//SlideShow Class
//Class to manage HSMO-Style slideshow
//Slides are expected to be in the form of <li id="slideID"><a class="choice" href="#">Text</a><span class="divider">: </span><a class="spotlight"><img src="url" alt="alt text"></a></li>
//Members:
// - slides : 
// - currentSlide : 
// - maxSlide : 
// - delay : 
//Methods:
// - addSlide : 
// - setDelay : 
// - changeSlide : 
// - reset : 
// - jumpToSlide : 
function SlideShow()
{
	this.slides = new Array();
	this.currentSlide = 0;
	this.maxSlide = -1;
	this.delay = 5; //Number of seconds per slide
}

//Returns page from the section
//Params:
// - id : HTML ID of the slide to add to the slideshow.
SlideShow.prototype.addSlide = 
	function(id)
	{
		var slide = $('#'+id);
		if (this.maxSlide >= 0)
		{
			var prevSlide = this.slides[this.maxSlide].children('.spotlight');
			slide.children('.spotlight').css({
				'position' : 'absolute',
				'top' : 0,
				'left' : 0
			});
		}
		else
		{
			slide.children('.spotlight').css({
				'position' : 'absolute',
				'top' : 0,
				'left' : 0
			});
		}
		this.slides.push(slide);
		this.maxSlide++;
	}

//Sets the delay for each slide in the slideshow
//Params:
// - delay : new delay for each slide in seconds
SlideShow.prototype.setDelay =
	function(delay)
	{
		this.delay = delay;
	}
	
//Changes the slide to the next on in the rotation.  If at the last slide, start over.
SlideShow.prototype.changeSlide =
	function()
	{
		this.slides[this.currentSlide].children('.spotlight').hide();
		this.slides[this.currentSlide].children('.divider').hide();
		this.slides[this.currentSlide].children('.choice').css('background-position', '0 0');
		this.currentSlide++;
		if (this.currentSlide > this.maxSlide)
		{
			this.reset();
			return;
		}
		this.slides[this.currentSlide].children().show();
		this.slides[this.currentSlide].children('.choice').css('background-position', '0 -58px');
	}
	
//Resets the slideshow back to its first slide
SlideShow.prototype.reset = 
	function()
	{
		//Hide all slides after the first
		for (var i = 1; i < this.currentSlide; i++)
		{
			this.slides[i].children('.spotlight').hide();
			this.slides[i].children('.divider').hide();
		}
		//Reset slide counter
		this.currentSlide = 0;
		this.slides[this.currentSlide].children().show();
		this.slides[this.currentSlide].children('.choice').css('background-position', '0 -58px');
	}
	
//Jumps to a certain slide
//Params:
// - slideID : HTML ID of slide to jump to.
SlideShow.prototype.jumpToSlide =
	function (slideID)
	{
		//Hide all slides
		for (i = 0; i <= this.maxSlide; i++)
		{
			this.slides[i].children('.spotlight').hide();
			this.slides[i].children('.divider').hide();
			this.slides[i].children('.choice').css('background-position', '0 0');
		}
		//Set slide counter to given slide and make visible
		for (var i = 0; i <= this.maxSlide; i++)
		{
			if (this.slides[i].attr('id') == slideID)
			{
				this.currentSlide = i;
				this.slides[this.currentSlide].children().show();
				this.slides[this.currentSlide].children('.choice').css('background-position', '0 -58px');
			}
		}
	}

//Load up new slideshow
var slideshow = new SlideShow();

var isActive = 0;
var timeOut;

function start()
{
	if (isActive == 0)
	{
		timeOut = setTimeout(changeSlide, slideshow.delay * 1000);
		isActive = 1;
	}
}

function changeSlide()
{
	if (isActive == 1)
	{
		slideshow.changeSlide();
		timeOut = setTimeout(changeSlide, slideshow.delay * 1000);
	}
}

function pause()
{
	if (isActive == 1)
	{
		clearTimeout(timeOut);
	}
	isActive = 0;
}

//Start Slideshow once the DOM is fully loaded
$(document).ready(function () {
	$('#mainpage').css('background-image', 'none');
	slideshow.addSlide('choice1');
	slideshow.addSlide('choice2');
	slideshow.addSlide('choice3');
	slideshow.addSlide('choice4');
	slideshow.addSlide('choice5');
	$('#mainpage li').each(function() { $(this).mouseover(function() { pause(); slideshow.jumpToSlide($(this).attr('id')); }); $(this).mouseout(function() { start(); }); });
	slideshow.reset();
	start(slideshow);
});