/*
    * ====================================================================
    * 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.impl.routing;
  
  import java.net.InetAddress;
  import java.util.Objects;
  
  import org.apache.hc.client5.http.HttpRoute;
  import org.apache.hc.client5.http.SchemePortResolver;
  import org.apache.hc.client5.http.config.RequestConfig;
  import org.apache.hc.client5.http.impl.DefaultSchemePortResolver;
  import org.apache.hc.client5.http.protocol.HttpClientContext;
  import org.apache.hc.client5.http.routing.HttpRoutePlanner;
  import org.apache.hc.client5.http.routing.RoutingSupport;
  import org.apache.hc.core5.annotation.Contract;
  import org.apache.hc.core5.annotation.ThreadingBehavior;
  import org.apache.hc.core5.http.HttpException;
  import org.apache.hc.core5.http.HttpHost;
  import org.apache.hc.core5.http.HttpRequest;
  import org.apache.hc.core5.http.ProtocolException;
  import org.apache.hc.core5.http.URIScheme;
  import org.apache.hc.core5.http.protocol.HttpContext;
  import org.apache.hc.core5.net.NamedEndpoint;
  import org.apache.hc.core5.net.URIAuthority;
  
  /**
   * Default implementation of an {@link HttpRoutePlanner}. It will not make use of
   * any Java system properties, nor of system or browser proxy settings.
   *
   * @since 4.3
   */
  @Contract(threading = ThreadingBehavior.STATELESS)
  public class DefaultRoutePlanner implements HttpRoutePlanner {
  
      private final SchemePortResolver schemePortResolver;
  
      public DefaultRoutePlanner(final SchemePortResolver schemePortResolver) {
          super();
          this.schemePortResolver = schemePortResolver != null ? schemePortResolver : DefaultSchemePortResolver.INSTANCE;
      }
  
      private static boolean sameNamedEndpoint(final NamedEndpoint n1, final NamedEndpoint n2) {
          if (n1 == null || n2 == null) {
              return false;
          }
          return Objects.equals(n1.getHostName(), n2.getHostName()) && n1.getPort() == n2.getPort();
      }
  
      @Override
      public final HttpRoute determineRoute(final HttpHost host, final HttpRequest request, final HttpContext context) throws HttpException {
          if (host == null) {
              throw new ProtocolException("Target host is not specified");
          }
          final HttpClientContext clientContext = HttpClientContext.cast(context);
          final RequestConfig config = clientContext.getRequestConfigOrDefault();
          @SuppressWarnings("deprecation")
          HttpHost proxy = config.getProxy();
          if (proxy == null) {
              proxy = determineProxy(host, context);
          }
          final HttpHost target = RoutingSupport.normalize(host, schemePortResolver);
          if (target.getPort() < 0) {
              throw new ProtocolException("Unroutable protocol scheme: " + target);
          }
          final boolean secure = URIScheme.HTTPS.same(target.getSchemeName());
          final URIAuthority authority;
          if (secure && request != null && !sameNamedEndpoint(request.getAuthority(), host)) {
              authority = request.getAuthority();
          } else {
              authority = null;
          }
          final InetAddress inetAddress = determineLocalAddress(target, context);
  
          if (proxy == null) {
             return new HttpRoute(target, authority, inetAddress, secure);
         }
         return new HttpRoute(target, authority, inetAddress, proxy, secure);
     }
 
     @Override
     public final HttpRoute determineRoute(final HttpHost host, final HttpContext context) throws HttpException {
         return determineRoute(host, null, context);
     }
 
     /**
      * This implementation returns null.
      *
      * @throws HttpException may be thrown if overridden
      */
     protected HttpHost determineProxy(
             final HttpHost target,
             final HttpContext context) throws HttpException {
         return null;
     }
 
     /**
      * This implementation returns null.
      *
      * @throws HttpException may be thrown if overridden
      */
     protected InetAddress determineLocalAddress(
             final HttpHost firstHop,
             final HttpContext context) throws HttpException {
         return null;
     }
 
 }