var ss = new Object;

ss.moveNext = function(e){
	nextPos = ss.pos - (86 * ss.increment);
	if(nextPos < ss.max){
		return;
	}	
	ss.pos = nextPos;
	ss.disableBtn(ss.prev);
	ss.disableBtn(ss.next);
  var anim = new YAHOO.util.Anim('thumbs', { marginLeft: {to: ss.pos} }, .6, YAHOO.util.Easing.easeOutStrong);
	anim.onComplete.subscribe(ss.setBtns);
	anim.animate();
}

ss.movePrev = function(){
	nextPos = ss.pos + (86 * ss.increment);
	if(nextPos > 0){
		return;
	}	
	ss.pos = nextPos;
	ss.disableBtn(ss.prev);
	ss.disableBtn(ss.next);
  var anim = new YAHOO.util.Anim('thumbs', { marginLeft: {to: ss.pos} }, .6, YAHOO.util.Easing.easeOutStrong);
	anim.onComplete.subscribe(ss.setBtns);
	anim.animate();
}

ss.setBtns = function(){
	if(ss.pos > ss.max){
		ss.enableBtn(ss.next);
	} else {
		ss.disableBtn(ss.next);
	}
	if(ss.pos < 0){
		ss.enableBtn(ss.prev);
	} else {
		ss.disableBtn(ss.prev);
	}
}

ss.disableBtn = function(btn){
	btn.style.cursor = 'default';
	switch(btn){
		case ss.next:
			YAHOO.util.Event.removeListener(btn, 'click', ss.moveNext);
			btn.src = 'img/btn_next_disabled.gif';
			break;
		default:
			YAHOO.util.Event.removeListener(btn, 'click', ss.movePrev);
			btn.src = 'img/btn_prev_disabled.gif';
	}
}

ss.enableBtn = function(btn){
	btn.style.cursor = 'pointer';
	switch(btn){
		case ss.next:
			YAHOO.util.Event.on(btn, 'click', ss.moveNext, false);
			btn.src = 'img/btn_next.gif';
			break;
		default:
			YAHOO.util.Event.on(btn, 'click', ss.movePrev, false);
			btn.src = 'img/btn_prev.gif';
	}
}

ss.swap = function(e){
	tn = YAHOO.util.Event.getTarget(e);
	for(i=0; i<ss.items.length; i++){
		ss.items[i].className = '';
	}
	tn.parentNode.parentNode.className = 'selected';
	ss.img.src = tn.src.replace('tn_', '');
	document.getElementById('download').href = 'download.php?'+ss.img.src;
	document.getElementById('download2').href = 'download.php?'+ss.img.src;
}

ss.init = function(){
	ss.increment = 3;
	ss.list		= document.getElementById('thumbs');
	ss.items	= ss.list.getElementsByTagName('li');
	ss.next		= document.getElementById('btnNext');
	ss.prev		= document.getElementById('btnPrev');
	ss.img		= document.getElementById('mainImage');
	ss.pos		= 0;
	ss.max		= (Math.floor(ss.items.length / ss.increment) - 2) * -86 * ss.increment;
	ss.list.style.marginLeft = (ss.items.length*-86)+'px';
  var anim = new YAHOO.util.Anim(ss.list, { marginLeft: {to: 0} }, 1.25, YAHOO.util.Easing.easeOut);
	anim.onComplete.subscribe(ss.setBtns);
	anim.animate();
	for(i=0; i<ss.items.length; i++){
		YAHOO.util.Event.on(ss.items[i].getElementsByTagName('a')[0], 'click', ss.swap, false);
	}
}

YAHOO.util.Event.on(window, 'load', ss.init, false);