *
             *  Users will not use Strophe.Handler objects directly, but instead they
             *  will use Strophe.Connection.addHandler() and
             *  Strophe.Connection.deleteHandler().
             */

            /** PrivateConstructor: Strophe.Handler
             *  Create and initialize a new Strophe.Handler.
             *
             *  Parameters:
             *    (Function) handler - A function to be executed when the handler is run.
             *    (String) ns - The namespace to match.
             *    (String) name - The element name to match.
             *    (String) type - The element type to match.
             *    (String) id - The element id attribute to match.
             *    (String) from - The element from attribute to match.
             *    (Object) options - Handler options
             *
             *  Returns:
             *    A new Strophe.Handler object.
             */

            Strophe.Handler = function (handler, ns, name, type, id, from, options) {
              this.handler = handler;
              this.ns = ns;
              this.name = name;
              this.type = type;
              this.id = id;
              this.options = options || {
                'matchBareFromJid': false,
                'ignoreNamespaceFragment': false
              }; // BBB: Maintain backward compatibility with old `matchBare` option

              if (this.options.matchBare) {
                Strophe.warn('The "matchBare" option is deprecated, use "matchBareFromJid" instead.');
                this.options.matchBareFromJid = this.options.matchBare;
                delete this.options.matchBare;
              }

              if (this.options.matchBareFromJid) {
                this.from = from ? Strophe.getBareJidFromJid(from) : null;
              } else {
                this.from = from;
              } // whether the handler is a user handler or a system handler


              this.user = true;
            };

            Strophe.Handler.prototype = {
              /** PrivateFunction: getNamespace
               *  Returns the XML namespace attribute on an element.
               *  If `ignoreNamespaceFragment` was passed in for this handler, then the
               *  URL fragment will be stripped.
               *
               *  Parameters:
               *    (XMLElement) elem - The XML element with the namespace.
               *
               *  Returns:
               *    The namespace, with optionally the fragment stripped.
               */
              getNamespace(elem) {
                let elNamespace = elem.getAttribute("xmlns");

                if (elNamespace && this.options.ignoreNamespaceFragment) {
                  elNamespace = elNamespace.split('#')[0];
                }

                return elNamespace;
              },

              /** PrivateFunction: namespaceMatch
               *  Tests if a stanza matches the namespace set for this Strophe.Handler.
               *
               *  Parameters:
               *    (XMLElement) elem - The XML element to test.
               *
               *  Returns:
               *    true if the stanza matches and false otherwise.
               */
              namespaceMatch(elem) {
                let nsMatch = false;

                if (!this.ns) {
                  return true;
                } else {
                  Strophe.forEachChild(elem, null, elem => {
                    if (this.getNamespace(elem) === this.ns) {
                      nsMatch = true;
                    }
                  });
                  return nsMatch || this.getNamespace(elem) === this.ns;
                }
              },

              /** PrivateFunction: isMatch
               *  Tests if a stanza matches the Strophe.Handler.
               *
               *  Parameters:
               *    (XMLElement) elem - The XML element to test.
               *
               *  Returns:
               *    true if the stanza matches and false otherwise.
               */
              isMatch(elem) {
                let from = elem.getAttribute('from');

                if (this.options.matchBareFromJid) {
                  from = Strophe.getBareJidFromJid(from);
                }

                const elem_type = elem.getAttribute("type");

                if (this.namespaceMatch(elem) && (!this.name || Strophe.isTagEqual(elem, this.name)) && (!this.type || (Array.isArray(this.type) ? this.type.indexOf(elem_type) !== -1 : elem_type === this.type)) && (!this.id || elem.getAttribute("id") === this.id) && (!this.from || from === this.from)) {
                  return true;
                }

                return false;
              },

              /** PrivateFunction: run
               *  Run the callback on a matching stanza.
               *
               *  Parameters:
               *    (XMLElement) elem - The DOM element that triggered the
               *      Strophe.Handler.
               *
               *  Returns:
               *    A boolean indicating if the handler should remain active.
               */
              run(elem) {
                let result = null;

                try {
                  result = this.handler(elem);
                } catch (e) {
                  Strophe._handleError(e);

                  throw e;
                }

                return result;
              },

              /** PrivateFunction: toString
               *  Get a String representation of the Strophe.Handler object.
               *
               *  Returns:
               *    A String.
               */
              toString() {
                return "{Handler: " + this.handler + "(" + this.name + "," + this.id + "," + this.ns + ")}";
              }

            };
            /** PrivateClass: Strophe.TimedHandler
             *  _Private_ helper class for managing timed handlers.
             *
             *  A Strophe.TimedHandler encapsulates a user provided callback that
             *  should be called after a certain period of time or at regular
             *  intervals.  The return value of the callback determines whether the
             *  Strophe.TimedHandler will continue to fire.
             *
             *  Users will not use Strophe.TimedHandler objects directly, but instead
             *  they will use Strophe.Connection.addTimedHandler() and
             *  Strophe.Connection.deleteTimedHandler().
             */

            Strophe.TimedHandler = class TimedHandler {
              /** PrivateConstructor: Strophe.TimedHandler
               *  Create and initialize a new Strophe.TimedHandler object.
               *
               *  Parameters:
               *    (Integer) period - The number of milliseconds to wait before the
               *      handler is called.
               *    (Function) handler - The callback to run when the handler fires.  This
               *      function should take no arguments.
               *
               *  Returns:
               *    A new Strophe.TimedHandler object.
               */
              constructor(period, handler) {
                this.period = period;
                this.handler = handler;
                this.lastCalled = new Date().getTime();
                this.user = true;
              }
              /** PrivateFunction: run
               *  Run the callback for the Strophe.TimedHandler.
               *
               *  Returns:
               *    true if the Strophe.TimedHandler should be called again, and false
               *      otherwise.
               */


              run() {
                this.lastCalled = new Date().getTime();
                return this.handler();
              }
              /** PrivateFunction: reset
               *  Reset the last called time for the Strophe.TimedHandler.
               */


              reset() {
                this.lastCalled = new Date().getTime();
              }
              /** PrivateFunction: toString
               *  Get a string representation of the Strophe.TimedHandler object.
               *
               *  Returns:
               *    The string representation.
               */


              toString() {
                return "{TimedHandler: " + this.handler + "(" + this.period + ")}";
              }

            };
            /** Class: Strophe.Connection
             *  XMPP Connection manager.
             *
             *  This class is the main part of Strophe.  It manages a BOSH or websocket
             *  connection to an XMPP server and dispatches events to the user callbacks
             *  as data arrives. It supports SASL PLAIN, SASL SCRAM-SHA-1
             *  and legacy authentication.
             *
             *  After creating a Strophe.Connection object, the user will typically
             *  call connect() with a user supplied callback to handle connection level
             *  events like authentication failure, disconnection, or connection
             *  complete.
             *
             *  The user will also have several event handlers defined by using
             *  addHandler() and addTimedHandler().  These will allow the user code to
             *  respond to interesting stanzas or do something periodically with the
             *  connection. These handlers will be active once authentication is
             *  finished.
             *
             *  To send data to the connection, use send().
             */

            /** Constructor: Strophe.Connection
             *  Create and initialize a Strophe.Connection object.
             *
             *  The transport-protocol for this connection will be chosen automatically
             *  based on the given service parameter. URLs starting with "ws://" or
             *  "wss://" will use WebSockets, URLs starting with "http://", "https://"
             *  or without a protocol will use BOSH.
             *
             *  To make Strophe connect to the current host you can leave out the protocol
             *  and host part and just pass the path, e.g.
             *
             *  > let conn = new Strophe.Connection("/http-bind/");
             *
             *  Options common to both Websocket and BOSH:
             *  ------------------------------------------
             *
             *  cookies:
             *
             *  The *cookies* option allows you to pass in cookies to be added to the
             *  document. These cookies will then be included in the BOSH XMLHttpRequest
             *  or in the websocket connection.
             *
             *  The passed in value must be a map of cookie names and string values.
             *
             *  > { "myCookie": {
             *  >     "value": "1234",
             *  >     "domain": ".example.org",
             *  >     "path": "/",
             *  >     "expires": expirationDate
             *  >     }
             *  > }
             *
             *  Note that cookies can't be set in this way for other domains (i.e. cross-domain).
             *  Those cookies need to be set under those domains, for example they can be
             *  set server-side by making a XHR call to that domain to ask it to set any
             *  necessary cookies.
             *
             *  mechanisms:
             *
             *  The *mechanisms* option allows you to specify the SASL mechanisms that this
             *  instance of Strophe.Connection (and therefore your XMPP client) will
             *  support.
             *
             *  The value must be an array of objects with Strophe.SASLMechanism
             *  prototypes.
             *
             *  If nothing is specified, then the following mechanisms (and their
             *  priorities) are registered:
             *
             *      SCRAM-SHA-1 - 60
             *      PLAIN       - 50
             *      OAUTHBEARER - 40
             *      X-OAUTH2    - 30
             *      ANONYMOUS   - 20
             *      EXTERNAL    - 10
             *
             *  explicitResourceBinding:
             *
             *  If `explicitResourceBinding` is set to a truthy value, then the XMPP client
             *  needs to explicitly call `Strophe.Connection.prototype.bind` once the XMPP
             *  server has advertised the "urn:ietf:params:xml:ns:xmpp-bind" feature.
             *
             *  Making this step explicit allows client authors to first finish other
             *  stream related tasks, such as setting up an XEP-0198 Stream Management
             *  session, before binding the JID resource for this session.
             *
             *  WebSocket options:
             *  ------------------
             *
             *  protocol:
             *
             *  If you want to connect to the current host with a WebSocket connection you
             *  can tell Strophe to use WebSockets through a "protocol" attribute in the
             *  optional options parameter. Valid values are "ws" for WebSocket and "wss"
             *  for Secure WebSocket.
             *  So to connect to "wss://CURRENT_HOSTNAME/xmpp-websocket" you would call
             *
             *  > let conn = new Strophe.Connection("/xmpp-websocket/", {protocol: "wss"});
             *
             *  Note that relative URLs _NOT_ starting with a "/" will also include the path
             *  of the current site.
             *
             *  Also because downgrading security is not permitted by browsers, when using
             *  relative URLs both BOSH and WebSocket connections will use their secure
             *  variants if the current connection to the site is also secure (https).
             *
             *  worker:
             *
             *  Set this option to URL from where the shared worker script should be loaded.
             *
             *  To run the websocket connection inside a shared worker.
             *  This allows you to share a single websocket-based connection between
             *  multiple Strophe.Connection instances, for example one per browser tab.
             *
             *  The script to use is the one in `src/shared-connection-worker.js`.
             *
             *  BOSH options:
             *  -------------
             *
             *  By adding "sync" to the options, you can control if requests will
             *  be made synchronously or not. The default behaviour is asynchronous.
             *  If you want to make requests synchronous, make "sync" evaluate to true.
             *  > let conn = new Strophe.Connection("/http-bind/", {sync: true});
             *
             *  You can also toggle this on an already established connection.
             *  > conn.options.sync = true;
             *
             *  The *customHeaders* option can be used to provide custom HTTP headers to be
             *  included in the XMLHttpRequests made.
             *
             *  The *keepalive* option can be used to instruct Strophe to maintain the
             *  current BOSH session across interruptions such as webpage reloads.
             *
             *  It will do this by caching the sessions tokens in sessionStorage, and when
             *  "restore" is called it will check whether there are cached tokens with
             *  which it can resume an existing session.
             *
             *  The *withCredentials* option should receive a Boolean value and is used to
             *  indicate wether cookies should be included in ajax requests (by default
             *  they're not).
             *  Set this value to true if you are connecting to a BOSH service
             *  and for some reason need to send cookies to it.
             *  In order for this to work cross-domain, the server must also enable
             *  credentials by setting the Access-Control-Allow-Credentials response header
             *  to "true". For most usecases however this setting should be false (which
             *  is the default).
             *  Additionally, when using Access-Control-Allow-Credentials, the
             *  Access-Control-Allow-Origin header can't be set to the wildcard "*", but
             *  instead must be restricted to actual domains.
             *
             *  The *contentType* option can be set to change the default Content-Type
             *  of "text/xml; charset=utf-8", which can be useful to reduce the amount of
             *  CORS preflight requests that are sent to the server.
             *
             *  Parameters:
             *    (String) service - The BOSH or WebSocket service URL.
             *    (Object) options - A hash of configuration options
             *
             *  Returns:
             *    A new Strophe.Connection object.
             */

            Strophe.Connection = class Connection {
              constructor(service, options) {
                // The service URL
                this.service = service; // Configuration options

                this.options = options || {};
                this.setProtocol();
                /* The connected JID. */

                this.jid = "";
                /* the JIDs domain */

                this.domain = null;
                /* stream:features */

                this.features = null; // SASL

                this._sasl_data = {};
                this.do_bind = false;
                this.do_session = false;
                this.mechanisms = {}; // handler lists

                this.timedHandlers = [];
                this.handlers = [];
                this.removeTimeds = [];
                this.removeHandlers = [];
                this.addTimeds = [];
                this.addHandlers = [];
                this.protocolErrorHandlers = {
                  'HTTP': {},
                  'websocket': {}
                };
                this._idleTimeout = null;
                this._disconnectTimeout = null;
                this.authenticated = false;
                this.connected = false;
                this.disconnecting = false;
                this.do_authentication = true;
                this.paused = false;
                this.restored = false;
                this._data = [];
                this._uniqueId = 0;
                this._sasl_success_handler = null;
                this._sasl_failure_handler = null;
                this._sasl_challenge_handler = null; // Max retries before disconnecting

                this.maxRetries = 5; // Call onIdle callback every 1/10th of a second

                this._idleTimeout = setTimeout(() => this._onIdle(), 100);
                utils.addCookies(this.options.cookies);
                this.registerSASLMechanisms(this.options.mechanisms); // A client must always respond to incoming IQ "set" and "get" stanzas.
                // See https://datatracker.ietf.org/doc/html/rfc6120#section-8.2.3
                //
                // This is a fallback handler which gets called when no other handler
                // was called for a received IQ "set" or "get".

                this.iqFallbackHandler = new Strophe.Handler(iq => this.send($iq({
                  type: 'error',
                  id: iq.getAttribute('id')
                }).c('error', {
                  'type': 'cancel'
                }).c('service-unavailable', {
                  'xmlns': Strophe.NS.STANZAS
                })), null, 'iq', ['get', 'set']); // initialize plugins

                for (const k in Strophe._connectionPlugins) {
                  if (Object.prototype.hasOwnProperty.call(Strophe._connectionPlugins, k)) {
                    const F = function () {};

