//
   //  ========================================================================
   //  Copyright (c) 1995-2016 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.fcgi.server;
  
  import java.nio.ByteBuffer;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  
  import org.eclipse.jetty.fcgi.FCGI;
  import org.eclipse.jetty.fcgi.generator.Flusher;
  import org.eclipse.jetty.fcgi.parser.ServerParser;
  import org.eclipse.jetty.http.HttpField;
  import org.eclipse.jetty.io.AbstractConnection;
  import org.eclipse.jetty.io.ByteBufferPool;
  import org.eclipse.jetty.io.EndPoint;
  import org.eclipse.jetty.server.Connector;
  import org.eclipse.jetty.server.HttpConfiguration;
  import org.eclipse.jetty.server.HttpInput;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  public class ServerFCGIConnection extends AbstractConnection
  {
      private static final Logger LOG = Log.getLogger(ServerFCGIConnection.class);
  
      private final ConcurrentMap<Integer, HttpChannelOverFCGI> channels = new ConcurrentHashMap<>();
      private final Connector connector;
      private final boolean sendStatus200;
      private final Flusher flusher;
      private final HttpConfiguration configuration;
      private final ServerParser parser;
  
      public ServerFCGIConnection(Connector connector, EndPoint endPoint, HttpConfiguration configuration, boolean sendStatus200)
      {
          super(endPoint, connector.getExecutor());
          this.connector = connector;
          this.flusher = new Flusher(endPoint);
          this.configuration = configuration;
          this.sendStatus200 = sendStatus200;
          this.parser = new ServerParser(new ServerListener());
      }
  
      @Override
      public void onOpen()
      {
          super.onOpen();
          fillInterested();
      }
  
      @Override
      public void onFillable()
      {
          EndPoint endPoint = getEndPoint();
          ByteBufferPool bufferPool = connector.getByteBufferPool();
          ByteBuffer buffer = bufferPool.acquire(configuration.getResponseHeaderSize(), true);
          try
          {
              while (true)
              {
                  int read = endPoint.fill(buffer);
                  if (LOG.isDebugEnabled()) // Avoid boxing of variable 'read'
                      LOG.debug("Read {} bytes from {}", read, endPoint);
                  if (read > 0)
                  {
                      parse(buffer);
                  }
                  else if (read == 0)
                  {
                      bufferPool.release(buffer);
                      fillInterested();
                      break;
                  }
                  else
                  {
                      bufferPool.release(buffer);
                      shutdown();
                      break;
                  }
              }
          }
          catch (Exception x)
          {
              if (LOG.isDebugEnabled())
                 LOG.debug(x);
             bufferPool.release(buffer);
             // TODO: fail and close ?
         }
     }
 
     private void parse(ByteBuffer buffer)
     {
         while (buffer.hasRemaining())
             parser.parse(buffer);
     }
 
     private void shutdown()
     {
         flusher.shutdown();
     }
 
     private class ServerListener implements ServerParser.Listener
     {
         @Override
         public void onStart(int request, FCGI.Role role, int flags)
         {
             // TODO: handle flags
             HttpChannelOverFCGI channel = new HttpChannelOverFCGI(connector, configuration, getEndPoint(),
                     new HttpTransportOverFCGI(connector.getByteBufferPool(), flusher, request, sendStatus200));
             HttpChannelOverFCGI existing = channels.putIfAbsent(request, channel);
             if (existing != null)
                 throw new IllegalStateException();
             if (LOG.isDebugEnabled())
                 LOG.debug("Request {} start on {}", request, channel);
         }
 
         @Override
         public void onHeader(int request, HttpField field)
         {
             HttpChannelOverFCGI channel = channels.get(request);
             if (LOG.isDebugEnabled())
                 LOG.debug("Request {} header {} on {}", request, field, channel);
             if (channel != null)
                 channel.header(field);
         }
 
         @Override
         public void onHeaders(int request)
         {
             HttpChannelOverFCGI channel = channels.get(request);
             if (LOG.isDebugEnabled())
                 LOG.debug("Request {} headers on {}", request, channel);
             if (channel != null)
             {
                 channel.onRequest();
                 channel.dispatch();
             }
         }
 
         @Override
         public boolean onContent(int request, FCGI.StreamType stream, ByteBuffer buffer)
         {
             HttpChannelOverFCGI channel = channels.get(request);
             if (LOG.isDebugEnabled())
                 LOG.debug("Request {} {} content {} on {}", request, stream, buffer, channel);
             if (channel != null)
             {
                 ByteBuffer copy = ByteBuffer.allocate(buffer.remaining());
                 copy.put(buffer).flip();
                 channel.onContent(new HttpInput.Content(copy));
             }
             return false;
         }
 
         @Override
         public void onEnd(int request)
         {
             HttpChannelOverFCGI channel = channels.remove(request);
             if (LOG.isDebugEnabled())
                 LOG.debug("Request {} end on {}", request, channel);
             if (channel != null)
             {
                 channel.onRequestComplete();
             }
         }
 
         @Override
         public void onFailure(int request, Throwable failure)
         {
             HttpChannelOverFCGI channel = channels.remove(request);
             if (LOG.isDebugEnabled())
                 LOG.debug("Request {} failure on {}: {}", request, channel, failure);
             if (channel != null)
             {
                 channel.onBadMessage(400, failure.toString());
             }
         }
     }
 }