package lava.net.mmp;

import java.util.Enumeration;
import java.util.Hashtable;
import lava.net.common.UNA;
import lava.net.common.Value;

/**
 *
 **/
public class MMPMultiplexer extends MMPCenter implements MMPPacketManager
{
   /**
    * mapping UNA remote -> UNA local
    **/
   private final Hashtable locals = new Hashtable();

   /**
    *
    **/
   private String name = "/";

   /**
    *
    **/
   private MMPPacketManager manager = null;

   /**
    *
    **/
   private final Hashtable slaves = new Hashtable();

   /**
    *
    **/
   private MMPCenter center = null;

public    class DummyManager implements MMPPacketManager
   {
      /**
       *
       **/
      public String getGreetingBody(UNA remote, UNA local)
      {
         return null;
      }

      /**
       *
       **/
      public void manage(MMPPacket packet)
      {
      }

      /**
       *
       **/
      public void error(MMPException e, UNA remote, UNA local, //
      MMPPacket packet)
      {
      }

   }

   /**
    *
    **/
   public MMPMultiplexer(String name, MMPPacketManager manager, //
   MMPCenter center)
   {
      this.name = normalize(name);
      setManager(manager);
      this.center = center;
   }

   /**
    *
    **/
   private String normalize(String name)
   {
      if(name == null || name.length() <= 0)
         name = this.name;
      if(name.charAt(0) != '/')
         name = this.name + name;
      int l = name.length();
      if(l > 1 && name.charAt(l - 1) != '/')
         name = name + "/";
      return name;
   }

   /**
    *
    **/
   public Value usingProtocols()
   {
      return center.usingProtocols();
   }

   /**
    *
    **/
   public UNA[] getListenLocations()
   {
      UNA[] listen = center.getListenLocations();
      if(listen == null)
         return null;
      for(int i = 0;i < listen.length;++i)
         listen[i] = new UNA(listen[i],name);
      return listen;
   }

   /**
    *
    **/
   public void setManager(MMPPacketManager manager)
   {
      if(manager == null)
         manager = new DummyManager();
      this.manager = manager;
      setManager(null,manager);
   }

   /**
    * TODO: security problem?
    **/
   public void setManager(String name, MMPPacketManager manager)
   {
      name = normalize(name);
      if(manager == null)
         manager = new DummyManager();
      slaves.put(name,manager);
   }

   /**
    *
    **/
   public String[] getVars(UNA remote)
   {
      return center.getVars(remote,getLocal(remote));
   }

   /**
    *
    **/
   protected String[] getVars(UNA remote, UNA local)
   {
      return center.getVars(remote,local);
   }

   /**
    *
    **/
   public Value getValue(UNA remote, String name)
   {
      return center.getValue(remote,getLocal(remote),name);
   }

   /**
    *
    **/
   protected Value getValue(UNA remote, UNA local, String name)
   {
      return center.getValue(remote,local,name);
   }

   /**
    *
    **/
   public Value removeValue(UNA remote, String name)
   {
      return center.removeValue(remote,getLocal(remote),name);
   }

   /**
    *
    **/
   protected Value removeValue(UNA remote, UNA local, String name)
   {
      return center.removeValue(remote,local,name);
   }

   /**
    *
    **/
   public void close()
   {
      for(Enumeration e = locals.keys();e.hasMoreElements();)
      {
         UNA remote = (UNA)e.nextElement();
         UNA local = (UNA)locals.get(remote);
         center.close(remote,local);
      }
   }

   /**
    *
    **/
   protected void close(UNA remote, UNA local)
   {
      center.close(remote,local);
   }

   /**
    *
    **/
   public void close(UNA remote)
   {
      center.close(remote,getLocal(remote));
   }

   /**
    *
    **/
   private String getName(String resource)
   {
      resource = normalize(resource);
      try
      {
         if(!resource.regionMatches(0,name,0,name.length()))
            return null;
         int end = resource.indexOf('/',name.length());
         if(end++ == -1)
            end = resource.length();
         return resource.substring(0,end);
      }
      catch(StringIndexOutOfBoundsException e)
      {
         return null;
      }
   }

   /**
    *
    **/
   public String getGreetingBody(UNA remote, UNA local)
   {
      if(remote == null)
         return null;
      // get the right local, deliver it
      String name = this.name;
      if(local != null)
         name = local.getResource();
      name = getName(name);
      if(name == null)
         // whoups, this was not for us
         return null;
      MMPPacketManager m = (MMPPacketManager)slaves.get(name);
      if(m == null)
      {
         manager.error(new MMPReceiverException(//
         MMPReceiverException.UNKNOWN_LOCAL),remote,local,null);
         m = (MMPPacketManager)slaves.get(name);
         if(m == null)
            return null;
      }
      return m.getGreetingBody(remote,local);
   }

