/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Skywriter.
 *
 * The Initial Developer of the Original Code is
 * Mozilla.
 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Julian Viereck (jviereck@mozilla.com)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

define(function(require, exports, module) {

var Promise = require('pilot/promise').Promise;

exports.xhr = function(method, url, async, beforeSendCallback) {
    var pr = new Promise();

    if (!skywriter.proxy || !skywriter.proxy.xhr) {
        var req = new XMLHttpRequest();
        req.onreadystatechange = function() {
            if (req.readyState !== 4) {
                return;
            }

            var status = req.status;
            if (status !== 0 && status !== 200) {
                var error = new Error(req.responseText + ' (Status ' + req.status + ")");
                error.xhr = req;
                pr.reject(error);
                return;
            }

            pr.resolve(req.responseText);
        }.bind(this);

        req.open("GET", url, async);
        if (beforeSendCallback) {
            beforeSendCallback(req);
        }
        req.send();
    } else {
        skywriter.proxy.xhr.call(this, method, url, async, beforeSendCallback, pr);
    }

    return pr;
};

exports.Worker = function(url) {
    if (!skywriter.proxy || !skywriter.proxy.worker) {
        return new Worker(url);
    } else {
        return new skywriter.proxy.worker(url);
    }
};

});