/* jsonstreams plugin

**

** This plugin upgrades Strophe to support XEP-0295: JSON Encodings for XMPP

**

*/

Strophe.addConnectionPlugin('jsonstreams', {

    init: function (conn) {

        var parseXMLString = function(xmlStr) {

			var xmlDoc = null;

			if (window.ActiveXObject) {

				xmlDoc = new ActiveXObject("Microsoft.XMLDOM");

				xmlDoc.async=false;

				xmlDoc.loadXML(xmlStr);

			} else {

				var parser = new DOMParser();

				xmlDoc = parser.parseFromString(xmlStr, "text/xml");

			}

			return xmlDoc;

        }

        // replace Strophe.Request._newXHR with new jsonstreams version

        // if JSON is detected

        if (window.JSON) {

        	var _newXHR = Strophe.Request.prototype._newXHR;

            Strophe.Request.prototype._newXHR = function () {

            	var _xhr = _newXHR.apply(this, arguments);

                var xhr = {

                	readyState: 0,

                	responseText: null,

                	responseXML: null,

                	status: null,

                	open: function(a, b, c) { return _xhr.open(a, b, c) },

                	abort: function() { _xhr.abort(); },

                	send: function(data) {

                		data = JSON.stringify({"s":data});

                		return _xhr.send(data);

                	}

                };

                var req = this;

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

                _xhr.onreadystatechange = function() {

                	xhr.readyState = _xhr.readyState;

                	if (xhr.readyState != 4) {

                		xhr.status = 0;

                		xhr.responseText = "";

                		xhr.responseXML = null;

                	} else {

	                	xhr.status = _xhr.status;

	               		xhr.responseText = _xhr.responseText;

	               		xhr.responseXML = _xhr.responseXML;

	                	if (_xhr.responseText && !(_xhr.responseXML

	                			&& _xhr.responseXML.documentElement

	                			&& _xhr.responseXML.documentElement.tagName != "parsererror")) {

	                		var data = JSON.parse(_xhr.responseText);

	                		if (data && data.s) {

	                			xhr.responseText = data.s;

	                			xhr.responseXML = parseXMLString(data.s);

	                		}

	                	}

	                }

                	if ("function" == typeof xhr.onreadystatechange) { xhr.onreadystatechange(req); }

                }

                return xhr;

            };

        } else {

            Strophe.error("jsonstreams plugin loaded, but JSON not found." +

                          "  Falling back to native XHR implementation.");

        }

    }

});