/*******************************************************************************

"FreePastry" Peer-to-Peer Application Development Substrate

Copyright 2002-2007, Rice University. Copyright 2006-2007, Max Planck Institute 
for Software Systems.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.

- Neither the name of Rice  University (RICE), Max Planck Institute for Software 
Systems (MPI-SWS) nor the names of its contributors may be used to endorse or 
promote products derived from this software without specific prior written 
permission.

This software is provided by RICE, MPI-SWS and the contributors on an "as is" 
basis, without any representations or warranties of any kind, express or implied 
including, but not limited to, representations or warranties of 
non-infringement, merchantability or fitness for a particular purpose. In no 
event shall RICE, MPI-SWS or contributors be liable for any direct, indirect, 
incidental, special, exemplary, or consequential damages (including, but not 
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or otherwise) arising in any way out of the use of this software, even if 
advised of the possibility of such damage.

*******************************************************************************/ 
package rice.tutorial.remotesocket;

import java.io.IOException;
import java.nio.ByteBuffer;

import rice.p2p.commonapi.*;
import rice.p2p.commonapi.appsocket.*;

/**
 * By calling sendMyMsgDirect(NodeHandle nh), this Application opens a socket to MyApp on the requested node, and sends it's Id. 
 * 
 * @author Jeff Hoye
 */
public class MyApp implements Application {
  /**
   * The Endpoint represents the underlieing node.  By making calls on the 
   * Endpoint, it assures that the message will be delivered to a MyApp on whichever
   * node the message is intended for.
   */
  protected Endpoint endpoint;
  
  /**
   * The node we were constructed on.
   */
  protected Node node;

  /**
   * The message to receive.
   */
  ByteBuffer in;
  
  int MSG_LENGTH;
  
  public MyApp(Node node, final IdFactory factory) {
    // register the endpoint
    this.endpoint = node.buildEndpoint(this, "myinstance");
    this.node = node;
    
    // create the output message
    MSG_LENGTH = node.getLocalNodeHandle().getId().toByteArray().length;
    
    // create a buffer for the input message
    in = ByteBuffer.allocate(MSG_LENGTH);
    
    // example receiver interface
    endpoint.accept(new AppSocketReceiver() {
      /**
       * When we accept a new socket.
       */
      public void receiveSocket(AppSocket socket) {
        // this code reuses "this" AppSocketReceiver, and registers for reading only, and a timeout of 30000. 
        socket.register(true, false, 30000, this);
        
        // it's critical to call this to be able to accept multiple times
        endpoint.accept(this);
      }    

      /**
       * Called when the socket is ready for reading or writing.
       */
      public void receiveSelectResult(AppSocket socket, boolean canRead, boolean canWrite) {
        in.clear();
        try {
          // read from the socket into ins
          long ret = socket.read(in);    
          
          if (ret != MSG_LENGTH) {
            // if you sent any kind of long message, you would need to handle this case better
            System.out.println("Error, we only received part of a message."+ret+" from "+socket);
            return;
          }
            
          System.out.println(MyApp.this.node.getLocalNodeHandle()+" Received message from "+factory.buildId(in.array()));        
        } catch (IOException ioe) {
          ioe.printStackTrace(); 
        }
        // only need to do this if expecting more messages
//        socket.register(true, false, 3000, this);        
      }
    
      /**
       * Called if we have a problem.
       */
      public void receiveException(AppSocket socket, Exception e) {
        e.printStackTrace();
      }    
    });
    
    // register after we have set the AppSocketReceiver
    endpoint.register();
  }

  /**
   * Getter for the node.
   */
  public Node getNode() {
    return node;
  }
  
  /**
   * Called when we receive a message.
   */
  public void deliver(Id id, Message message) {
    System.out.println(this+" received "+message);
  }

  /**
   * Called when you hear about a new neighbor.
   * Don't worry about this method for now.
   */
  public void update(NodeHandle handle, boolean joined) {
  }
  
  /**
   * Called a message travels along your path.
   * Don't worry about this method for now.
   */
  public boolean forward(RouteMessage message) {
    return true;
  }
  
  public String toString() {
    return "MyApp "+endpoint.getId();
  }
}