                    F.prototype = Strophe._connectionPlugins[k];
                    this[k] = new F();
                    this[k].init(this);
                  }
                }
              }
              /** Function: setProtocol
               *  Select protocal based on this.options or this.service
               */


              setProtocol() {
                const proto = this.options.protocol || "";

                if (this.options.worker) {
                  this._proto = new Strophe.WorkerWebsocket(this);
                } else if (this.service.indexOf("ws:") === 0 || this.service.indexOf("wss:") === 0 || proto.indexOf("ws") === 0) {
                  this._proto = new Strophe.Websocket(this);
                } else {
                  this._proto = new Strophe.Bosh(this);
                }
              }
              /** Function: reset
               *  Reset the connection.
               *
               *  This function should be called after a connection is disconnected
               *  before that connection is reused.
               */


              reset() {
                this._proto._reset(); // SASL


                this.do_session = false;
                this.do_bind = false; // handler lists

                this.timedHandlers = [];
                this.handlers = [];
                this.removeTimeds = [];
                this.removeHandlers = [];
                this.addTimeds = [];
                this.addHandlers = [];
                this.authenticated = false;
                this.connected = false;
                this.disconnecting = false;
                this.restored = false;
                this._data = [];
                this._requests = [];
                this._uniqueId = 0;
              }
              /** Function: pause
               *  Pause the request manager.
               *
               *  This will prevent Strophe from sending any more requests to the
               *  server.  This is very useful for temporarily pausing
               *  BOSH-Connections while a lot of send() calls are happening quickly.
               *  This causes Strophe to send the data in a single request, saving
               *  many request trips.
               */


              pause() {
                this.paused = true;
              }
              /** Function: resume
               *  Resume the request manager.
               *
               *  This resumes after pause() has been called.
               */


              resume() {
                this.paused = false;
              }
              /** Function: getUniqueId
               *  Generate a unique ID for use in <iq/> elements.
               *
               *  All <iq/> stanzas are required to have unique id attributes.  This
               *  function makes creating these easy.  Each connection instance has
               *  a counter which starts from zero, and the value of this counter
               *  plus a colon followed by the suffix becomes the unique id. If no
               *  suffix is supplied, the counter is used as the unique id.
               *
               *  Suffixes are used to make debugging easier when reading the stream
               *  data, and their use is recommended.  The counter resets to 0 for
               *  every new connection for the same reason.  For connections to the
               *  same server that authenticate the same way, all the ids should be
               *  the same, which makes it easy to see changes.  This is useful for
               *  automated testing as well.
               *
               *  Parameters:
               *    (String) suffix - A optional suffix to append to the id.
               *
               *  Returns:
               *    A unique string to be used for the id attribute.
               */


              getUniqueId(suffix) {
                // eslint-disable-line class-methods-use-this
                const uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
                  const r = Math.random() * 16 | 0,
                        v = c === 'x' ? r : r & 0x3 | 0x8;
                  return v.toString(16);
                });

                if (typeof suffix === "string" || typeof suffix === "number") {
                  return uuid + ":" + suffix;
                } else {
                  return uuid + "";
                }
              }
              /** Function: addProtocolErrorHandler
               *  Register a handler function for when a protocol (websocker or HTTP)
               *  error occurs.
               *
               *  NOTE: Currently only HTTP errors for BOSH requests are handled.
               *  Patches that handle websocket errors would be very welcome.
               *
               *  Parameters:
               *    (String) protocol - 'HTTP' or 'websocket'
               *    (Integer) status_code - Error status code (e.g 500, 400 or 404)
               *    (Function) callback - Function that will fire on Http error
               *
               *  Example:
               *  function onError(err_code){
               *    //do stuff
               *  }
               *
               *  let conn = Strophe.connect('http://example.com/http-bind');
               *  conn.addProtocolErrorHandler('HTTP', 500, onError);
               *  // Triggers HTTP 500 error and onError handler will be called
               *  conn.connect('user_jid@incorrect_jabber_host', 'secret', onConnect);
               */


              addProtocolErrorHandler(protocol, status_code, callback) {
                this.protocolErrorHandlers[protocol][status_code] = callback;
              }
              /** Function: connect
               *  Starts the connection process.
               *
               *  As the connection process proceeds, the user supplied callback will
               *  be triggered multiple times with status updates.  The callback
               *  should take two arguments - the status code and the error condition.
               *
               *  The status code will be one of the values in the Strophe.Status
               *  constants.  The error condition will be one of the conditions
               *  defined in RFC 3920 or the condition 'strophe-parsererror'.
               *
               *  The Parameters _wait_, _hold_ and _route_ are optional and only relevant
               *  for BOSH connections. Please see XEP 124 for a more detailed explanation
               *  of the optional parameters.
               *
               *  Parameters:
               *    (String) jid - The user's JID.  This may be a bare JID,
               *      or a full JID.  If a node is not supplied, SASL OAUTHBEARER or
               *      SASL ANONYMOUS authentication will be attempted (OAUTHBEARER will
               *      process the provided password value as an access token).
               *    (String) pass - The user's password.
               *    (Function) callback - The connect callback function.
               *    (Integer) wait - The optional HTTPBIND wait value.  This is the
               *      time the server will wait before returning an empty result for
               *      a request.  The default setting of 60 seconds is recommended.
               *    (Integer) hold - The optional HTTPBIND hold value.  This is the
               *      number of connections the server will hold at one time.  This
               *      should almost always be set to 1 (the default).
               *    (String) route - The optional route value.
               *    (String) authcid - The optional alternative authentication identity
               *      (username) if intending to impersonate another user.
               *      When using the SASL-EXTERNAL authentication mechanism, for example
               *      with client certificates, then the authcid value is used to
               *      determine whether an authorization JID (authzid) should be sent to
               *      the server. The authzid should NOT be sent to the server if the
               *      authzid and authcid are the same. So to prevent it from being sent
               *      (for example when the JID is already contained in the client
               *      certificate), set authcid to that same JID. See XEP-178 for more
               *      details.
               *     (Integer) disconnection_timeout - The optional disconnection timeout
               *      in milliseconds before _doDisconnect will be called.
               */


              connect(jid, pass, callback, wait, hold, route, authcid) {
                let disconnection_timeout = arguments.length > 7 && arguments[7] !== undefined ? arguments[7] : 3000;
                this.jid = jid;
                /** Variable: authzid
                 *  Authorization identity.
                 */

                this.authzid = Strophe.getBareJidFromJid(this.jid);
                /** Variable: authcid
                 *  Authentication identity (User name).
                 */

                this.authcid = authcid || Strophe.getNodeFromJid(this.jid);
                /** Variable: pass
                 *  Authentication identity (User password).
                 */

                this.pass = pass;
                this.connect_callback = callback;
                this.disconnecting = false;
                this.connected = false;
                this.authenticated = false;
                this.restored = false;
                this.disconnection_timeout = disconnection_timeout; // parse jid for domain

                this.domain = Strophe.getDomainFromJid(this.jid);

                this._changeConnectStatus(Strophe.Status.CONNECTING, null);

                this._proto._connect(wait, hold, route);
              }
              /** Function: attach
               *  Attach to an already created and authenticated BOSH session.
               *
               *  This function is provided to allow Strophe to attach to BOSH
               *  sessions which have been created externally, perhaps by a Web
               *  application.  This is often used to support auto-login type features
               *  without putting user credentials into the page.
               *
               *  Parameters:
               *    (String) jid - The full JID that is bound by the session.
               *    (String) sid - The SID of the BOSH session.
               *    (String) rid - The current RID of the BOSH session.  This RID
               *      will be used by the next request.
               *    (Function) callback The connect callback function.
               *    (Integer) wait - The optional HTTPBIND wait value.  This is the
               *      time the server will wait before returning an empty result for
               *      a request.  The default setting of 60 seconds is recommended.
               *      Other settings will require tweaks to the Strophe.TIMEOUT value.
               *    (Integer) hold - The optional HTTPBIND hold value.  This is the
               *      number of connections the server will hold at one time.  This
               *      should almost always be set to 1 (the default).
               *    (Integer) wind - The optional HTTBIND window value.  This is the
               *      allowed range of request ids that are valid.  The default is 5.
               */


              attach(jid, sid, rid, callback, wait, hold, wind) {
                if (this._proto._attach) {
                  return this._proto._attach(jid, sid, rid, callback, wait, hold, wind);
                } else {
                  const error = new Error('The "attach" method is not available for your connection protocol');
                  error.name = 'StropheSessionError';
                  throw error;
                }
              }
              /** Function: restore
               *  Attempt to restore a cached BOSH session.
               *
               *  This function is only useful in conjunction with providing the
               *  "keepalive":true option when instantiating a new Strophe.Connection.
               *
               *  When "keepalive" is set to true, Strophe will cache the BOSH tokens
               *  RID (Request ID) and SID (Session ID) and then when this function is
               *  called, it will attempt to restore the session from those cached
               *  tokens.
               *
               *  This function must therefore be called instead of connect or attach.
               *
               *  For an example on how to use it, please see examples/restore.js
               *
               *  Parameters:
               *    (String) jid - The user's JID.  This may be a bare JID or a full JID.
               *    (Function) callback - The connect callback function.
               *    (Integer) wait - The optional HTTPBIND wait value.  This is the
               *      time the server will wait before returning an empty result for
               *      a request.  The default setting of 60 seconds is recommended.
               *    (Integer) hold - The optional HTTPBIND hold value.  This is the
               *      number of connections the server will hold at one time.  This
               *      should almost always be set to 1 (the default).
               *    (Integer) wind - The optional HTTBIND window value.  This is the
               *      allowed range of request ids that are valid.  The default is 5.
               */


              restore(jid, callback, wait, hold, wind) {
                if (this._sessionCachingSupported()) {
                  this._proto._restore(jid, callback, wait, hold, wind);
                } else {
                  const error = new Error('The "restore" method can only be used with a BOSH connection.');
                  error.name = 'StropheSessionError';
                  throw error;
                }
              }
              /** PrivateFunction: _sessionCachingSupported
               * Checks whether sessionStorage and JSON are supported and whether we're
               * using BOSH.
               */


              _sessionCachingSupported() {
                if (this._proto instanceof Strophe.Bosh) {
                  if (!JSON) {
                    return false;
                  }

                  try {
                    sessionStorage.setItem('_strophe_', '_strophe_');
                    sessionStorage.removeItem('_strophe_');
                  } catch (e) {
                    return false;
                  }

                  return true;
                }

                return false;
              }
              /** Function: xmlInput
               *  User overrideable function that receives XML data coming into the
               *  connection.
               *
               *  The default function does nothing.  User code can override this with
               *  > Strophe.Connection.xmlInput = function (elem) {
               *  >   (user code)
               *  > };
               *
               *  Due to limitations of current Browsers' XML-Parsers the opening and closing
               *  <stream> tag for WebSocket-Connoctions will be passed as selfclosing here.
               *
               *  BOSH-Connections will have all stanzas wrapped in a <body> tag. See
               *  <Strophe.Bosh.strip> if you want to strip this tag.
               *
               *  Parameters:
               *    (XMLElement) elem - The XML data received by the connection.
               */


              xmlInput(elem) {
                // eslint-disable-line
                return;
              }
              /** Function: xmlOutput
               *  User overrideable function that receives XML data sent to the
               *  connection.
               *
               *  The default function does nothing.  User code can override this with
               *  > Strophe.Connection.xmlOutput = function (elem) {
               *  >   (user code)
               *  > };
               *
               *  Due to limitations of current Browsers' XML-Parsers the opening and closing
               *  <stream> tag for WebSocket-Connoctions will be passed as selfclosing here.
               *
               *  BOSH-Connections will have all stanzas wrapped in a <body> tag. See
               *  <Strophe.Bosh.strip> if you want to strip this tag.
               *
               *  Parameters:
               *    (XMLElement) elem - The XMLdata sent by the connection.
               */


              xmlOutput(elem) {
                // eslint-disable-line
                return;
              }
              /** Function: rawInput
               *  User overrideable function that receives raw data coming into the
               *  connection.
               *
               *  The default function does nothing.  User code can override this with
               *  > Strophe.Connection.rawInput = function (data) {
               *  >   (user code)
               *  > };
               *
               *  Parameters:
               *    (String) data - The data received by the connection.
               */


              rawInput(data) {
                // eslint-disable-line
                return;
              }
              /** Function: rawOutput
               *  User overrideable function that receives raw data sent to the
               *  connection.
               *
               *  The default function does nothing.  User code can override this with
               *  > Strophe.Connection.rawOutput = function (data) {
               *  >   (user code)
               *  > };
               *
               *  Parameters:
               *    (String) data - The data sent by the connection.
               */


              rawOutput(data) {
                // eslint-disable-line
                return;
              }
              /** Function: nextValidRid
               *  User overrideable function that receives the new valid rid.
               *
               *  The default function does nothing. User code can override this with
               *  > Strophe.Connection.nextValidRid = function (rid) {
               *  >    (user code)
               *  > };
               *
               *  Parameters:
               *    (Number) rid - The next valid rid
               */


              nextValidRid(rid) {
                // eslint-disable-line
                return;
              }
              /** Function: send
               *  Send a stanza.
               *
               *  This function is called to push data onto the send queue to
               *  go out over the wire.  Whenever a request is sent to the BOSH
               *  server, all pending data is sent and the queue is flushed.
               *
               *  Parameters:
               *    (XMLElement |
               *     [XMLElement] |
               *     Strophe.Builder) elem - The stanza to send.
               */


              send(elem) {
                if (elem === null) {
                  return;
                }

                if (typeof elem.sort === "function") {
                  for (let i = 0; i < elem.length; i++) {
                    this._queueData(elem[i]);
                  }
                } else if (typeof elem.tree === "function") {
                  this._queueData(elem.tree());
                } else {
                  this._queueData(elem);
                }

                this._proto._send();
              }
              /** Function: flush
               *  Immediately send any pending outgoing data.
               *
               *  Normally send() queues outgoing data until the next idle period
               *  (100ms), which optimizes network use in the common cases when
               *  several send()s are called in succession. flush() can be used to
               *  immediately send all pending data.
               */


              flush() {
                // cancel the pending idle period and run the idle function
                // immediately
                clearTimeout(this._idleTimeout);

                this._onIdle();
              }
              /** Function: sendPresence
               *  Helper function to send presence stanzas. The main benefit is for
               *  sending presence stanzas for which you expect a responding presence
               *  stanza with the same id (for example when leaving a chat room).
               *
               *  Parameters:
               *    (XMLElement) elem - The stanza to send.
               *    (Function) callback - The callback function for a successful request.
               *    (Function) errback - The callback function for a failed or timed
               *      out request.  On timeout, the stanza will be null.
               *    (Integer) timeout - The time specified in milliseconds for a
               *      timeout to occur.
               *
               *  Returns:
               *    The id used to send the presence.
               */


              sendPresence(elem, callback, errback, timeout) {
                let timeoutHandler = null;

                if (typeof elem.tree === "function") {
                  elem = elem.tree();
                }

                let id = elem.getAttribute('id');

                if (!id) {
                  // inject id if not found
                  id = this.getUniqueId("sendPresence");
                  elem.setAttribute("id", id);
                }

                if (typeof callback === "function" || typeof errback === "function") {
                  const handler = this.addHandler(stanza => {
                    // remove timeout handler if there is one
                    if (timeoutHandler) {
                      this.deleteTimedHandler(timeoutHandler);
                    }

                    if (stanza.getAttribute('type') === 'error') {
                      if (errback) {
                        errback(stanza);
                      }
                    } else if (callback) {
                      callback(stanza);
                    }
                  }, null, 'presence', null, id); // if timeout specified, set up a timeout handler.

