YAHOO.namespace('rumsby');

YAHOO.rumsby.PrevNext = function() {
	var count = 0;
	
	return {
		next: function() {
			count = Math.min(YAHOO.rumsby.PrevNext.MAX, ++count);
			return count;
		},
		
		prev: function() {
			count = Math.max(0, --count);
			return count;
		}
	};
}();

YAHOO.rumsby.PrevNext.MAX = 4;

YAHOO.util.Event.onDOMReady(
	function() {
		if (YAHOO.env.ua.ie > 0 && YAHOO.env.ua.ie < 7) {
			return;
		}
		
		var Dom = YAHOO.util.Dom;
		var Event = YAHOO.util.Event;
		var KeyListener = YAHOO.util.KeyListener;
				
		var ul = document.createElement('ul');
		ul.id = 'prevNext';
		var li = [];
		
		var next = document.createElement('a');
		next.href = '#';
		next.appendChild(document.createTextNode('next(j)'));
		
		li.push(document.createElement('li'));
		li[0].appendChild(next);

		var prev = document.createElement('a');
		prev.href = '#';
		prev.appendChild(document.createTextNode('prev(k)'));
		
		li.push(document.createElement('li'));
		li[1].appendChild(prev);										

		for (var i = 0; i < li.length; i++) {
			ul.appendChild(li[i]);
		}
		
		var choosePrev = function(e) {
			var n = YAHOO.rumsby.PrevNext.prev();
			
			window.location.href = n ? '#post-' + n : '#';
			Event.stopEvent(e);
		};
		
		var chooseNext = function(e) {
			window.location.href = '#post-' + YAHOO.rumsby.PrevNext.next();
			Event.stopEvent(e);
		};
		
		Event.addListener(next, 'click', chooseNext);
		Event.addListener(prev, 'click', choosePrev);
		new KeyListener(document, { keys: 74 }, chooseNext).enable();
		new KeyListener(document, { keys: 75 }, choosePrev).enable();

		Dom.insertAfter(ul, Dom.getElementsByClassName('Content', 'div')[0]);

		document.body.appendChild(ul);		
	}
);