/*
    * ====================================================================
    * 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.lang.reflect.UndeclaredThrowableException;
  
  import org.apache.http.HttpException;
  import org.apache.http.annotation.Contract;
  import org.apache.http.annotation.ThreadingBehavior;
  import org.apache.http.client.BackoffManager;
  import org.apache.http.client.ConnectionBackoffStrategy;
  import org.apache.http.client.methods.CloseableHttpResponse;
  import org.apache.http.client.methods.HttpExecutionAware;
  import org.apache.http.client.methods.HttpRequestWrapper;
  import org.apache.http.client.protocol.HttpClientContext;
  import org.apache.http.conn.routing.HttpRoute;
  import org.apache.http.util.Args;
  
  /**
   * @since 4.3
   */
  @Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
  public class BackoffStrategyExec implements ClientExecChain {
  
      private final ClientExecChain requestExecutor;
      private final ConnectionBackoffStrategy connectionBackoffStrategy;
      private final BackoffManager backoffManager;
  
      public BackoffStrategyExec(
              final ClientExecChain requestExecutor,
              final ConnectionBackoffStrategy connectionBackoffStrategy,
              final BackoffManager backoffManager) {
          super();
          Args.notNull(requestExecutor, "HTTP client request executor");
          Args.notNull(connectionBackoffStrategy, "Connection backoff strategy");
          Args.notNull(backoffManager, "Backoff manager");
          this.requestExecutor = requestExecutor;
          this.connectionBackoffStrategy = connectionBackoffStrategy;
          this.backoffManager = backoffManager;
      }
  
      @Override
      public CloseableHttpResponse execute(
              final HttpRoute route,
              final HttpRequestWrapper request,
              final HttpClientContext context,
              final HttpExecutionAware execAware) throws IOException, HttpException {
          Args.notNull(route, "HTTP route");
          Args.notNull(request, "HTTP request");
          Args.notNull(context, "HTTP context");
          CloseableHttpResponse out = null;
          try {
              out = this.requestExecutor.execute(route, request, context, execAware);
          } catch (final Exception ex) {
              if (out != null) {
                  out.close();
              }
              if (this.connectionBackoffStrategy.shouldBackoff(ex)) {
                  this.backoffManager.backOff(route);
              }
              if (ex instanceof RuntimeException) {
                  throw (RuntimeException) ex;
              }
              if (ex instanceof HttpException) {
                  throw (HttpException) ex;
              }
              if (ex instanceof IOException) {
                  throw (IOException) ex;
              }
              throw new UndeclaredThrowableException(ex);
          }
          if (this.connectionBackoffStrategy.shouldBackoff(out)) {
              this.backoffManager.backOff(route);
         } else {
             this.backoffManager.probe(route);
         }
         return out;
     }
 
 }