package org.opentrafficsim.base.compressedfiles;
   
   import java.io.FileOutputStream;
   import java.io.IOException;
   import java.io.OutputStream;
   import java.util.zip.GZIPOutputStream;
   import java.util.zip.ZipEntry;
   import java.util.zip.ZipOutputStream;
   
  import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream;
  
  /**
   * Writer for compressed files.
   * <p>
   * Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
   * <p>
   * @version $Revision$, $LastChangedDate$, by $Author$, initial version Oct 24, 2018 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
   */
  public final class Writer
  {
      /**
       * Class with only static methods should not be instantiated.
       */
      private Writer()
      {
          // Do not instantiate
      }
  
      /**
       * Construct a new OutputStream that performs a requested data compression.
       * @param fileName String; name of the file that will be created (possible
       * @param compressionType CompressionType; the type of data compression to use
       * @return OutputStream that accepts data to write and should eventually be closed
       * @throws IOException when the requested file could not be opened for writing, or the compression type is unknown
       */
      public static OutputStream createOutputStream(final String fileName, final CompressionType compressionType)
              throws IOException
      {
          if (CompressionType.AUTODETECT.equals(compressionType))
          {
              throw new IOException("AUTODETECT not allowed for Writer");
          }
          String extension = "." + compressionType.getExtension();
          int suffixPos = fileName.length() - extension.length();
          String currentSuffix = suffixPos > 0 ? fileName.substring(suffixPos) : "";
          String fixedFileName =
                  (currentSuffix.equalsIgnoreCase(extension) ? fileName.substring(0, suffixPos) : fileName) + extension;
          FileOutputStream fileOutputStream = new FileOutputStream(fixedFileName);
          switch (compressionType)
          {
              case AUTODETECT:
                  // Cannot happen
                  throw new IOException("AUTODETECT not allowed for Writer");
  
              case BZIP2:
                  return new BZip2CompressorOutputStream(fileOutputStream);
  
              case GZIP:
                  return new GZIPOutputStream(fileOutputStream);
  
              case NONE:
                  return fileOutputStream;
  
              case ZIP:
              {
                  ZipOutputStream zipOutputStream = new ZipOutputStream(fileOutputStream);
                  // Construct the name of the (single) TOC entry from the supplied file name
                  int lastSeparatorPos =
                          Math.max(Math.max(fileName.lastIndexOf("/"), fileName.lastIndexOf("\\")), fileName.lastIndexOf(":"));
                  String entryName = fileName.substring(lastSeparatorPos + 1);
                  zipOutputStream.putNextEntry(new ZipEntry(entryName));
                  return zipOutputStream;
              }
  
              default:
                  // Cannot happen
                  throw new IOException("Don't know how to create writer for compression type " + compressionType);
  
          }
      }
  
  }