/* java.util.zip.ZipOutputStream
   Copyright (C) 2001 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath 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; either version 2, or (at your option)
any later version.

GNU Classpath 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 GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

As a special exception, if you link this library with other files to
produce an executable, this library does not by itself cause the
resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why the
executable file might be covered by the GNU General Public License. */

package java.util.zip;
import java.io.OutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Vector;
import java.util.Enumeration;

/**
 * This is a FilterOutputStream that writes the files into a zip
 * archive one after another.  It has a special method to start a new
 * zip entry.  The zip entries contains information about the file name
 * size, compressed size, CRC, etc.
 *
 * It includes support for STORED and DEFLATED entries.
 *
 * This class is not thread safe.
 *
 * @author Jochen Hoenicke 
 */
public class ZipOutputStream extends DeflaterOutputStream implements ZipConstants
{
  private Vector entries = new Vector();
  private CRC32 crc = new CRC32();
  private ZipEntry curEntry = null;

  private int curMethod;
  private int size;
  private int offset = 0;

  private byte[] zipComment = new byte[0];
  private int defaultMethod = DEFLATED;

  /**
   * Our Zip version is hard coded to 1.0 resp. 2.0
   */
  private final static int ZIP_STORED_VERSION   = 10;
  private final static int ZIP_DEFLATED_VERSION = 20;

  /**
   * Compression method.  This method doesn't compress at all.
   */
  public final static int STORED      =  0;
  /**
   * Compression method.  This method uses the Deflater.
   */
  public final static int DEFLATED    =  8;

  /**
   * Creates a new Zip output stream, writing a zip archive.
   * @param out the output stream to which the zip archive is written.
   */
  public ZipOutputStream(OutputStream out)
  {
    super(out, new Deflater(Deflater.DEFAULT_COMPRESSION, true));
  }

  /**
   * Set the zip file comment.
   * @param comment the comment.
   * @exception IllegalArgumentException if UTF8 encoding of comment is
   * longer than 0xffff bytes.
   */
  public void setComment(String comment)
  {
    byte[] commentBytes;
    try
      {
	commentBytes = comment.getBytes("UTF8");
      }
    catch (UnsupportedEncodingException ex)
      {
	throw new InternalError("UTF8 encoding not found");
      }
    if (commentBytes.length > 0xffff)
      throw new IllegalArgumentException("Comment too long.");
    zipComment = commentBytes;
  }
  
  /**
   * Sets default compression method.  If the Zip entry specifies
   * another method its method takes precedence.
   * @param method the method.
   * @exception IllegalArgumentException if method is not supported.
   * @see #STORED
   * @see #DEFLATED
   */
  public void setMethod(int method)
  {
    if (method != STORED && method != DEFLATED)
      throw new IllegalArgumentException("Method not supported.");
    defaultMethod = method;
  }

  /**
   * Sets default compression level.  The new level will be activated
   * immediately.  
   * @exception IllegalArgumentException if level is not supported.
   * @see Deflater
   */
  public void setLevel(int level)
  {
    def.setLevel(level);
  }
  
  /**
   * Write an unsigned short in little endian byte order.
   */
  private final void writeLeShort(int value) throws IOException 
  {
    out.write(value & 0xff);
    out.write((value >> 8) & 0xff);
  }

  /**
   * Write an int in little endian byte order.
   */
  private final void writeLeInt(int value) throws IOException 
  {
    writeLeShort(value);
    writeLeShort(value >> 16);
  }

  /**
   * Starts a new Zip entry. It automatically closes the previous
   * entry if present.  If the compression method is stored, the entry
   * must have a valid size and crc, otherwise all elements (except
   * name) are optional, but must be correct if present.  If the time
   * is not set in the entry, the current time is used.
   * @param entry the entry.
   * @exception IOException if an I/O error occured.
   * @exception IllegalStateException if stream was finished
   */
  public void putNextEntry(ZipEntry entry) throws IOException
  {
    if (entries == null)
      throw new IllegalStateException("ZipOutputStream was finished");

    int method = entry.getMethod();
    int flags = 0;
    if (method == -1)
      method = defaultMethod;

    if (method == STORED)
      {
	if (entry.getCompressedSize() >= 0)
	  {
	    if (entry.getSize() < 0)
	      entry.setSize(entry.getCompressedSize());
	    else if (entry.getSize() != entry.getCompressedSize())
	      throw new ZipException
		("Method STORED, but compressed size != size");
	  }
	else
	  entry.setCompressedSize(entry.getSize());

	if (entry.getSize() < 0)
	  throw new ZipException("Method STORED, but size not set");
	if (entry.getCrc() < 0)
	  throw new ZipException("Method STORED, but crc not set");
      }
    else if (method == DEFLATED)
      {
	if (entry.getCompressedSize() < 0
	    || entry.getSize() < 0 || entry.getCrc() < 0)
	  flags |= 8;
      }

    if (curEntry != null)
      closeEntry();

    if (entry.getTime() < 0)
      entry.setTime(System.currentTimeMillis());

    entry.flags = flags;
    entry.offset = offset;
    entry.setMethod(method);
    curMethod = method;
    /* Write the local file header */
    writeLeInt(LOCSIG);
    writeLeShort(method == STORED
		 ? ZIP_STORED_VERSION : ZIP_DEFLATED_VERSION);
    writeLeShort(flags);
    writeLeShort(method);
    writeLeInt(entry.getDOSTime());
    if ((flags & 8) == 0)
      {
	writeLeInt((int)entry.getCrc());
	writeLeInt((int)entry.getCompressedSize());
	writeLeInt((int)entry.getSize());
      }
    else
      {
	writeLeInt(0);
	writeLeInt(0);
	writeLeInt(0);
      }
    byte[] name = entry.getName().getBytes("UTF8");
    if (name.length > 0xffff)
      throw new ZipException("Name too long.");
    byte[] extra = entry.getExtra();
    if (extra == null)
      extra = new byte[0];
    writeLeShort(name.length);
    writeLeShort(extra.length);
    out.write(name);
    out.write(extra);

    offset += LOCHDR + name.length + extra.length;

