/**
* =========================================
* LibFormula : a free Java formula library
* =========================================
*
* Project Info: http://reporting.pentaho.org/libformula/
*
* (C) Copyright 2006-2008, by Pentaho Corporation and Contributors.
*
* This library 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 2.1 of the License, or (at your option) any later version.
*
* This library 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 this
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
*
* ------------
* ModFunction.java
* ------------
*/
package org.pentaho.reporting.libraries.formula.function.math;
import org.pentaho.reporting.libraries.formula.EvaluationException;
import org.pentaho.reporting.libraries.formula.FormulaContext;
import org.pentaho.reporting.libraries.formula.LibFormulaErrorValue;
import org.pentaho.reporting.libraries.formula.function.Function;
import org.pentaho.reporting.libraries.formula.function.ParameterCallback;
import org.pentaho.reporting.libraries.formula.lvalues.TypeValuePair;
import org.pentaho.reporting.libraries.formula.typing.Type;
import org.pentaho.reporting.libraries.formula.typing.TypeRegistry;
import org.pentaho.reporting.libraries.formula.typing.coretypes.NumberType;
import org.pentaho.reporting.libraries.formula.util.NumberUtil;
import java.math.BigDecimal;
/**
* This function returns the remainder when one number is divided by another number.
*
* @author Cedric Pronzato
*/
public class ModFunction implements Function
{
private static final long serialVersionUID = -2492279311353854670L;
public ModFunction()
{
}
public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException
{
final int parameterCount = parameters.getParameterCount();
if (parameterCount != 2)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
}
final TypeRegistry typeRegistry = context.getTypeRegistry();
final Type type1 = parameters.getType(0);
final Object value1 = parameters.getValue(0);
final Number number1 = typeRegistry.convertToNumber(type1, value1);
if (number1 == null)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
final BigDecimal divided = NumberUtil.getAsBigDecimal(number1);
final Type type2 = parameters.getType(1);
final Object value2 = parameters.getValue(1);
final Number number2 = typeRegistry.convertToNumber(type2, value2);
if (number2 == null)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
final BigDecimal divisor = NumberUtil.getAsBigDecimal(number2);
if(divisor.signum() == 0)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_ARITHMETIC_VALUE);
}
final BigDecimal divide = new BigDecimal(divided.divide(divisor, 0, BigDecimal.ROUND_FLOOR).toString());
BigDecimal reminder = divided.subtract(divisor.multiply(divide));
if(divide.signum() == 0)
{
if((divided.signum() == -1 && divisor.signum() != -1) || (divisor.signum() == -1 && divided.signum() != -1))
{
reminder = divided.add(divisor);
}
}
return new TypeValuePair(NumberType.GENERIC_NUMBER, reminder);
}
public String getCanonicalName()
{
return "MOD";
}
}