/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* 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 Lesser General Public License for more details.
*
* Copyright (c) 2006 - 2013 Pentaho Corporation and Contributors. All rights reserved.
*/
package org.pentaho.reporting.libraries.formula.function.datetime;
import java.math.BigDecimal;
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.TypeRegistry;
import org.pentaho.reporting.libraries.formula.typing.coretypes.NumberType;
import org.pentaho.reporting.libraries.formula.util.NumberUtil;
/**
* This function extracts the hour (0 through 23) from a time.
*
* @author Cedric Pronzato
*/
public class HourFunction implements Function
{
private static final BigDecimal HOUR_24 = new BigDecimal(24.0);
private static final long serialVersionUID = 1877256236005061937L;
public HourFunction()
{
}
public String getCanonicalName()
{
return "HOUR";
}
public TypeValuePair evaluate(final FormulaContext context,
final ParameterCallback parameters) throws EvaluationException
{
if (parameters.getParameterCount() != 1)
{
throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
}
final TypeRegistry typeRegistry = context.getTypeRegistry();
final Number n = typeRegistry.convertToNumber(parameters.getType(0), parameters.getValue(0));
if (n == null)
{
throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
final BigDecimal bd = NumberUtil.getAsBigDecimal(n);
final BigDecimal day = new BigDecimal(NumberUtil.performIntRounding(bd).intValue());
final BigDecimal dayFraction = bd.subtract(day);
final BigDecimal hourAndMinutesVal = dayFraction.multiply(HOUR_24);
final BigDecimal hours = NumberUtil.performIntRounding(hourAndMinutesVal);
return new TypeValuePair(NumberType.GENERIC_NUMBER, hours);
}
}