package lava.net.psyc.packages;

import java.util.Enumeration;
import java.util.Hashtable;
import lava.net.common.UNL;
import lava.net.psyc.PSYCDeliveryException;
import lava.net.psyc.PSYCMessageCenter;
import lava.net.psyc.PSYCPackage;

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

   class DummyListener implements NotificationServerListener
   {
      /**
       *
       **/
      public void notificationRequestSubscribe(UNL source, String body)
      {
         try
         {
            subscribe(source);
         }
         catch(PSYCDeliveryException e)
         {
         }
      }

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

   }

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

   /**
    *
    **/
   private Hashtable subscribed = new Hashtable();

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

   /**
    *
    **/
   public NotificationServer(NotificationServerListener listener)
   {
      super();
      setPackageName(PackageName);
      addPackageMethod(Notification.subscribeTag,//
      Notification.subscribeAliases,true);
      addPackageMethod(Notification.unsubscribeTag,//
      Notification.unsubscribeAliases,true);
      addPackageMethod(Notification.subscribedTag,//
      Notification.subscribedAliases,false);
      addPackageMethod(Notification.refusedTag,//
      Notification.refusedAliases,false);
      addPackageMethod(Notification.unsubscribedTag,//
      Notification.unsubscribedAliases,false);
      addPackageMethod(Notification.signonTag,//
      Notification.signonAliases,false);
      addPackageMethod(Notification.signoffTag,//
      Notification.signoffAliases,false);
      if(listener != null)
         this.listener = listener;
   }

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

   /**
    *
    **/
   public boolean wantsErrors()
   {
      return true;
   }

   /**
    *
    **/
   public void received(UNL source, String method, String body)
   {
      if(method.equals(Notification.subscribeTag))
      {
         listener.notificationRequestSubscribe(source,body);
      }
      else
         if(method.equals(Notification.unsubscribeTag))
         {
            try
            {
               unsubscribe(source,body);
            }
            catch(PSYCDeliveryException e)
            {
            }
         }
   }

   /**
    *
    **/
   public void reset(UNL source)
   {
      removeSubscribed(source);
   }

   /**
    *
    **/
   public void addSubscribed(UNL source)
   {
      subscribed.put(source,source);
   }

   /**
    *
    **/
   public void removeSubscribed(UNL source)
   {
      subscribed.remove(source);
   }

   /**
    *
    **/
   public boolean isSubscribed(UNL source)
   {
      return subscribed.get(source) != null;
   }

   /**
    *
    **/
   public Enumeration getSubscribed()
   {
      return subscribed.keys();
   }

   /**
    *
    **/
   public void subscribe(UNL target, String body) throws PSYCDeliveryException
   {
      center.sendChecked(target,Notification.PackageName,//
      Notification.subscribedTag,body);
      addSubscribed(target);
   }

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

   /**
    *
    **/
   public void refuse(UNL target, String body) throws PSYCDeliveryException
   {
      removeSubscribed(target);
      center.sendChecked(target,Notification.PackageName,//
      Notification.refusedTag,body);
   }

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

   /**
    *
    **/
   public void unsubscribe(UNL target, String body) //
   throws PSYCDeliveryException
   {
      if(!isSubscribed(target))
         return;
      removeSubscribed(target);
      PSYCDeliveryException ex = null;
      try
      {
         center.sendChecked(target,Notification.PackageName,//
         Notification.unsubscribedTag,body);
      }
      catch(PSYCDeliveryException e)
      {
         ex = e;
      }
      listener.notificationUnsubscribed(target,body);
      if(ex != null)
         throw ex;
   }

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

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

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

   /**
    *
    **/
   public void signon(String body)
   {
      UNL target = null;
      for(Enumeration e = getSubscribed();e.hasMoreElements();)
         try
         {
            signon(target = (UNL)e.nextElement(),body);
         }
         catch(PSYCDeliveryException ex)
         {
            try
            {
               unsubscribe(target,body);
            }
            catch(PSYCDeliveryException exx)
            {
            }
         }
   }

   /**
    *
    **/
   public void signon()
   {
      signon((String)null);
   }

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

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

   /**
    *
    **/
   public void signoff(String body)
   {
      UNL target = null;
      for(Enumeration e = getSubscribed();e.hasMoreElements();)
         try
         {
            signoff(target = (UNL)e.nextElement(),body);
         }
         catch(PSYCDeliveryException ex)
         {
            try
            {
               unsubscribe(target,body);
            }
            catch(PSYCDeliveryException exx)
            {
            }
         }
   }

   /**
    *
    **/
   public void signoff()
   {
      signoff((String)null);
   }

}