/*
    * ====================================================================
    * 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.util.concurrent.Callable;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.apache.http.client.HttpClient;
  import org.apache.http.client.ResponseHandler;
  import org.apache.http.client.methods.HttpUriRequest;
  import org.apache.http.concurrent.FutureCallback;
  import org.apache.http.protocol.HttpContext;
  
  class HttpRequestTaskCallable<V> implements Callable<V> {
  
      private final HttpUriRequest request;
      private final HttpClient httpclient;
      private final AtomicBoolean cancelled = new AtomicBoolean(false);
  
      private final long scheduled = System.currentTimeMillis();
      private long started = -1;
      private long ended = -1;
  
      private final HttpContext context;
      private final ResponseHandler<V> responseHandler;
      private final FutureCallback<V> callback;
  
      private final FutureRequestExecutionMetrics metrics;
  
      HttpRequestTaskCallable(
              final HttpClient httpClient,
              final HttpUriRequest request,
              final HttpContext context,
              final ResponseHandler<V> responseHandler,
              final FutureCallback<V> callback,
              final FutureRequestExecutionMetrics metrics) {
          this.httpclient = httpClient;
          this.responseHandler = responseHandler;
          this.request = request;
          this.context = context;
          this.callback = callback;
          this.metrics = metrics;
      }
  
      public long getScheduled() {
          return scheduled;
      }
  
      public long getStarted() {
          return started;
      }
  
      public long getEnded() {
          return ended;
      }
  
      @Override
      public V call() throws Exception {
          if (!cancelled.get()) {
              try {
                  metrics.getActiveConnections().incrementAndGet();
                  started = System.currentTimeMillis();
                  try {
                      metrics.getScheduledConnections().decrementAndGet();
                      final V result = httpclient.execute(request, responseHandler, context);
                      ended = System.currentTimeMillis();
                      metrics.getSuccessfulConnections().increment(started);
                      if (callback != null) {
                          callback.completed(result);
                      }
                      return result;
                  } catch (final Exception e) {
                      metrics.getFailedConnections().increment(started);
                      ended = System.currentTimeMillis();
                      if (callback != null) {
                         callback.failed(e);
                     }
                     throw e;
                 }
             } finally {
                 metrics.getRequests().increment(started);
                 metrics.getTasks().increment(started);
                 metrics.getActiveConnections().decrementAndGet();
             }
         }
         throw new IllegalStateException("call has been cancelled for request " + request.getURI());
     }
 
     public void cancel() {
         cancelled.set(true);
         if (callback != null) {
             callback.cancelled();
         }
     }
 }