//
   //  ========================================================================
   //  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.util.Collection;
  import java.util.Collections;
  import java.util.Queue;
  import java.util.concurrent.ConcurrentLinkedQueue;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.eclipse.jetty.io.Connection;
  import org.eclipse.jetty.io.EndPoint;
  import org.eclipse.jetty.server.AbstractConnectionFactory;
  import org.eclipse.jetty.server.Connector;
  import org.eclipse.jetty.spdy.CompressionFactory;
  import org.eclipse.jetty.spdy.FlowControlStrategy;
  import org.eclipse.jetty.spdy.StandardCompressionFactory;
  import org.eclipse.jetty.spdy.StandardSession;
  import org.eclipse.jetty.spdy.api.GoAwayInfo;
  import org.eclipse.jetty.spdy.api.Session;
  import org.eclipse.jetty.spdy.api.server.ServerSessionFrameListener;
  import org.eclipse.jetty.spdy.client.FlowControlStrategyFactory;
  import org.eclipse.jetty.spdy.client.SPDYConnection;
  import org.eclipse.jetty.spdy.generator.Generator;
  import org.eclipse.jetty.spdy.parser.Parser;
  import org.eclipse.jetty.util.Callback;
  import org.eclipse.jetty.util.annotation.ManagedAttribute;
  import org.eclipse.jetty.util.annotation.ManagedObject;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  @ManagedObject("SPDY Server Connection Factory")
  public class SPDYServerConnectionFactory extends AbstractConnectionFactory
  {
      private static final Logger LOG = Log.getLogger(SPDYServerConnectionFactory.class);
  
      // This method is placed here so as to provide a check for NPN before attempting to load any
      // NPN classes.
      public static void checkNPNAvailable()
      {
          try
          {
              Class<?> npn = ClassLoader.getSystemClassLoader().loadClass("org.eclipse.jetty.npn.NextProtoNego");
              if (npn.getClassLoader() != null)
                  throw new IllegalStateException("NextProtoNego must be on JVM boot path");
          }
          catch (ClassNotFoundException e)
          {
              throw new IllegalStateException("No NextProtoNego on boot path", e);
          }
      }
  
      private final short version;
      private final ServerSessionFrameListener listener;
      private int initialWindowSize;
      private final Queue<Session> sessions = new ConcurrentLinkedQueue<>();
  
      public SPDYServerConnectionFactory(int version)
      {
          this(version, null);
      }
  
      public SPDYServerConnectionFactory(int version, ServerSessionFrameListener listener)
      {
          super("spdy/" + version);
          this.version = (short)version;
          this.listener = listener;
          setInitialWindowSize(65536);
      }
  
      @ManagedAttribute("SPDY version")
      public short getVersion()
      {
          return version;
      }
  
      public ServerSessionFrameListener getServerSessionFrameListener()
      {
          return listener;
      }
  
      @Override
      public Connection newConnection(Connector connector, EndPoint endPoint)
     {
         CompressionFactory compressionFactory = new StandardCompressionFactory();
         Parser parser = new Parser(compressionFactory.newDecompressor());
         Generator generator = new Generator(connector.getByteBufferPool(), compressionFactory.newCompressor());
 
         ServerSessionFrameListener listener = provideServerSessionFrameListener(connector, endPoint);
         SPDYConnection connection = new ServerSPDYConnection(connector, endPoint, parser, listener, getInputBufferSize());
 
         FlowControlStrategy flowControlStrategy = newFlowControlStrategy(version);
 
         StandardSession session = new StandardSession(getVersion(), connector.getByteBufferPool(),
                 connector.getExecutor(), connector.getScheduler(), connection, endPoint, connection, 2, listener,
                 generator, flowControlStrategy);
         session.setWindowSize(getInitialWindowSize());
         parser.addListener(session);
         connection.setSession(session);
 
         sessionOpened(session);
 
         return configure(connection, connector, endPoint);
     }
 
     protected FlowControlStrategy newFlowControlStrategy(short version)
     {
         return FlowControlStrategyFactory.newFlowControlStrategy(version);
     }
 
     protected ServerSessionFrameListener provideServerSessionFrameListener(Connector connector, EndPoint endPoint)
     {
         return listener;
     }
 
     @ManagedAttribute("Initial Window Size")
     public int getInitialWindowSize()
     {
         return initialWindowSize;
     }
 
     public void setInitialWindowSize(int initialWindowSize)
     {
         this.initialWindowSize = initialWindowSize;
     }
 
     protected boolean sessionOpened(Session session)
     {
         // Add sessions only if the connector is not stopping
         return sessions.offer(session);
     }
 
     protected boolean sessionClosed(Session session)
     {
         // Remove sessions only if the connector is not stopping
         // to avoid concurrent removes during iterations
         return sessions.remove(session);
     }
 
     void closeSessions()
     {
         for (Session session : sessions)
             session.goAway(new GoAwayInfo(), new Callback.Adapter());
         sessions.clear();
     }
 
     @Override
     protected void doStop() throws Exception
     {
         closeSessions();
         super.doStop();
     }
 
     public Collection<Session> getSessions()
     {
         return Collections.unmodifiableCollection(sessions);
     }
 
     private class ServerSPDYConnection extends SPDYConnection implements Runnable
     {
         private final ServerSessionFrameListener listener;
         private final AtomicBoolean connected = new AtomicBoolean();
 
         private ServerSPDYConnection(Connector connector, EndPoint endPoint, Parser parser, ServerSessionFrameListener listener, int bufferSize)
         {
             super(endPoint, connector.getByteBufferPool(), parser, connector.getExecutor(), bufferSize);
             this.listener = listener;
         }
 
         @Override
         public void onOpen()
         {
             super.onOpen();
             if (connected.compareAndSet(false, true))
                 getExecutor().execute(this);
         }
 
         @Override
         public void onClose()
         {
             super.onClose();
             sessionClosed(getSession());
         }
 
         @Override
         public void run()
         {
             // NPE guard to support tests
             if (listener != null)
                 listener.onConnect(getSession());
         }
     }
 
 }