package lava.net.psyc.packages;

import lava.net.common.UNL;
import lava.net.psyc.PSYCDeliveryException;
import lava.net.psyc.PSYCMessageCenter;
import lava.net.psyc.PSYCPackage;

/**
 *
 **/
public class Echo extends Skeleton 
{
   /**
    *
    **/
   public final static String PackageName = "Echo";

   /**
    *
    **/
   public final static String requestEchoTag = "_request_echo";

   /**
    *
    **/
   private final static String[] requestEchoAliases = {"request_echo"};

   /**
    *
    **/
   public final static String echoTag = "_echo_request";

   /**
    *
    **/
   private final static String[] echoAliases = {"echo_request"};

   class DummyListener implements EchoListener
   {
      /**
       *
       **/
      public void echoPing(UNL source, String body)
      {
         try
         {
            Echo.this.pong(source,body);
         }
         catch(PSYCDeliveryException e)
         {
         }
      }

      /**
       *
       **/
      public void echoPong(UNL source, String body)
      {
      }

   }

   /**
    *
    **/
   private EchoListener listener = new DummyListener();

   /**
    *
    **/
   public Echo()
   {
      this (null);
   }

   /**
    *
    **/
   public Echo(EchoListener listener)
   {
      super();
      setPackageName(PackageName);
      addPackageMethod(requestEchoTag,requestEchoAliases,true);
      addPackageMethod(echoTag,echoAliases,true);
      if(listener != null)
         this.listener = listener;
   }

   /**
    *
    **/
   public boolean understands()
   {
      return !(listener instanceof DummyListener);
   }

   /**
    *
    **/
   public void received(UNL source, String method, String body)
   {
      if(requestEchoTag.equals(method))
         listener.echoPing(source,body);
      else
         if(echoTag.equals(method))
            listener.echoPong(source,body);
   }

   /**
    *
    **/
   public void ping(UNL target, String body) throws PSYCDeliveryException
   {
      center.sendChecked(target,PackageName,requestEchoTag,body);
   }

   /**
    *
    **/
   public void ping(UNL target) throws PSYCDeliveryException
   {
      ping(target,null);
   }

   /**
    *
    **/
   public void pong(UNL target, String body) throws PSYCDeliveryException
   {
      center.sendChecked(target,PackageName,echoTag,body);
   }

   /**
    *
    **/
   public void pong(UNL target) throws PSYCDeliveryException
   {
      pong(target,null);
   }

}