﻿jQuery.extend({
    createUploadIframe: function (id, uri) {

        //create frame

        var frameId = 'jUploadFrame' + id;

        var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"';

        if (window.ActiveXObject) {

            if (typeof uri == 'boolean') {

                iframeHtml += ' src="' + 'javascript:false' + '"';
            }

            else if (typeof uri == 'string') {

                iframeHtml += ' src="' + uri + '"';
            }

        }

        iframeHtml += ' />';

        jQuery(iframeHtml).appendTo(document.body);
        return jQuery('#' + frameId).get(0);
    },

    createUploadForm: function (id, fileElementId, data) {
        //create form
        var formId = 'jUploadForm' + id;

        var fileId = 'jUploadFile' + id;

        var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');

        if (data) {

            for (var i in data) {

                jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);

            }

        }

        var oldElement = jQuery('#' + fileElementId);

        var newElement = jQuery(oldElement).clone();

        jQuery(oldElement).attr('id', fileId);

        jQuery(oldElement).before(newElement);

        jQuery(oldElement).appendTo(form);

        //set attributes

        jQuery(form).css('position', 'absolute');

        jQuery(form).css('top', '-1200px');

        jQuery(form).css('left', '-1200px');

        jQuery(form).appendTo('body');

        return form;

    },



    ajaxFileUpload: function (s) {

        // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout     

        s = jQuery.extend({}, jQuery.ajaxSettings, s);

        var id = new Date().getTime()

        var form = jQuery.createUploadForm(id, s.fileElementId, (typeof (s.data) == 'undefined' ? false : s.data));

        var io = jQuery.createUploadIframe(id, s.secureuri);

        var frameId = 'jUploadFrame' + id;

        var formId = 'jUploadForm' + id;

        // Watch for a new set of requests

        if (s.global && !jQuery.active++) {

            jQuery.event.trigger("ajaxStart");

        }

        var requestDone = false;

        // Create the request object

        var xml = {}

        if (s.global)

            jQuery.event.trigger("ajaxSend", [xml, s]);

        // Wait for a response to come back

        var uploadCallback = function (isTimeout) {

            var io = document.getElementById(frameId);

            try {

                if (io.contentWindow) {

                    xml.responseText = io.contentWindow.document.body ? io.contentWindow.document.body.innerHTML : null;

                    xml.responseXML = io.contentWindow.document.XMLDocument ? io.contentWindow.document.XMLDocument : io.contentWindow.document;



                } else if (io.contentDocument) {

                    xml.responseText = io.contentDocument.document.body ? io.contentDocument.document.body.innerHTML : null;

                    xml.responseXML = io.contentDocument.document.XMLDocument ? io.contentDocument.document.XMLDocument : io.contentDocument.document;

                }

            } catch (e) {

                jQuery.handleError(s, xml, null, e);

            }

            if (xml || isTimeout == "timeout") {

                requestDone = true;

                var status;

                try {

                    status = isTimeout != "timeout" ? "success" : "error";

                    // Make sure that the request was successful or notmodified

                    if (status != "error") {

                        // process the data (runs the xml through httpData regardless of callback)

                        var data = jQuery.uploadHttpData(xml, s.dataType);

                        // If a local callback was specified, fire it and pass it the data

                        if (s.success)

                            s.success(data, status);



                        // Fire the global callback

                        if (s.global)

                            jQuery.event.trigger("ajaxSuccess", [xml, s]);

                    } else

                        jQuery.handleError(s, xml, status);

                } catch (e) {

                    status = "error";

                    jQuery.handleError(s, xml, status, e);

                }



                // The request was completed

                if (s.global)

                    jQuery.event.trigger("ajaxComplete", [xml, s]);



                // Handle the global AJAX counter

                if (s.global && ! --jQuery.active)

                    jQuery.event.trigger("ajaxStop");



                // Process result

                if (s.complete)

                    s.complete(xml, status);



                jQuery(io).unbind()



                setTimeout(function () {
                    try {

                        jQuery(io).remove();

                        jQuery(form).remove();



                    } catch (e) {

                        jQuery.handleError(s, xml, null, e);

                    }



                }, 100)



                xml = null



            }

        }

        // Timeout checker

        if (s.timeout > 0) {

            setTimeout(function () {

                // Check to see if the request is still happening

                if (!requestDone) uploadCallback("timeout");

            }, s.timeout);

        }

        try {



            var form = jQuery('#' + formId);

            jQuery(form).attr('action', s.url);

            jQuery(form).attr('method', 'POST');

            jQuery(form).attr('target', frameId);

            if (form.encoding) {

                jQuery(form).attr('encoding', 'multipart/form-data');

            }

            else {

                jQuery(form).attr('enctype', 'multipart/form-data');

            }

            jQuery(form).submit();



        } catch (e) {

            jQuery.handleError(s, xml, null, e);

        }



        jQuery('#' + frameId).load(uploadCallback);

        return { abort: function () { } };



    },



    uploadHttpData: function (r, type) {

        var data = !type;

        data = type == "xml" || data ? r.responseXML : r.responseText;

        // If the type is "script", eval it in global context

        if (type == "script")

            jQuery.globalEval(data);

        // Get the JavaScript object, if JSON is used.

        if (type == "json")

            eval("data = " + data);

        // evaluate scripts within html

        if (type == "html")

            jQuery("<div>").html(data).evalScripts();
        return data;

    }

})