$(document).ready(function () {

	// some data used for the slider
	var sliderData = {
		container:		$('#spotlight'),
		totalSlides:	0,
		totalWidth:		0,
		slideWidth:		0,
		currentSlide:	0,
		autoPlay:		7000,
		timeoutVar:		null,
		moving:			false
	}
	
	/* assign unique IDs to each slide */
	$('.spotlightCell',sliderData.container).each(function (i) {
		$(this).data('id',i+1);
	});
	
	/* fill in some of the data */
	sliderData.totalSlides = $('.spotlightCell',sliderData.container).length;
	sliderData.slideWidth = 598;
	sliderData.totalWidth = 598 * sliderData.totalSlides;
	sliderData.currentSlide = 1;
	
	/* set the width of the slider - this will allow the slides to line up horizontally */
	$('#spotlightContent',sliderData.container).width(sliderData.totalWidth);
	
	/* functions to return the next and previous slide numbers based on the current slide */
	function getPreviousNum() {
		if (sliderData.currentSlide - 1 == 0)
			return sliderData.totalSlides;
		return sliderData.currentSlide - 1;
	}
	function getNextNum() {
		if (sliderData.currentSlide + 1 > sliderData.totalSlides)
			return 1;
		return sliderData.currentSlide + 1;
	}
	/* obtain a slide based on the given ID number */
	function getSlide(num) {
		var $slide = null;
		$('.spotlightCell',sliderData.container).each(function () {
			if ($(this).data('id') == num) {
				$slide = $(this);
				return;
			}
		});
		return $slide;
	}
	
	function autoPlay() {
		// clear the timeout var if it exists
		if (sliderData.timeoutVar != null) {
			sliderData.timeoutVar = clearTimeout(sliderData.timeoutVar);
		}
		// set interval for moving if autoplay is set
		if (sliderData.autoPlay != 0) {
			sliderData.timeoutVar = setTimeout(function () {
				move(true);
			}, sliderData.autoPlay);
		}
	}
	// call auto rotate right away
	autoPlay();
	
	/* this function is what makes the slider circular in nature 
	 * it will keep moving the first slide to the end or the last slide
	 * to the beginning depending on if the slide hit the front/end and
	 * the direction desired */
	function moveSlides(direction) {
		// Gather some information about the current slide and adjacent slide
		// *note: in this case the adjacent slide is the next one that should be served.
		// if there is none there, then we need to detach a slide and move it
		var $currentSlide = getSlide(sliderData.currentSlide);
		var nextSlideNum;
		var $adjacentSlide;
		if (direction == false) {
			nextSlideNum = getPreviousNum();
			$adjacentSlide = $currentSlide.prev();
		} else {
			nextSlideNum = getNextNum();
			$adjacentSlide = $currentSlide.next();
		}
		
		// If there is no slide where we are sliding to, we need to detach one from the end and
		// brint it to position
		if ($adjacentSlide.length == 0) {
			// Get the slide we are going to move
			var $slideToMove = getSlide(nextSlideNum);
			// Because we are moving slides around, as soon as they are actually repositioned, the position
			// of the slider needs to be adjusted to compensate for this so that when the slides are 
			// moved the slider remains showing the same slide
			if (direction == false) {
				// in this case we are taking a slide from the end and bringing to the front
				$('#spotlightContent',sliderData.container).css('marginLeft', function (index,val) {
					// so shift the margin to the left so the focused slide stays in view
					return parseInt(val) - sliderData.slideWidth;
				});
				// now that the slider has moved, we detach and move the slide
				// after both of these steps the slider will still show the same slide
				$slideToMove.detach().insertBefore($currentSlide);
			} else {
				// in this case we are taking a slide from the beginning and moving it to the end
				$('#spotlightContent',sliderData.container).css('marginLeft', function (index,val) {
					// so shift the margin of the slider to the right so the focused slide remains viewed
					return parseInt(val) + sliderData.slideWidth;
				});
				// see above
				$slideToMove.detach().insertAfter($currentSlide);
			}
		}
	}
	
	/** function called to move the slider in the given direction */
	function move(direction) {
		// Don't move the slider if it's already moving
		if (!sliderData.moving) {

			// move slides if necessary
			moveSlides(direction);
			// slider is now moving
			sliderData.moving = true;
	
			// determine if we add or subtract from the margin
			var operator;
			if (direction == false) {
				operator = '+=';
			} else {
				operator = '-=';
			}
			$('#spotlightContent',sliderData.container).animate(
				{
					// animate the margin
					marginLeft: operator+sliderData.slideWidth
				},
				function () {
					// call autoplay to reset timer
					autoPlay();
					// slider no longer moving...
					sliderData.moving = false;
					if (direction == false)
						sliderData.currentSlide = getPreviousNum();
					else
						sliderData.currentSlide = getNextNum();
				}
			);
		}
	}
	// arrow handlers
	$('.spotlightArrow-left',sliderData.container).click(function () {
		move(false);	
	});
	$('.spotlightArrow-right',sliderData.container).click(function () {
		move(true);	
	});
	// add pointer cursor to arrows
	$('.spotlightArrow',sliderData.container).css('cursor','pointer');
});