package org.eclipse.aether.transport.http;
   
   /*
    * 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.
   */
  
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.http.client.utils.URIUtils;
  
  /**
   * Helps to deal with URIs.
   */
  final class UriUtils
  {
  
      public static URI resolve( URI base, URI ref )
      {
          String path = ref.getRawPath();
          if ( path != null && path.length() > 0 )
          {
              path = base.getRawPath();
              if ( path == null || !path.endsWith( "/" ) )
              {
                  try
                  {
                      base = new URI( base.getScheme(), base.getAuthority(), base.getPath() + '/', null, null );
                  }
                  catch ( URISyntaxException e )
                  {
                      throw new IllegalStateException( e );
                  }
              }
          }
          return URIUtils.resolve( base, ref );
      }
  
      public static List<URI> getDirectories( URI base, URI uri )
      {
          List<URI> dirs = new ArrayList<>();
          for ( URI dir = uri.resolve( "." ); !isBase( base, dir ); dir = dir.resolve( ".." ) )
          {
              dirs.add( dir );
          }
          return dirs;
      }
  
      private static boolean isBase( URI base, URI uri )
      {
          String path = uri.getRawPath();
          if ( path == null || "/".equals( path ) )
          {
              return true;
          }
          if ( base != null )
          {
              URI rel = base.relativize( uri );
              if ( rel.getRawPath() == null || rel.getRawPath().isEmpty() || rel.equals( uri ) )
              {
                  return true;
              }
          }
          return false;
      }
  
  }