/*
    * ====================================================================
    * 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.execchain;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.SocketException;
  
  import org.apache.http.HttpEntity;
  import org.apache.http.HttpResponse;
  import org.apache.http.conn.EofSensorInputStream;
  import org.apache.http.conn.EofSensorWatcher;
  import org.apache.http.entity.HttpEntityWrapper;
  
  /**
   * A wrapper class for {@link HttpEntity} enclosed in a response message.
   *
   * @since 4.3
   */
  class ResponseEntityProxy extends HttpEntityWrapper implements EofSensorWatcher {
  
      private final ConnectionHolder connHolder;
  
      public static void enchance(final HttpResponse response, final ConnectionHolder connHolder) {
          final HttpEntity entity = response.getEntity();
          if (entity != null && entity.isStreaming() && connHolder != null) {
              response.setEntity(new ResponseEntityProxy(entity, connHolder));
          }
      }
  
      ResponseEntityProxy(final HttpEntity entity, final ConnectionHolder connHolder) {
          super(entity);
          this.connHolder = connHolder;
      }
  
      private void cleanup() throws IOException {
          if (this.connHolder != null) {
              this.connHolder.close();
          }
      }
  
      private void abortConnection() {
          if (this.connHolder != null) {
              this.connHolder.abortConnection();
          }
      }
  
      public void releaseConnection() {
          if (this.connHolder != null) {
              this.connHolder.releaseConnection();
          }
      }
  
      @Override
      public boolean isRepeatable() {
          return false;
      }
  
      @Override
      public InputStream getContent() throws IOException {
          return new EofSensorInputStream(this.wrappedEntity.getContent(), this);
      }
  
      @Override
      public void consumeContent() throws IOException {
          releaseConnection();
      }
  
      @Override
      public void writeTo(final OutputStream outStream) throws IOException {
          try {
              if (outStream != null) {
                  this.wrappedEntity.writeTo(outStream);
             }
             releaseConnection();
         } catch (final IOException ex) {
             abortConnection();
             throw ex;
         } catch (final RuntimeException ex) {
             abortConnection();
             throw ex;
         } finally {
             cleanup();
         }
     }
 
     @Override
     public boolean eofDetected(final InputStream wrapped) throws IOException {
         try {
             // there may be some cleanup required, such as
             // reading trailers after the response body:
             if (wrapped != null) {
                 wrapped.close();
             }
             releaseConnection();
         } catch (final IOException ex) {
             abortConnection();
             throw ex;
         } catch (final RuntimeException ex) {
             abortConnection();
             throw ex;
         } finally {
             cleanup();
         }
         return false;
     }
 
     @Override
     public boolean streamClosed(final InputStream wrapped) throws IOException {
         try {
             final boolean open = connHolder != null && !connHolder.isReleased();
             // this assumes that closing the stream will
             // consume the remainder of the response body:
             try {
                 if (wrapped != null) {
                     wrapped.close();
                 }
                 releaseConnection();
             } catch (final SocketException ex) {
                 if (open) {
                     throw ex;
                 }
             }
         } catch (final IOException ex) {
             abortConnection();
             throw ex;
         } catch (final RuntimeException ex) {
             abortConnection();
             throw ex;
         } finally {
             cleanup();
         }
         return false;
     }
 
     @Override
     public boolean streamAbort(final InputStream wrapped) throws IOException {
         cleanup();
         return false;
     }
 
     @Override
     public String toString() {
         final StringBuilder sb = new StringBuilder("ResponseEntityProxy{");
         sb.append(wrappedEntity);
         sb.append('}');
         return sb.toString();
     }
 
 }