/*
 * AirportBaseStationConfigurator
 *
 * Copyright (C) 2000, Jonathan Sevy <jsevy@mcs.drexel.edu>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


package snmp;



import java.math.*;


/** 
*	Defines a 32-bit counter, whose value wraps if initialized with a larger
* 	value. For an indicator which "pegs" at its maximum value if initialized with
* 	a larger value, use SNMPGauge32; for a counter with a wider range, use SNMPCounter64.
* 	@see snmp.SNMPGauge32
*	@see snmp.SNMPCounter64
*/


public class SNMPCounter32 extends SNMPInteger
{
	// maximum value is 2^32 - 1
	private static BigInteger maxValue = new BigInteger("4294967295");
	protected byte tag = SNMPBERCodec.SNMPCOUNTER32;
	
	
	
	/** Initialize value to 0.
	*/
	
	public SNMPCounter32()
	{
		this(0);	// initialize value to 0
	}
	
	
	public SNMPCounter32(long newValue)
	{
		value = new BigInteger(new Long(newValue).toString());
		
		// wrap if value > maxValue
		value = value.mod(maxValue);
	}
	
	
	
	/** Used to initialize from the BER encoding, usually received in a response from 
	* an SNMP device responding to an SNMPGetRequest.
	* @throws SNMPBadValueException Indicates an invalid BER encoding supplied. Shouldn't
	* occur in normal operation, i.e., when valid responses are received from devices.
	*/
	
	public SNMPCounter32(byte[] enc)
		throws SNMPBadValueException
	{
		extractValueFromBEREncoding(enc);
		
		// wrap if value > maxValue
		value = value.mod(maxValue);
	}
	
	
	
	
	
	/** Used to set the value with an instance of java.lang.Integer or
	* java.lang.BigInteger. The value of the constructed SNMPCounter32 object is the
	* supplied value mod 2^32.
	* @throws SNMPBadValueException Indicates an incorrect object type supplied.
	*/
	
	public void setValue(Object newValue)
		throws SNMPBadValueException
	{
		if (newValue instanceof BigInteger)
		{
			value = (BigInteger)newValue;
			value = value.mod(maxValue);	// wrap when value exceeds 2^32
		}
		else if (newValue instanceof Integer)
		{
			value = new BigInteger(newValue.toString());
			value = value.mod(maxValue);	// wrap when value exceeds 2^32
		}
		else if (newValue instanceof String)
		{
			value = value = new BigInteger((String)newValue);
			value = value.mod(maxValue);	// wrap when value exceeds 2^32
		}
		else
			throw new SNMPBadValueException(" Counter32: bad object supplied to set value ");
	}
	
	
	
	
}