/*
 * jQuery File Upload Processing Plugin
 * https://github.com/blueimp/jQuery-File-Upload
 *
 * Copyright 2012, Sebastian Tschan
 * https://blueimp.net
 *
 * Licensed under the MIT license:
 * http://www.opensource.org/licenses/MIT
 */

/* jshint nomen:false */
/* global define, require, window */

(function (factory) {
    'use strict';
    if (typeof define === 'function' && define.amd) {
        // Register as an anonymous AMD module:
        define([
            'jquery',
            './jquery.fileupload'
        ], factory);
    } else if (typeof exports === 'object') {
        // Node/CommonJS:
        factory(require('jquery'));
    } else {
        // Browser globals:
        factory(
            window.jQuery
        );
    }
}(function ($) {
    'use strict';

    var originalAdd = $.blueimp.fileupload.prototype.options.add;

    // The File Upload Processing plugin extends the fileupload widget
    // with file processing functionality:
    $.widget('blueimp.fileupload', $.blueimp.fileupload, {

        options: {
            // The list of processing actions:
            processQueue: [
                /*
                {
                    action: 'log',
                    type: 'debug'
                }
                */
            ],
            add: function (e, data) {
                var $this = $(this);
                data.process(function () {
                    return $this.fileupload('process', data);
                });
                originalAdd.call(this, e, data);
            }
        },

        processActions: {
            /*
            log: function (data, options) {
                console[options.type](
                    'Processing "' + data.files[data.index].name + '"'
                );
            }
            */
        },

        _processFile: function (data, originalData) {
            var that = this,
                dfd = $.Deferred().resolveWith(that, [data]),
                chain = dfd.promise();
            this._trigger('process', null, data);
            $.each(data.processQueue, function (i, settings) {
                var func = function (data) {
                    if (originalData.errorThrown) {
                        return $.Deferred()
                                .rejectWith(that, [originalData]).promise();
                    }
                    return that.processActions[settings.action].call(
                        that,
                        data,
                        settings
                    );
                };
                chain = chain.then(func, settings.always && func);
            });
            chain
                .done(function () {
                    that._trigger('processdone', null, data);
                    that._trigger('processalways', null, data);
                })
                .fail(function () {
                    that._trigger('processfail', null, data);
                    that._trigger('processalways', null, data);
                });
            return chain;
        },

        // Replaces the settings of each processQueue item that
        // are strings starting with an "@", using the remaining
        // substring as key for the option map,
        // e.g. "@autoUpload" is replaced with options.autoUpload:
        _transformProcessQueue: function (options) {
            var processQueue = [];
            $.each(options.processQueue, function () {
                var settings = {},
                    action = this.action,
                    prefix = this.prefix === true ? action : this.prefix;
                $.each(this, function (key, value) {
                    if ($.type(value) === 'string' &&
                            value.charAt(0) === '@') {
                        settings[key] = options[
                            value.slice(1) || (prefix ? prefix +
                                key.charAt(0).toUpperCase() + key.slice(1) : key)
                        ];
                    } else {
                        settings[key] = value;
                    }

                });
                processQueue.push(settings);
            });
            options.processQueue = processQueue;
        },

        // Returns the number of files currently in the processsing queue:
        processing: function () {
            return this._processing;
        },

        // Processes the files given as files property of the data parameter,
        // returns a Promise object that allows to bind callbacks:
        process: function (data) {
            var that = this,
                options = $.extend({}, this.options, data);
            if (options.processQueue && options.processQueue.length) {
                this._transformProcessQueue(options);
                if (this._processing === 0) {
                    this._trigger('processstart');
                }
                $.each(data.files, function (index) {
                    var opts = index ? $.extend({}, options) : options,
                        func = function () {
                            if (data.errorThrown) {
                                return $.Deferred()
                                        .rejectWith(that, [data]).promise();
                            }
                            return that._processFile(opts, data);
                        };
                    opts.index = index;
                    that._processing += 1;
                    that._processingQueue = that._processingQueue.then(func, func)
                        .always(function () {
                            that._processing -= 1;
                            if (that._processing === 0) {
                                that._trigger('processstop');
                            }
                        });
                });
            }
            return this._processingQueue;
        },

        _create: function () {
            this._super();
            this._processing = 0;
            this._processingQueue = $.Deferred().resolveWith(this)
                .promise();
        }

    });

}));
