YUI().use("node", "anim", function(Y) {

		// Constants
		var WINDOW_WIDTH,TOTAL_PAGES,
		// Class names
			RIGHT_BUTTON = "right-button",
			LEFT_BUTTON = "left-button",
			PAGINATION = "pagination",

			// YNode references
			_carousel,

			// Animator
			_anim,

			// Current X position used in animation
			_currentXPosition,
			_startXPosition,

			_startIndex = 0,
			_lastIndex,

			// Current pagination page shown; it contains a integer like 1, 2, etc.
			_currentIndex = 0;

		// Event handlers
		function init() {
			// Initialize the DOM references
			_body = Y.get(document.body);
			_carousel = _body.query(".carousel"),

			// Animation stuff
			_anim = new Y.Anim({
				node: _carousel,
				duration: 0.5,
				easing: Y.Easing.easeOut
			});

			// Get the offsetWidth of the list containing the photos
			WINDOW_WIDTH = _carousel.get("children").item(0).get("offsetWidth");
			TOTAL_PAGES = _carousel.get("children").size();

			_lastIndex = TOTAL_PAGES - 1;
			_currentXPosition = _carousel.getX();

			// Add a custom attribute to track the current page that we're on
			_anim.addAtt("currentPage", { value : _currentIndex });

			_anim.on("end", handleScrollEnd);

		}

		// When the scrolling animation ends, this event handler is called.
		function handleScrollEnd(e) {
			_body.query(".selected").removeClass("selected");

			// After we've removed the selected class from the old node,
			// We get the new selected node and set the selected class
			_body.query(".page" + this.get("currentPage").value).addClass("selected");
		}

		// Detect the click and then scroll appropriately
		function scrollControl(e) {

			var target = e.target,
				hasLeftButton = target.hasClass(LEFT_BUTTON),
				hasRightButton = target.hasClass(RIGHT_BUTTON),
				hasPagination = target.get("parentNode").hasClass(PAGINATION),
				gotoPage;

			if (hasLeftButton) {
				scrollLeft();
			} else if (hasRightButton) {
				scrollRight();
			} else if (hasPagination) {

				// Parse out class name "page" to get the integer
				gotoPage = parseInt(target.get("className").substring(4), 10);
				paginate(gotoPage);

			}

			if (hasLeftButton || hasRightButton || hasPagination) {

				_anim.set("to", { xy: [_currentXPosition, _carousel.getY()] });
				_anim.set("currentPage", { value : _currentIndex });
				_anim.run();

			}
		}

		// Handles scrolling left
		function scrollLeft() {

			if (_currentIndex === _startIndex) {

				_currentXPosition = -1 * WINDOW_WIDTH * (TOTAL_PAGES - 1) + _carousel.getX();
				_currentIndex = TOTAL_PAGES - 1;

			} else {

				_currentXPosition = _carousel.getX() + WINDOW_WIDTH;
				--_currentIndex;

			}

		}

		// Handles scrolling right
		function scrollRight() {

			if (_currentIndex === _lastIndex) {

				// We go to the first page
				_currentXPosition = WINDOW_WIDTH * (TOTAL_PAGES - 1) + _carousel.getX();
				_currentIndex = 0;

			} else {

				_currentXPosition = _carousel.getX() - WINDOW_WIDTH;
				++_currentIndex;

			}

		}

		// Handles pagination
		function paginate(gotoPage) {
			var multiple;

			if (gotoPage > _currentIndex) {

				// This is like clicking go right
				multiple = gotoPage - _currentIndex;

				for (var i = 0;i < multiple;i++) {
					_currentXPosition -= WINDOW_WIDTH;
				}

			} else if (gotoPage < _currentIndex) {

				// This is like clicking go left
				multiple = _currentIndex - gotoPage;

				for (var i = 0;i < multiple;i++) {
					_currentXPosition += WINDOW_WIDTH;
				}

			}

			_currentIndex = gotoPage;

		}

		// When the DOM is ready load the photos!
		Y.on("domready", init);
		Y.on("click", scrollControl, "body .container");

	});