/*
This file is part of Ext JS 3.4

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-04-03 15:07:25
*/
/*
* 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'],
        CONTENTTYPE = 'Content-Type';

    // private
    function setHeader(o) {
        var conn = o.conn,
            prop,
            headers = {};

        function setTheHeaders(conn, headers){
            for (prop in headers) {
                if (headers.hasOwnProperty(prop)) {
                    conn.setRequestHeader(prop, headers[prop]);
                }
            }
        }

        Ext.apply(headers, pub.headers, pub.defaultHeaders);
        setTheHeaders(conn, headers);
        delete pub.headers;
    }

    // private
    function createExceptionObject(tId, callbackArg, isAbort, isTimeout) {
        return {
            tId : tId,
            status : isAbort ? -1 : 0,
            statusText : isAbort ? 'transaction aborted' : 'communication failure',
            isAbort: isAbort,
            isTimeout: isTimeout,
            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,
            // see: https://prototype.lighthouseapp.com/projects/8886/tickets/129-ie-mangles-http-response-status-code-204-to-1223
            isBrokenStatus = conn.status == 1223;

        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,
            // Normalize the status and statusText when IE returns 1223, see the above link.
            status : isBrokenStatus ? 204 : conn.status,
            statusText : isBrokenStatus ? 'No Content' : 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) {
        if (o.tId) {
            pub.conn[o.tId] = null;
        }
        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;
    }
    
    function checkResponse(o, callback, conn, tId, poll, cbTimeout){
        if (conn && conn.readyState == 4) {
            clearInterval(poll[tId]);
            poll[tId] = null;

            if (cbTimeout) {
                clearTimeout(pub.timeout[tId]);
                pub.timeout[tId] = null;
            }
            handleTransactionResponse(o, callback);
        }
    }
    
    function checkTimeout(o, callback){
        pub.abort(o, callback, true);
    }
    

    // private
    function handleReadyState(o, callback){
        callback = callback || {};
        var conn = o.conn,
            tId = o.tId,
            poll = pub.poll,
            cbTimeout = callback.timeout || null;

        if (cbTimeout) {
            pub.conn[tId] = conn;
            pub.timeout[tId] = setTimeout(checkTimeout.createCallback(o, callback), cbTimeout);
        }
        poll[tId] = setInterval(checkResponse.createCallback(o, callback, conn, tId, poll, cbTimeout), 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 = Ext.isIE6 ? 1 : 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.isPrimitive(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, 
                name, 
                data = '', 
                type, 
                hasValue;
    
            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) {
                                hasValue = opt.hasAttribute ? opt.hasAttribute('value') : opt.getAttributeNode('value').specified;
                                data += String.format("{0}={1}&", encoder(name), encoder(hasValue ? 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 : {},
        conn: {},
        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;
                clearTimeout(pub.timeout[tId]);
                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;
}();