/*************************************************************************
 * Copyright 2009-2012 Eucalyptus Systems, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3 of the License.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/.
 *
 * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
 * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
 * additional information or have any questions.
 *
 * This file may incorporate work covered under the following copyright
 * and permission notice:
 *
 *   Software License Agreement (BSD License)
 *
 *   Copyright (c) 2008, Regents of the University of California
 *   All rights reserved.
 *
 *   Redistribution and use of this software in source and binary forms,
 *   with or without modification, are permitted provided that the
 *   following conditions are met:
 *
 *     Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *     Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer
 *     in the documentation and/or other materials provided with the
 *     distribution.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *   COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 *   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *   CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 *   ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *   POSSIBILITY OF SUCH DAMAGE. USERS OF THIS SOFTWARE ACKNOWLEDGE
 *   THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE LICENSED MATERIAL,
 *   COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS SOFTWARE,
 *   AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING
 *   IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA,
 *   SANTA BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY,
 *   WHICH IN THE REGENTS' DISCRETION MAY INCLUDE, WITHOUT LIMITATION,
 *   REPLACEMENT OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO
 *   IDENTIFIED, OR WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT
 *   NEEDED TO COMPLY WITH ANY SUCH LICENSES OR RIGHTS.
 ************************************************************************/

package com.eucalyptus.objectstorage.bittorrent;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.log4j.Logger;

import com.eucalyptus.auth.util.Hashes;
import com.eucalyptus.objectstorage.util.ObjectStorageProperties;
import com.eucalyptus.records.Logs;

import edu.ucsb.eucalyptus.util.StreamConsumer;

public class TorrentCreator {
  private static Logger LOG = Logger.getLogger(TorrentCreator.class);
  private String torrentFilePath;
  private String filePath;
  private String trackerUrl;
  private String objectKey;
  private String objectName;
  private final String NAME_TAG = "name";

  public TorrentCreator(String filePath, String objectKey, String objectName, String torrentFilePath, String trackerUrl) {
    this.filePath = filePath;
    this.torrentFilePath = torrentFilePath;
    this.trackerUrl = trackerUrl;
    this.objectKey = objectKey;
    this.objectName = objectName;
  }

  private void makeTorrent() {
    new File(ObjectStorageProperties.TRACKER_DIR).mkdirs();
    try {
      Runtime rt = Runtime.getRuntime();
      Process proc = rt.exec(new String[] {ObjectStorageProperties.TORRENT_CREATOR_BINARY, filePath, trackerUrl, "--target", torrentFilePath});
      StreamConsumer error = new StreamConsumer(proc.getErrorStream());
      StreamConsumer output = new StreamConsumer(proc.getInputStream());
      error.start();
      output.start();
      int pid = proc.waitFor();
      output.join();
      String errValue = error.getReturnValue();
      String outValue = output.getReturnValue();
      if (errValue.length() > 0)
        LOG.warn(errValue);
      if (outValue.length() > 0)
        LOG.warn(outValue);
    } catch (Exception t) {
      LOG.error(t);
    }
  }

  private void changeName() throws Exception {
    File inFile = new File(torrentFilePath);
    File outFile = new File(torrentFilePath + Hashes.getRandom(6));
    BufferedInputStream inStream = new BufferedInputStream(new FileInputStream(inFile));
    BufferedOutputStream outStream = new BufferedOutputStream(new FileOutputStream(outFile));

    int bytesRead;
    int totalBytesRead = 0;
    byte[] bytes = new byte[102400];
    String inString = "";

    try {
      while ((bytesRead = inStream.read(bytes)) > 0) {
        inString += new String(bytes, 0, bytesRead);
        totalBytesRead += bytesRead;
      }
    } catch (IOException ex) {
      LOG.error(ex);
      Logs.extreme().error(ex, ex);
      throw ex;
    } finally {
      try {
        inStream.close();
      } catch (IOException ex) {
        LOG.error(ex);
      }
    }

    int len = inString.length();
    int idx = inString.indexOf(NAME_TAG);
    int lastidx = inString.indexOf(objectName) + objectName.length();

    try {
      outStream.write(bytes, 0, idx + NAME_TAG.length());
      outStream.write(new String(objectKey.length() + ":" + objectKey).getBytes());
      outStream.write(bytes, lastidx, totalBytesRead - lastidx);
    } catch (IOException ex) {
      LOG.error(ex);
      Logs.extreme().error(ex, ex);
      throw ex;
    } finally {
      try {
        outStream.close();
      } catch (IOException ex) {
        LOG.error(ex);
      }
    }
    outFile.renameTo(inFile);
  }

  public void create() throws Exception {
    makeTorrent();
    changeName();
  }
}
