/*

 GNU-Classpath Extensions: javamail

 Copyright (C) 2002 Chris Burdess

 For more information on the classpathx please mail:

 nferrier@tapsellferrier.co.uk

 This program 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 2

 of the License, or (at your option) any later version.

 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, write to the Free Software

 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

  */

 package org.sonews.util.io; // original package: gnu.mail.providers.smtp

 import java.io.FilterOutputStream;

 import java.io.IOException;

 /**

  * An output stream implementing the SMTP specification for dot escaping.

  * Objects of this class are intended to be chained with CRLFOutputStream

  * instances as all SMTP output is intended to be CRLF-escaped.

  *

  * @author dog@gnu.org

  * @version 0.1

  */

 public class SMTPOutputStream extends FilterOutputStream {

 	/**

 	 * The LF octet.

 	 */

 	public static final int LF = 0x0a;

 	/**

 	 * The dot octet.

 	 */

 	public static final int DOT = 0x2e;

 	/**

 	 * The last octet read.

 	 */

 	protected int last;

 	/**

 	 * Constructs an SMTP output stream connected to the specified output stream.

 	 * The underlying output stream should coordinate proper CRLF pairs at

 	 * line ends.

 	 * @param out a CRLFOutputStream

 	 */

 	public SMTPOutputStream(CRLFOutputStream out) {

 		super(out);

 	}

 	/**

 	 * Writes a character to the underlying stream.

 	 * @exception IOException if an I/O error occurred

 	 */

 	@Override

 	public void write(int ch) throws IOException {

 		if (ch == DOT) {

 			if (last == LF) {

 				out.write(DOT);

 			}

 		}

 		out.write(ch);

 		last = ch;

 	}

 	/**

 	 * Writes a byte array to the underlying stream.

 	 * @exception IOException if an I/O error occurred

 	 */

 	@Override

 	public void write(byte b[]) throws IOException {

 		write(b, 0, b.length);

 	}

 	/**

 	 * Writes a portion of a byte array to the underlying stream.

 	 * @exception IOException if an I/O error occurred

 	 */

 	@Override

 	public void write(byte b[], int off, int len) throws IOException {

 		int d = off;

 		len += off;

 		for (int i = off; i < len; i++) {

 			switch (b[i]) {

 				case DOT:

 					int l = (i - d);

 					if (l > 0) {

 						out.write(b, d, l);

 					}

 					d = i;

 					if (last == LF) {

 						out.write(DOT);

 					}

 					break;

 			}

 			last = b[i];

 		}

 		if (len - d > 0) {

 			out.write(b, d, len - d);

 		}

 	}

 }