package
{
	import flash.utils.getTimer;
	
	/**
	 * TimeSync maintains a seperate time value from the system clock.
	 */
	public class TimeSync
	{
		private static var _instance:TimeSync;
		
		public static function getInstance():TimeSync
		{
			if (_instance == null) _instance = new TimeSync();
			return _instance; 
		}
		
		/**
		 * Internal time-stamp value to sync to.
		 * Must be set using sync().
		 */
		protected var _syncStamp:Number;
		
		/**
		 * Time-stamp for the internal flash getTimer().
		 */
		protected var _timerStamp:Number;
		
		public function TimeSync() {}
		
		/**
		 * The time elapsed since the last sync, in millseconds.
		 */
		public function get delta():Number
		{
			return (getTimer() - _timerStamp);
		}
		
		/**
		 * The synchronized time value, in milliseconds. Pass this into
		 * a new Date object to get formatted time: new Date(time);
		 */
		public function get time():Number
		{
			return (_syncStamp + delta);
		}
				
		/**
		 * Sync the timer to a new time value.
		 * @param time Unix time value in milliseconds
		 */
		public function sync(time:Number):void
		{
			_syncStamp = time;
			_timerStamp = getTimer();
		}
	}
}