package cz.cuni.amis.pogamut.ut2004.communication.translator;
   
   import java.util.ArrayList;
   import java.util.List;
   
   import com.google.inject.ImplementedBy;
   
   import cz.cuni.amis.pogamut.base.communication.translator.event.IWorldChangeEvent;
   
  /**
   * Interface for the world event queue that is used to transport new world events from the FSM to MessageTranslator. 
   * @author Jimmy
   */
  @ImplementedBy(value=IWorldEventQueue.Queue.class)
  public interface IWorldEventQueue {
  	
  	/**
  	 * Add event to the queue.
  	 * @param event
  	 */
  	public void pushEvent(IWorldChangeEvent event);
  	
  	/**
  	 * Add events to the queue.
  	 * @param events
  	 */
  	public void pushEvent(IWorldChangeEvent[] events);
  	
  	/**
  	 * Returns all events in the queue + removes them from the queue.
  	 * <p><p>
  	 * If there are no event this must return an empty array. 
  	 * @return
  	 */
  	public IWorldChangeEvent[] popEvents();
  	
  	public static class Queue implements IWorldEventQueue {
  		
  		private List<IWorldChangeEvent> events = new ArrayList<IWorldChangeEvent>(50);
  
  		@Override
  		public IWorldChangeEvent[] popEvents() {
  			IWorldChangeEvent[] newEvents = this.events.toArray(new IWorldChangeEvent[events.size()]);
  			this.events.clear();
  			return newEvents;
  		}
  		
  		@Override
  		public void pushEvent(IWorldChangeEvent event) {
  			events.add(event);
  		}
  
  		@Override
  		public void pushEvent(IWorldChangeEvent[] events) {
  			for (IWorldChangeEvent event : events) this.events.add(event);
  		} 
  		
  	}
  
  }