/*
* jQuery MultiSelect UI Widget Filtering Plugin 1.2
* Copyright (c) 2011 Eric Hynds
*
* http://www.erichynds.com/jquery/jquery-ui-multiselect-widget/
*
* Depends:
*   - jQuery UI MultiSelect widget
*
* Dual licensed under the MIT and GPL licenses:
*   http://www.opensource.org/licenses/mit-license.php
*   http://www.gnu.org/licenses/gpl.html
*
*/
(function ($) {
    var rEscape = /[\-\[\]{}()*+?.,\\^$|#\s]/g;

    $.widget("ech.multiselectfilter", {

        options: {
            label: "",
            width: null, /* override default width set in css file (px). null will inherit */
            placeholder: "Enter keywords"
        },

        _create: function () {
            var self = this,
				opts = this.options,
				instance = (this.instance = $(this.element).data("multiselect")),

            // store header; add filter class so the close/check all/uncheck all links can be positioned correctly
				header = (this.header = instance.menu.find(".ui-multiselect-header").addClass("ui-multiselect-hasfilter")),

            // wrapper elem
				wrapper = (this.wrapper = $('<div class="ui-multiselect-filter">' + (opts.label.length ? opts.label : '') + '<input placeholder="' + opts.placeholder + '" type="search"' + (/\d/.test(opts.width) ? 'style="width:' + opts.width + 'px"' : '') + ' /></div>').prependTo(this.header));

            // reference to the actual inputs
            this.inputs = instance.menu.find('input[type="checkbox"], input[type="radio"]');

            // build the input box
            this.input = wrapper
			.find("input")
			.bind({
			    keydown: function (e) {
			        // prevent the enter key from submitting the form / closing the widget
			        if (e.which === 13) {
			            e.preventDefault();
			        }
			    },
			    keyup: $.proxy(self._handler, self),
			    click: $.proxy(self._handler, self)
			});

            // cache input values for searching
            this.updateCache();

            // rewrite internal _toggleChecked fn so that when checkAll/uncheckAll is fired,
            // only the currently filtered elements are checked
            instance._toggleChecked = function (flag, group) {
                var $inputs = (group && group.length) ?
						group :
						this.labels.find('input'),

					_self = this,

                // do not include hidden elems if the menu isn't open.
					selector = self.instance._isOpen ?
						":disabled, :hidden" :
						":disabled";

                $inputs = $inputs.not(selector).each(this._toggleCheckbox('checked', flag));

                // update text
                this.update();

                // figure out which option tags need to be selected
                var values = $inputs.map(function () {
                    return this.value;
                }).get();

                // select option tags
                this.element
					.find('option')
					.filter(function () {
					    if (!this.disabled && $.inArray(this.value, values) > -1) {
					        _self._toggleCheckbox('selected', flag).call(this);
					    }
					});
            };

            // rebuild cache when multiselect is updated
            $(document).bind("multiselectrefresh", function () {
                self.updateCache();
                self._handler();
            });
        },

        // thx for the logic here ben alman
        _handler: function (e) {
            var term = $.trim(this.input[0].value.toLowerCase()),

            // speed up lookups
				rows = this.rows, inputs = this.inputs, cache = this.cache;

            if (!term) {
                rows.show();
            } else {
                rows.hide();

                var regex = new RegExp(term.replace(rEscape, "\\$&"), 'gi');

                this._trigger("filter", e, $.map(cache, function (v, i) {
                    if (v.search(regex) !== -1) {
                        rows.eq(i).show();
                        return inputs.get(i);
                    }

                    return null;
                }));
            }

            // show/hide optgroups
            this.instance.menu.find(".ui-multiselect-optgroup-label").each(function () {
                var $this = $(this);
                $this[$this.nextUntil('.ui-multiselect-optgroup-label').filter(':visible').length ? 'show' : 'hide']();
            });
        },

        updateCache: function () {
            // each list item
            this.rows = this.instance.menu.find(".ui-multiselect-checkboxes li:not(.ui-multiselect-optgroup-label)");

            // cache
            this.cache = this.element.children().map(function () {
                var self = $(this);

                // account for optgroups
                if (this.tagName.toLowerCase() === "optgroup") {
                    self = self.children();
                }

                // see _create() in jquery.multiselect.js
                if (!self.val().length) {
                    return null;
                }

                return self.map(function () {
                    return this.innerHTML.toLowerCase();
                }).get();
            }).get();
        },

        widget: function () {
            return this.wrapper;
        },

        destroy: function () {
            $.Widget.prototype.destroy.call(this);
            this.input.val('').trigger("keyup");
            this.wrapper.remove();
        }
    });
})(jQuery);