/*
    * 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.
   */
  package org.apache.chemistry.opencmis.server.filter;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletRequestWrapper;
  
  
  public class ProxyHttpServletRequestWrapper extends HttpServletRequestWrapper
  {
      public static final String FORWARDED_HOST_HEADER = "X-Forwarded-Host";
      public static final String FORWARDED_PROTO_HEADER = "X-Forwarded-Proto";
      public static final String HTTPS_SCHEME = "https";
      public static final String HTTP_SCHEME = "http";
      private String scheme;
      private String serverName;
      private int serverPort;
  
      public ProxyHttpServletRequestWrapper( HttpServletRequest request )
      {
          super( request );
  
          scheme = request.getHeader( FORWARDED_PROTO_HEADER );
  
          if ( !HTTP_SCHEME.equalsIgnoreCase( scheme ) && !HTTPS_SCHEME.equalsIgnoreCase( scheme ) )
          {
              scheme = request.getScheme(  );
          }
  
          serverName = request.getServerName(  );
          serverPort = request.getServerPort(  );
  
          String host = request.getHeader( FORWARDED_HOST_HEADER );
  
          if ( ( host != null ) && ( host.length(  ) > 0 ) )
          {
              int index = host.indexOf( ':' );
  
              if ( index < 0 )
              {
                  serverName = host;
                  serverPort = getDefaultPort( scheme );
              }
              else
              {
                  serverName = host.substring( 0, index );
  
                  try
                  {
                      serverPort = Integer.parseInt( host.substring( index + 1 ) );
                  }
                  catch ( NumberFormatException e )
                  {
                      serverPort = getDefaultPort( scheme );
                  }
              }
          }
      }
  
      private int getDefaultPort( String scheme )
      {
          if ( HTTPS_SCHEME.equalsIgnoreCase( scheme ) )
          {
              return 443;
          }
  
          return 80;
      }
  
      @Override
      public String getScheme(  )
      {
          return scheme;
      }
  
      @Override
      public String getServerName(  )
      {
          return serverName;
      }
  
      @Override
      public int getServerPort(  )
     {
         return serverPort;
     }
 }