/*
    * ====================================================================
    * 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.examples;
  
  import java.io.IOException;
  import java.util.concurrent.Future;
  
  import org.apache.hc.client5.http.async.AsyncExecCallback;
  import org.apache.hc.client5.http.async.AsyncExecChain;
  import org.apache.hc.client5.http.async.AsyncExecChainHandler;
  import org.apache.hc.client5.http.async.methods.SimpleHttpRequest;
  import org.apache.hc.client5.http.async.methods.SimpleHttpResponse;
  import org.apache.hc.client5.http.async.methods.SimpleRequestBuilder;
  import org.apache.hc.client5.http.async.methods.SimpleRequestProducer;
  import org.apache.hc.client5.http.async.methods.SimpleResponseConsumer;
  import org.apache.hc.client5.http.impl.ChainElement;
  import org.apache.hc.client5.http.impl.async.CloseableHttpAsyncClient;
  import org.apache.hc.client5.http.impl.async.HttpAsyncClients;
  import org.apache.hc.core5.concurrent.FutureCallback;
  import org.apache.hc.core5.http.ContentType;
  import org.apache.hc.core5.http.HttpException;
  import org.apache.hc.core5.http.HttpRequest;
  import org.apache.hc.core5.http.message.StatusLine;
  import org.apache.hc.core5.http.nio.AsyncEntityProducer;
  import org.apache.hc.core5.http.nio.entity.DigestingEntityProducer;
  import org.apache.hc.core5.io.CloseMode;
  import org.apache.hc.core5.reactor.IOReactorConfig;
  import org.apache.hc.core5.util.Timeout;
  
  /**
   * This example demonstrates how to use a custom execution interceptor
   * to add trailers to all outgoing request enclosing an entity.
   */
  public class AsyncClientMessageTrailers {
  
      public final static void main(final String[] args) throws Exception {
  
          final IOReactorConfig ioReactorConfig = IOReactorConfig.custom()
                  .setSoTimeout(Timeout.ofSeconds(5))
                  .build();
  
          final CloseableHttpAsyncClient client = HttpAsyncClients.custom()
                  .setIOReactorConfig(ioReactorConfig)
                  .addExecInterceptorAfter(ChainElement.PROTOCOL.name(), "custom", new AsyncExecChainHandler() {
  
                      @Override
                      public void execute(
                              final HttpRequest request,
                              final AsyncEntityProducer entityProducer,
                              final AsyncExecChain.Scope scope,
                              final AsyncExecChain chain,
                              final AsyncExecCallback asyncExecCallback) throws HttpException, IOException {
                          // Send MD5 hash in a trailer by decorating the original entity producer
                          chain.proceed(
                                  request,
                                  entityProducer != null ? new DigestingEntityProducer("MD5", entityProducer) : null,
                                  scope,
                                  asyncExecCallback);
                      }
  
                  })
                  .build();
  
          client.start();
  
          final SimpleHttpRequest request = SimpleRequestBuilder.post("http://httpbin.org/post")
                  .setBody("some stuff", ContentType.TEXT_PLAIN)
                  .build();
  
          System.out.println("Executing request " + request);
          final Future<SimpleHttpResponse> future = client.execute(
                  SimpleRequestProducer.create(request),
                  SimpleResponseConsumer.create(),
                  new FutureCallback<SimpleHttpResponse>() {
 
                     @Override
                     public void completed(final SimpleHttpResponse response) {
                         System.out.println(request + "->" + new StatusLine(response));
                         System.out.println(response.getBody());
                     }
 
                     @Override
                     public void failed(final Exception ex) {
                         System.out.println(request + "->" + ex);
                     }
 
                     @Override
                     public void cancelled() {
                         System.out.println(request + " cancelled");
                     }
 
                 });
         future.get();
 
         System.out.println("Shutting down");
         client.close(CloseMode.GRACEFUL);
     }
 
 }