/*
 * Copyright (C) 2006-2010 Alfresco Software Limited.
 *
 * This file is part of Alfresco
 *
 * Alfresco 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 3 of the License, or
 * (at your option) any later version.
 *
 * Alfresco 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 */

package org.alfresco.jlan.smb;

import java.util.Calendar;
import java.util.Date;

/**
 *  SMB date/time class.
 *  
 *  <p>Date/time encoding returned by older SMB/CIFS requests.
 *
 * @author gkspencer
 */
public final class SMBDate extends Date {

  // Constants
  //
  // Bit masks for extracting the date/time fields from an SMB encoded date/time.
  //

  private static final int Days 	= 0x001F;
  private static final int Month 	= 0x01E0;
  private static final int Year 	= 0xFE00;

  private static final int TwoSeconds = 0x001F;
  private static final int Minutes 		= 0x07E0;
  private static final int Hours 			= 0xF800;

  /**
   * Construct the SMBDate using a seconds since 1-Jan-1970 00:00:00 value.
   *
   * @param secs   Seconds since base date/time 1970 value
   */

  public SMBDate(int secs) {
    super (secs & 0x7FFFFFFF);
  }

  /**
   * Construct the SMBDate using the SMB encoded date/time values.
   *
   * @param dat    SMB encoded date value
   * @param tim    SMB encoded time value
   */

  public SMBDate(int dat, int tim) {

    //  Extract the date from the SMB encoded value

    int days = dat & Days;
    int months = (dat & Month) >> 5;
    int year = (dat & Year) >> 9;

    //  Extract the time from the SMB encoded value

    int secs = (tim & TwoSeconds) * 2;
    int mins = (tim & Minutes) >> 5;
    int hours = (tim & Hours) >> 11;

    //  Use a calendar object to create the date/time value

    Calendar cal = Calendar.getInstance();
    cal.clear();
    cal.set(year + 1980, months - 1, days, hours, mins, secs);

    //  Initialize this dates raw value

    this.setTime(cal.getTime().getTime());
  }
  
  /**
   * Create a new SMBDate using the long time value.
   *
   * @param dattim long
   */
  public SMBDate(long dattim) {
    super(dattim);
  }
  
  /**
   * Return this date as an SMB encoded date.
   *
   * @return     SMB encoded date value.
   */

  public final int asSMBDate() {

    //  Use a calendar object to get the day, month and year values

    Calendar cal = Calendar.getInstance();
    cal.setTime(this);

    //  Build the SMB encoded date value

    int smbDate = cal.get(Calendar.DAY_OF_MONTH);
    smbDate += (cal.get(Calendar.MONTH) + 1) << 5;
    smbDate += (cal.get(Calendar.YEAR) - 1980) << 9;

    //  Return the SMB encoded date value

    return smbDate;
  }
  
  /**
   * Return this time as an SMB encoded time.
   *
   * @return    SMB encoded time value.
   */

  public final int asSMBTime() {

    //  Use a calendar object to get the hour, minutes and seconds values

    Calendar cal = Calendar.getInstance();
    cal.setTime(this);

    //  Build the SMB encoded time value

    int smbTime = cal.get(Calendar.SECOND) / 2;
    smbTime += cal.get(Calendar.MINUTE) << 5;
    smbTime += cal.get(Calendar.HOUR_OF_DAY) << 11;

    //  Return the SMB encoded time value

    return smbTime;
  }
}