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

   /**
    *
    **/
   public final static String requestTraceTag = "_request_trace";

   /**
    *
    **/
   private final static String[] requestTraceAliases = {"request_trace"};

   /**
    *
    **/
   public final static String echoTraceTag = "_echo_trace";

   /**
    *
    **/
   private final static String[] echoTraceAliases = //
   {"echo_trace"};

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

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

   }

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

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

   /**
    *
    **/
   public Trace(TraceListener listener)
   {
      super();
      setPackageName(PackageName);
      addPackageMethod(requestTraceTag,requestTraceAliases,true);
      addPackageMethod(echoTraceTag,echoTraceAliases,true);
      if(listener != null)
         this.listener = listener;
   }

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

   /**
    *
    **/
   public void received(UNL source, String method, String body)
   {
      if(requestTraceTag.equals(method))
         listener.tracePing(source,body);
      else
         if(echoTraceTag.equals(method))
            listener.tracePong(source,body);
   }

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

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

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

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

}