/*
    * ====================================================================
    * 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.examples;
  
  import java.io.IOException;
  import java.util.concurrent.TimeUnit;
  
  import org.apache.hc.core5.http.ClassicHttpResponse;
  import org.apache.hc.core5.http.ContentType;
  import org.apache.hc.core5.http.HttpException;
  import org.apache.hc.core5.http.HttpStatus;
  import org.apache.hc.core5.http.impl.bootstrap.HttpServer;
  import org.apache.hc.core5.http.impl.bootstrap.ServerBootstrap;
  import org.apache.hc.core5.http.impl.bootstrap.StandardFilter;
  import org.apache.hc.core5.http.io.HttpFilterChain;
  import org.apache.hc.core5.http.io.SocketConfig;
  import org.apache.hc.core5.http.io.entity.StringEntity;
  import org.apache.hc.core5.http.io.support.AbstractHttpServerAuthFilter;
  import org.apache.hc.core5.http.message.BasicClassicHttpResponse;
  import org.apache.hc.core5.http.protocol.HttpContext;
  import org.apache.hc.core5.io.CloseMode;
  import org.apache.hc.core5.net.URIAuthority;
  import org.apache.hc.core5.util.TimeValue;
  
  /**
   * Example of using classic I/O request filters with an embedded HTTP/1.1 server.
   */
  public class ClassicServerFilterExample {
  
      public static void main(final String[] args) throws Exception {
          int port = 8080;
          if (args.length >= 1) {
              port = Integer.parseInt(args[0]);
          }
          final SocketConfig socketConfig = SocketConfig.custom()
                  .setSoTimeout(15, TimeUnit.SECONDS)
                  .setTcpNoDelay(true)
                  .build();
  
          final HttpServer server = ServerBootstrap.bootstrap()
                  .setListenerPort(port)
                  .setSocketConfig(socketConfig)
  
                  // Replace standard expect-continue handling with a custom auth filter
  
                  .replaceFilter(StandardFilter.EXPECT_CONTINUE.name(), new AbstractHttpServerAuthFilter<String>(false) {
  
                      @Override
                      protected String parseChallengeResponse(
                              final String authorizationValue, final HttpContext context) throws HttpException {
                          return authorizationValue;
                      }
  
                      @Override
                      protected boolean authenticate(
                              final String challengeResponse,
                              final URIAuthority authority,
                              final String requestUri,
                              final HttpContext context) {
                          return "let me pass".equals(challengeResponse);
                      }
  
                      @Override
                      protected String generateChallenge(
                              final String challengeResponse,
                              final URIAuthority authority,
                              final String requestUri,
                              final HttpContext context) {
                          return "who goes there?";
                      }
  
                  })
  
                  // Add a custom request filter at the beginning of the processing pipeline
 
                 .addFilterFirst("my-filter", (request, responseTrigger, context, chain) -> {
                     if (request.getRequestUri().equals("/back-door")) {
                         final ClassicHttpResponse response = new BasicClassicHttpResponse(HttpStatus.SC_OK);
                         response.setEntity(new StringEntity("Welcome", ContentType.TEXT_PLAIN));
                         responseTrigger.submitResponse(response);
                     } else {
                         chain.proceed(request, new HttpFilterChain.ResponseTrigger() {
 
                             @Override
                             public void sendInformation(final ClassicHttpResponse response) throws HttpException, IOException {
                                 responseTrigger.sendInformation(response);
                             }
 
                             @Override
                             public void submitResponse(final ClassicHttpResponse response) throws HttpException, IOException {
                                 response.addHeader("X-Filter", "My-Filter");
                                 responseTrigger.submitResponse(response);
                             }
 
                         }, context);
                     }
                 })
 
                 // Application request handler
 
                 .register("*", (request, response, context) -> {
                     // do something useful
                     response.setCode(HttpStatus.SC_OK);
                     response.setEntity(new StringEntity("Hello"));
                 })
                 .create();
 
         server.start();
         Runtime.getRuntime().addShutdownHook(new Thread(() -> server.close(CloseMode.GRACEFUL)));
         System.out.println("Listening on port " + port);
 
         server.awaitTermination(TimeValue.MAX_VALUE);
 
     }
 
 }