/**
* @author alexander.farkas
* 
* @version 2.5.3
* project site: http://plugins.jquery.com/project/AjaxManager
*/
(function($) {
    $.support.ajax = !!(window.XMLHttpRequest);
    var needActiveXFix = false;
    if (window.ActiveXObject) {
        try {
            new ActiveXObject("Microsoft.XMLHTTP");
            $.support.ajax = true;
        } catch (e) {
            $.support.ajax = false;
            if (window.XMLHttpRequest) {
                $.ajaxSetup({ xhr: function() {
                    return new XMLHttpRequest();
                } 
                });
                $.support.ajax = true;
            }
        }
    }
    $.manageAjax = (function() {
        var cache = {},
			queues = {},
			presets = {},
			activeRequest = {},
			allRequests = {},
			triggerEndCache = {},
			defaults = {
			    queue: true, //clear
			    maxRequests: 1,
			    abortOld: false,
			    preventDoubbleRequests: true,
			    cacheResponse: false,
			    complete: function() { },
			    error: function(ahr, status) {
			        var opts = this;
			        if (status && status.indexOf('error') != -1) {
			            setTimeout(function() {
			                var errStr = status + ': ';
			                if (ahr.status) {
			                    errStr += 'status: ' + ahr.status + ' | ';
			                }
			                errStr += 'URL: ' + opts.url;
			                throw new Error(errStr);
			            }, 1);
			        }
			    },
			    success: function() { },
			    abort: function() { }
			}
		;

        function create(name, settings) {
            var publicMethods = {};
            presets[name] = presets[name] ||
				{};

            $.extend(true, presets[name], $.ajaxSettings, defaults, settings);

            if (!allRequests[name]) {
                allRequests[name] = {};
                activeRequest[name] = {};
                activeRequest[name].queue = [];
                queues[name] = [];
                triggerEndCache[name] = [];
            }
            $.each($.manageAjax, function(fnName, fn) {
                if ($.isFunction(fn) && fnName.indexOf('_') !== 0) {
                    publicMethods[fnName] = function(param, param2) {
                        if (param2 && typeof param === 'string') {
                            param = param2;
                        }
                        fn(name, param);
                    };
                }
            });
            return publicMethods;
        }

        function complete(opts, args) {

            if (args[1] == 'success' || args[1] == 'notmodified') {
                opts.success.apply(opts, [args[0].successData, args[1]]);
                if (opts.global) {
                    $.event.trigger("ajaxSuccess", args);
                }
            }

            if (args[1] === 'abort') {
                opts.abort.apply(opts, args);
                if (opts.global) {
                    $.active--;
                    $.event.trigger("ajaxAbort", args);
                }
            }

            opts.complete.apply(opts, args);

            if (opts.global) {
                $.event.trigger("ajaxComplete", args);
            }

            if (opts.global && !$.active) {
                $.event.trigger("ajaxStop");
            }
            //args[0] = null; 
        }

        function proxy(oldFn, fn) {
            return function(xhr, s, e) {
                fn.call(this, xhr, s, e);
                oldFn.call(this, xhr, s, e);
                xhr = null;
                e = null;
            };
        }


        function callQueueFn(name) {
            var q = queues[name];
            if (q && q.length) {
                var fn = q.shift();
                if (fn) {
                    fn();
                }
            }
        }


        function add(name, opts) {
            if (!presets[name]) {
                create(name, opts);
            }
            opts = $.extend({}, presets[name], opts);
            //aliases
            var allR = allRequests[name],
				activeR = activeRequest[name],
				queue = queues[name];

            var id = opts.type + '_' + opts.url.replace(/\./g, '_'),
				triggerStart = true,
				oldComplete = opts.complete,
				ajaxFn = function() {
				    activeR.queue.push(id);
				    activeR[id] = {
				        xhr: false,
				        ajaxManagerOpts: opts
				    };
				    activeR[id].xhr = $.ajax(opts);
				    return id;
				}
				;

            if (opts.data) {
                id += (typeof opts.data == 'string') ? opts.data : $.param(opts.data);
            }

            if (opts.preventDoubbleRequests && allRequests[name][id]) {
                return false;
            }

            allR[id] = true;