                  if (timeout) {
                    timeoutHandler = this.addTimedHandler(timeout, () => {
                      // get rid of normal handler
                      this.deleteHandler(handler); // call errback on timeout with null stanza

                      if (errback) {
                        errback(null);
                      }

                      return false;
                    });
                  }
                }

                this.send(elem);
                return id;
              }
              /** Function: sendIQ
               *  Helper function to send IQ stanzas.
               *
               *  Parameters:
               *    (XMLElement) elem - The stanza to send.
               *    (Function) callback - The callback function for a successful request.
               *    (Function) errback - The callback function for a failed or timed
               *      out request.  On timeout, the stanza will be null.
               *    (Integer) timeout - The time specified in milliseconds for a
               *      timeout to occur.
               *
               *  Returns:
               *    The id used to send the IQ.
              */


              sendIQ(elem, callback, errback, timeout) {
                let timeoutHandler = null;

                if (typeof elem.tree === "function") {
                  elem = elem.tree();
                }

                let id = elem.getAttribute('id');

                if (!id) {
                  // inject id if not found
                  id = this.getUniqueId("sendIQ");
                  elem.setAttribute("id", id);
                }

                if (typeof callback === "function" || typeof errback === "function") {
                  const handler = this.addHandler(stanza => {
                    // remove timeout handler if there is one
                    if (timeoutHandler) {
                      this.deleteTimedHandler(timeoutHandler);
                    }

                    const iqtype = stanza.getAttribute('type');

                    if (iqtype === 'result') {
                      if (callback) {
                        callback(stanza);
                      }
                    } else if (iqtype === 'error') {
                      if (errback) {
                        errback(stanza);
                      }
                    } else {
                      const error = new Error(`Got bad IQ type of ${iqtype}`);
                      error.name = "StropheError";
                      throw error;
                    }
                  }, null, 'iq', ['error', 'result'], id); // if timeout specified, set up a timeout handler.

                  if (timeout) {
                    timeoutHandler = this.addTimedHandler(timeout, () => {
                      // get rid of normal handler
                      this.deleteHandler(handler); // call errback on timeout with null stanza

                      if (errback) {
                        errback(null);
                      }

                      return false;
                    });
                  }
                }

                this.send(elem);
                return id;
              }
              /** PrivateFunction: _queueData
               *  Queue outgoing data for later sending.  Also ensures that the data
               *  is a DOMElement.
               */


              _queueData(element) {
                if (element === null || !element.tagName || !element.childNodes) {
                  const error = new Error("Cannot queue non-DOMElement.");
                  error.name = "StropheError";
                  throw error;
                }

                this._data.push(element);
              }
              /** PrivateFunction: _sendRestart
               *  Send an xmpp:restart stanza.
               */


              _sendRestart() {
                this._data.push("restart");

                this._proto._sendRestart();

                this._idleTimeout = setTimeout(() => this._onIdle(), 100);
              }
              /** Function: addTimedHandler
               *  Add a timed handler to the connection.
               *
               *  This function adds a timed handler.  The provided handler will
               *  be called every period milliseconds until it returns false,
               *  the connection is terminated, or the handler is removed.  Handlers
               *  that wish to continue being invoked should return true.
               *
               *  Because of method binding it is necessary to save the result of
               *  this function if you wish to remove a handler with
               *  deleteTimedHandler().
               *
               *  Note that user handlers are not active until authentication is
               *  successful.
               *
               *  Parameters:
               *    (Integer) period - The period of the handler.
               *    (Function) handler - The callback function.
               *
               *  Returns:
               *    A reference to the handler that can be used to remove it.
               */


              addTimedHandler(period, handler) {
                const thand = new Strophe.TimedHandler(period, handler);
                this.addTimeds.push(thand);
                return thand;
              }
              /** Function: deleteTimedHandler
               *  Delete a timed handler for a connection.
               *
               *  This function removes a timed handler from the connection.  The
               *  handRef parameter is *not* the function passed to addTimedHandler(),
               *  but is the reference returned from addTimedHandler().
               *
               *  Parameters:
               *    (Strophe.TimedHandler) handRef - The handler reference.
               */


              deleteTimedHandler(handRef) {
                // this must be done in the Idle loop so that we don't change
                // the handlers during iteration
                this.removeTimeds.push(handRef);
              }
              /** Function: addHandler
               *  Add a stanza handler for the connection.
               *
               *  This function adds a stanza handler to the connection.  The
               *  handler callback will be called for any stanza that matches
               *  the parameters.  Note that if multiple parameters are supplied,
               *  they must all match for the handler to be invoked.
               *
               *  The handler will receive the stanza that triggered it as its argument.
               *  *The handler should return true if it is to be invoked again;
               *  returning false will remove the handler after it returns.*
               *
               *  As a convenience, the ns parameters applies to the top level element
               *  and also any of its immediate children.  This is primarily to make
               *  matching /iq/query elements easy.
               *
               *  Options
               *  ~~~~~~~
               *  With the options argument, you can specify boolean flags that affect how
               *  matches are being done.
               *
               *  Currently two flags exist:
               *
               *  - matchBareFromJid:
               *      When set to true, the from parameter and the
               *      from attribute on the stanza will be matched as bare JIDs instead
               *      of full JIDs. To use this, pass {matchBareFromJid: true} as the
               *      value of options. The default value for matchBareFromJid is false.
               *
               *  - ignoreNamespaceFragment:
               *      When set to true, a fragment specified on the stanza's namespace
               *      URL will be ignored when it's matched with the one configured for
               *      the handler.
               *
               *      This means that if you register like this:
               *      >   connection.addHandler(
               *      >       handler,
               *      >       'http://jabber.org/protocol/muc',
               *      >       null, null, null, null,
               *      >       {'ignoreNamespaceFragment': true}
               *      >   );
               *
               *      Then a stanza with XML namespace of
               *      'http://jabber.org/protocol/muc#user' will also be matched. If
               *      'ignoreNamespaceFragment' is false, then only stanzas with
               *      'http://jabber.org/protocol/muc' will be matched.
               *
               *  Deleting the handler
               *  ~~~~~~~~~~~~~~~~~~~~
               *  The return value should be saved if you wish to remove the handler
               *  with deleteHandler().
               *
               *  Parameters:
               *    (Function) handler - The user callback.
               *    (String) ns - The namespace to match.
               *    (String) name - The stanza name to match.
               *    (String|Array) type - The stanza type (or types if an array) to match.
               *    (String) id - The stanza id attribute to match.
               *    (String) from - The stanza from attribute to match.
               *    (String) options - The handler options
               *
               *  Returns:
               *    A reference to the handler that can be used to remove it.
               */


              addHandler(handler, ns, name, type, id, from, options) {
                const hand = new Strophe.Handler(handler, ns, name, type, id, from, options);
                this.addHandlers.push(hand);
                return hand;
              }
              /** Function: deleteHandler
               *  Delete a stanza handler for a connection.
               *
               *  This function removes a stanza handler from the connection.  The
               *  handRef parameter is *not* the function passed to addHandler(),
               *  but is the reference returned from addHandler().
               *
               *  Parameters:
               *    (Strophe.Handler) handRef - The handler reference.
               */


              deleteHandler(handRef) {
                // this must be done in the Idle loop so that we don't change
                // the handlers during iteration
                this.removeHandlers.push(handRef); // If a handler is being deleted while it is being added,
                // prevent it from getting added

                const i = this.addHandlers.indexOf(handRef);

                if (i >= 0) {
                  this.addHandlers.splice(i, 1);
                }
              }
              /** Function: registerSASLMechanisms
               *
               * Register the SASL mechanisms which will be supported by this instance of
               * Strophe.Connection (i.e. which this XMPP client will support).
               *
               *  Parameters:
               *    (Array) mechanisms - Array of objects with Strophe.SASLMechanism prototypes
               *
               */


              registerSASLMechanisms(mechanisms) {
                this.mechanisms = {};
                mechanisms = mechanisms || [Strophe.SASLAnonymous, Strophe.SASLExternal, Strophe.SASLOAuthBearer, Strophe.SASLXOAuth2, Strophe.SASLPlain, Strophe.SASLSHA1];
                mechanisms.forEach(m => this.registerSASLMechanism(m));
              }
              /** Function: registerSASLMechanism
               *
               * Register a single SASL mechanism, to be supported by this client.
               *
               *  Parameters:
               *    (Object) mechanism - Object with a Strophe.SASLMechanism prototype
               *
               */


              registerSASLMechanism(Mechanism) {
                const mechanism = new Mechanism();
                this.mechanisms[mechanism.mechname] = mechanism;
              }
              /** Function: disconnect
               *  Start the graceful disconnection process.
               *
               *  This function starts the disconnection process.  This process starts
               *  by sending unavailable presence and sending BOSH body of type
               *  terminate.  A timeout handler makes sure that disconnection happens
               *  even if the BOSH server does not respond.
               *  If the Connection object isn't connected, at least tries to abort all pending requests
               *  so the connection object won't generate successful requests (which were already opened).
               *
               *  The user supplied connection callback will be notified of the
               *  progress as this process happens.
               *
               *  Parameters:
               *    (String) reason - The reason the disconnect is occuring.
               */


              disconnect(reason) {
                this._changeConnectStatus(Strophe.Status.DISCONNECTING, reason);

                if (reason) {
                  Strophe.warn("Disconnect was called because: " + reason);
                } else {
                  Strophe.info("Disconnect was called");
                }

                if (this.connected) {
                  let pres = false;
                  this.disconnecting = true;

                  if (this.authenticated) {
                    pres = $pres({
                      'xmlns': Strophe.NS.CLIENT,
                      'type': 'unavailable'
                    });
                  } // setup timeout handler


                  this._disconnectTimeout = this._addSysTimedHandler(this.disconnection_timeout, this._onDisconnectTimeout.bind(this));

                  this._proto._disconnect(pres);
                } else {
                  Strophe.warn("Disconnect was called before Strophe connected to the server");

                  this._proto._abortAllRequests();

                  this._doDisconnect();
                }
              }
              /** PrivateFunction: _changeConnectStatus
               *  _Private_ helper function that makes sure plugins and the user's
               *  callback are notified of connection status changes.
               *
               *  Parameters:
               *    (Integer) status - the new connection status, one of the values
               *      in Strophe.Status
               *    (String) condition - the error condition or null
               *    (XMLElement) elem - The triggering stanza.
               */


              _changeConnectStatus(status, condition, elem) {
                // notify all plugins listening for status changes
                for (const k in Strophe._connectionPlugins) {
                  if (Object.prototype.hasOwnProperty.call(Strophe._connectionPlugins, k)) {
                    const plugin = this[k];

                    if (plugin.statusChanged) {
                      try {
                        plugin.statusChanged(status, condition);
                      } catch (err) {
                        Strophe.error(`${k} plugin caused an exception changing status: ${err}`);
                      }
                    }
                  }
                } // notify the user's callback


                if (this.connect_callback) {
                  try {
                    this.connect_callback(status, condition, elem);
                  } catch (e) {
                    Strophe._handleError(e);

                    Strophe.error(`User connection callback caused an exception: ${e}`);
                  }
                }
              }
              /** PrivateFunction: _doDisconnect
               *  _Private_ function to disconnect.
               *
               *  This is the last piece of the disconnection logic.  This resets the
               *  connection and alerts the user's connection callback.
               */


              _doDisconnect(condition) {
                if (typeof this._idleTimeout === "number") {
                  clearTimeout(this._idleTimeout);
                } // Cancel Disconnect Timeout


                if (this._disconnectTimeout !== null) {
                  this.deleteTimedHandler(this._disconnectTimeout);
                  this._disconnectTimeout = null;
                }

                Strophe.debug("_doDisconnect was called");

                this._proto._doDisconnect();

                this.authenticated = false;
                this.disconnecting = false;
                this.restored = false; // delete handlers

                this.handlers = [];
                this.timedHandlers = [];
                this.removeTimeds = [];
                this.removeHandlers = [];
                this.addTimeds = [];
                this.addHandlers = []; // tell the parent we disconnected

                this._changeConnectStatus(Strophe.Status.DISCONNECTED, condition);

                this.connected = false;
              }
              /** PrivateFunction: _dataRecv
               *  _Private_ handler to processes incoming data from the the connection.
               *
               *  Except for _connect_cb handling the initial connection request,
               *  this function handles the incoming data for all requests.  This
               *  function also fires stanza handlers that match each incoming
               *  stanza.
               *
               *  Parameters:
               *    (Strophe.Request) req - The request that has data ready.
               *    (string) req - The stanza a raw string (optiona).
               */


              _dataRecv(req, raw) {
                const elem = this._proto._reqToData(req);

                if (elem === null) {
                  return;
                }

                if (this.xmlInput !== Strophe.Connection.prototype.xmlInput) {
                  if (elem.nodeName === this._proto.strip && elem.childNodes.length) {
                    this.xmlInput(elem.childNodes[0]);
                  } else {
                    this.xmlInput(elem);
                  }
                }

                if (this.rawInput !== Strophe.Connection.prototype.rawInput) {
                  if (raw) {
                    this.rawInput(raw);
                  } else {
                    this.rawInput(Strophe.serialize(elem));
                  }
                } // remove handlers scheduled for deletion


                while (this.removeHandlers.length > 0) {
                  const hand = this.removeHandlers.pop();
                  const i = this.handlers.indexOf(hand);

                  if (i >= 0) {
                    this.handlers.splice(i, 1);
                  }
                } // add handlers scheduled for addition


                while (this.addHandlers.length > 0) {
                  this.handlers.push(this.addHandlers.pop());
                } // handle graceful disconnect


                if (this.disconnecting && this._proto._emptyQueue()) {
                  this._doDisconnect();

                  return;
                }

                const type = elem.getAttribute("type");

                if (type !== null && type === "terminate") {
                  // Don't process stanzas that come in after disconnect
                  if (this.disconnecting) {
                    return;
                  } // an error occurred


                  let cond = elem.getAttribute("condition");
                  const conflict = elem.getElementsByTagName("conflict");

                  if (cond !== null) {
                    if (cond === "remote-stream-error" && conflict.length > 0) {
                      cond = "conflict";
                    }

                    this._changeConnectStatus(Strophe.Status.CONNFAIL, cond);
                  } else {
                    this._changeConnectStatus(Strophe.Status.CONNFAIL, Strophe.ErrorCondition.UNKOWN_REASON);
                  }

                  this._doDisconnect(cond);

                  return;
                } // send each incoming stanza through the handler chain


                Strophe.forEachChild(elem, null, child => {
                  const matches = [];
                  this.handlers = this.handlers.reduce((handlers, handler) => {
                    try {
                      if (handler.isMatch(child) && (this.authenticated || !handler.user)) {
                        if (handler.run(child)) {
                          handlers.push(handler);
                        }

                        matches.push(handler);
                      } else {
                        handlers.push(handler);
                      }
                    } catch (e) {
                      // if the handler throws an exception, we consider it as false
                      Strophe.warn('Removing Strophe handlers due to uncaught exception: ' + e.message);
                    }

                    return handlers;
                  }, []); // If no handler was fired for an incoming IQ with type="set",
                  // then we return an IQ error stanza with service-unavailable.

