/**
 * Ajax Queue Plugin
 * 
 * Homepage: http://jquery.com/plugins/project/ajaxqueue
 * Documentation: http://docs.jquery.com/AjaxQueue
 * Queued Ajax requests.
 * A new Ajax request won't be started until the previous queued 
 * request has finished.
 * Synced Ajax requests.
 * The Ajax request will happen as soon as you call this method, but
 * the callbacks (success/error/complete) won't fire until all previous
 * synced requests have been completed.
 */
(function($) {
    var ajax = $.ajax;
    var pendingRequests = {};
    var synced = [];
    var syncedData = [];

    $.ajax = function(settings) {
        // create settings for compatibility with ajaxSetup
        settings = jQuery.extend(settings, jQuery.extend({}, jQuery.ajaxSettings, settings));

        var port = settings.port;

        switch (settings.mode) {
            case "abort":
                if (pendingRequests[port]) {
                    pendingRequests[port].abort();
                }
                return pendingRequests[port] = ajax.apply(this, arguments);
            case "queue":
                var _old = settings.complete;
                settings.complete = function() {
                    if (_old)
                        _old.apply(this, arguments);
                    jQuery([ajax]).dequeue("ajax" + port); ;
                };

                jQuery([ajax]).queue("ajax" + port, function() {
                    ajax(settings);
                });
                return;
            case "sync":
                var pos = synced.length;

                synced[pos] = {
                    error: settings.error,
                    success: settings.success,
                    complete: settings.complete,
                    done: false
                };

                syncedData[pos] = {
                    error: [],
                    success: [],
                    complete: []
                };

                settings.error = function() { syncedData[pos].error = arguments; };
                settings.success = function() { syncedData[pos].success = arguments; };
                settings.complete = function() {
                    syncedData[pos].complete = arguments;
                    synced[pos].done = true;

                    if (pos == 0 || !synced[pos - 1])
                        for (var i = pos; i < synced.length && synced[i].done; i++) {
                        if (synced[i].error) synced[i].error.apply(jQuery, syncedData[i].error);
                        if (synced[i].success) synced[i].success.apply(jQuery, syncedData[i].success);
                        if (synced[i].complete) synced[i].complete.apply(jQuery, syncedData[i].complete);

                        synced[i] = null;
                        syncedData[i] = null;
                    }
                };
        }
        return ajax.apply(this, arguments);
    };
    return false;
})(jQuery);