/*!
 * Ext JS Library 3.0.0
 * Copyright(c) 2006-2009 Ext JS, LLC
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
/*

 * Portions of this file are based on pieces of Yahoo User Interface Library

 * Copyright (c) 2007, Yahoo! Inc. All rights reserved.

 * YUI licensed under the BSD License:

 * http://developer.yahoo.net/yui/license.txt

 */

    Ext.lib.Ajax = function() {	    

	    var activeX = ['MSXML2.XMLHTTP.3.0',

			           'MSXML2.XMLHTTP',

			           'Microsoft.XMLHTTP'],

            CONTENTTYPE = 'Content-Type';

			           

		// private

		function setHeader(o) {

	        var conn = o.conn,

	        	prop;

	        

	        function setTheHeaders(conn, headers){

		     	for (prop in headers) {

                    if (headers.hasOwnProperty(prop)) {

                        conn.setRequestHeader(prop, headers[prop]);

                    }

                }   

	        }		

	        

            if (pub.defaultHeaders) {

	            setTheHeaders(conn, pub.defaultHeaders);

            }



            if (pub.headers) {

				setTheHeaders(conn, pub.headers);

                pub.headers = null;                

            }

        }    

        

        // private

        function createExceptionObject(tId, callbackArg, isAbort, isTimeout) {	        

            return {

	            tId : tId,

	            status : isAbort ? -1 : 0,

	            statusText : isAbort ? 'transaction aborted' : 'communication failure',

                    isAbort: true,

                    isTimeout: true,

	            argument : callbackArg

            };

        }  

        

        // private 

        function initHeader(label, value) {         

			(pub.headers = pub.headers || {})[label] = value;			            

        }

	    

        // private

        function createResponseObject(o, callbackArg) {

            var headerObj = {},

                headerStr,              

                conn = o.conn,

                t,

                s;



            try {

                headerStr = o.conn.getAllResponseHeaders();   

                Ext.each(headerStr.replace(/\r\n/g, '\n').split('\n'), function(v){

                    t = v.indexOf(':');

                    if(t >= 0){

                        s = v.substr(0, t).toLowerCase();

                        if(v.charAt(t + 1) == ' '){

                            ++t;

                        }

                        headerObj[s] = v.substr(t + 1);

                    }

                });

            } catch(e) {}

                        

            return {

                tId : o.tId,

                status : conn.status,

                statusText : conn.statusText,

                getResponseHeader : function(header){return headerObj[header.toLowerCase()];},

                getAllResponseHeaders : function(){return headerStr},

                responseText : conn.responseText,

                responseXML : conn.responseXML,

                argument : callbackArg

            };

        }

        

        // private

        function releaseObject(o) {

            o.conn = null;

            o = null;

        }        

	    

        // private

        function handleTransactionResponse(o, callback, isAbort, isTimeout) {

            if (!callback) {

                releaseObject(o);

                return;

            }



            var httpStatus, responseObject;



            try {

                if (o.conn.status !== undefined && o.conn.status != 0) {

                    httpStatus = o.conn.status;

                }

                else {

                    httpStatus = 13030;

                }

            }

            catch(e) {

                httpStatus = 13030;

            }



            if ((httpStatus >= 200 && httpStatus < 300) || (Ext.isIE && httpStatus == 1223)) {

                responseObject = createResponseObject(o, callback.argument);

                if (callback.success) {

                    if (!callback.scope) {

                        callback.success(responseObject);

                    }

                    else {

                        callback.success.apply(callback.scope, [responseObject]);

                    }

                }

            }

            else {

                switch (httpStatus) {

                    case 12002:

                    case 12029:

                    case 12030:

                    case 12031:

                    case 12152:

                    case 13030:

                        responseObject = createExceptionObject(o.tId, callback.argument, (isAbort ? isAbort : false), isTimeout);

                        if (callback.failure) {

                            if (!callback.scope) {

                                callback.failure(responseObject);

                            }

                            else {

                                callback.failure.apply(callback.scope, [responseObject]);

                            }

                        }

                        break;

                    default:

                        responseObject = createResponseObject(o, callback.argument);

                        if (callback.failure) {

                            if (!callback.scope) {

                                callback.failure(responseObject);

                            }

                            else {

                                callback.failure.apply(callback.scope, [responseObject]);

                            }

                        }

                }

            }



            releaseObject(o);

            responseObject = null;

        }  

        

        // private

        function handleReadyState(o, callback){

	    callback = callback || {};

            var conn = o.conn,

            	tId = o.tId,

            	poll = pub.poll,

		cbTimeout = callback.timeout || null;



            if (cbTimeout) {

                pub.timeout[tId] = setTimeout(function() {

                    pub.abort(o, callback, true);

                }, cbTimeout);

            }



            poll[tId] = setInterval(

                function() {

                    if (conn && conn.readyState == 4) {

                        clearInterval(poll[tId]);

                        poll[tId] = null;



                        if (cbTimeout) {

                            clearTimeout(pub.timeout[tId]);

                            pub.timeout[tId] = null;

                        }



                        handleTransactionResponse(o, callback);

                    }

                },

                pub.pollInterval);

        }

        