                  if (!matches.length && this.iqFallbackHandler.isMatch(child)) {
                    this.iqFallbackHandler.run(child);
                  }
                });
              }
              /** PrivateFunction: _connect_cb
               *  _Private_ handler for initial connection request.
               *
               *  This handler is used to process the initial connection request
               *  response from the BOSH server. It is used to set up authentication
               *  handlers and start the authentication process.
               *
               *  SASL authentication will be attempted if available, otherwise
               *  the code will fall back to legacy authentication.
               *
               *  Parameters:
               *    (Strophe.Request) req - The current request.
               *    (Function) _callback - low level (xmpp) connect callback function.
               *      Useful for plugins with their own xmpp connect callback (when they
               *      want to do something special).
               */


              _connect_cb(req, _callback, raw) {
                Strophe.debug("_connect_cb was called");
                this.connected = true;
                let bodyWrap;

                try {
                  bodyWrap = this._proto._reqToData(req);
                } catch (e) {
                  if (e.name !== Strophe.ErrorCondition.BAD_FORMAT) {
                    throw e;
                  }

                  this._changeConnectStatus(Strophe.Status.CONNFAIL, Strophe.ErrorCondition.BAD_FORMAT);

                  this._doDisconnect(Strophe.ErrorCondition.BAD_FORMAT);
                }

                if (!bodyWrap) {
                  return;
                }

                if (this.xmlInput !== Strophe.Connection.prototype.xmlInput) {
                  if (bodyWrap.nodeName === this._proto.strip && bodyWrap.childNodes.length) {
                    this.xmlInput(bodyWrap.childNodes[0]);
                  } else {
                    this.xmlInput(bodyWrap);
                  }
                }

                if (this.rawInput !== Strophe.Connection.prototype.rawInput) {
                  if (raw) {
                    this.rawInput(raw);
                  } else {
                    this.rawInput(Strophe.serialize(bodyWrap));
                  }
                }

                const conncheck = this._proto._connect_cb(bodyWrap);

                if (conncheck === Strophe.Status.CONNFAIL) {
                  return;
                } // Check for the stream:features tag


                let hasFeatures;

                if (bodyWrap.getElementsByTagNameNS) {
                  hasFeatures = bodyWrap.getElementsByTagNameNS(Strophe.NS.STREAM, "features").length > 0;
                } else {
                  hasFeatures = bodyWrap.getElementsByTagName("stream:features").length > 0 || bodyWrap.getElementsByTagName("features").length > 0;
                }

                if (!hasFeatures) {
                  this._proto._no_auth_received(_callback);

                  return;
                }

                const matched = Array.from(bodyWrap.getElementsByTagName("mechanism")).map(m => this.mechanisms[m.textContent]).filter(m => m);

                if (matched.length === 0) {
                  if (bodyWrap.getElementsByTagName("auth").length === 0) {
                    // There are no matching SASL mechanisms and also no legacy
                    // auth available.
                    this._proto._no_auth_received(_callback);

                    return;
                  }
                }

                if (this.do_authentication !== false) {
                  this.authenticate(matched);
                }
              }
              /** Function: sortMechanismsByPriority
               *
               *  Sorts an array of objects with prototype SASLMechanism according to
               *  their priorities.
               *
               *  Parameters:
               *    (Array) mechanisms - Array of SASL mechanisms.
               *
               */


              sortMechanismsByPriority(mechanisms) {
                // eslint-disable-line class-methods-use-this
                // Sorting mechanisms according to priority.
                for (let i = 0; i < mechanisms.length - 1; ++i) {
                  let higher = i;

                  for (let j = i + 1; j < mechanisms.length; ++j) {
                    if (mechanisms[j].priority > mechanisms[higher].priority) {
                      higher = j;
                    }
                  }

                  if (higher !== i) {
                    const swap = mechanisms[i];
                    mechanisms[i] = mechanisms[higher];
                    mechanisms[higher] = swap;
                  }
                }

                return mechanisms;
              }
              /** Function: authenticate
               * Set up authentication
               *
               *  Continues the initial connection request by setting up authentication
               *  handlers and starting the authentication process.
               *
               *  SASL authentication will be attempted if available, otherwise
               *  the code will fall back to legacy authentication.
               *
               *  Parameters:
               *    (Array) matched - Array of SASL mechanisms supported.
               *
               */


              authenticate(matched) {
                if (!this._attemptSASLAuth(matched)) {
                  this._attemptLegacyAuth();
                }
              }
              /** PrivateFunction: _attemptSASLAuth
               *
               *  Iterate through an array of SASL mechanisms and attempt authentication
               *  with the highest priority (enabled) mechanism.
               *
               *  Parameters:
               *    (Array) mechanisms - Array of SASL mechanisms.
               *
               *  Returns:
               *    (Boolean) mechanism_found - true or false, depending on whether a
               *          valid SASL mechanism was found with which authentication could be
               *          started.
               */


              _attemptSASLAuth(mechanisms) {
                mechanisms = this.sortMechanismsByPriority(mechanisms || []);
                let mechanism_found = false;

                for (let i = 0; i < mechanisms.length; ++i) {
                  if (!mechanisms[i].test(this)) {
                    continue;
                  }

                  this._sasl_success_handler = this._addSysHandler(this._sasl_success_cb.bind(this), null, "success", null, null);
                  this._sasl_failure_handler = this._addSysHandler(this._sasl_failure_cb.bind(this), null, "failure", null, null);
                  this._sasl_challenge_handler = this._addSysHandler(this._sasl_challenge_cb.bind(this), null, "challenge", null, null);
                  this._sasl_mechanism = mechanisms[i];

                  this._sasl_mechanism.onStart(this);

                  const request_auth_exchange = $build("auth", {
                    'xmlns': Strophe.NS.SASL,
                    'mechanism': this._sasl_mechanism.mechname
                  });

                  if (this._sasl_mechanism.isClientFirst) {
                    const response = this._sasl_mechanism.clientChallenge(this);

                    request_auth_exchange.t(abab.btoa(response));
                  }

                  this.send(request_auth_exchange.tree());
                  mechanism_found = true;
                  break;
                }

                return mechanism_found;
              }
              /** PrivateFunction: _sasl_challenge_cb
               *  _Private_ handler for the SASL challenge
               *
               */


              _sasl_challenge_cb(elem) {
                const challenge = abab.atob(Strophe.getText(elem));

                const response = this._sasl_mechanism.onChallenge(this, challenge);

                const stanza = $build('response', {
                  'xmlns': Strophe.NS.SASL
                });

                if (response !== "") {
                  stanza.t(abab.btoa(response));
                }

                this.send(stanza.tree());
                return true;
              }
              /** PrivateFunction: _attemptLegacyAuth
               *
               *  Attempt legacy (i.e. non-SASL) authentication.
               */


              _attemptLegacyAuth() {
                if (Strophe.getNodeFromJid(this.jid) === null) {
                  // we don't have a node, which is required for non-anonymous
                  // client connections
                  this._changeConnectStatus(Strophe.Status.CONNFAIL, Strophe.ErrorCondition.MISSING_JID_NODE);

                  this.disconnect(Strophe.ErrorCondition.MISSING_JID_NODE);
                } else {
                  // Fall back to legacy authentication
                  this._changeConnectStatus(Strophe.Status.AUTHENTICATING, null);

                  this._addSysHandler(this._onLegacyAuthIQResult.bind(this), null, null, null, "_auth_1");

                  this.send($iq({
                    'type': "get",
                    'to': this.domain,
                    'id': "_auth_1"
                  }).c("query", {
                    xmlns: Strophe.NS.AUTH
                  }).c("username", {}).t(Strophe.getNodeFromJid(this.jid)).tree());
                }
              }
              /** PrivateFunction: _onLegacyAuthIQResult
               *  _Private_ handler for legacy authentication.
               *
               *  This handler is called in response to the initial <iq type='get'/>
               *  for legacy authentication.  It builds an authentication <iq/> and
               *  sends it, creating a handler (calling back to _auth2_cb()) to
               *  handle the result
               *
               *  Parameters:
               *    (XMLElement) elem - The stanza that triggered the callback.
               *
               *  Returns:
               *    false to remove the handler.
               */


              _onLegacyAuthIQResult(elem) {
                // eslint-disable-line no-unused-vars
                // build plaintext auth iq
                const iq = $iq({
                  type: "set",
                  id: "_auth_2"
                }).c('query', {
                  xmlns: Strophe.NS.AUTH
                }).c('username', {}).t(Strophe.getNodeFromJid(this.jid)).up().c('password').t(this.pass);

                if (!Strophe.getResourceFromJid(this.jid)) {
                  // since the user has not supplied a resource, we pick
                  // a default one here.  unlike other auth methods, the server
                  // cannot do this for us.
                  this.jid = Strophe.getBareJidFromJid(this.jid) + '/strophe';
                }

                iq.up().c('resource', {}).t(Strophe.getResourceFromJid(this.jid));

                this._addSysHandler(this._auth2_cb.bind(this), null, null, null, "_auth_2");

                this.send(iq.tree());
                return false;
              }
              /** PrivateFunction: _sasl_success_cb
               *  _Private_ handler for succesful SASL authentication.
               *
               *  Parameters:
               *    (XMLElement) elem - The matching stanza.
               *
               *  Returns:
               *    false to remove the handler.
               */


              _sasl_success_cb(elem) {
                if (this._sasl_data["server-signature"]) {
                  let serverSignature;
                  const success = abab.atob(Strophe.getText(elem));
                  const attribMatch = /([a-z]+)=([^,]+)(,|$)/;
                  const matches = success.match(attribMatch);

                  if (matches[1] === "v") {
                    serverSignature = matches[2];
                  }

                  if (serverSignature !== this._sasl_data["server-signature"]) {
                    // remove old handlers
                    this.deleteHandler(this._sasl_failure_handler);
                    this._sasl_failure_handler = null;

                    if (this._sasl_challenge_handler) {
                      this.deleteHandler(this._sasl_challenge_handler);
                      this._sasl_challenge_handler = null;
                    }

                    this._sasl_data = {};
                    return this._sasl_failure_cb(null);
                  }
                }

                Strophe.info("SASL authentication succeeded.");

                if (this._sasl_mechanism) {
                  this._sasl_mechanism.onSuccess();
                } // remove old handlers


                this.deleteHandler(this._sasl_failure_handler);
                this._sasl_failure_handler = null;

                if (this._sasl_challenge_handler) {
                  this.deleteHandler(this._sasl_challenge_handler);
                  this._sasl_challenge_handler = null;
                }

                const streamfeature_handlers = [];

                const wrapper = (handlers, elem) => {
                  while (handlers.length) {
                    this.deleteHandler(handlers.pop());
                  }

                  this._onStreamFeaturesAfterSASL(elem);

                  return false;
                };

                streamfeature_handlers.push(this._addSysHandler(elem => wrapper(streamfeature_handlers, elem), null, "stream:features", null, null));
                streamfeature_handlers.push(this._addSysHandler(elem => wrapper(streamfeature_handlers, elem), Strophe.NS.STREAM, "features", null, null)); // we must send an xmpp:restart now

                this._sendRestart();

                return false;
              }
              /** PrivateFunction: _onStreamFeaturesAfterSASL
               *  Parameters:
               *    (XMLElement) elem - The matching stanza.
               *
               *  Returns:
               *    false to remove the handler.
               */


              _onStreamFeaturesAfterSASL(elem) {
                // save stream:features for future usage
                this.features = elem;

                for (let i = 0; i < elem.childNodes.length; i++) {
                  const child = elem.childNodes[i];

                  if (child.nodeName === 'bind') {
                    this.do_bind = true;
                  }

                  if (child.nodeName === 'session') {
                    this.do_session = true;
                  }
                }

                if (!this.do_bind) {
                  this._changeConnectStatus(Strophe.Status.AUTHFAIL, null);

                  return false;
                } else if (!this.options.explicitResourceBinding) {
                  this.bind();
                } else {
                  this._changeConnectStatus(Strophe.Status.BINDREQUIRED, null);
                }

                return false;
              }
              /** Function: bind
               *
               *  Sends an IQ to the XMPP server to bind a JID resource for this session.
               *
               *  https://tools.ietf.org/html/rfc6120#section-7.5
               *
               *  If `explicitResourceBinding` was set to a truthy value in the options
               *  passed to the Strophe.Connection constructor, then this function needs
               *  to be called explicitly by the client author.
               *
               *  Otherwise it'll be called automatically as soon as the XMPP server
               *  advertises the "urn:ietf:params:xml:ns:xmpp-bind" stream feature.
               */


              bind() {
                if (!this.do_bind) {
                  Strophe.log(Strophe.LogLevel.INFO, `Strophe.Connection.prototype.bind called but "do_bind" is false`);
                  return;
                }

                this._addSysHandler(this._onResourceBindResultIQ.bind(this), null, null, null, "_bind_auth_2");

                const resource = Strophe.getResourceFromJid(this.jid);

                if (resource) {
                  this.send($iq({
                    type: "set",
                    id: "_bind_auth_2"
                  }).c('bind', {
                    xmlns: Strophe.NS.BIND
                  }).c('resource', {}).t(resource).tree());
                } else {
                  this.send($iq({
                    type: "set",
                    id: "_bind_auth_2"
                  }).c('bind', {
                    xmlns: Strophe.NS.BIND
                  }).tree());
                }
              }
              /** PrivateFunction: _onResourceBindIQ
               *  _Private_ handler for binding result and session start.
               *
               *  Parameters:
               *    (XMLElement) elem - The matching stanza.
               *
               *  Returns:
               *    false to remove the handler.
               */


              _onResourceBindResultIQ(elem) {
                if (elem.getAttribute("type") === "error") {
                  Strophe.warn("Resource binding failed.");
                  const conflict = elem.getElementsByTagName("conflict");
                  let condition;

                  if (conflict.length > 0) {
                    condition = Strophe.ErrorCondition.CONFLICT;
                  }

                  this._changeConnectStatus(Strophe.Status.AUTHFAIL, condition, elem);

                  return false;
                } // TODO - need to grab errors


                const bind = elem.getElementsByTagName("bind");

                if (bind.length > 0) {
                  const jidNode = bind[0].getElementsByTagName("jid");

                  if (jidNode.length > 0) {
                    this.authenticated = true;
                    this.jid = Strophe.getText(jidNode[0]);

                    if (this.do_session) {
                      this._establishSession();
                    } else {
                      this._changeConnectStatus(Strophe.Status.CONNECTED, null);
                    }
                  }
                } else {
                  Strophe.warn("Resource binding failed.");

                  this._changeConnectStatus(Strophe.Status.AUTHFAIL, null, elem);

                  return false;
                }
              }
              /** PrivateFunction: _establishSession
               *  Send IQ request to establish a session with the XMPP server.
               *
               *  See https://xmpp.org/rfcs/rfc3921.html#session
               *
               *  Note: The protocol for session establishment has been determined as
               *  unnecessary and removed in RFC-6121.
               */