    /* Activate the entry. */

    curEntry = entry;
    crc.reset();
    if (method == DEFLATED)
      def.reset();
    size = 0;
  }

  /**
   * Closes the current entry.
   * @exception IOException if an I/O error occured.
   * @exception IllegalStateException if no entry is active.
   */
  public void closeEntry() throws IOException
  {
    if (curEntry == null)
      throw new IllegalStateException("No open entry");

    /* First finish the deflater, if appropriate */
    if (curMethod == DEFLATED)
      super.finish();

    int csize = curMethod == DEFLATED ? def.getTotalOut() : size;

    if (curEntry.getSize() < 0)
      curEntry.setSize(size);
    else if (curEntry.getSize() != size)
      throw new ZipException("size was "+size
			     +", but I expected "+curEntry.getSize());

    if (curEntry.getCompressedSize() < 0)
      curEntry.setCompressedSize(csize);
    else if (curEntry.getCompressedSize() != csize)
      throw new ZipException("compressed size was "+csize
			     +", but I expected "+curEntry.getSize());

    if (curEntry.getCrc() < 0)
      curEntry.setCrc(crc.getValue());
    else if (curEntry.getCrc() != crc.getValue())
      throw new ZipException("crc was " + Long.toHexString(crc.getValue())
			     + ", but I expected " 
			     + Long.toHexString(curEntry.getCrc()));

    offset += csize;

    /* Now write the data descriptor entry if needed. */
    if (curMethod == DEFLATED && (curEntry.flags & 8) != 0)
      {
	writeLeInt(EXTSIG);
	writeLeInt((int)curEntry.getCrc());
	writeLeInt((int)curEntry.getCompressedSize());
	writeLeInt((int)curEntry.getSize());
	offset += EXTHDR;
      }

    entries.addElement(curEntry);
    curEntry = null;
  }

  /**
   * Writes the given buffer to the current entry.
   * @exception IOException if an I/O error occured.
   * @exception IllegalStateException if no entry is active.
   */
  public void write(byte[] b, int off, int len) throws IOException
  {
    if (curEntry == null)
      throw new IllegalStateException("No open entry.");

    switch (curMethod)
      {
      case DEFLATED:
	super.write(b, off, len);
	break;
	
      case STORED:
	out.write(b, off, len);
	break;
      }

    crc.update(b, off, len);
    size += len;
  }

  /**
   * Finishes the stream.  This will write the central directory at the
   * end of the zip file and flush the stream.
   * @exception IOException if an I/O error occured.
   */
  public void finish() throws IOException
  {
    if (entries == null)
      return;
    if (curEntry != null)
      closeEntry();

    int numEntries = 0;
    int sizeEntries = 0;
    
    Enumeration enum = entries.elements();
    while (enum.hasMoreElements())
      {
	ZipEntry entry = (ZipEntry) enum.nextElement();
	
	int method = entry.getMethod();
	writeLeInt(CENSIG);
	writeLeShort(method == STORED
		     ? ZIP_STORED_VERSION : ZIP_DEFLATED_VERSION);
	writeLeShort(method == STORED
		     ? ZIP_STORED_VERSION : ZIP_DEFLATED_VERSION);
	writeLeShort(entry.flags);
	writeLeShort(method);
	writeLeInt(entry.getDOSTime());
	writeLeInt((int)entry.getCrc());
	writeLeInt((int)entry.getCompressedSize());
	writeLeInt((int)entry.getSize());

	byte[] name = entry.getName().getBytes("UTF8");
	if (name.length > 0xffff)
	  throw new ZipException("Name too long.");
	byte[] extra = entry.getExtra();
	if (extra == null)
	  extra = new byte[0];
	String strComment = entry.getComment();
	byte[] comment = strComment != null
	  ? strComment.getBytes("UTF8") : new byte[0];
	if (comment.length > 0xffff)
	  throw new ZipException("Comment too long.");

	writeLeShort(name.length);
	writeLeShort(extra.length);
	writeLeShort(comment.length);
	writeLeShort(0); /* disk number */
	writeLeShort(0); /* internal file attr */
	writeLeInt(0);   /* external file attr */
	writeLeInt(entry.offset);

	out.write(name);
	out.write(extra);
	out.write(comment);
	numEntries++;
	sizeEntries += CENHDR + name.length + extra.length + comment.length;
      }

    writeLeInt(ENDSIG);
    writeLeShort(0); /* disk number */
    writeLeShort(0); /* disk with start of central dir */
    writeLeShort(numEntries);
    writeLeShort(numEntries);
    writeLeInt(sizeEntries);
    writeLeInt(offset);
    writeLeShort(zipComment.length);
    out.write(zipComment);
    out.flush();
    entries = null;
  }
}