/* ContentType.java -- record layer content type.
   Copyright (C) 2003  Casey Marshall <rsdio@metastatic.org>

This file is a part of Jessie.

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

Jessie 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 Jessie; if not, write to the

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

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under terms
of your choice, provided that you also meet, for each linked independent
module, the terms and conditions of the license of that module.  An
independent module is a module which is not derived from or based on
this library.  If you modify this library, you may extend this exception
to your version of the library, but you are not obligated to do so.  If
you do not wish to do so, delete this exception statement from your
version.  */


package org.metastatic.jessie.provider;

import java.io.EOFException;
import java.io.InputStream;
import java.io.IOException;

/**
 * The content type enumeration, which marks packets in the record layer.
 *
 * <pre>enum { change_cipher_spec(20), alert(21), handshake(22),
 *             application_data(23), (255) } ContentType;</pre>
 *
 * @author Casey Marshall (rsdio@metastatic.org)
 */
final class ContentType implements Enumerated
{

  // Constants and fields.
  // ------------------------------------------------------------------------

  static final ContentType CLIENT_HELLO_V2    = new ContentType( 1);
  static final ContentType CHANGE_CIPHER_SPEC = new ContentType(20);
  static final ContentType ALERT              = new ContentType(21);
  static final ContentType HANDSHAKE          = new ContentType(22);
  static final ContentType APPLICATION_DATA   = new ContentType(23);

  private int value;

  // Constructors.
  // ------------------------------------------------------------------------

  private ContentType(int value)
  {
    this.value = value;
  }

  // Class methods.
  // ------------------------------------------------------------------------

  static final ContentType read(InputStream in) throws IOException
  {
    int value = in.read();
    if (value == -1)
      {
        throw new EOFException("unexpected end of input stream");
      }
    switch (value & 0xFF)
      {
      case  1: return CLIENT_HELLO_V2;
      case 20: return CHANGE_CIPHER_SPEC;
      case 21: return ALERT;
      case 22: return HANDSHAKE;
      case 23: return APPLICATION_DATA;
      default: return new ContentType(value);
      }
  }

  // Instance methods.
  // ------------------------------------------------------------------------

  public byte[] getEncoded()
  {
    return new byte[] { (byte) value };
  }

  public int getValue()
  {
    return value;
  }

  public boolean equals(Object o)
  {
    if (o == null || !(o instanceof ContentType))
      {
        return false;
      }
    return ((ContentType) o).value == value;
  }

  public int hashCode()
  {
    return getValue();
  }

  public String toString()
  {
    switch (value)
      {
      case  1: return "v2_client_hello";
      case 20: return "change_cipher_spec";
      case 21: return "alert";
      case 22: return "handshake";
      case 23: return "application_data";
      default: return "unknown(" + value + ")";
      }
  }
}