package cz.cuni.amis.pogamut.ut2004.communication.translator.observer.support;
   
   import java.util.ArrayList;
   import java.util.List;
   
   import cz.cuni.amis.fsm.IFSMState;
   import cz.cuni.amis.pogamut.base.communication.messages.InfoMessage;
   import cz.cuni.amis.pogamut.ut2004.communication.translator.TranslatorContext;
   import cz.cuni.amis.pogamut.ut2004.communication.translator.TranslatorMessages;
  import cz.cuni.amis.pogamut.ut2004.communication.translator.UnexpectedMessageException;
  
  /**
   * Support class that takes care of batch of messages in the form of:<p>
   * START_MSG MSG MSG .... MSG END_MSG
   * <p><p>
   * Performs class checks over the symbols that are used to enter / leave the state.
   * <p><p>
   * Stores all the MSGs inside a list.
   * <p><p>
   * To use this state you have to subclass this abstract class, use correct super() inside the constructor of your class
   * and override stateLeaving() method (first by calling super.stateLeaving()) and use getList() to obtain the list
   * of all messages that came between START and END message. 
   * 
   * @author Jimmy
   *
   * @param <MESSAGE>
   * @param <CONTEXT>
   */
  public abstract class ObserverListState<MESSAGE, CONTEXT extends TranslatorContext> extends AbstractObserverFSMState<InfoMessage, CONTEXT> {
  	
  	private List<MESSAGE> messages = null;
  	@SuppressWarnings("unchecked")
  	private Class beginMessage;
  	private Class<MESSAGE> message;
  	@SuppressWarnings("unchecked")
  	private Class endMessage;
  	
  	/**
  	 * @param beginMessage message class that should be used to enter this state
  	 * @param message class of messages we should store inside the list (must be the same as generic type MESSAGE!)
  	 * @param endMessage message class that should be used to leave this state
  	 */
  	@SuppressWarnings("unchecked")
  	public ObserverListState(Class beginMessage, Class<MESSAGE> message, Class endMessage) {
  		this.beginMessage = beginMessage;
  		this.message = message;
  		this.endMessage = endMessage;
  	}
  	
  	protected List<MESSAGE> getList() {
  		return messages;
  	}
  	
  	protected void newList() {
  		messages = new ArrayList<MESSAGE>();
  	}
  
  	@Override
  	public void init(CONTEXT context) {
  		messages = new ArrayList<MESSAGE>();
  	}
  
  	@Override
  	public void restart(CONTEXT context) {
  		messages = new ArrayList<MESSAGE>();
  	}
  
  	@Override
  	public void stateEntering(CONTEXT context, IFSMState<InfoMessage, CONTEXT> fromState, InfoMessage symbol) {
  		if (!symbol.getClass().equals(beginMessage)) throw new UnexpectedMessageException(TranslatorMessages.unexpectedMessage(this, symbol, beginMessage), context.getLogger(), this);
  	}
  
  	@Override
  	public void stateLeaving(CONTEXT context,
  			IFSMState<InfoMessage, CONTEXT> toState, InfoMessage symbol) {
  		if (!symbol.getClass().equals(endMessage)) throw new UnexpectedMessageException(TranslatorMessages.unexpectedMessage(this, symbol, endMessage), context.getLogger(), this);		
  	}
  
  	@Override
  	protected void innerStateSymbol(CONTEXT context, InfoMessage symbol) {
  		if (!symbol.getClass().equals(message)) {
  			if (!message.isAssignableFrom(symbol.getClass())) {
  				throw new UnexpectedMessageException(TranslatorMessages.unexpectedMessage(this, symbol, message), context.getLogger(), this);
  			}
  		}
  		messages.add(message.cast(symbol));
  	}
  
  }