/*
    * 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.url;
  
  import java.net.URI;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  
  import org.apache.commons.vfs2.Capability;
  import org.apache.commons.vfs2.FileName;
  import org.apache.commons.vfs2.FileObject;
  import org.apache.commons.vfs2.FileSystem;
  import org.apache.commons.vfs2.FileSystemConfigBuilder;
  import org.apache.commons.vfs2.FileSystemException;
  import org.apache.commons.vfs2.FileSystemOptions;
  import org.apache.commons.vfs2.provider.AbstractFileProvider;
  
  /**
   * A file provider backed by Java's URL API.
   */
  public class UrlFileProvider extends AbstractFileProvider {
  
      /** The provider's capabilities */
      protected static final Collection<Capability> capabilities = Collections.unmodifiableCollection(
              Arrays.asList(Capability.READ_CONTENT, Capability.URI, Capability.GET_LAST_MODIFIED));
  
      /**
       * Constructs a new instance.
       */
      public UrlFileProvider() {
          setFileNameParser(new UrlFileNameParser());
      }
  
      /**
       * Locates a file object, by absolute URI.
       *
       * @param baseFile The base FileObject.
       * @param fileUri The uri of the file to locate.
       * @param fileSystemOptions The FileSystemOptions
       * @return The FileObject
       * @throws FileSystemException if an error occurs.
       */
      @Override
      public synchronized FileObject findFile(final FileObject baseFile, final String fileUri,
              final FileSystemOptions fileSystemOptions) throws FileSystemException {
          try {
              final URI uri = URI.create(fileUri);
              final URI rootUri = uri.resolve("/");
              final String key = this.getClass().getName() + rootUri;
              FileSystem fs = findFileSystem(key, fileSystemOptions);
              if (fs == null) {
                  final String extForm = rootUri.toString();
                  final FileName rootName = getContext().parseURI(extForm);
                  // final FileName rootName =
                  // new BasicFileName(rootUrl, FileName.ROOT_PATH);
                  fs = new UrlFileSystem(rootName, fileSystemOptions);
                  addFileSystem(key, fs);
              }
              return fs.resolveFile(uri.getPath());
          } catch (final Exception e) {
              throw new FileSystemException("vfs.provider.url/badly-formed-uri.error", fileUri, e);
          }
      }
  
      @Override
      public Collection<Capability> getCapabilities() {
          return capabilities;
      }
  
      @Override
      public FileSystemConfigBuilder getConfigBuilder() {
          return org.apache.commons.vfs2.provider.res.ResourceFileSystemConfigBuilder.getInstance();
      }
  }