/*globals jQuery, qq*/
(function($) {
    "use strict";
    var uploader, $el, init, dataStore, pluginOption, pluginOptions, addCallbacks, transformVariables, isValidCommand,
        delegateCommand;

    pluginOptions = ['uploaderType'];

    init = function (options) {
        if (options) {
            var xformedOpts = transformVariables(options);
            addCallbacks(xformedOpts);

            if (pluginOption('uploaderType') === 'basic') {
                uploader(new qq.FineUploaderBasic(xformedOpts));
            }
            else {
                uploader(new qq.FineUploader(xformedOpts));
            }
        }

        return $el;
    };

    dataStore = function(key, val) {
        var data = $el.data('fineuploader');

        if (val) {
            if (data === undefined) {
                data = {};
            }
            data[key] = val;
            $el.data('fineuploader', data);
        }
        else {
            if (data === undefined) {
                return null;
            }
            return data[key];
        }
    };

    //the underlying Fine Uploader instance is stored in jQuery's data stored, associated with the element
    // tied to this instance of the plug-in
    uploader = function(instanceToStore) {
        return dataStore('uploader', instanceToStore);
    };

    pluginOption = function(option, optionVal) {
        return dataStore(option, optionVal);
    };

    //implement all callbacks defined in Fine Uploader as functions that trigger appropriately names events and
    // return the result of executing the bound handler back to Fine Uploader
    addCallbacks = function(transformedOpts) {
        var callbacks = transformedOpts.callbacks = {},
            uploaderInst = new qq.FineUploaderBasic();

        $.each(uploaderInst._options.callbacks, function(prop, func) {
            var name, $callbackEl;

            name = /^on(\w+)/.exec(prop)[1];
            name = name.substring(0, 1).toLowerCase() + name.substring(1);
            $callbackEl = $el;

            callbacks[prop] = function() {
                var args = Array.prototype.slice.call(arguments);

                return $callbackEl.triggerHandler(name, args);
            };
        });
    };

    //transform jQuery objects into HTMLElements, and pass along all other option properties
    transformVariables = function(source, dest) {
        var xformed, arrayVals;

        if (dest === undefined) {
            if (source.uploaderType !== 'basic') {
                xformed = { element : $el[0] };
            }
            else {
                xformed = {};
            }
        }
        else {
            xformed = dest;
        }

        $.each(source, function(prop, val) {
            if ($.inArray(prop, pluginOptions) >= 0) {
                pluginOption(prop, val);
            }
            else if (val instanceof $) {
                xformed[prop] = val[0];
            }
            else if ($.isPlainObject(val)) {
                xformed[prop] = {};
                transformVariables(val, xformed[prop]);
            }
            else if ($.isArray(val)) {
                arrayVals = [];
                $.each(val, function(idx, arrayVal) {
                    if (arrayVal instanceof $) {
                        $.merge(arrayVals, arrayVal);
                    }
                    else {
                        arrayVals.push(arrayVal);
                    }
                });
                xformed[prop] = arrayVals;
            }
            else {
                xformed[prop] = val;
            }
        });

        if (dest === undefined) {
            return xformed;
        }
    };

    isValidCommand = function(command) {
        return $.type(command) === "string" &&
            !command.match(/^_/) && //enforce private methods convention
            uploader()[command] !== undefined;
    };

    //assuming we have already verified that this is a valid command, call the associated function in the underlying
    // Fine Uploader instance (passing along the arguments from the caller) and return the result of the call back to the caller
    delegateCommand = function(command) {
        var xformedArgs = [], origArgs = Array.prototype.slice.call(arguments, 1);

        transformVariables(origArgs, xformedArgs);

        return uploader()[command].apply(uploader(), xformedArgs);
    };

    $.fn.fineUploader = function(optionsOrCommand) {
        var self = this, selfArgs = arguments, retVals = [];

        this.each(function(index, el) {
            $el = $(el);

            if (uploader() && isValidCommand(optionsOrCommand)) {
                retVals.push(delegateCommand.apply(self, selfArgs));

                if (self.length === 1) {
                    return false;
                }
            }
            else if (typeof optionsOrCommand === 'object' || !optionsOrCommand) {
                init.apply(self, selfArgs);
            }
            else {
                $.error('Method ' +  optionsOrCommand + ' does not exist on jQuery.fineUploader');
            }
        });

        if (retVals.length === 1) {
            return retVals[0];
        }
        else if (retVals.length > 1) {
            return retVals;
        }

        return this;
    };

}(jQuery));