//
   //  ========================================================================
   //  Copyright (c) 1995-2014 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.client;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.nio.channels.AsynchronousCloseException;
  import java.util.List;
  import java.util.Queue;
  import java.util.concurrent.RejectedExecutionException;
  
  import org.eclipse.jetty.client.api.Connection;
  import org.eclipse.jetty.client.api.Destination;
  import org.eclipse.jetty.client.api.Response;
  import org.eclipse.jetty.http.HttpField;
  import org.eclipse.jetty.http.HttpHeader;
  import org.eclipse.jetty.http.HttpScheme;
  import org.eclipse.jetty.io.ClientConnectionFactory;
  import org.eclipse.jetty.io.ssl.SslClientConnectionFactory;
  import org.eclipse.jetty.util.BlockingArrayQueue;
  import org.eclipse.jetty.util.Promise;
  import org.eclipse.jetty.util.component.ContainerLifeCycle;
  import org.eclipse.jetty.util.component.Dumpable;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  public abstract class HttpDestination implements Destination, Closeable, Dumpable
  {
      protected static final Logger LOG = Log.getLogger(HttpDestination.class);
  
      private final HttpClient client;
      private final Origin origin;
      private final Queue<HttpExchange> exchanges;
      private final RequestNotifier requestNotifier;
      private final ResponseNotifier responseNotifier;
      private final ProxyConfiguration.Proxy proxy;
      private final ClientConnectionFactory connectionFactory;
      private final HttpField hostField;
  
      public HttpDestination(HttpClient client, Origin origin)
      {
          this.client = client;
          this.origin = origin;
  
          this.exchanges = new BlockingArrayQueue<>(client.getMaxRequestsQueuedPerDestination());
  
          this.requestNotifier = new RequestNotifier(client);
          this.responseNotifier = new ResponseNotifier();
  
          ProxyConfiguration proxyConfig = client.getProxyConfiguration();
          proxy = proxyConfig.match(origin);
          ClientConnectionFactory connectionFactory = client.getTransport();
          if (proxy != null)
          {
              connectionFactory = proxy.newClientConnectionFactory(connectionFactory);
          }
          else
          {
              if (HttpScheme.HTTPS.is(getScheme()))
                  connectionFactory = newSslClientConnectionFactory(connectionFactory);
          }
          this.connectionFactory = connectionFactory;
  
          String host = getHost();
          if (!client.isDefaultPort(getScheme(), getPort()))
              host += ":" + getPort();
          hostField = new HttpField(HttpHeader.HOST, host);
      }
  
      protected ClientConnectionFactory newSslClientConnectionFactory(ClientConnectionFactory connectionFactory)
      {
          return new SslClientConnectionFactory(client.getSslContextFactory(), client.getByteBufferPool(), client.getExecutor(), connectionFactory);
      }
  
      public HttpClient getHttpClient()
      {
          return client;
      }
  
      public Origin getOrigin()
      {
          return origin;
      }
 
     public Queue<HttpExchange> getHttpExchanges()
     {
         return exchanges;
     }
 
     public RequestNotifier getRequestNotifier()
     {
         return requestNotifier;
     }
 
     public ResponseNotifier getResponseNotifier()
     {
         return responseNotifier;
     }
 
     public ProxyConfiguration.Proxy getProxy()
     {
         return proxy;
     }
 
     public ClientConnectionFactory getClientConnectionFactory()
     {
         return connectionFactory;
     }
 
     @Override
     public String getScheme()
     {
         return origin.getScheme();
     }
 
     @Override
     public String getHost()
     {
         // InetSocketAddress.getHostString() transforms the host string
         // in case of IPv6 addresses, so we return the original host string
         return origin.getAddress().getHost();
     }
 
     @Override
     public int getPort()
     {
         return origin.getAddress().getPort();
     }
 
     public Origin.Address getConnectAddress()
     {
         return proxy == null ? origin.getAddress() : proxy.getAddress();
     }
 
     public HttpField getHostField()
     {
         return hostField;
     }
 
     protected void send(HttpRequest request, List<Response.ResponseListener> listeners)
     {
         if (!getScheme().equals(request.getScheme()))
             throw new IllegalArgumentException("Invalid request scheme " + request.getScheme() + " for destination " + this);
         if (!getHost().equals(request.getHost()))
             throw new IllegalArgumentException("Invalid request host " + request.getHost() + " for destination " + this);
         int port = request.getPort();
         if (port >= 0 && getPort() != port)
             throw new IllegalArgumentException("Invalid request port " + port + " for destination " + this);
 
         HttpExchange exchange = new HttpExchange(this, request, listeners);
 
         if (client.isRunning())
         {
             if (exchanges.offer(exchange))
             {
                 if (!client.isRunning() && exchanges.remove(exchange))
                 {
                     request.abort(new RejectedExecutionException(client + " is stopping"));
                 }
                 else
                 {
                     if (LOG.isDebugEnabled())
                         LOG.debug("Queued {} for {}", request, this);
                     requestNotifier.notifyQueued(request);
                     send();
                 }
             }
             else
             {
                 if (LOG.isDebugEnabled())
                     LOG.debug("Max queue size {} exceeded by {} for {}", client.getMaxRequestsQueuedPerDestination(), request, this);
                 request.abort(new RejectedExecutionException("Max requests per destination " + client.getMaxRequestsQueuedPerDestination() + " exceeded for " + this));
             }
         }
         else
         {
             request.abort(new RejectedExecutionException(client + " is stopped"));
         }
     }
 
     protected abstract void send();
 
     public void newConnection(Promise<Connection> promise)
     {
         createConnection(promise);
     }
 
     protected void createConnection(Promise<Connection> promise)
     {
         client.newConnection(this, promise);
     }
 
     public boolean remove(HttpExchange exchange)
     {
         return exchanges.remove(exchange);
     }
 
     public void close()
     {
         abort(new AsynchronousCloseException());
         if (LOG.isDebugEnabled())
             LOG.debug("Closed {}", this);
     }
 
     public void release(Connection connection)
     {
     }
 
     public void close(Connection connection)
     {
     }
 
     /**
      * Aborts all the {@link HttpExchange}s queued in this destination.
      *
      * @param cause the abort cause
      */
     public void abort(Throwable cause)
     {
         HttpExchange exchange;
         // Just peek(), the abort() will remove it from the queue.
         while ((exchange = exchanges.peek()) != null)
             exchange.getRequest().abort(cause);
     }
 
     @Override
     public String dump()
     {
         return ContainerLifeCycle.dump(this);
     }
 
     @Override
     public void dump(Appendable out, String indent) throws IOException
     {
         ContainerLifeCycle.dumpObject(out, this + " - requests queued: " + exchanges.size());
     }
 
     public String asString()
     {
         return origin.asString();
     }
 
     @Override
     public String toString()
     {
         return String.format("%s[%s]%s,queue=%d",
                 HttpDestination.class.getSimpleName(),
                 asString(),
                 proxy == null ? "" : "(via " + proxy + ")",
                 exchanges.size());
     }
 }