package org.pentaho.reporting.libraries.formula.function.datetime;
import java.util.Date;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;
import java.util.Locale;
import java.math.BigDecimal;
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.FormulaContext;
import org.pentaho.reporting.libraries.formula.EvaluationException;
import org.pentaho.reporting.libraries.formula.LibFormulaErrorValue;
import org.pentaho.reporting.libraries.formula.LocalizationContext;
import org.pentaho.reporting.libraries.formula.typing.TypeRegistry;
import org.pentaho.reporting.libraries.formula.typing.coretypes.NumberType;
/**
* This is the same as DATEDIFF(date_1, date_2, "d");
*
* @author Thomas Morgner
*/
public class DaysFunction implements Function
{
public DaysFunction()
{
}
public String getCanonicalName()
{
return "DAYS";
}
public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException
{
if (parameters.getParameterCount() != 2)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
}
final TypeRegistry typeRegistry = context.getTypeRegistry();
final Date date1 = typeRegistry.convertToDate
(parameters.getType(0), parameters.getValue(0));
final Date date2 = typeRegistry.convertToDate
(parameters.getType(1), parameters.getValue(1));
if (date1 == null || date2 == null)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
final LocalizationContext localizationContext = context.getLocalizationContext();
final TimeZone timeZone = localizationContext.getTimeZone();
final Locale locale = localizationContext.getLocale();
final GregorianCalendar calandar1 =
new GregorianCalendar(timeZone, locale);
calandar1.setTime(date1);
final GregorianCalendar calandar2 =
new GregorianCalendar(timeZone, locale);
calandar2.setTime(date2);
final int dayOfYear1 = calandar1.get(Calendar.DAY_OF_YEAR);
final int dayOfYear2 = calandar2.get(Calendar.DAY_OF_YEAR);
final int year1 = calandar1.get(Calendar.YEAR);
final int year2 = calandar2.get(Calendar.YEAR);
final GregorianCalendar workingCalandar =
new GregorianCalendar(timeZone, locale);
int res = dayOfYear2 - dayOfYear1;
// run through the inner years, without counting the border years
// Always run from the lower to the higher, so that we prevent infinite
// loops ..
final int targetYear = Math.max(year1, year2);
for (int i = Math.min(year1, year2); i < targetYear; i++)
{
workingCalandar.set(Calendar.YEAR, i);
res += workingCalandar.getActualMaximum(Calendar.DAY_OF_YEAR);
}
//noinspection UnpredictableBigDecimalConstructorCall
return new TypeValuePair(NumberType.GENERIC_NUMBER, new BigDecimal((double)res));
}
}