/*
    * 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.io.FileNotFoundException;
  import java.io.InputStream;
  import java.net.HttpURLConnection;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.net.URLConnection;
  
  import org.apache.commons.httpclient.URIException;
  import org.apache.commons.vfs2.FileName;
  import org.apache.commons.vfs2.FileSystemException;
  import org.apache.commons.vfs2.FileType;
  import org.apache.commons.vfs2.provider.AbstractFileName;
  import org.apache.commons.vfs2.provider.AbstractFileObject;
  import org.apache.commons.vfs2.provider.URLFileName;
  
  /**
   * A {@link org.apache.commons.vfs2.FileObject FileObject} implementation backed by a {@link URL}.
   * <p>
   * TODO - Implement set lastModified and get/set attribute
   * </p>
   * <p>
   * TODO - Implement getOutputStream().
   * </p>
   */
  public class UrlFileObject extends AbstractFileObject<UrlFileSystem> {
      private URL url;
  
      protected UrlFileObject(final UrlFileSystem fs, final AbstractFileName fileName) {
          super(fileName, fs);
      }
  
      /**
       * Attaches this file object to its file resource. This method is called before any of the doBlah() or onBlah()
       * methods. Sub-classes can use this method to perform lazy initialization.
       */
      @Override
      protected void doAttach() throws Exception {
          if (url == null) {
              // url = new URL(getName().getURI());
              url = createURL(getName());
          }
      }
  
      protected URL createURL(final FileName name) throws MalformedURLException, FileSystemException, URIException {
          if (name instanceof URLFileName) {
              final URLFileName../../../../org/apache/commons/vfs2/provider/URLFileName.html#URLFileName">URLFileName urlName = (URLFileName) getName();
  
              // TODO: charset
              return new URL(urlName.getURIEncoded(null));
          }
          return new URL(getName().getURI());
      }
  
      /**
       * Determines the type of the file.
       */
      @Override
      protected FileType doGetType() throws Exception {
          try {
              // Attempt to connect & check status
              final URLConnection conn = url.openConnection();
              try (InputStream in = conn.getInputStream()) {
                  if (conn instanceof HttpURLConnection) {
                      final int status = ((HttpURLConnection) conn).getResponseCode();
                      // 200 is good, maybe add more later...
                      if (HttpURLConnection.HTTP_OK != status) {
                          return FileType.IMAGINARY;
                      }
                  }
  
                  return FileType.FILE;
              }
          } catch (final FileNotFoundException e) {
              return FileType.IMAGINARY;
          }
      }
  
      /**
       * Returns the size of the file content (in bytes).
       */
      @Override
     protected long doGetContentSize() throws Exception {
         final URLConnection conn = url.openConnection();
         try (InputStream in = conn.getInputStream()) {
             return conn.getContentLength();
         }
     }
 
     /**
      * Returns the last modified time of this file.
      */
     @Override
     protected long doGetLastModifiedTime() throws Exception {
         final URLConnection conn = url.openConnection();
         try (InputStream in = conn.getInputStream()) {
             return conn.getLastModified();
         }
     }
 
     /**
      * Lists the children of the file.
      */
     @Override
     protected String[] doListChildren() throws Exception {
         throw new FileSystemException("Not implemented.");
     }
 
     /**
      * Creates an input stream to read the file content from.
      */
     @Override
     protected InputStream doGetInputStream(final int bufferSize) throws Exception {
         return url.openStream();
     }
 }