var slide_stepSize = 984;
var slide_index = 0;
var slide_length;

window.addEvent('load', function(){
	var as = $$('div#head_slideshow_iface_inner a.switch_link');
	for(var a=0; a<as.length; a++){
		as[a].setProperty('rel', a);
		as[a].addEvent('click', function(){
			slide_setSlide($(this).getProperty('rel'), false);
		});
	}
	slide_length = as.length;
	$('head_slideshow_iface').setStyle('width', (slide_length * 21 + 20) + 'px');
	if(slide_length > 0){
		var slideshow_overlay = new Element('div', {'id':'head_image_overlay'});
		var prev_button = new Element('a', {'href':'javascript:slide_previous();', 'id':'slideshow_prev'});
		prev_button.addClass('slideshow_button');
		var next_button = new Element('a', {'href':'javascript:slide_next();', 'id':'slideshow_next'});
		next_button.addClass('slideshow_button');
		slideshow_overlay.adopt(prev_button);
		slideshow_overlay.adopt(next_button);
		slideshow_overlay.inject($('wrapper'), 'before');
	}
	if( $('head_slideshow_items').getChildren('div.slideshow_item').length > 1 ){
		if( $('head_slideshow_items').getFirst('div.slideshow_item') != null ){
			var newLast = $('head_slideshow_items').getFirst('div.slideshow_item').clone();
			newLast.inject( $('head_slideshow_items').getLast('div.slideshow_item'), 'after' );
		}
	}
});

function slide_setSlide(i, tween){
	var nl = i.toInt() * slide_stepSize * -1;
	var transition = (i > slide_index) ? 'back:out' : 'back:in:out';
	var tween = new Fx.Tween($('head_slideshow_items'), {duration:'long', transition:transition});
	tween.onComplete = function(){
		if( slide_index >= slide_length ){
			$('head_slideshow_items').setStyle('left', '0px');
			slide_index = 0;
			slide_setSlide(0, false);
		}
	}
	if(tween){
		tween.start('left', nl + 'px');
	}else{
		tween.set('left', nl + 'px');
	}
	var as = $$('div#head_slideshow_iface_inner a.switch_link');
	for(var a=0; a<as.length; a++){
		as[a].removeClass('active');
	}
	if(as[i] != null){
		as[i].addClass('active');
	}
	slide_index = i.toInt();
}

function slide_previous(){
	var ni = slide_index - 1;
	if(ni < 0){
		var nl = slide_length.toInt() * slide_stepSize * -1;
		$('head_slideshow_items').setStyle('left', nl + 'px');
		ni = slide_length - 1;
	}
	slide_setSlide(ni, true);
}

function slide_next(){
	var ni = slide_index + 1;
	if(ni > slide_length){
		ni = 0;
	}
	slide_setSlide(ni, true);
}