              _establishSession() {
                if (!this.do_session) {
                  throw new Error(`Strophe.Connection.prototype._establishSession ` + `called but apparently ${Strophe.NS.SESSION} wasn't advertised by the server`);
                }

                this._addSysHandler(this._onSessionResultIQ.bind(this), null, null, null, "_session_auth_2");

                this.send($iq({
                  type: "set",
                  id: "_session_auth_2"
                }).c('session', {
                  xmlns: Strophe.NS.SESSION
                }).tree());
              }
              /** PrivateFunction: _onSessionResultIQ
               *  _Private_ handler for the server's IQ response to a client's session
               *  request.
               *
               *  This sets Connection.authenticated to true on success, which
               *  starts the processing of user handlers.
               *
               *  See https://xmpp.org/rfcs/rfc3921.html#session
               *
               *  Note: The protocol for session establishment has been determined as
               *  unnecessary and removed in RFC-6121.
               *
               *  Parameters:
               *    (XMLElement) elem - The matching stanza.
               *
               *  Returns:
               *    false to remove the handler.
               */


              _onSessionResultIQ(elem) {
                if (elem.getAttribute("type") === "result") {
                  this.authenticated = true;

                  this._changeConnectStatus(Strophe.Status.CONNECTED, null);
                } else if (elem.getAttribute("type") === "error") {
                  this.authenticated = false;
                  Strophe.warn("Session creation failed.");

                  this._changeConnectStatus(Strophe.Status.AUTHFAIL, null, elem);

                  return false;
                }

                return false;
              }
              /** PrivateFunction: _sasl_failure_cb
               *  _Private_ handler for SASL authentication failure.
               *
               *  Parameters:
               *    (XMLElement) elem - The matching stanza.
               *
               *  Returns:
               *    false to remove the handler.
               */


              _sasl_failure_cb(elem) {
                // delete unneeded handlers
                if (this._sasl_success_handler) {
                  this.deleteHandler(this._sasl_success_handler);
                  this._sasl_success_handler = null;
                }

                if (this._sasl_challenge_handler) {
                  this.deleteHandler(this._sasl_challenge_handler);
                  this._sasl_challenge_handler = null;
                }

                if (this._sasl_mechanism) this._sasl_mechanism.onFailure();

                this._changeConnectStatus(Strophe.Status.AUTHFAIL, null, elem);

                return false;
              }
              /** PrivateFunction: _auth2_cb
               *  _Private_ handler to finish legacy authentication.
               *
               *  This handler is called when the result from the jabber:iq:auth
               *  <iq/> stanza is returned.
               *
               *  Parameters:
               *    (XMLElement) elem - The stanza that triggered the callback.
               *
               *  Returns:
               *    false to remove the handler.
               */


              _auth2_cb(elem) {
                if (elem.getAttribute("type") === "result") {
                  this.authenticated = true;

                  this._changeConnectStatus(Strophe.Status.CONNECTED, null);
                } else if (elem.getAttribute("type") === "error") {
                  this._changeConnectStatus(Strophe.Status.AUTHFAIL, null, elem);

                  this.disconnect('authentication failed');
                }

                return false;
              }
              /** PrivateFunction: _addSysTimedHandler
               *  _Private_ function to add a system level timed handler.
               *
               *  This function is used to add a Strophe.TimedHandler for the
               *  library code.  System timed handlers are allowed to run before
               *  authentication is complete.
               *
               *  Parameters:
               *    (Integer) period - The period of the handler.
               *    (Function) handler - The callback function.
               */


              _addSysTimedHandler(period, handler) {
                const thand = new Strophe.TimedHandler(period, handler);
                thand.user = false;
                this.addTimeds.push(thand);
                return thand;
              }
              /** PrivateFunction: _addSysHandler
               *  _Private_ function to add a system level stanza handler.
               *
               *  This function is used to add a Strophe.Handler for the
               *  library code.  System stanza handlers are allowed to run before
               *  authentication is complete.
               *
               *  Parameters:
               *    (Function) handler - The callback function.
               *    (String) ns - The namespace to match.
               *    (String) name - The stanza name to match.
               *    (String) type - The stanza type attribute to match.
               *    (String) id - The stanza id attribute to match.
               */


              _addSysHandler(handler, ns, name, type, id) {
                const hand = new Strophe.Handler(handler, ns, name, type, id);
                hand.user = false;
                this.addHandlers.push(hand);
                return hand;
              }
              /** PrivateFunction: _onDisconnectTimeout
               *  _Private_ timeout handler for handling non-graceful disconnection.
               *
               *  If the graceful disconnect process does not complete within the
               *  time allotted, this handler finishes the disconnect anyway.
               *
               *  Returns:
               *    false to remove the handler.
               */


              _onDisconnectTimeout() {
                Strophe.debug("_onDisconnectTimeout was called");

                this._changeConnectStatus(Strophe.Status.CONNTIMEOUT, null);

                this._proto._onDisconnectTimeout(); // actually disconnect


                this._doDisconnect();

                return false;
              }
              /** PrivateFunction: _onIdle
               *  _Private_ handler to process events during idle cycle.
               *
               *  This handler is called every 100ms to fire timed handlers that
               *  are ready and keep poll requests going.
               */


              _onIdle() {
                // add timed handlers scheduled for addition
                // NOTE: we add before remove in the case a timed handler is
                // added and then deleted before the next _onIdle() call.
                while (this.addTimeds.length > 0) {
                  this.timedHandlers.push(this.addTimeds.pop());
                } // remove timed handlers that have been scheduled for deletion


                while (this.removeTimeds.length > 0) {
                  const thand = this.removeTimeds.pop();
                  const i = this.timedHandlers.indexOf(thand);

                  if (i >= 0) {
                    this.timedHandlers.splice(i, 1);
                  }
                } // call ready timed handlers


                const now = new Date().getTime();
                const newList = [];

                for (let i = 0; i < this.timedHandlers.length; i++) {
                  const thand = this.timedHandlers[i];

                  if (this.authenticated || !thand.user) {
                    const since = thand.lastCalled + thand.period;

                    if (since - now <= 0) {
                      if (thand.run()) {
                        newList.push(thand);
                      }
                    } else {
                      newList.push(thand);
                    }
                  }
                }

                this.timedHandlers = newList;
                clearTimeout(this._idleTimeout);

                this._proto._onIdle(); // reactivate the timer only if connected


                if (this.connected) {
                  this._idleTimeout = setTimeout(() => this._onIdle(), 100);
                }
              }

            };
            Strophe.SASLMechanism = SASLMechanism;
            /** Constants: SASL mechanisms
             *  Available authentication mechanisms
             *
             *  Strophe.SASLAnonymous   - SASL ANONYMOUS authentication.
             *  Strophe.SASLPlain       - SASL PLAIN authentication.
             *  Strophe.SASLSHA1        - SASL SCRAM-SHA-1 authentication
             *  Strophe.SASLOAuthBearer - SASL OAuth Bearer authentication
             *  Strophe.SASLExternal    - SASL EXTERNAL authentication
             *  Strophe.SASLXOAuth2     - SASL X-OAuth2 authentication
             */

            Strophe.SASLAnonymous = SASLAnonymous;
            Strophe.SASLPlain = SASLPlain;
            Strophe.SASLSHA1 = SASLSHA1;
            Strophe.SASLOAuthBearer = SASLOAuthBearer;
            Strophe.SASLExternal = SASLExternal;
            Strophe.SASLXOAuth2 = SASLXOAuth2;
            var core = {
              'Strophe': Strophe,
              '$build': $build,
              '$iq': $iq,
              '$msg': $msg,
              '$pres': $pres,
              'SHA1': SHA1,
              'MD5': MD5,
              'b64_hmac_sha1': SHA1.b64_hmac_sha1,
              'b64_sha1': SHA1.b64_sha1,
              'str_hmac_sha1': SHA1.str_hmac_sha1,
              'str_sha1': SHA1.str_sha1
            };

            /*
                This program is distributed under the terms of the MIT license.
                Please see the LICENSE file for details.

                Copyright 2006-2008, OGG, LLC
            */
            /** PrivateClass: Strophe.Request
             *  _Private_ helper class that provides a cross implementation abstraction
             *  for a BOSH related XMLHttpRequest.
             *
             *  The Strophe.Request class is used internally to encapsulate BOSH request
             *  information.  It is not meant to be used from user's code.
             */

            Strophe.Request = class Request {
              /** PrivateConstructor: Strophe.Request
               *  Create and initialize a new Strophe.Request object.
               *
               *  Parameters:
               *    (XMLElement) elem - The XML data to be sent in the request.
               *    (Function) func - The function that will be called when the
               *      XMLHttpRequest readyState changes.
               *    (Integer) rid - The BOSH rid attribute associated with this request.
               *    (Integer) sends - The number of times this same request has been sent.
               */
              constructor(elem, func, rid, sends) {
                this.id = ++Strophe._requestId;
                this.xmlData = elem;
                this.data = Strophe.serialize(elem); // save original function in case we need to make a new request
                // from this one.

                this.origFunc = func;
                this.func = func;
                this.rid = rid;
                this.date = NaN;
                this.sends = sends || 0;
                this.abort = false;
                this.dead = null;

                this.age = function () {
                  if (!this.date) {
                    return 0;
                  }

                  const now = new Date();
                  return (now - this.date) / 1000;
                };

                this.timeDead = function () {
                  if (!this.dead) {
                    return 0;
                  }

                  const now = new Date();
                  return (now - this.dead) / 1000;
                };

                this.xhr = this._newXHR();
              }
              /** PrivateFunction: getResponse
               *  Get a response from the underlying XMLHttpRequest.
               *
               *  This function attempts to get a response from the request and checks
               *  for errors.
               *
               *  Throws:
               *    "parsererror" - A parser error occured.
               *    "bad-format" - The entity has sent XML that cannot be processed.
               *
               *  Returns:
               *    The DOM element tree of the response.
               */


              getResponse() {
                let node = null;

                if (this.xhr.responseXML && this.xhr.responseXML.documentElement) {
                  node = this.xhr.responseXML.documentElement;

                  if (node.tagName === "parsererror") {
                    Strophe.error("invalid response received");
                    Strophe.error("responseText: " + this.xhr.responseText);
                    Strophe.error("responseXML: " + Strophe.serialize(this.xhr.responseXML));
                    throw new Error("parsererror");
                  }
                } else if (this.xhr.responseText) {
                  // In React Native, we may get responseText but no responseXML.  We can try to parse it manually.
                  Strophe.debug("Got responseText but no responseXML; attempting to parse it with DOMParser...");
                  node = new DOMParser().parseFromString(this.xhr.responseText, 'application/xml').documentElement;

                  if (!node) {
                    throw new Error('Parsing produced null node');
                  } else if (node.querySelector('parsererror')) {
                    Strophe.error("invalid response received: " + node.querySelector('parsererror').textContent);
                    Strophe.error("responseText: " + this.xhr.responseText);
                    const error = new Error();
                    error.name = Strophe.ErrorCondition.BAD_FORMAT;
                    throw error;
                  }
                }

                return node;
              }
              /** PrivateFunction: _newXHR
               *  _Private_ helper function to create XMLHttpRequests.
               *
               *  This function creates XMLHttpRequests across all implementations.
               *
               *  Returns:
               *    A new XMLHttpRequest.
               */


              _newXHR() {
                let xhr = null;

                if (window.XMLHttpRequest) {
                  xhr = new XMLHttpRequest();

                  if (xhr.overrideMimeType) {
                    xhr.overrideMimeType("text/xml; charset=utf-8");
                  }
                } else if (window.ActiveXObject) {
                  xhr = new ActiveXObject("Microsoft.XMLHTTP");
                } // use Function.bind() to prepend ourselves as an argument


                xhr.onreadystatechange = this.func.bind(null, this);
                return xhr;
              }

            };
            /** Class: Strophe.Bosh
             *  _Private_ helper class that handles BOSH Connections
             *
             *  The Strophe.Bosh class is used internally by Strophe.Connection
             *  to encapsulate BOSH sessions. It is not meant to be used from user's code.
             */

            /** File: bosh.js
             *  A JavaScript library to enable BOSH in Strophejs.
             *
             *  this library uses Bidirectional-streams Over Synchronous HTTP (BOSH)
             *  to emulate a persistent, stateful, two-way connection to an XMPP server.
             *  More information on BOSH can be found in XEP 124.
             */

            /** PrivateConstructor: Strophe.Bosh
             *  Create and initialize a Strophe.Bosh object.
             *
             *  Parameters:
             *    (Strophe.Connection) connection - The Strophe.Connection that will use BOSH.
             *
             *  Returns:
             *    A new Strophe.Bosh object.
             */

            Strophe.Bosh = class Bosh {
              constructor(connection) {
                this._conn = connection;
                /* request id for body tags */

                this.rid = Math.floor(Math.random() * 4294967295);
                /* The current session ID. */

                this.sid = null; // default BOSH values

                this.hold = 1;
                this.wait = 60;
                this.window = 5;
                this.errors = 0;
                this.inactivity = null;
                this.lastResponseHeaders = null;
                this._requests = [];
              }
              /** PrivateFunction: _buildBody
               *  _Private_ helper function to generate the <body/> wrapper for BOSH.
               *
               *  Returns:
               *    A Strophe.Builder with a <body/> element.
               */


              _buildBody() {
                const bodyWrap = $build('body', {
                  'rid': this.rid++,
                  'xmlns': Strophe.NS.HTTPBIND
                });

                if (this.sid !== null) {
                  bodyWrap.attrs({
                    'sid': this.sid
                  });
                }

                if (this._conn.options.keepalive && this._conn._sessionCachingSupported()) {
                  this._cacheSession();
                }

                return bodyWrap;
              }
              /** PrivateFunction: _reset
               *  Reset the connection.
               *
               *  This function is called by the reset function of the Strophe Connection
               */


              _reset() {
                this.rid = Math.floor(Math.random() * 4294967295);
                this.sid = null;
                this.errors = 0;

                if (this._conn._sessionCachingSupported()) {
                  window.sessionStorage.removeItem('strophe-bosh-session');
                }

                this._conn.nextValidRid(this.rid);
              }
              /** PrivateFunction: _connect
               *  _Private_ function that initializes the BOSH connection.
               *
               *  Creates and sends the Request that initializes the BOSH connection.
               */


