//YAHOO.util.UserAction.click(document.body); 

var __ROTATE_MEDIA_CENTER__ = true;
var __SELECTED_MEDIA_CENTER__ = 0;
var __TABS_MEDIA_CENTER__ = null;
var __BG_MEDIA_CENTER__ = null;

// a = ul.id, b = time interval in seconds
function
rotateMediaCenter(a, b) {
	var obj = document.getElementById(a);
	var tabs = (obj) ? obj.getElementsByTagName("a") : null; 
	if ( tabs ) {	
		// keep track of root object
		__BG_MEDIA_CENTER__ = obj;
		// keep track of the tab
		__TABS_MEDIA_CENTER__ = tabs;
		
		// set click event for each tab
		for ( var i = 0; i < tabs.length; i++) {
			var clickObj = { sel: i };
			YAHOO.util.Event.addListener(tabs[i], "click", function(ev, evObj) { 
				__ROTATE_MEDIA_CENTER__ = false; 
				for ( var idx = 0; idx < 4; idx++) {
					deactMediaCenterTab (idx);
				}
				actMediaCenterTab (evObj.sel);
			}, clickObj); 
		}
		
		var cycle = b*1000;
		var fn = function () {
				if (__ROTATE_MEDIA_CENTER__ && __TABS_MEDIA_CENTER__){
					var _a = __TABS_MEDIA_CENTER__;
					__SELECTED_MEDIA_CENTER__ = __SELECTED_MEDIA_CENTER__ + 1;
					if ( __SELECTED_MEDIA_CENTER__ >= _a.length ) {
						__SELECTED_MEDIA_CENTER__ = 0;
					}
					// select and deselect
					for ( var _i = 0; _i < _a.length; _i++) {
						deactMediaCenterTab (_i);
					}
					actMediaCenterTab (__SELECTED_MEDIA_CENTER__);
				}
			}
		
		// set pulse
		setInterval( fn, cycle );
	}
}

function
actMediaCenterTab (i) {
	var a = __TABS_MEDIA_CENTER__;
	
	if (a[i]) {
		var stage = "tab" + (i+1);
		var btn = "tabbtn" + (i+1);
		var p = a[i].parentNode;

		p.title = "active";
		YAHOO.util.Dom.addClass( btn, "selected" );
		YAHOO.util.Dom.removeClass(  stage, "yui-hidden" );
		
		var pos = i * -1 * 350; // 350 = height of media center
		__BG_MEDIA_CENTER__.style.backgroundPosition = "0 " + pos + "px";
	}
}

function
deactMediaCenterTab (i) {
	var a = __TABS_MEDIA_CENTER__;
	if (a[i]) {
		var stage = "tab" + (i+1);
		var btn = "tabbtn" + (i+1);
		var p = a[i].parentNode;
		
		p.title = "";
		YAHOO.util.Dom.removeClass( btn, "selected" );
		YAHOO.util.Dom.addClass( stage, "yui-hidden" );
	}
}

function
toggleMediaCenter() {
	__ROTATE_MEDIA_CENTER__ = !__ROTATE_MEDIA_CENTER__;
	
	var o = YAHOO.util.Dom.getElementsByClassName('btn-pause', 'a');
	for( var i=0; i < o.length; i++) {
		o[i].innerHTML = (__ROTATE_MEDIA_CENTER__) ? "Pause" : "Play";
	}
}