/**
    * Licensed to jclouds, Inc. (jclouds) under one or more
    * contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  jclouds 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.
   */
  package org.jclouds.http;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import java.util.concurrent.ExecutionException;
  
  import javax.annotation.Resource;
  import javax.inject.Inject;
  
  import org.jclouds.logging.Logger;
  import org.jclouds.rest.internal.GeneratedHttpRequest;
  
  import com.google.common.base.Function;
  import com.google.common.util.concurrent.ListenableFuture;
  
  /**
   * Executor which will invoke and transform the response of an {@code EndpointCommand} into generic
   * type <T>.
   * 
   * @see TransformingHttpCommand
   * 
   * @author Adrian Cole
   */
  public class TransformingHttpCommandImpl<T> implements TransformingHttpCommand<T> {
  
     protected final TransformingHttpCommandExecutorService executorService;
     protected final Function<HttpResponse, T> transformer;
  
     protected volatile HttpRequest request;
     protected volatile int failureCount;
     protected volatile int redirectCount;
     protected volatile Exception exception;
  
     @Resource
     protected Logger logger = Logger.NULL;
  
     @Inject
     public TransformingHttpCommandImpl(TransformingHttpCommandExecutorService executorService, HttpRequest request,
              Function<HttpResponse, T> transformer) {
        this.request = checkNotNull(request, "request");
        this.executorService = checkNotNull(executorService, "executorService");
        this.transformer = checkNotNull(transformer, "transformer");
        this.failureCount = 0;
        this.redirectCount = 0;
     }
  
     /**
      * {@inheritDoc}
      */
     @Override
     public ListenableFuture<T> execute() throws ExecutionException {
        if (exception != null)
           throw new ExecutionException(exception);
        return executorService.submit(this, transformer);
     }
  
     /**
      * {@inheritDoc}
      */
     @Override
     public int getFailureCount() {
        return failureCount;
     }
  
     /**
      * {@inheritDoc}
      */
     @Override
     public int incrementFailureCount() {
        return ++failureCount;
     }
  
     /**
      * {@inheritDoc}
      */
     @Override
     public void setException(Exception exception) {
        this.exception = exception;
     }
  
     /**
     * {@inheritDoc}
     */
    @Override
    public Exception getException() {
       return exception;
    }
 
    /**
     * {@inheritDoc}
     */
    @Override
    public int incrementRedirectCount() {
       return ++redirectCount;
    }
 
    /**
     * {@inheritDoc}
     */
    @Override
    public int getRedirectCount() {
       return redirectCount;
    }
 
    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isReplayable() {
       return (request.getPayload() == null) ? true : request.getPayload().isRepeatable();
    }
 
    /**
     * {@inheritDoc}
     */
    @Override
    public HttpRequest getCurrentRequest() {
       return request;
    }
 
    /**
     * {@inheritDoc}
     */
    @Override
    public void setCurrentRequest(HttpRequest request) {
       this.request = request;
    }
 
    @Override
    public String toString() {
       if (request instanceof GeneratedHttpRequest<?>)
          return String.format("[method=%s.%s, request=%s]", GeneratedHttpRequest.class.cast(request).getDeclaring()
                   .getSimpleName(), GeneratedHttpRequest.class.cast(request).getJavaMethod().getName(), request
                   .getRequestLine());
       else
          return "[request=" + request.getRequestLine() + "]";
    }
 
 }