            opts.complete = function(xhr, s, e) {
                var triggerEnd = true;
                if (opts.abortOld) {
                    $.each(activeR.queue, function(i, activeID) {
                        if (activeID == id) {
                            return false;
                        }
                        abort(name, activeID);
                        return activeID;
                    });
                }
                oldComplete.call(this, xhr, s, e);
                //stop memory leak
                if (activeRequest[name][id]) {
                    if (activeRequest[name][id] && activeRequest[name][id].xhr) {
                        activeRequest[name][id].xhr = null;
                    }
                    activeRequest[name][id] = null;
                }
                triggerEndCache[name].push({ xhr: xhr, status: s });
                xhr = null;
                activeRequest[name].queue = $.grep(activeRequest[name].queue, function(qid) {
                    return (qid !== id);
                });
                allR[id] = false;

                e = null;

                delete activeRequest[name][id];

                $.each(activeR, function(id, queueRunning) {
                    if (id !== 'queue' || queueRunning.length) {
                        triggerEnd = false;
                        return false;
                    }
                });

                if (triggerEnd) {
                    $.event.trigger(name + 'End', [triggerEndCache[name]]);
                    $.each(triggerEndCache[name], function(i, cached) {
                        cached.xhr = null; //memory leak
                    });
                    triggerEndCache[name] = [];
                }
            };

            if (cache[id]) {
                ajaxFn = function() {
                    activeR.queue.push(id);
                    complete(opts, cache[id]);
                    return id;
                };
            } else if (opts.cacheResponse) {
                opts.complete = proxy(opts.complete, function(xhr, s) {
                    if (s !== "success" && s !== "notmodified") {
                        return false;
                    }
                    cache[id][0].responseXML = xhr.responseXML;
                    cache[id][0].responseText = xhr.responseText;
                    cache[id][1] = s;
                    //stop memory leak
                    xhr = null;
                    return id; //strict
                });

                opts.success = proxy(opts.success, function(data, s) {
                    cache[id] = [{
                        successData: data,
                        ajaxManagerOpts: opts
                    }, s];
                    data = null;
                });
            }

            ajaxFn.ajaxID = id;

            $.each(activeR, function(id, queueRunning) {
                if (id !== 'queue' || queueRunning.length) {
                    triggerStart = false;
                    return false;
                }
            });

            if (triggerStart) {
                $.event.trigger(name + 'Start');
            }
            if (opts.queue) {
                opts.complete = proxy(opts.complete, function() {

                    callQueueFn(name);
                });

                if (opts.queue === 'clear') {
                    queue = clear(name);
                }

                queue.push(ajaxFn);

                if (activeR.queue.length < opts.maxRequests) {
                    callQueueFn(name);
                }
                return id;
            }



            return ajaxFn();
        }

        function clear(name, shouldAbort) {
            $.each(queues[name], function(i, fn) {
                allRequests[name][fn.ajaxID] = false;
            });
            queues[name] = [];

            if (shouldAbort) {
                abort(name);
            }
            return queues[name];
        }

        function getXHR(name, id) {
            var ar = activeRequest[name];
            if (!ar || !allRequests[name][id]) {
                return false;
            }
            if (ar[id]) {
                return ar[id].xhr;
            }
            var queue = queues[name],
				xhrFn;
            $.each(queue, function(i, fn) {
                if (fn.ajaxID == id) {
                    xhrFn = [fn, i];
                    return false;
                }
                return xhrFn;
            });
            return xhrFn;
        }

        function abort(name, id) {
            var ar = activeRequest[name];
            if (!ar) {
                return false;
            }
            function abortID(qid) {
                if (qid !== 'queue' && ar[qid] && ar[qid].xhr) {
                    try {
                        ar[qid].xhr.abort();
                    } catch (e) { }
                    complete(ar[qid].ajaxManagerOpts, [ar[qid].xhr, 'abort']);
                }
                return null;
            }
            if (id) {
                return abortID(id);
            }
            return $.each(ar, abortID);
        }

        function unload() {
            $.each(presets, function(name) {
                clear(name, true);
            });
            cache = {};
        }

        return {
            defaults: defaults,
            add: add,
            create: create,
            cache: cache,
            abort: abort,
            clear: clear,
            getXHR: getXHR,
            _activeRequest: activeRequest,
            _complete: complete,
            _allRequests: allRequests,
            _unload: unload
        };
    })();
    //stop memory leaks
    $(window).unload($.manageAjax._unload);
})(jQuery);