/* $Id$
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.etch.util.cmd;

/**
 * Description of ParityConstraint.
 */
public class ParityConstraint implements Constraint
{
	/**
	 * Constructs the ParityConstraint.
	 *
	 * @param wantsOdd
	 */
	public ParityConstraint( boolean wantsOdd )
	{
		this.wantsOdd = wantsOdd;
	}
	
	private final boolean wantsOdd;
	
	public void checkValue( Object value ) throws Exception
	{
		int v = ((Integer) value).intValue();
		boolean valueIsOdd = (v & 1) != 0;
		if (valueIsOdd != wantsOdd)
			throw new Exception( wantsOdd ? "is not odd" : "is not even" );
	}

	@Override
	public String toString()
	{
		return wantsOdd ? "must be odd" : "must be even";
	}
}