              _connect(wait, hold, route) {
                this.wait = wait || this.wait;
                this.hold = hold || this.hold;
                this.errors = 0;

                const body = this._buildBody().attrs({
                  "to": this._conn.domain,
                  "xml:lang": "en",
                  "wait": this.wait,
                  "hold": this.hold,
                  "content": "text/xml; charset=utf-8",
                  "ver": "1.6",
                  "xmpp:version": "1.0",
                  "xmlns:xmpp": Strophe.NS.BOSH
                });

                if (route) {
                  body.attrs({
                    'route': route
                  });
                }

                const _connect_cb = this._conn._connect_cb;

                this._requests.push(new Strophe.Request(body.tree(), this._onRequestStateChange.bind(this, _connect_cb.bind(this._conn)), body.tree().getAttribute("rid")));

                this._throttledRequestHandler();
              }
              /** PrivateFunction: _attach
               *  Attach to an already created and authenticated BOSH session.
               *
               *  This function is provided to allow Strophe to attach to BOSH
               *  sessions which have been created externally, perhaps by a Web
               *  application.  This is often used to support auto-login type features
               *  without putting user credentials into the page.
               *
               *  Parameters:
               *    (String) jid - The full JID that is bound by the session.
               *    (String) sid - The SID of the BOSH session.
               *    (String) rid - The current RID of the BOSH session.  This RID
               *      will be used by the next request.
               *    (Function) callback The connect callback function.
               *    (Integer) wait - The optional HTTPBIND wait value.  This is the
               *      time the server will wait before returning an empty result for
               *      a request.  The default setting of 60 seconds is recommended.
               *      Other settings will require tweaks to the Strophe.TIMEOUT value.
               *    (Integer) hold - The optional HTTPBIND hold value.  This is the
               *      number of connections the server will hold at one time.  This
               *      should almost always be set to 1 (the default).
               *    (Integer) wind - The optional HTTBIND window value.  This is the
               *      allowed range of request ids that are valid.  The default is 5.
               */


              _attach(jid, sid, rid, callback, wait, hold, wind) {
                this._conn.jid = jid;
                this.sid = sid;
                this.rid = rid;
                this._conn.connect_callback = callback;
                this._conn.domain = Strophe.getDomainFromJid(this._conn.jid);
                this._conn.authenticated = true;
                this._conn.connected = true;
                this.wait = wait || this.wait;
                this.hold = hold || this.hold;
                this.window = wind || this.window;

                this._conn._changeConnectStatus(Strophe.Status.ATTACHED, null);
              }
              /** PrivateFunction: _restore
               *  Attempt to restore a cached BOSH session
               *
               *  Parameters:
               *    (String) jid - The full JID that is bound by the session.
               *      This parameter is optional but recommended, specifically in cases
               *      where prebinded BOSH sessions are used where it's important to know
               *      that the right session is being restored.
               *    (Function) callback The connect callback function.
               *    (Integer) wait - The optional HTTPBIND wait value.  This is the
               *      time the server will wait before returning an empty result for
               *      a request.  The default setting of 60 seconds is recommended.
               *      Other settings will require tweaks to the Strophe.TIMEOUT value.
               *    (Integer) hold - The optional HTTPBIND hold value.  This is the
               *      number of connections the server will hold at one time.  This
               *      should almost always be set to 1 (the default).
               *    (Integer) wind - The optional HTTBIND window value.  This is the
               *      allowed range of request ids that are valid.  The default is 5.
               */


              _restore(jid, callback, wait, hold, wind) {
                const session = JSON.parse(window.sessionStorage.getItem('strophe-bosh-session'));

                if (typeof session !== "undefined" && session !== null && session.rid && session.sid && session.jid && (typeof jid === "undefined" || jid === null || Strophe.getBareJidFromJid(session.jid) === Strophe.getBareJidFromJid(jid) || // If authcid is null, then it's an anonymous login, so
                // we compare only the domains:
                Strophe.getNodeFromJid(jid) === null && Strophe.getDomainFromJid(session.jid) === jid)) {
                  this._conn.restored = true;

                  this._attach(session.jid, session.sid, session.rid, callback, wait, hold, wind);
                } else {
                  const error = new Error("_restore: no restoreable session.");
                  error.name = "StropheSessionError";
                  throw error;
                }
              }
              /** PrivateFunction: _cacheSession
               *  _Private_ handler for the beforeunload event.
               *
               *  This handler is used to process the Bosh-part of the initial request.
               *  Parameters:
               *    (Strophe.Request) bodyWrap - The received stanza.
               */


              _cacheSession() {
                if (this._conn.authenticated) {
                  if (this._conn.jid && this.rid && this.sid) {
                    window.sessionStorage.setItem('strophe-bosh-session', JSON.stringify({
                      'jid': this._conn.jid,
                      'rid': this.rid,
                      'sid': this.sid
                    }));
                  }
                } else {
                  window.sessionStorage.removeItem('strophe-bosh-session');
                }
              }
              /** PrivateFunction: _connect_cb
               *  _Private_ handler for initial connection request.
               *
               *  This handler is used to process the Bosh-part of the initial request.
               *  Parameters:
               *    (Strophe.Request) bodyWrap - The received stanza.
               */


              _connect_cb(bodyWrap) {
                const typ = bodyWrap.getAttribute("type");

                if (typ !== null && typ === "terminate") {
                  // an error occurred
                  let cond = bodyWrap.getAttribute("condition");
                  Strophe.error("BOSH-Connection failed: " + cond);
                  const conflict = bodyWrap.getElementsByTagName("conflict");

                  if (cond !== null) {
                    if (cond === "remote-stream-error" && conflict.length > 0) {
                      cond = "conflict";
                    }

                    this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, cond);
                  } else {
                    this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "unknown");
                  }

                  this._conn._doDisconnect(cond);

                  return Strophe.Status.CONNFAIL;
                } // check to make sure we don't overwrite these if _connect_cb is
                // called multiple times in the case of missing stream:features


                if (!this.sid) {
                  this.sid = bodyWrap.getAttribute("sid");
                }

                const wind = bodyWrap.getAttribute('requests');

                if (wind) {
                  this.window = parseInt(wind, 10);
                }

                const hold = bodyWrap.getAttribute('hold');

                if (hold) {
                  this.hold = parseInt(hold, 10);
                }

                const wait = bodyWrap.getAttribute('wait');

                if (wait) {
                  this.wait = parseInt(wait, 10);
                }

                const inactivity = bodyWrap.getAttribute('inactivity');

                if (inactivity) {
                  this.inactivity = parseInt(inactivity, 10);
                }
              }
              /** PrivateFunction: _disconnect
               *  _Private_ part of Connection.disconnect for Bosh
               *
               *  Parameters:
               *    (Request) pres - This stanza will be sent before disconnecting.
               */


              _disconnect(pres) {
                this._sendTerminate(pres);
              }
              /** PrivateFunction: _doDisconnect
               *  _Private_ function to disconnect.
               *
               *  Resets the SID and RID.
               */


              _doDisconnect() {
                this.sid = null;
                this.rid = Math.floor(Math.random() * 4294967295);

                if (this._conn._sessionCachingSupported()) {
                  window.sessionStorage.removeItem('strophe-bosh-session');
                }

                this._conn.nextValidRid(this.rid);
              }
              /** PrivateFunction: _emptyQueue
               * _Private_ function to check if the Request queue is empty.
               *
               *  Returns:
               *    True, if there are no Requests queued, False otherwise.
               */


              _emptyQueue() {
                return this._requests.length === 0;
              }
              /** PrivateFunction: _callProtocolErrorHandlers
               *  _Private_ function to call error handlers registered for HTTP errors.
               *
               *  Parameters:
               *    (Strophe.Request) req - The request that is changing readyState.
               */


              _callProtocolErrorHandlers(req) {
                const reqStatus = Bosh._getRequestStatus(req);

                const err_callback = this._conn.protocolErrorHandlers.HTTP[reqStatus];

                if (err_callback) {
                  err_callback.call(this, reqStatus);
                }
              }
              /** PrivateFunction: _hitError
               *  _Private_ function to handle the error count.
               *
               *  Requests are resent automatically until their error count reaches
               *  5.  Each time an error is encountered, this function is called to
               *  increment the count and disconnect if the count is too high.
               *
               *  Parameters:
               *    (Integer) reqStatus - The request status.
               */


              _hitError(reqStatus) {
                this.errors++;
                Strophe.warn("request errored, status: " + reqStatus + ", number of errors: " + this.errors);

                if (this.errors > 4) {
                  this._conn._onDisconnectTimeout();
                }
              }
              /** PrivateFunction: _no_auth_received
               *
               * Called on stream start/restart when no stream:features
               * has been received and sends a blank poll request.
               */


              _no_auth_received(callback) {
                Strophe.warn("Server did not yet offer a supported authentication " + "mechanism. Sending a blank poll request.");

                if (callback) {
                  callback = callback.bind(this._conn);
                } else {
                  callback = this._conn._connect_cb.bind(this._conn);
                }

                const body = this._buildBody();

                this._requests.push(new Strophe.Request(body.tree(), this._onRequestStateChange.bind(this, callback), body.tree().getAttribute("rid")));

                this._throttledRequestHandler();
              }
              /** PrivateFunction: _onDisconnectTimeout
               *  _Private_ timeout handler for handling non-graceful disconnection.
               *
               *  Cancels all remaining Requests and clears the queue.
               */


              _onDisconnectTimeout() {
                this._abortAllRequests();
              }
              /** PrivateFunction: _abortAllRequests
               *  _Private_ helper function that makes sure all pending requests are aborted.
               */


              _abortAllRequests() {
                while (this._requests.length > 0) {
                  const req = this._requests.pop();

                  req.abort = true;
                  req.xhr.abort();

                  req.xhr.onreadystatechange = function () {};
                }
              }
              /** PrivateFunction: _onIdle
               *  _Private_ handler called by Strophe.Connection._onIdle
               *
               *  Sends all queued Requests or polls with empty Request if there are none.
               */


              _onIdle() {
                const data = this._conn._data; // if no requests are in progress, poll

                if (this._conn.authenticated && this._requests.length === 0 && data.length === 0 && !this._conn.disconnecting) {
                  Strophe.debug("no requests during idle cycle, sending blank request");
                  data.push(null);
                }

                if (this._conn.paused) {
                  return;
                }

                if (this._requests.length < 2 && data.length > 0) {
                  const body = this._buildBody();

                  for (let i = 0; i < data.length; i++) {
                    if (data[i] !== null) {
                      if (data[i] === "restart") {
                        body.attrs({
                          "to": this._conn.domain,
                          "xml:lang": "en",
                          "xmpp:restart": "true",
                          "xmlns:xmpp": Strophe.NS.BOSH
                        });
                      } else {
                        body.cnode(data[i]).up();
                      }
                    }
                  }

                  delete this._conn._data;
                  this._conn._data = [];

                  this._requests.push(new Strophe.Request(body.tree(), this._onRequestStateChange.bind(this, this._conn._dataRecv.bind(this._conn)), body.tree().getAttribute("rid")));

                  this._throttledRequestHandler();
                }

                if (this._requests.length > 0) {
                  const time_elapsed = this._requests[0].age();

                  if (this._requests[0].dead !== null) {
                    if (this._requests[0].timeDead() > Math.floor(Strophe.SECONDARY_TIMEOUT * this.wait)) {
                      this._throttledRequestHandler();
                    }
                  }

                  if (time_elapsed > Math.floor(Strophe.TIMEOUT * this.wait)) {
                    Strophe.warn("Request " + this._requests[0].id + " timed out, over " + Math.floor(Strophe.TIMEOUT * this.wait) + " seconds since last activity");

                    this._throttledRequestHandler();
                  }
                }
              }
              /** PrivateFunction: _getRequestStatus
               *
               *  Returns the HTTP status code from a Strophe.Request
               *
               *  Parameters:
               *    (Strophe.Request) req - The Strophe.Request instance.
               *    (Integer) def - The default value that should be returned if no
               *          status value was found.
               */


              static _getRequestStatus(req, def) {
                let reqStatus;

                if (req.xhr.readyState === 4) {
                  try {
                    reqStatus = req.xhr.status;
                  } catch (e) {
                    // ignore errors from undefined status attribute. Works
                    // around a browser bug
                    Strophe.error("Caught an error while retrieving a request's status, " + "reqStatus: " + reqStatus);
                  }
                }

                if (typeof reqStatus === "undefined") {
                  reqStatus = typeof def === 'number' ? def : 0;
                }

                return reqStatus;
              }
              /** PrivateFunction: _onRequestStateChange
               *  _Private_ handler for Strophe.Request state changes.
               *
               *  This function is called when the XMLHttpRequest readyState changes.
               *  It contains a lot of error handling logic for the many ways that
               *  requests can fail, and calls the request callback when requests
               *  succeed.
               *
               *  Parameters:
               *    (Function) func - The handler for the request.
               *    (Strophe.Request) req - The request that is changing readyState.
               */


              _onRequestStateChange(func, req) {
                Strophe.debug("request id " + req.id + "." + req.sends + " state changed to " + req.xhr.readyState);

                if (req.abort) {
                  req.abort = false;
                  return;
                }

                if (req.xhr.readyState !== 4) {
                  // The request is not yet complete
                  return;
                }

                const reqStatus = Bosh._getRequestStatus(req);

                this.lastResponseHeaders = req.xhr.getAllResponseHeaders();

                if (this._conn.disconnecting && reqStatus >= 400) {
                  this._hitError(reqStatus);

                  this._callProtocolErrorHandlers(req);

                  return;
                }

                const reqIs0 = this._requests[0] === req;
                const reqIs1 = this._requests[1] === req;
                const valid_request = reqStatus > 0 && reqStatus < 500;
                const too_many_retries = req.sends > this._conn.maxRetries;

                if (valid_request || too_many_retries) {
                  // remove from internal queue
                  this._removeRequest(req);

                  Strophe.debug("request id " + req.id + " should now be removed");
                }

                if (reqStatus === 200) {
                  // request succeeded
                  // if request 1 finished, or request 0 finished and request
                  // 1 is over Strophe.SECONDARY_TIMEOUT seconds old, we need to
                  // restart the other - both will be in the first spot, as the
                  // completed request has been removed from the queue already
                  if (reqIs1 || reqIs0 && this._requests.length > 0 && this._requests[0].age() > Math.floor(Strophe.SECONDARY_TIMEOUT * this.wait)) {
                    this._restartRequest(0);
                  }

                  this._conn.nextValidRid(Number(req.rid) + 1);

                  Strophe.debug("request id " + req.id + "." + req.sends + " got 200");
                  func(req); // call handler

                  this.errors = 0;
                } else if (reqStatus === 0 || reqStatus >= 400 && reqStatus < 600 || reqStatus >= 12000) {
                  // request failed
                  Strophe.error("request id " + req.id + "." + req.sends + " error " + reqStatus + " happened");

                  this._hitError(reqStatus);

                  this._callProtocolErrorHandlers(req);

                  if (reqStatus >= 400 && reqStatus < 500) {
                    this._conn._changeConnectStatus(Strophe.Status.DISCONNECTING, null);

                    this._conn._doDisconnect();
                  }
                } else {
                  Strophe.error("request id " + req.id + "." + req.sends + " error " + reqStatus + " happened");
                }

                if (!valid_request && !too_many_retries) {
                  this._throttledRequestHandler();
                } else if (too_many_retries && !this._conn.connected) {
                  this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "giving-up");
                }
              }
              /** PrivateFunction: _processRequest
               *  _Private_ function to process a request in the queue.
               *
               *  This function takes requests off the queue and sends them and
               *  restarts dead requests.
               *
               *  Parameters:
               *    (Integer) i - The index of the request in the queue.
               */


