/*
 * Copyright (C) 2006-2008 Alfresco Software Limited.
 *
 * 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; 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 * As a special exception to the terms and conditions of version 2.0 of 
 * the GPL, you may redistribute this Program in connection with Free/Libre 
 * and Open Source Software ("FLOSS") applications as described in Alfresco's 
 * FLOSS exception.  You should have recieved a copy of the text describing 
 * the FLOSS exception, and it is also available here: 
 * http://www.alfresco.com/legal/licensing"
 */

package org.alfresco.jlan.smb.mailslot.win32;

import org.alfresco.jlan.netbios.NetBIOSName;
import org.alfresco.jlan.netbios.win32.Win32NetBIOS;
import org.alfresco.jlan.smb.mailslot.HostAnnouncer;
import org.alfresco.jlan.smb.server.win32.Win32NetBIOSSessionSocketHandler;

/**
 * <p>The host announcer class periodically broadcasts a host announcement datagram to inform other
 * Windows networking hosts of the local hosts existence and capabilities.
 * 
 * <p>The Win32 NetBIOS host announcer sends out the announcements using datagrams sent via the Win32
 * Netbios() Netapi32 call.
 *
 * @author gkspencer
 */
public class Win32NetBIOSHostAnnouncer extends HostAnnouncer {

  //	Associated session handler
  
  Win32NetBIOSSessionSocketHandler m_handler;
  
  /**
   * Create a host announcer.
   *
   * @param handler Win32NetBIOSSessionSocketHandler
   * @param domain  Domain name to announce to
   * @param intval  Announcement interval, in minutes
   */
  public Win32NetBIOSHostAnnouncer(Win32NetBIOSSessionSocketHandler handler, String domain, int intval) {

    //	Save the handler
    
    m_handler = handler;
    
		//	Add the host to the list of names to announce
		
    addHostName(handler.getServerName());
    setDomain(domain);
    setInterval(intval);
  }

  /**
   * Return the LANA
   * 
   * @return int
   */
  public final int getLana() {
    return m_handler.getLANANumber();
  }
  
  /**
   * Return the host name NetBIOS number
   * 
   * @return int
   */
  public final int getNameNumber() {
    return m_handler.getNameNumber();
  }

  /**
   * Initialize the host announcer.
   * 
   * @exception Exception
   */
  protected void initialize()
  	throws Exception {
    
    //	Set the thread name
    
    setName("Win32HostAnnouncer_L" + getLana());
  }

  /**
   * Determine if the network connection used for the host announcement is valid
   * 
   * @return boolean
   */
  public boolean isNetworkEnabled() {
    return m_handler.isLANAValid();
  }
  
  /**
   * Send an announcement broadcast.
   *
   * @param hostName	Host name being announced
   * @param buf				Buffer containing the host announcement mailslot message.
   * @param offset		Offset to the start of the host announcement message.
   * @param len				Host announcement message length.
   */
  protected void sendAnnouncement( String hostName, byte[] buf, int offset, int len)
  	throws Exception {
    
    //	Build the destination NetBIOS name using the domain/workgroup name
    
    NetBIOSName destNbName = new NetBIOSName(getDomain(), NetBIOSName.MasterBrowser, false);
    byte[] destName = destNbName.getNetBIOSName();
    
    //  Send the host announce datagram via the Win32 Netbios() API call
    
    Win32NetBIOS.SendDatagram( getLana(), getNameNumber(), destName, buf, 0, len);
  }
}