/*
    * ====================================================================
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  package org.apache.http.impl.conn;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.Socket;
  
  import javax.net.ssl.SSLSession;
  
  import org.apache.http.HttpClientConnection;
  import org.apache.http.HttpConnectionMetrics;
  import org.apache.http.HttpEntityEnclosingRequest;
  import org.apache.http.HttpException;
  import org.apache.http.HttpRequest;
  import org.apache.http.HttpResponse;
  import org.apache.http.conn.ManagedHttpClientConnection;
  import org.apache.http.protocol.HttpContext;
  
  /**
   * @since 4.3
   */
  class CPoolProxy implements ManagedHttpClientConnection, HttpContext {
  
      private volatile CPoolEntry poolEntry;
  
      CPoolProxy(final CPoolEntry entry) {
          super();
          this.poolEntry = entry;
      }
  
      CPoolEntry getPoolEntry() {
          return this.poolEntry;
      }
  
      CPoolEntry detach() {
          final CPoolEntry local = this.poolEntry;
          this.poolEntry = null;
          return local;
      }
  
      ManagedHttpClientConnection getConnection() {
          final CPoolEntry local = this.poolEntry;
          if (local == null) {
              return null;
          }
          return local.getConnection();
      }
  
      ManagedHttpClientConnection getValidConnection() {
          final ManagedHttpClientConnection conn = getConnection();
          if (conn == null) {
              throw new ConnectionShutdownException();
          }
          return conn;
      }
  
      @Override
      public void close() throws IOException {
          final CPoolEntry local = this.poolEntry;
          if (local != null) {
              local.closeConnection();
          }
      }
  
      @Override
      public void shutdown() throws IOException {
          final CPoolEntry local = this.poolEntry;
          if (local != null) {
              local.shutdownConnection();
          }
      }
  
      @Override
      public boolean isOpen() {
         final CPoolEntry local = this.poolEntry;
         return local != null ? !local.isClosed() : false;
     }
 
     @Override
     public boolean isStale() {
         final HttpClientConnection conn = getConnection();
         return conn != null ? conn.isStale() : true;
     }
 
     @Override
     public void setSocketTimeout(final int timeout) {
         getValidConnection().setSocketTimeout(timeout);
     }
 
     @Override
     public int getSocketTimeout() {
         return getValidConnection().getSocketTimeout();
     }
 
     @Override
     public String getId() {
         return getValidConnection().getId();
     }
 
     @Override
     public void bind(final Socket socket) throws IOException {
         getValidConnection().bind(socket);
     }
 
     @Override
     public Socket getSocket() {
         return getValidConnection().getSocket();
     }
 
     @Override
     public SSLSession getSSLSession() {
         return getValidConnection().getSSLSession();
     }
 
     @Override
     public boolean isResponseAvailable(final int timeout) throws IOException {
         return getValidConnection().isResponseAvailable(timeout);
     }
 
     @Override
     public void sendRequestHeader(final HttpRequest request) throws HttpException, IOException {
         getValidConnection().sendRequestHeader(request);
     }
 
     @Override
     public void sendRequestEntity(final HttpEntityEnclosingRequest request) throws HttpException, IOException {
         getValidConnection().sendRequestEntity(request);
     }
 
     @Override
     public HttpResponse receiveResponseHeader() throws HttpException, IOException {
         return getValidConnection().receiveResponseHeader();
     }
 
     @Override
     public void receiveResponseEntity(final HttpResponse response) throws HttpException, IOException {
         getValidConnection().receiveResponseEntity(response);
     }
 
     @Override
     public void flush() throws IOException {
         getValidConnection().flush();
     }
 
     @Override
     public HttpConnectionMetrics getMetrics() {
         return getValidConnection().getMetrics();
     }
 
     @Override
     public InetAddress getLocalAddress() {
         return getValidConnection().getLocalAddress();
     }
 
     @Override
     public int getLocalPort() {
         return getValidConnection().getLocalPort();
     }
 
     @Override
     public InetAddress getRemoteAddress() {
         return getValidConnection().getRemoteAddress();
     }
 
     @Override
     public int getRemotePort() {
         return getValidConnection().getRemotePort();
     }
 
     @Override
     public Object getAttribute(final String id) {
         final ManagedHttpClientConnection conn = getValidConnection();
         return conn instanceof HttpContext ? ((HttpContext) conn).getAttribute(id) : null;
     }
 
     @Override
     public void setAttribute(final String id, final Object obj) {
         final ManagedHttpClientConnection conn = getValidConnection();
         if (conn instanceof HttpContext) {
             ((HttpContext) conn).setAttribute(id, obj);
         }
     }
 
     @Override
     public Object removeAttribute(final String id) {
         final ManagedHttpClientConnection conn = getValidConnection();
         return conn instanceof HttpContext ? ((HttpContext) conn).removeAttribute(id) : null;
     }
 
     @Override
     public String toString() {
         final StringBuilder sb = new StringBuilder("CPoolProxy{");
         final ManagedHttpClientConnection conn = getConnection();
         if (conn != null) {
             sb.append(conn);
         } else {
             sb.append("detached");
         }
         sb.append('}');
         return sb.toString();
     }
 
     public static HttpClientConnection newProxy(final CPoolEntry poolEntry) {
         return new CPoolProxy(poolEntry);
     }
 
     private static CPoolProxy getProxy(final HttpClientConnection conn) {
         if (!CPoolProxy.class.isInstance(conn)) {
             throw new IllegalStateException("Unexpected connection proxy class: " + conn.getClass());
         }
         return CPoolProxy.class.cast(conn);
     }
 
     public static CPoolEntry getPoolEntry(final HttpClientConnection proxy) {
         final CPoolEntry entry = getProxy(proxy).getPoolEntry();
         if (entry == null) {
             throw new ConnectionShutdownException();
         }
         return entry;
     }
 
     public static CPoolEntry detach(final HttpClientConnection conn) {
         return getProxy(conn).detach();
     }
 
 }