              _processRequest(i) {
                let req = this._requests[i];

                const reqStatus = Bosh._getRequestStatus(req, -1); // make sure we limit the number of retries


                if (req.sends > this._conn.maxRetries) {
                  this._conn._onDisconnectTimeout();

                  return;
                }

                const time_elapsed = req.age();
                const primary_timeout = !isNaN(time_elapsed) && time_elapsed > Math.floor(Strophe.TIMEOUT * this.wait);
                const secondary_timeout = req.dead !== null && req.timeDead() > Math.floor(Strophe.SECONDARY_TIMEOUT * this.wait);
                const server_error = req.xhr.readyState === 4 && (reqStatus < 1 || reqStatus >= 500);

                if (primary_timeout || secondary_timeout || server_error) {
                  if (secondary_timeout) {
                    Strophe.error(`Request ${this._requests[i].id} timed out (secondary), restarting`);
                  }

                  req.abort = true;
                  req.xhr.abort(); // setting to null fails on IE6, so set to empty function

                  req.xhr.onreadystatechange = function () {};

                  this._requests[i] = new Strophe.Request(req.xmlData, req.origFunc, req.rid, req.sends);
                  req = this._requests[i];
                }

                if (req.xhr.readyState === 0) {
                  Strophe.debug("request id " + req.id + "." + req.sends + " posting");

                  try {
                    const content_type = this._conn.options.contentType || "text/xml; charset=utf-8";
                    req.xhr.open("POST", this._conn.service, this._conn.options.sync ? false : true);

                    if (typeof req.xhr.setRequestHeader !== 'undefined') {
                      // IE9 doesn't have setRequestHeader
                      req.xhr.setRequestHeader("Content-Type", content_type);
                    }

                    if (this._conn.options.withCredentials) {
                      req.xhr.withCredentials = true;
                    }
                  } catch (e2) {
                    Strophe.error("XHR open failed: " + e2.toString());

                    if (!this._conn.connected) {
                      this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "bad-service");
                    }

                    this._conn.disconnect();

                    return;
                  } // Fires the XHR request -- may be invoked immediately
                  // or on a gradually expanding retry window for reconnects


                  const sendFunc = () => {
                    req.date = new Date();

                    if (this._conn.options.customHeaders) {
                      const headers = this._conn.options.customHeaders;

                      for (const header in headers) {
                        if (Object.prototype.hasOwnProperty.call(headers, header)) {
                          req.xhr.setRequestHeader(header, headers[header]);
                        }
                      }
                    }

                    req.xhr.send(req.data);
                  }; // Implement progressive backoff for reconnects --
                  // First retry (send === 1) should also be instantaneous


                  if (req.sends > 1) {
                    // Using a cube of the retry number creates a nicely
                    // expanding retry window
                    const backoff = Math.min(Math.floor(Strophe.TIMEOUT * this.wait), Math.pow(req.sends, 3)) * 1000;
                    setTimeout(function () {
                      // XXX: setTimeout should be called only with function expressions (23974bc1)
                      sendFunc();
                    }, backoff);
                  } else {
                    sendFunc();
                  }

                  req.sends++;

                  if (this._conn.xmlOutput !== Strophe.Connection.prototype.xmlOutput) {
                    if (req.xmlData.nodeName === this.strip && req.xmlData.childNodes.length) {
                      this._conn.xmlOutput(req.xmlData.childNodes[0]);
                    } else {
                      this._conn.xmlOutput(req.xmlData);
                    }
                  }

                  if (this._conn.rawOutput !== Strophe.Connection.prototype.rawOutput) {
                    this._conn.rawOutput(req.data);
                  }
                } else {
                  Strophe.debug("_processRequest: " + (i === 0 ? "first" : "second") + " request has readyState of " + req.xhr.readyState);
                }
              }
              /** PrivateFunction: _removeRequest
               *  _Private_ function to remove a request from the queue.
               *
               *  Parameters:
               *    (Strophe.Request) req - The request to remove.
               */


              _removeRequest(req) {
                Strophe.debug("removing request");

                for (let i = this._requests.length - 1; i >= 0; i--) {
                  if (req === this._requests[i]) {
                    this._requests.splice(i, 1);
                  }
                } // IE6 fails on setting to null, so set to empty function


                req.xhr.onreadystatechange = function () {};

                this._throttledRequestHandler();
              }
              /** PrivateFunction: _restartRequest
               *  _Private_ function to restart a request that is presumed dead.
               *
               *  Parameters:
               *    (Integer) i - The index of the request in the queue.
               */


              _restartRequest(i) {
                const req = this._requests[i];

                if (req.dead === null) {
                  req.dead = new Date();
                }

                this._processRequest(i);
              }
              /** PrivateFunction: _reqToData
               * _Private_ function to get a stanza out of a request.
               *
               * Tries to extract a stanza out of a Request Object.
               * When this fails the current connection will be disconnected.
               *
               *  Parameters:
               *    (Object) req - The Request.
               *
               *  Returns:
               *    The stanza that was passed.
               */


              _reqToData(req) {
                try {
                  return req.getResponse();
                } catch (e) {
                  if (e.message !== "parsererror") {
                    throw e;
                  }

                  this._conn.disconnect("strophe-parsererror");
                }
              }
              /** PrivateFunction: _sendTerminate
               *  _Private_ function to send initial disconnect sequence.
               *
               *  This is the first step in a graceful disconnect.  It sends
               *  the BOSH server a terminate body and includes an unavailable
               *  presence if authentication has completed.
               */


              _sendTerminate(pres) {
                Strophe.debug("_sendTerminate was called");

                const body = this._buildBody().attrs({
                  type: "terminate"
                });

                if (pres) {
                  body.cnode(pres.tree());
                }

                const req = new Strophe.Request(body.tree(), this._onRequestStateChange.bind(this, this._conn._dataRecv.bind(this._conn)), body.tree().getAttribute("rid"));

                this._requests.push(req);

                this._throttledRequestHandler();
              }
              /** PrivateFunction: _send
               *  _Private_ part of the Connection.send function for BOSH
               *
               * Just triggers the RequestHandler to send the messages that are in the queue
               */


              _send() {
                clearTimeout(this._conn._idleTimeout);

                this._throttledRequestHandler();

                this._conn._idleTimeout = setTimeout(() => this._conn._onIdle(), 100);
              }
              /** PrivateFunction: _sendRestart
               *
               *  Send an xmpp:restart stanza.
               */


              _sendRestart() {
                this._throttledRequestHandler();

                clearTimeout(this._conn._idleTimeout);
              }
              /** PrivateFunction: _throttledRequestHandler
               *  _Private_ function to throttle requests to the connection window.
               *
               *  This function makes sure we don't send requests so fast that the
               *  request ids overflow the connection window in the case that one
               *  request died.
               */


              _throttledRequestHandler() {
                if (!this._requests) {
                  Strophe.debug("_throttledRequestHandler called with " + "undefined requests");
                } else {
                  Strophe.debug("_throttledRequestHandler called with " + this._requests.length + " requests");
                }

                if (!this._requests || this._requests.length === 0) {
                  return;
                }

                if (this._requests.length > 0) {
                  this._processRequest(0);
                }

                if (this._requests.length > 1 && Math.abs(this._requests[0].rid - this._requests[1].rid) < this.window) {
                  this._processRequest(1);
                }
              }

            };
            /** Variable: strip
             *
             *  BOSH-Connections will have all stanzas wrapped in a <body> tag when
             *  passed to <Strophe.Connection.xmlInput> or <Strophe.Connection.xmlOutput>.
             *  To strip this tag, User code can set <Strophe.Bosh.strip> to "body":
             *
             *  > Strophe.Bosh.prototype.strip = "body";
             *
             *  This will enable stripping of the body tag in both
             *  <Strophe.Connection.xmlInput> and <Strophe.Connection.xmlOutput>.
             */

            Strophe.Bosh.prototype.strip = null;

            /*
                This program is distributed under the terms of the MIT license.
                Please see the LICENSE file for details.

                Copyright 2006-2008, OGG, LLC
            */
            /** Class: Strophe.WebSocket
             *  _Private_ helper class that handles WebSocket Connections
             *
             *  The Strophe.WebSocket class is used internally by Strophe.Connection
             *  to encapsulate WebSocket sessions. It is not meant to be used from user's code.
             */

            /** File: websocket.js
             *  A JavaScript library to enable XMPP over Websocket in Strophejs.
             *
             *  This file implements XMPP over WebSockets for Strophejs.
             *  If a Connection is established with a Websocket url (ws://...)
             *  Strophe will use WebSockets.
             *  For more information on XMPP-over-WebSocket see RFC 7395:
             *  http://tools.ietf.org/html/rfc7395
             *
             *  WebSocket support implemented by Andreas Guth (andreas.guth@rwth-aachen.de)
             */

            Strophe.Websocket = class Websocket {
              /** PrivateConstructor: Strophe.Websocket
               *  Create and initialize a Strophe.WebSocket object.
               *  Currently only sets the connection Object.
               *
               *  Parameters:
               *    (Strophe.Connection) connection - The Strophe.Connection that will use WebSockets.
               *
               *  Returns:
               *    A new Strophe.WebSocket object.
               */
              constructor(connection) {
                this._conn = connection;
                this.strip = "wrapper";
                const service = connection.service;

                if (service.indexOf("ws:") !== 0 && service.indexOf("wss:") !== 0) {
                  // If the service is not an absolute URL, assume it is a path and put the absolute
                  // URL together from options, current URL and the path.
                  let new_service = "";

                  if (connection.options.protocol === "ws" && window.location.protocol !== "https:") {
                    new_service += "ws";
                  } else {
                    new_service += "wss";
                  }

                  new_service += "://" + window.location.host;

                  if (service.indexOf("/") !== 0) {
                    new_service += window.location.pathname + service;
                  } else {
                    new_service += service;
                  }

                  connection.service = new_service;
                }
              }
              /** PrivateFunction: _buildStream
               *  _Private_ helper function to generate the <stream> start tag for WebSockets
               *
               *  Returns:
               *    A Strophe.Builder with a <stream> element.
               */


              _buildStream() {
                return $build("open", {
                  "xmlns": Strophe.NS.FRAMING,
                  "to": this._conn.domain,
                  "version": '1.0'
                });
              }
              /** PrivateFunction: _checkStreamError
               * _Private_ checks a message for stream:error
               *
               *  Parameters:
               *    (Strophe.Request) bodyWrap - The received stanza.
               *    connectstatus - The ConnectStatus that will be set on error.
               *  Returns:
               *     true if there was a streamerror, false otherwise.
               */


              _checkStreamError(bodyWrap, connectstatus) {
                let errors;

                if (bodyWrap.getElementsByTagNameNS) {
                  errors = bodyWrap.getElementsByTagNameNS(Strophe.NS.STREAM, "error");
                } else {
                  errors = bodyWrap.getElementsByTagName("stream:error");
                }

                if (errors.length === 0) {
                  return false;
                }

                const error = errors[0];
                let condition = "";
                let text = "";
                const ns = "urn:ietf:params:xml:ns:xmpp-streams";

                for (let i = 0; i < error.childNodes.length; i++) {
                  const e = error.childNodes[i];

                  if (e.getAttribute("xmlns") !== ns) {
                    break;
                  }

                  if (e.nodeName === "text") {
                    text = e.textContent;
                  } else {
                    condition = e.nodeName;
                  }
                }

                let errorString = "WebSocket stream error: ";

                if (condition) {
                  errorString += condition;
                } else {
                  errorString += "unknown";
                }

                if (text) {
                  errorString += " - " + text;
                }

                Strophe.error(errorString); // close the connection on stream_error

                this._conn._changeConnectStatus(connectstatus, condition);

                this._conn._doDisconnect();

                return true;
              }
              /** PrivateFunction: _reset
               *  Reset the connection.
               *
               *  This function is called by the reset function of the Strophe Connection.
               *  Is not needed by WebSockets.
               */


              _reset() {
                // eslint-disable-line class-methods-use-this
                return;
              }
              /** PrivateFunction: _connect
               *  _Private_ function called by Strophe.Connection.connect
               *
               *  Creates a WebSocket for a connection and assigns Callbacks to it.
               *  Does nothing if there already is a WebSocket.
               */


              _connect() {
                // Ensure that there is no open WebSocket from a previous Connection.
                this._closeSocket();

                this.socket = new WebSocket(this._conn.service, "xmpp");

                this.socket.onopen = () => this._onOpen();

                this.socket.onerror = e => this._onError(e);

                this.socket.onclose = e => this._onClose(e); // Gets replaced with this._onMessage once _onInitialMessage is called


                this.socket.onmessage = message => this._onInitialMessage(message);
              }
              /** PrivateFunction: _connect_cb
               *  _Private_ function called by Strophe.Connection._connect_cb
               *
               * checks for stream:error
               *
               *  Parameters:
               *    (Strophe.Request) bodyWrap - The received stanza.
               */


              _connect_cb(bodyWrap) {
                const error = this._checkStreamError(bodyWrap, Strophe.Status.CONNFAIL);

                if (error) {
                  return Strophe.Status.CONNFAIL;
                }
              }
              /** PrivateFunction: _handleStreamStart
               * _Private_ function that checks the opening <open /> tag for errors.
               *
               * Disconnects if there is an error and returns false, true otherwise.
               *
               *  Parameters:
               *    (Node) message - Stanza containing the <open /> tag.
               */


              _handleStreamStart(message) {
                let error = false; // Check for errors in the <open /> tag

                const ns = message.getAttribute("xmlns");

                if (typeof ns !== "string") {
                  error = "Missing xmlns in <open />";
                } else if (ns !== Strophe.NS.FRAMING) {
                  error = "Wrong xmlns in <open />: " + ns;
                }

                const ver = message.getAttribute("version");

                if (typeof ver !== "string") {
                  error = "Missing version in <open />";
                } else if (ver !== "1.0") {
                  error = "Wrong version in <open />: " + ver;
                }

                if (error) {
                  this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, error);

                  this._conn._doDisconnect();

                  return false;
                }

                return true;
              }
              /** PrivateFunction: _onInitialMessage
               * _Private_ function that handles the first connection messages.
               *
               * On receiving an opening stream tag this callback replaces itself with the real
               * message handler. On receiving a stream error the connection is terminated.
               */


