/*
    * ====================================================================
    * 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.client;
  
  import java.io.IOException;
  import java.io.InterruptedIOException;
  import java.net.ConnectException;
  import java.net.UnknownHostException;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.Set;
  
  import javax.net.ssl.SSLException;
  
  import org.apache.http.HttpEntityEnclosingRequest;
  import org.apache.http.HttpRequest;
  import org.apache.http.annotation.Immutable;
  import org.apache.http.client.HttpRequestRetryHandler;
  import org.apache.http.client.methods.HttpUriRequest;
  import org.apache.http.client.protocol.HttpClientContext;
  import org.apache.http.protocol.HttpContext;
  import org.apache.http.util.Args;
  
  /**
   * The default {@link HttpRequestRetryHandler} used by request executors.
   *
   * @since 4.0
   */
  @Immutable
  public class DefaultHttpRequestRetryHandler implements HttpRequestRetryHandler {
  
      public static final DefaultHttpRequestRetryHandler INSTANCE = new DefaultHttpRequestRetryHandler();
  
      /** the number of times a method will be retried */
      private final int retryCount;
  
      /** Whether or not methods that have successfully sent their request will be retried */
      private final boolean requestSentRetryEnabled;
  
      private final Set<Class<? extends IOException>> nonRetriableClasses;
  
      /**
       * @since 4.3
       */
      protected DefaultHttpRequestRetryHandler(
              final int retryCount,
              final boolean requestSentRetryEnabled,
              final Collection<Class<? extends IOException>> clazzes) {
          super();
          this.retryCount = retryCount;
          this.requestSentRetryEnabled = requestSentRetryEnabled;
          this.nonRetriableClasses = new HashSet<Class<? extends IOException>>();
          for (final Class<? extends IOException> clazz: clazzes) {
              this.nonRetriableClasses.add(clazz);
          }
      }
  
      /**
       * Default constructor
       */
      @SuppressWarnings("unchecked")
      public DefaultHttpRequestRetryHandler(final int retryCount, final boolean requestSentRetryEnabled) {
          this(retryCount, requestSentRetryEnabled, Arrays.asList(
                  InterruptedIOException.class,
                  UnknownHostException.class,
                  ConnectException.class,
                  SSLException.class));
      }
  
      /**
       * Default constructor
       */
      public DefaultHttpRequestRetryHandler() {
         this(3, false);
     }
     /**
      * Used <code>retryCount</code> and <code>requestSentRetryEnabled</code> to determine
      * if the given method should be retried.
      */
     public boolean retryRequest(
             final IOException exception,
             final int executionCount,
             final HttpContext context) {
         Args.notNull(exception, "Exception parameter");
         Args.notNull(context, "HTTP context");
         if (executionCount > this.retryCount) {
             // Do not retry if over max retry count
             return false;
         }
         if (this.nonRetriableClasses.contains(exception.getClass())) {
             return false;
         } else {
             for (final Class<? extends IOException> rejectException : this.nonRetriableClasses) {
                 if (rejectException.isInstance(exception)) {
                     return false;
                 }
             }
         }
         final HttpClientContext clientContext = HttpClientContext.adapt(context);
         final HttpRequest request = clientContext.getRequest();
 
         if(requestIsAborted(request)){
             return false;
         }
 
         if (handleAsIdempotent(request)) {
             // Retry if the request is considered idempotent
             return true;
         }
 
         if (!clientContext.isRequestSent() || this.requestSentRetryEnabled) {
             // Retry if the request has not been sent fully or
             // if it's OK to retry methods that have been sent
             return true;
         }
         // otherwise do not retry
         return false;
     }
 
     /**
      * @return <code>true</code> if this handler will retry methods that have
      * successfully sent their request, <code>false</code> otherwise
      */
     public boolean isRequestSentRetryEnabled() {
         return requestSentRetryEnabled;
     }
 
     /**
      * @return the maximum number of times a method will be retried
      */
     public int getRetryCount() {
         return retryCount;
     }
 
     /**
      * @since 4.2
      */
     protected boolean handleAsIdempotent(final HttpRequest request) {
         return !(request instanceof HttpEntityEnclosingRequest);
     }
 
     /**
      * @since 4.2
      *
      * @deprecated (4.3)
      */
     @Deprecated
     protected boolean requestIsAborted(final HttpRequest request) {
         HttpRequest req = request;
         if (request instanceof RequestWrapper) { // does not forward request to original
             req = ((RequestWrapper) request).getOriginal();
         }
         return (req instanceof HttpUriRequest && ((HttpUriRequest)req).isAborted());
     }
 
 }