/*
 * jQuery Iframe Transport Plugin 1.2.2
 * https://github.com/blueimp/jQuery-File-Upload
 *
 * Copyright 2011, Sebastian Tschan
 * https://blueimp.net
 *
 * Licensed under the MIT license:
 * http://creativecommons.org/licenses/MIT/
 */

/*jslint unparam: true */
/*global jQuery */

(function ($) {
    'use strict';

    // Helper variable to create unique names for the transport iframes:
    var counter = 0;

    // The iframe transport accepts three additional options:
    // options.fileInput: a jQuery collection of file input fields
    // options.paramName: the parameter name for the file form data,
    //  overrides the name property of the file input field(s)
    // options.formData: an array of objects with name and value properties,
    //  equivalent to the return data of .serializeArray(), e.g.:
    //  [{name: a, value: 1}, {name: b, value: 2}]
    $.ajaxTransport('iframe', function (options, originalOptions, jqXHR) {
        if (options.type === 'POST' || options.type === 'GET') {
            var form,
                iframe;
            return {
                send: function (headers, completeCallback) {
                    form = $('<form style="display:none;"></form>');
                    // javascript:false as initial iframe src
                    // prevents warning popups on HTTPS in IE6.
                    // IE versions below IE8 cannot set the name property of
                    // elements that have already been added to the DOM,
                    // so we set the name along with the iframe HTML markup:
                    iframe = $(
                        '<iframe src="javascript:false;" name="iframe-transport-' +
                            (counter += 1) + '"></iframe>'
                    ).bind('load', function () {
                        var fileInputClones;
                        iframe
                            .unbind('load')
                            .bind('load', function () {
                                var response;
                                // Wrap in a try/catch block to catch exceptions thrown
                                // when trying to access cross-domain iframe contents:
                                try {
                                    response = iframe.contents();
                                    // Google Chrome and Firefox do not throw an
                                    // exception when calling iframe.contents() on
                                    // cross-domain requests, so we unify the response:
                                    if (!response.length || !response[0].firstChild) {
                                        throw new Error();
                                    }
                                } catch (e) {
                                    response = undefined;
                                }
                                // The complete callback returns the
                                // iframe content document as response object:
                                completeCallback(
                                    200,
                                    'success',
                                    {'iframe': response}
                                );
                                // Fix for IE endless progress bar activity bug
                                // (happens on form submits to iframe targets):
                                $('<iframe src="javascript:false;"></iframe>')
                                    .appendTo(form);
                                form.remove();
                            });
                        form
                            .prop('target', iframe.prop('name'))
                            .prop('action', options.url)
                            .prop('method', options.type);
                        if (options.formData) {
                            $.each(options.formData, function (index, field) {
                                $('<input type="hidden"/>')
                                    .prop('name', field.name)
                                    .val(field.value)
                                    .appendTo(form);
                            });
                        }
                        if (options.fileInput && options.fileInput.length &&
                                options.type === 'POST') {
                            fileInputClones = options.fileInput.clone();
                            // Insert a clone for each file input field:
                            options.fileInput.after(function (index) {
                                return fileInputClones[index];
                            });
                            if (options.paramName) {
                                options.fileInput.each(function () {
                                    $(this).prop('name', options.paramName);
                                });
                            }
                            // Appending the file input fields to the hidden form
                            // removes them from their original location:
                            form
                                .append(options.fileInput)
                                .prop('enctype', 'multipart/form-data')
                                // enctype must be set as encoding for IE:
                                .prop('encoding', 'multipart/form-data');
                        }
                        form.submit();
                        // Insert the file input fields at their original location
                        // by replacing the clones with the originals:
                        if (fileInputClones && fileInputClones.length) {
                            options.fileInput.each(function (index, input) {
                                var clone = $(fileInputClones[index]);
                                $(input).prop('name', clone.prop('name'));
                                clone.replaceWith(input);
                            });
                        }
                    });
                    form.append(iframe).appendTo('body');
                },
                abort: function () {
                    if (iframe) {
                        // javascript:false as iframe src aborts the request
                        // and prevents warning popups on HTTPS in IE6.
                        // concat is used to avoid the "Script URL" JSLint error:
                        iframe
                            .unbind('load')
                            .prop('src', 'javascript'.concat(':false;'));
                    }
                    if (form) {
                        form.remove();
                    }
                }
            };
        }
    });

    // The iframe transport returns the iframe content document as response.
    // The following adds converters from iframe to text, json, html, and script:
    $.ajaxSetup({
        converters: {
            'iframe text': function (iframe) {
                return iframe.text();
            },
            'iframe json': function (iframe) {
                return $.parseJSON(iframe.text());
            },
            'iframe html': function (iframe) {
                return iframe.find('body').html();
            },
            'iframe script': function (iframe) {
                return $.globalEval(iframe.text());
            }
        }
    });

}(jQuery));