/*
    * ====================================================================
    * 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.hc.client5.http.fluent;
  
  import java.util.concurrent.Future;
  
  import org.apache.hc.core5.concurrent.BasicFuture;
  import org.apache.hc.core5.concurrent.FutureCallback;
  import org.apache.hc.core5.http.io.HttpClientResponseHandler;
  
  /**
   * Asynchronous executor for {@link Request}s.
   *
   * @since 4.3
   */
  public class Async {
  
      private Executor executor;
      private java.util.concurrent.Executor concurrentExec;
  
      public static Async newInstance() {
          return new Async();
      }
  
      Async() {
          super();
      }
  
      public Async use(final Executor executor) {
          this.executor = executor;
          return this;
      }
  
      public Async use(final java.util.concurrent.Executor concurrentExec) {
          this.concurrentExec = concurrentExec;
          return this;
      }
  
      static class ExecRunnable<T> implements Runnable {
  
          private final BasicFuture<T> future;
          private final Request request;
          private final Executor executor;
          private final HttpClientResponseHandler<T> handler;
  
          ExecRunnable(
                  final BasicFuture<T> future,
                  final Request request,
                  final Executor executor,
                  final HttpClientResponseHandler<T> handler) {
              super();
              this.future = future;
              this.request = request;
              this.executor = executor;
              this.handler = handler;
          }
  
          @Override
          public void run() {
              try {
                  final Response response = this.executor.execute(this.request);
                  final T result = response.handleResponse(this.handler);
                  this.future.completed(result);
              } catch (final Exception ex) {
                  this.future.failed(ex);
              }
          }
  
      }
  
      public <T> Future<T> execute(
              final Request request, final HttpClientResponseHandler<T> handler, final FutureCallback<T> callback) {
          final BasicFuture<T> future = new BasicFuture<>(callback);
          final ExecRunnable<T> runnable = new ExecRunnable<>(
                  future,
                 request,
                 this.executor != null ? this.executor : Executor.newInstance(),
                 handler);
         if (this.concurrentExec != null) {
             this.concurrentExec.execute(runnable);
         } else {
             final Thread t = new Thread(runnable);
             t.setDaemon(true);
             t.start();
         }
         return future;
     }
 
     public <T> Future<T> execute(final Request request, final HttpClientResponseHandler<T> handler) {
         return execute(request, handler, null);
     }
 
     public Future<Content> execute(final Request request, final FutureCallback<Content> callback) {
         return execute(request, new ContentResponseHandler(), callback);
     }
 
     public Future<Content> execute(final Request request) {
         return execute(request, new ContentResponseHandler(), null);
     }
 
 }