// Extension of jquery autocomplete for styling purposes
// Author: Kees Hoogendijk
$.Autocompleter.Select = function (options, input, select, config) {
	var CLASSES = {
		ACTIVE: "ac_over"
	};

	var listItems,
		active = -1,
		data,
		term = "",
		needsInit = true,
		element,
		list;

	// Create results
	function init() {
		if (!needsInit)
			return;
		element = jQuery("<div><p>Producten:</p></div>")
		.hide()
		.addClass(options.resultsClass)
		.css("position", "absolute")
		.appendTo(document.body);

		list = jQuery("<ul/>").appendTo(element).mouseover( function(event) {
			if(target(event).nodeName && target(event).nodeName.toUpperCase() == 'LI') {
	            active = jQuery("li", list).removeClass(CLASSES.ACTIVE).index(target(event));
			    jQuery(target(event)).addClass(CLASSES.ACTIVE);
	        }
		}).click(function(event) {
			jQuery(target(event)).addClass(CLASSES.ACTIVE);
			select();
			// TODO provide option to avoid setting focus again after selection? useful for cleanup-on-focus
			input.focus();
			return false;
		}).mousedown(function() {
			config.mouseDownOnSelect = true;
		}).mouseup(function() {
			config.mouseDownOnSelect = false;
		});

		if( options.width > 0 )
			element.css("width", options.width);

		needsInit = false;
	}

	function target(event) {
		var element = event.target;
		while(element && element.tagName != "LI")
			element = element.parentNode;
		// more fun with IE, sometimes event.target is empty, just ignore it then
		if(!element)
			return [];
		return element;
	}

	function moveSelect(step) {
		listItems.slice(active, active + 1).removeClass(CLASSES.ACTIVE);
		movePosition(step);
        var activeItem = listItems.slice(active, active + 1).addClass(CLASSES.ACTIVE);
        if(options.scroll) {
            var offset = 0;
            listItems.slice(0, active).each(function() {
				offset += this.offsetHeight;
			});
            if((offset + activeItem[0].offsetHeight - list.scrollTop()) > list[0].clientHeight) {
                list.scrollTop(offset + activeItem[0].offsetHeight - list.innerHeight());
            } else if(offset < list.scrollTop()) {
                list.scrollTop(offset);
            }
        }
	};

	function movePosition(step) {
		active += step;
		if (active < 0) {
			active = listItems.size() - 1;
		} else if (active >= listItems.size()) {
			active = 0;
		}
	}

	function limitNumberOfItems(available) {
		return options.max && options.max < available
			? options.max
			: available;
	}

	function fillList() {
		list.empty();
		var max = limitNumberOfItems(data.length);
		for (var i=0; i < max; i++) {
			if (!data[i])
				continue;
			var formatted = options.formatItem(data[i].data, i+1, max, data[i].value, term);
			if ( formatted === false )
				continue;
			var li = jQuery("<li/>").html( options.highlight(formatted, term) ).addClass(i%2 == 0 ? "ac_even" : "ac_odd").appendTo(list)[0];
			jQuery.data(li, "ac_data", data[i]);
		}
		listItems = list.find("li");
		if ( options.selectFirst ) {
			listItems.slice(0, 1).addClass(CLASSES.ACTIVE);
			active = 0;
		}
		// apply bgiframe if available
		if ( jQuery.fn.bgiframe )
			list.bgiframe();
	}

	return {
		display: function(d, q) {
			init();
			data = d;
			term = q;
			fillList();
		},
		next: function() {
			moveSelect(1);
		},
		prev: function() {
			moveSelect(-1);
		},
		pageUp: function() {
			if (active != 0 && active - 8 < 0) {
				moveSelect( -active );
			} else {
				moveSelect(-8);
			}
		},
		pageDown: function() {
			if (active != listItems.size() - 1 && active + 8 > listItems.size()) {
				moveSelect( listItems.size() - 1 - active );
			} else {
				moveSelect(8);
			}
		},
		hide: function() {
			element && element.hide();
			listItems && listItems.removeClass(CLASSES.ACTIVE);
			active = -1;
		},
		visible : function() {
			return element && element.is(":visible");
		},
		current: function() {
			return this.visible() && (listItems.filter("." + CLASSES.ACTIVE)[0] || options.selectFirst && listItems[0]);
		},
		show: function() {
			var offset = jQuery(input).offset();
			element.css({
				width: typeof options.width == "string" || options.width > 0 ? options.width : jQuery(input).width(),
				top: offset.top + input.offsetHeight + options.topOffset,
				left: offset.left + options.leftOffset
			}).show();
            if(options.scroll) {
                list.scrollTop(0);
                list.css({
					maxHeight: options.scrollHeight,
					overflow: 'auto'
				});

                if(jQuery.browser.msie && typeof document.body.style.maxHeight === "undefined") {
					var listHeight = 0;
					listItems.each(function() {
						listHeight += this.offsetHeight;
					});
					var scrollbarsVisible = listHeight > options.scrollHeight;
                    list.css('height', scrollbarsVisible ? options.scrollHeight : listHeight );
					if (!scrollbarsVisible) {
						// IE doesn't recalculate width when scrollbar disappears
						listItems.width( list.width() - parseInt(listItems.css("padding-left")) - parseInt(listItems.css("padding-right")) );
					}
                }

            }
		},
		selected: function() {
			var selected = listItems && listItems.filter("." + CLASSES.ACTIVE).removeClass(CLASSES.ACTIVE);
			return selected && selected.length && jQuery.data(selected[0], "ac_data");
		},
		emptyList: function (){
			list && list.empty();
		},
		unbind: function() {
			element && element.remove();
		}
	};
};