/*
----
This file is part of SECONDO.

Copyright (C) 2021,
Faculty of Mathematics and Computer Science,
Database Systems for New Applications.

SECONDO 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; either version 2 of the License, or
(at your option) any later version.

SECONDO 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 SECONDO; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
----

//[$][\$]

*/

#include "ResultIteratorMySQL.h"

namespace BasicEngine {

/*
  1.1 Is a new tuple available in the iterator

*/
    bool ResultIteratorMySQL::hasNextTuple() {
        return currentTuple < totalTuples;
    }

/*
  1.2 Return the next tuple from the iterator

*/
    Tuple* ResultIteratorMySQL::getNextTuple() {

        Tuple* result = basicTuple->Clone();
        MYSQL_ROW row = mysql_fetch_row(res);
    
        if(row == nullptr) {
            BOOST_LOG_TRIVIAL(error) <<
                "Unable to fetch next row from MySQL result";
            totalTuples = currentTuple;
            return nullptr;
        }

        for(size_t i = 0; i < attributeInstances.size(); i++) {
            
            Attribute* attr = attributeInstances[i]->Clone();

            if(! row[i]) {
                attr->SetDefined(false);
            } else {
                char* value = row[i];
                attr->ReadFromString(value);
                attr->SetDefined(true);
            }

            result->PutAttribute(i, attr);
        }

        currentTuple++;

        return result;
    }
}; // End namespace