/*
    * 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.commons.vfs2.provider.local;
  
  import java.net.URI;
  
  import org.apache.commons.vfs2.FileName;
  import org.apache.commons.vfs2.FileSystemException;
  import org.apache.commons.vfs2.FileType;
  import org.apache.commons.vfs2.provider.AbstractFileNameParser;
  import org.apache.commons.vfs2.provider.UriParser;
  import org.apache.commons.vfs2.provider.VfsComponentContext;
  
  /**
   * A name parser.
   */
  public abstract class LocalFileNameParser extends AbstractFileNameParser {
  
      /**
       * Constructs a new instance.
       */
      public LocalFileNameParser() {
          // empty
      }
  
      /**
       * Creates a FileName.
       *
       * @param scheme The scheme.
       * @param rootFile the root file.
       * @param path the path.
       * @param fileType the file type.
       * @return a FileName.
       */
      protected abstract FileName createFileName(String scheme, String rootFile, String path, FileType fileType);
  
      /**
       * Pops the root prefix off a URI, which has had the scheme removed.
       *
       * @param name the URI to modify.
       * @param uri the whole URI for error reporting.
       * @return the root prefix extracted.
       * @throws FileSystemException if an error occurs.
       */
      protected abstract String extractRootPrefix(String uri, StringBuilder name) throws FileSystemException;
  
      private String[] getSchemes(final VfsComponentContext context, final FileName base, final String uri) {
          if (context == null) {
              return new String[] {base != null ? base.getScheme() : URI.create(uri).getScheme()};
          }
          return context.getFileSystemManager().getSchemes();
      }
  
      /**
       * Determines if a name is an absolute file name.
       *
       * @param name The file name.
       * @return true if the name is absolute, false otherwise.
       */
      public boolean isAbsoluteName(final String name) {
          // TODO - this is yucky
          final StringBuilder b = new StringBuilder(name);
          try {
              UriParser.fixSeparators(b);
              extractRootPrefix(name, b);
              return true;
          } catch (final FileSystemException e) {
              return false;
          }
      }
  
      @Override
      public FileName parseUri(final VfsComponentContext context, final FileName base, final String uri)
              throws FileSystemException {
          final StringBuilder nameBuilder = new StringBuilder();
  
          // Extract the scheme
          String scheme = UriParser.extractScheme(getSchemes(context, base, uri), uri, nameBuilder);
          if (scheme == null && base != null) {
              scheme = base.getScheme();
          }
          if (scheme == null) {
              scheme = "file";
          }
  
         // Remove encoding, and adjust the separators
         UriParser.canonicalizePath(nameBuilder, 0, nameBuilder.length(), this);
 
         UriParser.fixSeparators(nameBuilder);
 
         // Extract the root prefix
         final String rootFile = extractRootPrefix(uri, nameBuilder);
 
         // Normalise the path
         final FileType fileType = UriParser.normalisePath(nameBuilder);
 
         final String path = nameBuilder.toString();
 
         return createFileName(scheme, rootFile, path, fileType);
     }
 }