//
   //  ========================================================================
   //  Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.spdy.server;
  
  import java.io.IOException;
  import java.util.List;
  
  import javax.net.ssl.SSLEngine;
  import javax.net.ssl.SSLEngineResult;
  
  import org.eclipse.jetty.io.AbstractConnection;
  import org.eclipse.jetty.io.Connection;
  import org.eclipse.jetty.io.EndPoint;
  import org.eclipse.jetty.npn.NextProtoNego;
  import org.eclipse.jetty.server.ConnectionFactory;
  import org.eclipse.jetty.server.Connector;
  import org.eclipse.jetty.util.BufferUtil;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  public class NPNServerConnection extends AbstractConnection implements NextProtoNego.ServerProvider
  {
      private final Logger LOG = Log.getLogger(getClass());
      private final Connector connector;
      private final SSLEngine engine;
      private final List<String> protocols;
      private final String defaultProtocol;
      private String nextProtocol; // No need to be volatile: it is modified and read by the same thread
  
      public NPNServerConnection(EndPoint endPoint, SSLEngine engine, Connector connector, List<String> protocols, String defaultProtocol)
      {
          super(endPoint, connector.getExecutor());
          this.connector = connector;
          this.protocols = protocols;
          this.defaultProtocol = defaultProtocol;
          this.engine = engine;
          NextProtoNego.put(engine, this);
      }
  
      @Override
      public void onOpen()
      {
          super.onOpen();
          fillInterested();
      }
  
      @Override
      public void onFillable()
      {
          int filled = fill();
  
          if (filled == 0)
          {
              if (nextProtocol == null)
              {
                  if (engine.getHandshakeStatus() == SSLEngineResult.HandshakeStatus.NOT_HANDSHAKING)
                  {
                      // Here the SSL handshake is finished, but while the client sent
                      // the NPN extension, the server application did not select the
                      // protocol; we need to close as the protocol cannot be negotiated.
                      LOG.debug("{} missing next protocol. SSLEngine: {}", this, engine);
                      close();
                  }
                  else
                  {
                      // Here the SSL handshake is not finished yet but we filled 0 bytes,
                      // so we need to read more.
                      fillInterested();
                  }
              }
              else
              {
                  ConnectionFactory connectionFactory = connector.getConnectionFactory(nextProtocol);
                  if (connectionFactory == null)
                  {
                      LOG.debug("{} application selected protocol '{}', but no correspondent {} has been configured",
                              this, nextProtocol, ConnectionFactory.class.getName());
                      close();
                  }
                  else
                  {
                      EndPoint endPoint = getEndPoint();
                      Connection oldConnection = endPoint.getConnection();
                     Connection newConnection = connectionFactory.newConnection(connector, endPoint);
                     LOG.debug("{} switching from {} to {}", this, oldConnection, newConnection);
                     oldConnection.onClose();
                     endPoint.setConnection(newConnection);
                     getEndPoint().getConnection().onOpen();
                 }
             }
         }
         else if (filled < 0)
         {
             // Something went bad, we need to close.
             LOG.debug("{} closing on client close", this);
             close();
         }
         else
         {
             // Must never happen, since we fill using an empty buffer
             throw new IllegalStateException();
         }
     }
 
     private int fill()
     {
         try
         {
             return getEndPoint().fill(BufferUtil.EMPTY_BUFFER);
         }
         catch (IOException x)
         {
             LOG.debug(x);
             close();
             return -1;
         }
     }
 
     @Override
     public void unsupported()
     {
         protocolSelected(defaultProtocol);
     }
 
     @Override
     public List<String> protocols()
     {
         return protocols;
     }
 
     @Override
     public void protocolSelected(String protocol)
     {
         LOG.debug("{} protocol selected {}", this, protocol);
         nextProtocol = protocol != null ? protocol : defaultProtocol;
         NextProtoNego.remove(engine);
     }
 
     @Override
     public void close()
     {
         NextProtoNego.remove(engine);
         EndPoint endPoint = getEndPoint();
         endPoint.shutdownOutput();
         endPoint.close();
     }
 }