/* Adapted from http://jqueryui.com/autocomplete/#combobox */

(function ($)
{
	$.widget("custom.combobox", {
		_create: function ()
		{
			this.wrapper = $("<span>")
			.addClass("custom-combobox")
			.insertAfter(this.element);
			this.element.hide();
			this._createAutocomplete();
			this._createShowAllButton();
		},
		_createAutocomplete: function ()
		{
			var selected = this.element.children(":selected"),
			value = selected.val() ? selected.text() : "";
			this.input = $("<input>")
			.appendTo(this.wrapper)
			.val(value)
			.attr("title", "")
			.addClass("custom-combobox-input ui-widget ui-widget-content ui-state-default ui-corner-left")
			.autocomplete({
				delay: 0,
				minLength: 0,
				source: $.proxy(this, "_source"),
				position: { collision: "flip" }
			})
			.tooltip({
				tooltipClass: "ui-state-highlight"
			});
			this._on(this.input, {
				autocompleteselect: function (event, ui)
				{
					ui.item.option.selected = true;
					this._trigger("select", event, {
						item: ui.item.option
					});
				},
				autocompletechange: "_removeIfInvalid"
			});
		},
		_createShowAllButton: function ()
		{
			var input = this.input,
			wasOpen = false;
			$("<a>")
			.attr("tabIndex", -1)
			.attr("title", "Alle Einträge anzeigen")
			.tooltip()
			.appendTo(this.wrapper)
			.button({
				icons: {
					primary: "ui-icon-triangle-1-s"
				},
				text: false
			})
			.removeClass("ui-corner-all")
			.addClass("custom-combobox-toggle ui-corner-right")
			.mousedown(function ()
			{
				wasOpen = input.autocomplete("widget").is(":visible");
			})
			.click(function ()
			{
				input.focus();
				// Close if already visible
				if (wasOpen)
				{
					return;
				}
				// Pass empty string as value to search for, displaying all results
				input.autocomplete("search", "");
			});
		},
		_source: function (request, response)
		{
			var matcher = new RegExp($.ui.autocomplete.escapeRegex(request.term), "i");
			response(this.element.children("option").map(function ()
			{
				var text = $(this).text();

				if ((!request.term || matcher.test(text)))
					if (text === undefined || text === null || text == "")
					{
						return {
							label: "-- Eingabe löschen --",
							value: "",
							option: this
						};
					}
					else
					{
						return {
							label: text,
							value: text,
							option: this
						};
					}
			}));
		},
		_removeIfInvalid: function (event, ui)
		{
			return;
		},
		_destroy: function ()
		{
			this.wrapper.remove();
			this.element.show();
		}
	});
})(jQuery);