   /**
    *
    **/
   public void error(MMPException e, UNA remote, UNA local, MMPPacket packet)
   {
      if(e == null)
         return;
      // get the right local, deliver it
      String name = this.name;
      if(local != null)
         name = local.getResource();
      name = getName(name);
      if(name == null)
         // whoups, this was not for us
         return;
      MMPPacketManager m = (MMPPacketManager)slaves.get(name);
      if(m == null)
      {
         manager.error(new MMPReceiverException(//
         MMPReceiverException.UNKNOWN_LOCAL),remote,local,packet);
         m = (MMPPacketManager)slaves.get(name);
         if(m == null)
            return;
      }
      m.error(e,remote,local,packet);
      if(e instanceof MMPReceiverException && //
      e.getErrorCode() == MMPReceiverException.CLOSED && remote != null)
         locals.remove(remote);
      if(e instanceof MMPDeliveryException && //
      e.getErrorCode() == MMPDeliveryException.CANNOT_DELIVER && //
      remote != null)
         locals.remove(remote);
   }

   /**
    *
    **/
   public void manage(MMPPacket packet)
   {
      UNA remote = packet.getRemote();
      if(remote == null)
         return;
      UNA local = packet.getLocal();
      if(local != null)
         locals.put(remote,local);
      else
         locals.put(remote,new UNA(null,name));
      // get the right local, deliver it
      String name = this.name;
      if(local != null)
         name = local.getResource();
      name = getName(name);
      if(name == null)
         // whoups, this was not for us
         return;
      MMPPacketManager m = (MMPPacketManager)slaves.get(name);
      if(m == null)
      {
         manager.error(new MMPReceiverException(//
         MMPReceiverException.UNKNOWN_LOCAL),remote,local,packet);
         m = (MMPPacketManager)slaves.get(name);
         if(m == null)
            return;
      }
      m.manage(packet);
   }

   /**
    *
    **/
   public UNA getLocal(UNA remote)
   {
      if(remote == null)
         return new UNA(null,name);
      UNA local = (UNA)locals.get(remote);
      if(local == null)
      {
         local = center.getLocal(remote);
         local = new UNA(local,name);
         locals.put(remote,local);
      }
      return local;
   }

   /**
    *
    **/
   public void assignVariable(UNA remote, String name, Value value)
   {
      center.assignVariable(remote,getLocal(remote),name,value);
   }

   /**
    *
    **/
   protected void assignVariable(UNA remote, UNA local, //
   String name, Value value)
   {
      center.assignVariable(remote,local,name,value);
   }

   /**
    *
    **/
   public void augmentVariable(UNA remote, String name, Value value)
   {
      center.augmentVariable(remote,getLocal(remote),name,value);
   }

   /**
    *
    **/
   protected void augmentVariable(UNA remote, UNA local, //
   String name, Value value)
   {
      center.augmentVariable(remote,local,name,value);
   }

   /**
    *
    **/
   public void diminishVariable(UNA remote, String name, Value value)
   {
      center.diminishVariable(remote,getLocal(remote),name,value);
   }

   /**
    *
    **/
   protected void diminishVariable(UNA remote, UNA local, //
   String name, Value value)
   {
      center.diminishVariable(remote,local,name,value);
   }

   /**
    *
    **/
   public void send(UNA remote, MMPPacket packet)
   {
      center.send(remote,getLocal(remote),packet);
   }

   /**
    *
    **/
   protected void send(UNA remote, UNA local, MMPPacket packet)
   {
      center.send(remote,local,packet);
   }

   /**
    *
    **/
   public Enumeration getAllRemotes()
   {
      return locals.keys();
   }

   /**
    *
    **/
   protected Enumeration getAllRemotes(UNA local)
   {
      return center.getAllRemotes(local);
   }

   /**
    *
    **/
   public void broadcast(MMPPacket packet)
   {
      for(Enumeration e = locals.keys();e.hasMoreElements();)
      {
         UNA remote = (UNA)e.nextElement();
         UNA local = (UNA)locals.get(remote);
         center.send(remote,local,packet);
      }
   }

   /**
    *
    **/
   protected void broadcast(UNA local, MMPPacket packet)
   {
      center.broadcast(local,packet);
   }

}