/*
 * This file is part of the Vamsas Client version 0.1. 
 * Copyright 2009 by Jim Procter, Iain Milne, Pierre Marguerite, 
 *  Andrew Waterhouse and Dominik Lindner.
 * 
 * Earlier versions have also been incorporated into Jalview version 2.4 
 * since 2008, and TOPALi version 2 since 2007.
 * 
 * The Vamsas Client is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *  
 * The Vamsas Client is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the Vamsas Client.  If not, see <http://www.gnu.org/licenses/>.
 */
package uk.ac.vamsas.client.simpleclient;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.channels.FileChannel;

import org.apache.commons.logging.LogFactory;

/**
 * @author Jim
 * 
 */
public class LockedFileOutputStream extends FileOutputStream {
  private static org.apache.commons.logging.Log log = LogFactory
      .getLog(LockedFileOutputStream.class);

  // FileOutputStream ostream=null;
  boolean closed = true;

  private void init() {
    FileChannel ch = super.getChannel();
    if (ch != null) {
      try {
        closed = !ch.isOpen();
      } catch (Exception e) {
        closed = true;
        log.debug("Invalid LockedOutputStream marked closed.", e);
      }
    }
  }

  /**
   * @param file
   * @throws FileNotFoundException
   */
  public LockedFileOutputStream(File file) throws FileNotFoundException {
    super(file); // super(file);
    init();
  }

  /**
   * @param file
   * @param append
   * @throws FileNotFoundException
   */
  public LockedFileOutputStream(File file, boolean append)
      throws FileNotFoundException {
    super(file, append);
    init();
  }

  /**
   * @param fdObj
   */
  public LockedFileOutputStream(FileDescriptor fdObj) {
    super(fdObj);
    init();
    if (fdObj.valid())
      closed = false;
  }

  /**
   * @param name
   * @throws FileNotFoundException
   */
  public LockedFileOutputStream(String name) throws FileNotFoundException {
    super(name);
    init();
  }

  /**
   * @param name
   * @param append
   * @throws FileNotFoundException
   */
  public LockedFileOutputStream(String name, boolean append)
      throws FileNotFoundException {
    super(name, append);
    init();
  }

  /**
   * closes - actually just flushes the stream instead.
   */
  public void close() throws IOException {
    if (!closed) {
      super.flush();
      super.getChannel().force(true);
      log.debug("Marking Lockedoutputstream closed.");
    } else
      throw new IOException("Close on already closed FileOutputStream.");
    closed = true;
  }

  /**
   * @throws IOException
   * @see java.io.OutputStream#flush()
   */
  public void flush() throws IOException {
    if (!closed)
      super.flush();
    else
      throw new IOException("flush on closed FileOutputStream");
  }

  /**
   * @return
   * @see java.io.FileOutputStream#getChannel()
   */
  public FileChannel getChannel() {
    if (!closed)
      return super.getChannel();
    else
      return null;
  }

  /**
   * @param b
   * @param off
   * @param len
   * @throws IOException
   * @see java.io.FileOutputStream#write(byte[], int, int)
   */
  public void write(byte[] b, int off, int len) throws IOException {
    if (!closed)
      super.write(b, off, len);
    else
      throw new IOException("write on Closed FileOutputStream");
  }

  /**
   * @param b
   * @throws IOException
   * @see java.io.FileOutputStream#write(byte[])
   */
  public void write(byte[] b) throws IOException {
    if (!closed)
      super.write(b);
    else
      throw new IOException("write on Closed FileOutputStream");
  }

  /**
   * @param b
   * @throws IOException
   * @see java.io.FileOutputStream#write(int)
   */
  public void write(int b) throws IOException {
    if (!closed)
      super.write(b);
    else
      throw new IOException("write on Closed FileOutputStream");
  }

}