/*
 * SNMP Package
 *
 * Copyright (C) 2002, Jonathan Sevy <jsevy@mcs.drexel.edu>
 *
 * This is free software. Redistribution and use in source and binary forms, with
 * or without modification, are permitted provided that the following conditions
 * are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice, this
 *     list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation 
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products 
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */


package snmp;

import java.math.*;



/** 
*	Defines a 32-bit unsigned integer value; wraps if initialized with a larger value.
* 	@see snmp.SNMPInteger
*/
public class SNMPUInteger32 extends SNMPInteger
{
	// maximum value is 2^32 - 1
	private static BigInteger maxValue = new BigInteger("4294967295");
	
	
	/**
	*	Initialize value to 0.
	*/
	
	public SNMPUInteger32()
	{
		this(0);	// initialize value to 0
	}
	
	
	
	
	/**
	*	Initialize value to newValue; wrap if newValue too big for 32 bits.
	*/
	
	public SNMPUInteger32(long newValue)
	{
		tag = SNMPBERCodec.SNMPUINTEGER32;
		
		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.
	*/
	
	protected SNMPUInteger32(byte[] enc)
		throws SNMPBadValueException
	{
		tag = SNMPBERCodec.SNMPUINTEGER32;
		
		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 SNMPUInteger32 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 = 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(" Unsigned Integer: bad object supplied to set value ");
	}
	
	
	
	
}