/* Copyright (C) 2014 InfiniDB, Inc.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; version 2 of
   the License.

   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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

/****************************************************************************
* $Id: func_elt.cpp 2665 2011-06-01 20:42:52Z rdempsey $
*
*
****************************************************************************/

#include <cstdlib>
#include <string>
using namespace std;

#include "functor_str.h"
#include "funchelpers.h"
#include "functioncolumn.h"
#include "rowgroup.h"
using namespace execplan;

#include "dataconvert.h"
using namespace dataconvert;

namespace funcexp
{

CalpontSystemCatalog::ColType Func_elt::operationType( FunctionParm& fp, CalpontSystemCatalog::ColType& resultType )
{
	return resultType;
}

string Func_elt::getStrVal(rowgroup::Row& row,
							FunctionParm& parm,
							bool& isNull,
							CalpontSystemCatalog::ColType&)
{
	uint64_t number = 0;

	//get number
	switch (parm[0]->data()->resultType().colDataType)
	{
		case CalpontSystemCatalog::BIGINT:
		case CalpontSystemCatalog::MEDINT:
		case CalpontSystemCatalog::SMALLINT:
		case CalpontSystemCatalog::TINYINT:
		case CalpontSystemCatalog::INT:
		case CalpontSystemCatalog::DOUBLE:
		case CalpontSystemCatalog::FLOAT:
		case CalpontSystemCatalog::CHAR:
		case CalpontSystemCatalog::TEXT:
		case CalpontSystemCatalog::VARCHAR:
		{
			double value = parm[0]->data()->getDoubleVal(row, isNull);
			number = (int64_t) value;
			break;
		}
		case CalpontSystemCatalog::DECIMAL:
		{
			IDB_Decimal d = parm[0]->data()->getDecimalVal(row, isNull);
			number = d.value / helpers::power(d.scale);
			int lefto = (d.value - number * helpers::power(d.scale)) / helpers::power(d.scale-1);
			if ( number >= 0 && lefto > 4 )
				number++;
			if ( number < 0 && lefto < -4 )
				number--;
			break;
		}
		default:
			isNull = true;
			return "";
	}

	if (number < 1)
	{
		isNull = true;
		return "";
	}

	if (number > parm.size()-1 )
	{
		isNull = true;
		return "";
	}

	return stringValue(parm[number], row, isNull);

}


} // namespace funcexp
// vim:ts=4 sw=4: