/*
    * ====================================================================
    * 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.InterruptedIOException;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.http.HttpException;
  import org.apache.http.annotation.Immutable;
  import org.apache.http.client.ServiceUnavailableRetryStrategy;
  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;
  
  /**
   * {@link ClientExecChain} implementation that can automatically retry the request in case of
   * a non-2xx response using the {@link ServiceUnavailableRetryStrategy} interface.
   *
   * @since 4.3
   */
  @Immutable
  public class ServiceUnavailableRetryExec implements ClientExecChain {
  
      private final Log log = LogFactory.getLog(getClass());
  
      private final ClientExecChain requestExecutor;
      private final ServiceUnavailableRetryStrategy retryStrategy;
  
      public ServiceUnavailableRetryExec(
              final ClientExecChain requestExecutor,
              final ServiceUnavailableRetryStrategy retryStrategy) {
          super();
          Args.notNull(requestExecutor, "HTTP request executor");
          Args.notNull(retryStrategy, "Retry strategy");
          this.requestExecutor = requestExecutor;
          this.retryStrategy = retryStrategy;
      }
  
      public CloseableHttpResponse execute(
              final HttpRoute route,
              final HttpRequestWrapper request,
              final HttpClientContext context,
              final HttpExecutionAware execAware) throws IOException, HttpException {
          for (int c = 1;; c++) {
              final CloseableHttpResponse response = this.requestExecutor.execute(
                      route, request, context, execAware);
              try {
                  if (this.retryStrategy.retryRequest(response, c, context)) {
                      response.close();
                      final long nextInterval = this.retryStrategy.getRetryInterval();
                      try {
                          this.log.trace("Wait for " + nextInterval);
                          Thread.sleep(nextInterval);
                      } catch (final InterruptedException e) {
                          Thread.currentThread().interrupt();
                          throw new InterruptedIOException();
                      }
                  } else {
                      return response;
                  }
              } catch (final RuntimeException ex) {
                  response.close();
                  throw ex;
              } catch (final IOException ex) {
                  response.close();
                  throw ex;
              }
          }
      }
 
 }