(function(SKY,$){

	var defOptions = {
		type: null,
		nullable: true,
		
		lookup: function(pattern,response){}
	};

	class SkySelect {
		constructor(element,options){
			this.options = Object.assign({},defOptions);
			Object.assign(this.options, options);

			var self = this;

			element = $(element);
			element.data("skySelect", this);
			
			this.element = element;
			this.wrap = $("<div></div>");
			this.element.appendTo(this.wrap);
			this.popup = $("<div></div>")
				.addClass("skyselect-popup")
				.appendTo(this.wrap);

			this.element
				.on("keydown", function(ev){ self.onKeyDown(ev); } )
				.on("focusin", function(ev){ self.onFocusIn(ev); } )
				.on("focusout", function(ev){ self.onFocusOut(ev); } )
				.on("dblclick", function(ev){ 
					self.open();
					self.update();
				} );

			this.wrap.addClass("skyselect-wrapper");

			this.type = SKY.type(this.options.type);

			this.selectedItem = null;
			this.activeItem = null;
			this.timer = null;
		}
		html(){ return this.wrap; }

		value(item){
			if (arguments.length)
			{
				this.select(item);
				return this;
			}
			return this.selectedItem;
		}

		open(){ this.popup.slideDown(); this.isOpen = true; return this; }
		close(){
			if (this.isOpen)
			{
				clearInterval(this.timer);

				this.popup.hide();
				this.isOpen = false;

				this.activeItem = null;
			}
			return this;
		}

		restoreSelection(){
			if (this.options.nullable && (this.element.val()==""))
			{
				this.selectedItem = null;
			} else {
				this.element.val(
					this.selectedItem ? this.options.render(this.selectedItem) : ""
					);
			}
		}

		markCurrentSelected(){
			var self = this;
			var currentSelectedIdentity = self.options.identity(self.selectedItem);
			this.popup.children(".skyselect-item").each(function(){
				var li = $(this);
				var item = li.data("skyselectItem");
				if (self.options.identity(item) == currentSelectedIdentity)
					li.addClass("selected");
				else
					li.removeClass("selected");
			});
		}

		markActive(item){
			var self = this;
			var currentActiveIdentity = self.type.identity(item);
			self.activeItem = item;

			this.popup.children(".skyselect-item").each(function(){
				var li = $(this);
				var item = li.data("skyselectItem");
				if (self.type.identity(item) == currentActiveIdentity)
					li.addClass("active");
				else
					li.removeClass("active");
			});
		}

		select(item){
			this.close();
			this.selectedItem = item;
			this.element.val(this.type.render(item));
			this.markCurrentSelected();
		}

		update(){
			var self = this;
			self.options.lookup(
				self.element.val(),
				function(items){
					self.items(items);
				}
				);
		}

		items(items){
			var self = this;
			this.popup.empty();
			$.each( items, function(){
				var item = this;
				var identity = self.type.identity(item);
				var li = $("<div></div>")
				.addClass("skyselect-item")
				.append(self.type.render(this))
				.appendTo(self.popup)
				.data("skyselectItem", item)
				.on("click", function(ev){ 
					self.select( item ); 
				} )
				.on("mouseover", function(ev){
					self.markActive(item);
				});
				if (self.currentActiveIdentity == identity)
					li.addClass("active");
			})
			this.markCurrentSelected();
		}

		valid(){
			return true;
		}

		onKeyDown(ev){
			var self = this;

			switch (ev.which)
			{
				case 13:	// RETURN
					if (this.isOpen){

					}
					break;
				case 27:	// ESC
					this.close();
					break;
				case 38:	// UP
					if (this.isOpen){
						var currentActiveLi = $(".skyselect-item.active", this.popup);
						if (currentActiveLi.length){
							var prevLi = currentActiveLi.prev(".skyselect-item");
							if (prevLi.length)
							{
								this.markActive(prevLi.data("skyselectItem"));
							}
						} else {
							var firstLi = $(this.popup.children(".skyselect-item").get(0));
							if (firstLi.length)
								this.markActive(firstLi.data("skyselectItem"));
						}
					}
					break;
				case 40:	// DOWN
					if (this.isOpen){
						var currentActiveLi = $(".skyselect-item.active", this.popup);
						if (currentActiveLi.length){
							var nextLi = currentActiveLi.next(".skyselect-item");
							if (nextLi.length)
							{
								this.markActive(nextLi.data("skyselectItem"));
							}
						} else {
							var firstLi = $(this.popup.children(".skyselect-item").get(0));
							if (firstLi.length){
								this.markActive(firstLi.data("skyselectItem"));
							}
						}
					} else {
						this.open();
					}
					break;
				default:
					console.log("ev.which=" + ev.which);

					if ((ev.which >= 32))
					{
						clearInterval(this.timer);
						this.timer = setInterval( function(){
							self.update();
						}, 250);

						this.open();
					}

					break;
			}
		}
		onFocusIn(ev){
			this.element.select();
		}
		onFocusOut(ev){
			var self = this;
			setTimeout( function(){ self.close(); }, 100 );
			this.restoreSelection();
		}

	}

	$.fn.skySelect = function(options){
/*		$.each( this, function(index,item){
			var skySelect = $(item).data("skySelect");
			if (!skySelect)
				skySelect = new SkySelect(item,options);
		});

		var me = $(this.get(0));
		if (me.hasClass("skyselect-wrapper"))
			return me;
		return me.parents(".skyselect-wrapper").data("skySelect");
		*/
		var me = $(this.get(0));
		var skySelect = me.data("skySelect");
		if (skySelect && options){
			throw "skySelect() must not be called with options when already initiaized";
		}
		if (!skySelect)
			skySelect = new SkySelect(me,options);
		return skySelect;
	}

}( SKY, jQuery ));