              _onInitialMessage(message) {
                if (message.data.indexOf("<open ") === 0 || message.data.indexOf("<?xml") === 0) {
                  // Strip the XML Declaration, if there is one
                  const data = message.data.replace(/^(<\?.*?\?>\s*)*/, "");
                  if (data === '') return;
                  const streamStart = new DOMParser().parseFromString(data, "text/xml").documentElement;

                  this._conn.xmlInput(streamStart);

                  this._conn.rawInput(message.data); //_handleStreamSteart will check for XML errors and disconnect on error


                  if (this._handleStreamStart(streamStart)) {
                    //_connect_cb will check for stream:error and disconnect on error
                    this._connect_cb(streamStart);
                  }
                } else if (message.data.indexOf("<close ") === 0) {
                  // <close xmlns="urn:ietf:params:xml:ns:xmpp-framing />
                  // Parse the raw string to an XML element
                  const parsedMessage = new DOMParser().parseFromString(message.data, "text/xml").documentElement; // Report this input to the raw and xml handlers

                  this._conn.xmlInput(parsedMessage);

                  this._conn.rawInput(message.data);

                  const see_uri = parsedMessage.getAttribute("see-other-uri");

                  if (see_uri) {
                    const service = this._conn.service; // Valid scenarios: WSS->WSS, WS->ANY

                    const isSecureRedirect = service.indexOf("wss:") >= 0 && see_uri.indexOf("wss:") >= 0 || service.indexOf("ws:") >= 0;

                    if (isSecureRedirect) {
                      this._conn._changeConnectStatus(Strophe.Status.REDIRECT, "Received see-other-uri, resetting connection");

                      this._conn.reset();

                      this._conn.service = see_uri;

                      this._connect();
                    }
                  } else {
                    this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "Received closing stream");

                    this._conn._doDisconnect();
                  }
                } else {
                  this._replaceMessageHandler();

                  const string = this._streamWrap(message.data);

                  const elem = new DOMParser().parseFromString(string, "text/xml").documentElement;

                  this._conn._connect_cb(elem, null, message.data);
                }
              }
              /** PrivateFunction: _replaceMessageHandler
               *
               * Called by _onInitialMessage in order to replace itself with the general message handler.
               * This method is overridden by Strophe.WorkerWebsocket, which manages a
               * websocket connection via a service worker and doesn't have direct access
               * to the socket.
               */


              _replaceMessageHandler() {
                this.socket.onmessage = m => this._onMessage(m);
              }
              /** PrivateFunction: _disconnect
               *  _Private_ function called by Strophe.Connection.disconnect
               *
               *  Disconnects and sends a last stanza if one is given
               *
               *  Parameters:
               *    (Request) pres - This stanza will be sent before disconnecting.
               */


              _disconnect(pres) {
                if (this.socket && this.socket.readyState !== WebSocket.CLOSED) {
                  if (pres) {
                    this._conn.send(pres);
                  }

                  const close = $build("close", {
                    "xmlns": Strophe.NS.FRAMING
                  });

                  this._conn.xmlOutput(close.tree());

                  const closeString = Strophe.serialize(close);

                  this._conn.rawOutput(closeString);

                  try {
                    this.socket.send(closeString);
                  } catch (e) {
                    Strophe.warn("Couldn't send <close /> tag.");
                  }
                }

                setTimeout(() => this._conn._doDisconnect, 0);
              }
              /** PrivateFunction: _doDisconnect
               *  _Private_ function to disconnect.
               *
               *  Just closes the Socket for WebSockets
               */


              _doDisconnect() {
                Strophe.debug("WebSockets _doDisconnect was called");

                this._closeSocket();
              }
              /** PrivateFunction _streamWrap
               *  _Private_ helper function to wrap a stanza in a <stream> tag.
               *  This is used so Strophe can process stanzas from WebSockets like BOSH
               */


              _streamWrap(stanza) {
                // eslint-disable-line class-methods-use-this
                return "<wrapper>" + stanza + '</wrapper>';
              }
              /** PrivateFunction: _closeSocket
               *  _Private_ function to close the WebSocket.
               *
               *  Closes the socket if it is still open and deletes it
               */


              _closeSocket() {
                if (this.socket) {
                  try {
                    this.socket.onclose = null;
                    this.socket.onerror = null;
                    this.socket.onmessage = null;
                    this.socket.close();
                  } catch (e) {
                    Strophe.debug(e.message);
                  }
                }

                this.socket = null;
              }
              /** PrivateFunction: _emptyQueue
               * _Private_ function to check if the message queue is empty.
               *
               *  Returns:
               *    True, because WebSocket messages are send immediately after queueing.
               */


              _emptyQueue() {
                // eslint-disable-line class-methods-use-this
                return true;
              }
              /** PrivateFunction: _onClose
               * _Private_ function to handle websockets closing.
               */


              _onClose(e) {
                if (this._conn.connected && !this._conn.disconnecting) {
                  Strophe.error("Websocket closed unexpectedly");

                  this._conn._doDisconnect();
                } else if (e && e.code === 1006 && !this._conn.connected && this.socket) {
                  // in case the onError callback was not called (Safari 10 does not
                  // call onerror when the initial connection fails) we need to
                  // dispatch a CONNFAIL status update to be consistent with the
                  // behavior on other browsers.
                  Strophe.error("Websocket closed unexcectedly");

                  this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "The WebSocket connection could not be established or was disconnected.");

                  this._conn._doDisconnect();
                } else {
                  Strophe.debug("Websocket closed");
                }
              }
              /** PrivateFunction: _no_auth_received
               *
               * Called on stream start/restart when no stream:features
               * has been received.
               */


              _no_auth_received(callback) {
                Strophe.error("Server did not offer a supported authentication mechanism");

                this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, Strophe.ErrorCondition.NO_AUTH_MECH);

                if (callback) {
                  callback.call(this._conn);
                }

                this._conn._doDisconnect();
              }
              /** PrivateFunction: _onDisconnectTimeout
               *  _Private_ timeout handler for handling non-graceful disconnection.
               *
               *  This does nothing for WebSockets
               */


              _onDisconnectTimeout() {} // eslint-disable-line class-methods-use-this

              /** PrivateFunction: _abortAllRequests
               *  _Private_ helper function that makes sure all pending requests are aborted.
               */


              _abortAllRequests() {} // eslint-disable-line class-methods-use-this

              /** PrivateFunction: _onError
               * _Private_ function to handle websockets errors.
               *
               * Parameters:
               * (Object) error - The websocket error.
               */


              _onError(error) {
                Strophe.error("Websocket error " + JSON.stringify(error));

                this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "The WebSocket connection could not be established or was disconnected.");

                this._disconnect();
              }
              /** PrivateFunction: _onIdle
               *  _Private_ function called by Strophe.Connection._onIdle
               *
               *  sends all queued stanzas
               */


              _onIdle() {
                const data = this._conn._data;

                if (data.length > 0 && !this._conn.paused) {
                  for (let i = 0; i < data.length; i++) {
                    if (data[i] !== null) {
                      let stanza;

                      if (data[i] === "restart") {
                        stanza = this._buildStream().tree();
                      } else {
                        stanza = data[i];
                      }

                      const rawStanza = Strophe.serialize(stanza);

                      this._conn.xmlOutput(stanza);

                      this._conn.rawOutput(rawStanza);

                      this.socket.send(rawStanza);
                    }
                  }

                  this._conn._data = [];
                }
              }
              /** PrivateFunction: _onMessage
               * _Private_ function to handle websockets messages.
               *
               * This function parses each of the messages as if they are full documents.
               * [TODO : We may actually want to use a SAX Push parser].
               *
               * Since all XMPP traffic starts with
               *  <stream:stream version='1.0'
               *                 xml:lang='en'
               *                 xmlns='jabber:client'
               *                 xmlns:stream='http://etherx.jabber.org/streams'
               *                 id='3697395463'
               *                 from='SERVER'>
               *
               * The first stanza will always fail to be parsed.
               *
               * Additionally, the seconds stanza will always be <stream:features> with
               * the stream NS defined in the previous stanza, so we need to 'force'
               * the inclusion of the NS in this stanza.
               *
               * Parameters:
               * (string) message - The websocket message.
               */


              _onMessage(message) {
                let elem; // check for closing stream

                const close = '<close xmlns="urn:ietf:params:xml:ns:xmpp-framing" />';

                if (message.data === close) {
                  this._conn.rawInput(close);

                  this._conn.xmlInput(message);

                  if (!this._conn.disconnecting) {
                    this._conn._doDisconnect();
                  }

                  return;
                } else if (message.data.search("<open ") === 0) {
                  // This handles stream restarts
                  elem = new DOMParser().parseFromString(message.data, "text/xml").documentElement;

                  if (!this._handleStreamStart(elem)) {
                    return;
                  }
                } else {
                  const data = this._streamWrap(message.data);

                  elem = new DOMParser().parseFromString(data, "text/xml").documentElement;
                }

                if (this._checkStreamError(elem, Strophe.Status.ERROR)) {
                  return;
                } //handle unavailable presence stanza before disconnecting


                if (this._conn.disconnecting && elem.firstChild.nodeName === "presence" && elem.firstChild.getAttribute("type") === "unavailable") {
                  this._conn.xmlInput(elem);

                  this._conn.rawInput(Strophe.serialize(elem)); // if we are already disconnecting we will ignore the unavailable stanza and
                  // wait for the </stream:stream> tag before we close the connection


                  return;
                }

                this._conn._dataRecv(elem, message.data);
              }
              /** PrivateFunction: _onOpen
               * _Private_ function to handle websockets connection setup.
               *
               * The opening stream tag is sent here.
               */


              _onOpen() {
                Strophe.debug("Websocket open");

                const start = this._buildStream();

                this._conn.xmlOutput(start.tree());

                const startString = Strophe.serialize(start);

                this._conn.rawOutput(startString);

                this.socket.send(startString);
              }
              /** PrivateFunction: _reqToData
               * _Private_ function to get a stanza out of a request.
               *
               * WebSockets don't use requests, so the passed argument is just returned.
               *
               *  Parameters:
               *    (Object) stanza - The stanza.
               *
               *  Returns:
               *    The stanza that was passed.
               */


              _reqToData(stanza) {
                // eslint-disable-line class-methods-use-this
                return stanza;
              }
              /** PrivateFunction: _send
               *  _Private_ part of the Connection.send function for WebSocket
               *
               * Just flushes the messages that are in the queue
               */


              _send() {
                this._conn.flush();
              }
              /** PrivateFunction: _sendRestart
               *
               *  Send an xmpp:restart stanza.
               */


              _sendRestart() {
                clearTimeout(this._conn._idleTimeout);

                this._conn._onIdle.bind(this._conn)();
              }

            };

            /*
                This program is distributed under the terms of the MIT license.
                Please see the LICENSE file for details.

                Copyright 2020, JC Brand
            */
            const lmap = {};
            lmap['debug'] = Strophe.LogLevel.DEBUG;
            lmap['info'] = Strophe.LogLevel.INFO;
            lmap['warn'] = Strophe.LogLevel.WARN;
            lmap['error'] = Strophe.LogLevel.ERROR;
            lmap['fatal'] = Strophe.LogLevel.FATAL;
            /** Class: Strophe.WorkerWebsocket
             *  _Private_ helper class that handles a websocket connection inside a shared worker.
             */

            Strophe.WorkerWebsocket = class WorkerWebsocket extends Strophe.Websocket {
              /** PrivateConstructor: Strophe.WorkerWebsocket
               *  Create and initialize a Strophe.WorkerWebsocket object.
               *
               *  Parameters:
               *    (Strophe.Connection) connection - The Strophe.Connection
               *
               *  Returns:
               *    A new Strophe.WorkerWebsocket object.
               */
              constructor(connection) {
                super(connection);
                this._conn = connection;
                this.worker = new SharedWorker(this._conn.options.worker, 'Strophe XMPP Connection');

                this.worker.onerror = e => {
                  var _console;

                  (_console = console) === null || _console === void 0 ? void 0 : _console.error(e);
                  Strophe.log(Strophe.LogLevel.ERROR, `Shared Worker Error: ${e}`);
                };
              }

              get socket() {
                return {
                  'send': str => this.worker.port.postMessage(['send', str])
                };
              }

              _connect() {
                this._messageHandler = m => this._onInitialMessage(m);

                this.worker.port.start();

                this.worker.port.onmessage = ev => this._onWorkerMessage(ev);

                this.worker.port.postMessage(['_connect', this._conn.service, this._conn.jid]);
              }

              _attach(callback) {
                this._messageHandler = m => this._onMessage(m);

                this._conn.connect_callback = callback;
                this.worker.port.start();

                this.worker.port.onmessage = ev => this._onWorkerMessage(ev);

                this.worker.port.postMessage(['_attach', this._conn.service]);
              }

              _attachCallback(status, jid) {
                if (status === Strophe.Status.ATTACHED) {
                  this._conn.jid = jid;
                  this._conn.authenticated = true;
                  this._conn.connected = true;
                  this._conn.restored = true;

                  this._conn._changeConnectStatus(Strophe.Status.ATTACHED);
                } else if (status === Strophe.Status.ATTACHFAIL) {
                  this._conn.authenticated = false;
                  this._conn.connected = false;
                  this._conn.restored = false;

                  this._conn._changeConnectStatus(Strophe.Status.ATTACHFAIL);
                }
              }

              _disconnect(readyState, pres) {
                pres && this._conn.send(pres);
                const close = $build("close", {
                  "xmlns": Strophe.NS.FRAMING
                });

                this._conn.xmlOutput(close.tree());

                const closeString = Strophe.serialize(close);

                this._conn.rawOutput(closeString);

                this.worker.port.postMessage(['send', closeString]);

                this._conn._doDisconnect();
              }

              _onClose(e) {
                if (this._conn.connected && !this._conn.disconnecting) {
                  Strophe.error("Websocket closed unexpectedly");

                  this._conn._doDisconnect();
                } else if (e && e.code === 1006 && !this._conn.connected) {
                  // in case the onError callback was not called (Safari 10 does not
                  // call onerror when the initial connection fails) we need to
                  // dispatch a CONNFAIL status update to be consistent with the
                  // behavior on other browsers.
                  Strophe.error("Websocket closed unexcectedly");

                  this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "The WebSocket connection could not be established or was disconnected.");

                  this._conn._doDisconnect();
                } else {
                  Strophe.debug("Websocket closed");
                }
              }

              _closeSocket() {
                this.worker.port.postMessage(['_closeSocket']);
              }
              /** PrivateFunction: _replaceMessageHandler
               *
               * Called by _onInitialMessage in order to replace itself with the general message handler.
               * This method is overridden by Strophe.WorkerWebsocket, which manages a
               * websocket connection via a service worker and doesn't have direct access
               * to the socket.
               */


              _replaceMessageHandler() {
                this._messageHandler = m => this._onMessage(m);
              }
              /** PrivateFunction: _onWorkerMessage
               * _Private_ function that handles messages received from the service worker
               */


              _onWorkerMessage(ev) {
                const {
                  data
                } = ev;
                const method_name = data[0];

                if (method_name === '_onMessage') {
                  this._messageHandler(data[1]);
                } else if (method_name in this) {
                  try {
                    this[method_name].apply(this, ev.data.slice(1));
                  } catch (e) {
                    Strophe.log(Strophe.LogLevel.ERROR, e);
                  }
                } else if (method_name === 'log') {
                  const level = data[1];
                  const msg = data[2];
                  Strophe.log(lmap[level], msg);
                } else {
                  Strophe.log(Strophe.LogLevel.ERROR, `Found unhandled service worker message: ${data}`);
                }
              }

            };

            global$1.$build = core.$build;
            global$1.$iq = core.$iq;
            global$1.$msg = core.$msg;
            global$1.$pres = core.$pres;
            global$1.Strophe = core.Strophe;
            const {
              b64_sha1
            } = SHA1;

            exports.$build = $build;
            exports.$iq = $iq;
            exports.$msg = $msg;
            exports.$pres = $pres;
            exports.Strophe = Strophe;
            exports.b64_sha1 = b64_sha1;

            Object.defineProperty(exports, '__esModule', { value: true });

}));