        // private

        function asyncRequest(method, uri, callback, postData) {

            var o = getConnectionObject() || null;



            if (o) {

                o.conn.open(method, uri, true);



                if (pub.useDefaultXhrHeader) {                    

                	initHeader('X-Requested-With', pub.defaultXhrHeader);

                }



                if(postData && pub.useDefaultHeader && (!pub.headers || !pub.headers[CONTENTTYPE])){

                    initHeader(CONTENTTYPE, pub.defaultPostHeader);

                }



                if (pub.defaultHeaders || pub.headers) {

                    setHeader(o);

                }



                handleReadyState(o, callback);

                o.conn.send(postData || null);

            }

            return o;

        }

        

        // private

        function getConnectionObject() {

            var o;      	



            try {

                if (o = createXhrObject(pub.transactionId)) {

                    pub.transactionId++;

                }

            } catch(e) {

            } finally {

                return o;

            }

        }

	       

        // private

        function createXhrObject(transactionId) {

            var http;

            	

            try {

                http = new XMLHttpRequest();                

            } catch(e) {

                for (var i = 0; i < activeX.length; ++i) {	            

                    try {

                        http = new ActiveXObject(activeX[i]);                        

                        break;

                    } catch(e) {}

                }

            } finally {

                return {conn : http, tId : transactionId};

            }

        }

	         

	    var pub = {

	        request : function(method, uri, cb, data, options) {

			    if(options){

			        var me = this,		        

			        	xmlData = options.xmlData,

			        	jsonData = options.jsonData,

                        hs;

			        	

			        Ext.applyIf(me, options);	        

		            

		            if(xmlData || jsonData){

                        hs = me.headers;

                        if(!hs || !hs[CONTENTTYPE]){

			                initHeader(CONTENTTYPE, xmlData ? 'text/xml' : 'application/json');

                        }

			            data = xmlData || (Ext.isObject(jsonData) ? Ext.encode(jsonData) : jsonData);

			        }

			    }		    		    

			    return asyncRequest(method || options.method || "POST", uri, cb, data);

	        },

	

	        serializeForm : function(form) {

		        var fElements = form.elements || (document.forms[form] || Ext.getDom(form)).elements,

	            	hasSubmit = false,

	            	encoder = encodeURIComponent,

		        	element,

	            	options, 

	            	name, 

	            	val,             	

	            	data = '',

	            	type;

	            	

		        Ext.each(fElements, function(element) {		            

	                name = element.name;	             

					type = element.type;

					

	                if (!element.disabled && name){

		                if(/select-(one|multiple)/i.test(type)){			                

				            Ext.each(element.options, function(opt) {

					            if (opt.selected) {

						            data += String.format("{0}={1}&", 						            					  

						            					 encoder(name),						            					 

						            					  (opt.hasAttribute ? opt.hasAttribute('value') : opt.getAttributeNode('value').specified) ? opt.value : opt.text);

                                }								

                            });

		                } else if(!/file|undefined|reset|button/i.test(type)) {

			                if(!(/radio|checkbox/i.test(type) && !element.checked) && !(type == 'submit' && hasSubmit)){

                                    

                                data += encoder(name) + '=' + encoder(element.value) + '&';                     

                                hasSubmit = /submit/i.test(type);    

                            } 		                

		                } 

	                }

	            });            

	            return data.substr(0, data.length - 1);

	        },

	        

	        useDefaultHeader : true,

	        defaultPostHeader : 'application/x-www-form-urlencoded; charset=UTF-8',

	        useDefaultXhrHeader : true,

	        defaultXhrHeader : 'XMLHttpRequest',        

	        poll : {},

	        timeout : {},

	        pollInterval : 50,

	        transactionId : 0,

	        

//	This is never called - Is it worth exposing this?  		        

// 	        setProgId : function(id) {

// 	            activeX.unshift(id);

// 	        },



//	This is never called - Is it worth exposing this?  	

// 	        setDefaultPostHeader : function(b) {

// 	            this.useDefaultHeader = b;

// 	        },

	        

//	This is never called - Is it worth exposing this?  	

// 	        setDefaultXhrHeader : function(b) {

// 	            this.useDefaultXhrHeader = b;

// 	        },



//	This is never called - Is it worth exposing this?        	

// 	        setPollingInterval : function(i) {

// 	            if (typeof i == 'number' && isFinite(i)) {

// 	                this.pollInterval = i;

// 	            }

// 	        },

	        

//	This is never called - Is it worth exposing this?

// 	        resetDefaultHeaders : function() {

// 	            this.defaultHeaders = null;

// 	        },

	

	        abort : function(o, callback, isTimeout) {

		        var me = this,

		        	tId = o.tId,

		        	isAbort = false;

		        

	            if (me.isCallInProgress(o)) {

	                o.conn.abort();

	                clearInterval(me.poll[tId]);

	               	me.poll[tId] = null;

	                if (isTimeout) {

	                    me.timeout[tId] = null;

	                }

					

	                handleTransactionResponse(o, callback, (isAbort = true), isTimeout);                

	            }

	            return isAbort;

	        },

	

	        isCallInProgress : function(o) {

	            // if there is a connection and readyState is not 0 or 4

	            return o.conn && !{0:true,4:true}[o.conn.readyState];	        

	        }

	    };

	    return pub;

    }();