/*
    * 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.res;
  
  import java.net.URL;
  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;
  
  /**
   * The Resource provider.
   */
  public class ResourceFileProvider extends AbstractFileProvider {
  
      /** The provider's capabilities */
      protected static final Collection<Capability> capabilities = Collections
              .unmodifiableCollection(Arrays.asList(Capability.DISPATCHER));
  
      /**
       * Constructs a new instance.
       */
      public ResourceFileProvider() {
          setFileNameParser(ResourceFileNameParser.getInstance());
      }
  
      @Override
      public void closeFileSystem(final FileSystem filesystem) {
          // no filesystem created here - so nothing to do
      }
  
      /**
       * Locates a file object, by absolute URI.
       *
       * @param baseFile The base file.
       * @param uri The URI of the file to locate.
       * @param fileSystemOptions The FileSystem options.
       * @return the FileObject.
       * @throws FileSystemException if an error occurs.
       */
      @Override
      public FileObject findFile(final FileObject baseFile, final String uri, final FileSystemOptions fileSystemOptions)
          throws FileSystemException {
          final FileName fileName;
          if (baseFile != null) {
              fileName = parseUri(baseFile.getName(), uri);
          } else {
              fileName = parseUri(null, uri);
          }
          final String resourceName = fileName.getPath();
  
          ClassLoader classLoader = ResourceFileSystemConfigBuilder.getInstance().getClassLoader(fileSystemOptions);
          if (classLoader == null) {
              classLoader = getClass().getClassLoader();
          }
          FileSystemException.requireNonNull(classLoader, "vfs.provider.url/badly-formed-uri.error", uri);
          final URL url = classLoader.getResource(resourceName);
  
          FileSystemException.requireNonNull(url, "vfs.provider.url/badly-formed-uri.error", uri);
  
          return getContext().getFileSystemManager().resolveFile(url.toExternalForm());
      }
  
      @Override
      public Collection<Capability> getCapabilities() {
          return capabilities;
      }
  
      @Override
      public FileSystemConfigBuilder getConfigBuilder() {
          return ResourceFileSystemConfigBuilder.getInstance();
      }
  }