window.addEvent('domready', function() {

	/* ----------Config Vars----------- */
	var slideTimer = 15000;  //time between slides (1 second = 1000), a.k.a. the interval duration
	var transitionTime = 1000; //transition time (1 second = 1000)
	var items = $$('.slide');  //Get array of elements for sliding
	var prevBtn = $('prevbtn');
	var playBtn = $('playbtn');
	var nextBtn = $('nextbtn');
	var itemNum = 0;  //initialize a variable to hold the current slide index
	var isPaused = 0;

	/* --------end config vars-------- */

	//Setup positions
	items.each(function(element, index) {

		//since the viewer obviously has javascript on, we can remove the 'first_item' class
		if(index == 0){
			element.removeClass('first_item');
			element.setStyle('left', "0");
		}
		else{
			element.setStyle('left', "671px");
		}

	});

	var numItems = items.length;  //get number of slider items
	//end setup



	//Slider Stuff
	var slideForward = function(){ 

		//get item to slide out
		var curItem = items[itemNum];  

		//change index
		if(itemNum < (numItems - 1)){
			itemNum++; 
		}
		else{
			itemNum = 0;
		}

		//now get item to slide in using new index
		var newItem = items[itemNum];


		//set up our animation stylings for out and in motions (note:  Fx.Styles does NOT exist in moo 1.2, so we must use Fx.Morph or Fx.Tween)
		var item_in = new Fx.Morph(newItem, {
				 duration: transitionTime, 
				 transition: Fx.Transitions.Quad.easeInOut, 
				 wait:false
		});

		var item_out = new Fx.Morph(curItem, {
				 duration: transitionTime, 
				 transition: Fx.Transitions.Quad.easeInOut, 
				 wait:false
		});

		//we will set a beginning value here
		//this is so that it gives the illusion of continuous motion from one direction, even after the first cycle of items
		item_in.start({
		'left': [671, 0]
		});

		//no beginning values needed, since we always want to push the old item out to the left
		item_out.start({
		'left': '-671'
		});

	};


	var slideBackward = function(){ 

		//get item to slide out
		var curItem = items[itemNum];  

		//change index for reverse movement
		if(itemNum > 0){
			itemNum--; 
		}
		else{
			itemNum = (numItems - 1);
		}

		//now get item to slide in using new index
		var newItem = items[itemNum];


		var item_in = new Fx.Morph(newItem, {
				 duration: transitionTime, 
				 transition: Fx.Transitions.Quad.easeInOut, 
				 wait:false
		});

		var item_out = new Fx.Morph(curItem, {
				 duration: transitionTime, 
				 transition: Fx.Transitions.Quad.easeInOut, 
				 wait:false
		});


		//we will set a beginning value here too, but this time to make it come from left to right
		item_in.start({
		'left': [-671, 0]
		});

		//no beginning values needed
		item_out.start({
		'left': '671'
		});

	};
	//end slideBackward


	//call the slider function periodically
	var theTimer = slideForward.periodical(slideTimer, this); 

	nextBtn.addEvent('click', function(){
		if(isPaused == 0){
			$clear(theTimer);
			theTimer = slideForward.periodical(slideTimer);
		}
		slideForward();
	});

	prevBtn.addEvent('click', function(){
		if(isPaused == 0){
			$clear(theTimer);
			theTimer = slideForward.periodical(slideTimer);
		}				     
		slideBackward();
	});

	playBtn.addEvent('click', function(){
		if(isPaused == 0){
			isPaused = 1;
			$clear(theTimer);
			this.set('html', 'přehrávat automaticky');
		}
		else{
			isPaused = 0;
			slideForward();
			theTimer = slideForward.periodical(slideTimer); 
			this.set('html', 'zastavit');
		}
	 });


});