/*
    * ====================================================================
    * 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.core5.http.nio.support;
  
  import java.io.IOException;
  import java.util.Set;
  
  import org.apache.hc.core5.annotation.Contract;
  import org.apache.hc.core5.annotation.ThreadingBehavior;
  import org.apache.hc.core5.http.EntityDetails;
  import org.apache.hc.core5.http.HttpException;
  import org.apache.hc.core5.http.HttpRequest;
  import org.apache.hc.core5.http.HttpResponse;
  import org.apache.hc.core5.http.HttpStatus;
  import org.apache.hc.core5.http.message.BasicHttpResponse;
  import org.apache.hc.core5.http.nio.AsyncDataConsumer;
  import org.apache.hc.core5.http.nio.AsyncEntityProducer;
  import org.apache.hc.core5.http.nio.AsyncFilterChain;
  import org.apache.hc.core5.http.nio.AsyncFilterHandler;
  import org.apache.hc.core5.http.nio.AsyncPushProducer;
  import org.apache.hc.core5.http.nio.AsyncServerExchangeHandler;
  import org.apache.hc.core5.http.nio.DataStreamChannel;
  import org.apache.hc.core5.http.nio.HandlerFactory;
  import org.apache.hc.core5.http.nio.ResponseChannel;
  import org.apache.hc.core5.http.nio.entity.AsyncEntityProducers;
  import org.apache.hc.core5.http.protocol.HttpContext;
  import org.apache.hc.core5.util.Args;
  
  /**
   * {@link AsyncFilterHandler} implementation represents a terminal handler
   * in an asynchronous request processing pipeline that makes use of {@link HandlerFactory}
   * to dispatch the request to a particular {@link AsyncServerExchangeHandler}.
   *
   * @since 5.0
   */
  @Contract(threading = ThreadingBehavior.STATELESS)
  public final class TerminalAsyncServerFilter implements AsyncFilterHandler {
  
      final private HandlerFactory<AsyncServerExchangeHandler> handlerFactory;
  
      public TerminalAsyncServerFilter(final HandlerFactory<AsyncServerExchangeHandler> handlerFactory) {
          this.handlerFactory = Args.notNull(handlerFactory, "Handler factory");
      }
  
      @Override
      public AsyncDataConsumer handle(
              final HttpRequest request,
              final EntityDetails entityDetails,
              final HttpContext context,
              final AsyncFilterChain.ResponseTrigger responseTrigger,
              final AsyncFilterChain chain) throws HttpException, IOException {
          final AsyncServerExchangeHandler exchangeHandler = handlerFactory.create(request, context);
          if (exchangeHandler != null) {
              exchangeHandler.handleRequest(request, entityDetails, new ResponseChannel() {
  
                  @Override
                  public void sendInformation(final HttpResponse response, final HttpContext httpContext) throws HttpException, IOException {
                      responseTrigger.sendInformation(response);
                  }
  
                  @Override
                  public void sendResponse(final HttpResponse response, final EntityDetails entityDetails, final HttpContext httpContext) throws HttpException, IOException {
                      responseTrigger.submitResponse(response, entityDetails != null ? new AsyncEntityProducer() {
  
                          @Override
                          public void failed(final Exception cause) {
                              exchangeHandler.failed(cause);
                          }
  
                          @Override
                          public boolean isRepeatable() {
                              return false;
                          }
  
                          @Override
                         public long getContentLength() {
                             return entityDetails.getContentLength();
                         }
 
                         @Override
                         public String getContentType() {
                             return entityDetails.getContentType();
                         }
 
                         @Override
                         public String getContentEncoding() {
                             return entityDetails.getContentEncoding();
                         }
 
                         @Override
                         public boolean isChunked() {
                             return entityDetails.isChunked();
                         }
 
                         @Override
                         public Set<String> getTrailerNames() {
                             return entityDetails.getTrailerNames();
                         }
 
                         @Override
                         public int available() {
                             return exchangeHandler.available();
                         }
 
                         @Override
                         public void produce(final DataStreamChannel channel) throws IOException {
                             exchangeHandler.produce(channel);
                         }
 
                         @Override
                         public void releaseResources() {
                             exchangeHandler.releaseResources();
                         }
 
                     } : null);
                 }
 
                 @Override
                 public void pushPromise(final HttpRequest promise, final AsyncPushProducer pushProducer, final HttpContext httpContext) throws HttpException, IOException {
                     responseTrigger.pushPromise(promise, pushProducer);
                 }
 
             }, context);
             return exchangeHandler;
         }
         responseTrigger.submitResponse(new BasicHttpResponse(HttpStatus.SC_NOT_FOUND), AsyncEntityProducers.create("Not found"));
         return null;
     }
 
 }