/*
 * 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 - 2009 Pentaho Corporation and Contributors.  All rights reserved.
 */

package org.pentaho.reporting.libraries.formula.function.datetime;

import java.sql.Time;

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.LocalizationContext;
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.DateTimeType;
import org.pentaho.reporting.libraries.formula.util.DateUtil;

/**
 * This fonction constructs a time from hours, minutes, and seconds.
 * 
 * @author Cedric Pronzato
 */
public class TimeFunction implements Function
{
  private static final long serialVersionUID = -9175775325047486483L;

  public TimeFunction()
  {
  }

  public String getCanonicalName()
  {
    return "TIME";
  }

  public TypeValuePair evaluate(final FormulaContext context,
      final ParameterCallback parameters) throws EvaluationException
  {
    if (parameters.getParameterCount() != 3)
    {
      throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
    }
    final Number n1;
    final Number n2;
    final Number n3;
    try
    {
      final TypeRegistry typeRegistry = context.getTypeRegistry();
      n1 = typeRegistry.convertToNumber(parameters.getType(0), parameters.getValue(0));
      n2 = typeRegistry.convertToNumber(parameters.getType(1), parameters.getValue(1));
      n3 = typeRegistry.convertToNumber(parameters.getType(2), parameters.getValue(2));
    } catch (NumberFormatException e)
    {
      throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
    }

    if (n1 == null || n2 == null || n3 == null)
    {
      throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
    }
    final int hours = n1.intValue();
    final int minutes = n2.intValue();
    final int seconds = n3.intValue();

    final LocalizationContext localizationContext = context.getLocalizationContext();
    final Time time = DateUtil.createTime(hours, minutes, seconds, localizationContext);
    return new TypeValuePair(DateTimeType.TIME_TYPE, time);
  }
}
