~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems

 *

 *  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 St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include "config.h"

#include "drizzled/temporal.h"

#include "drizzled/error.h"

#include "drizzled/function/time/weekday.h"

namespace drizzled

{

int64_t Item_func_weekday::val_int()

{

  assert(fixed);

  if (args[0]->is_null())

  {

    /* For NULL argument, we return a NULL result */

    null_value= true;

    return 0;

  }

  /* Grab the first argument as a DateTime object */

  DateTime temporal;

  Item_result arg0_result_type= args[0]->result_type();

  switch (arg0_result_type)

  {

    case DECIMAL_RESULT: 

      /* 

       * For doubles supplied, interpret the arg as a string, 

       * so intentionally fall-through here...

       * This allows us to accept double parameters like 

       * 19971231235959.01 and interpret it the way MySQL does:

       * as a TIMESTAMP-like thing with a microsecond component.

       * Ugh, but need to keep backwards-compat.

       */

    case STRING_RESULT:

      {

        char buff[DRIZZLE_MAX_LENGTH_DATETIME_AS_STRING];

        String tmp(buff,sizeof(buff), &my_charset_utf8_bin);

        String *res= args[0]->val_str(&tmp);

        if (! temporal.from_string(res->c_ptr(), res->length()))

        {

          /* 

          * Could not interpret the function argument as a temporal value, 

          * so throw an error and return 0

          */

          my_error(ER_INVALID_DATETIME_VALUE, MYF(0), res->c_ptr());

          return 0;

        }

      }

      break;

    case INT_RESULT:

      if (temporal.from_int64_t(args[0]->val_int()))

        break;

      /* Intentionally fall-through on invalid conversion from integer */

    default:

      {

        /* 

        * Could not interpret the function argument as a temporal value, 

        * so throw an error and return 0

        */

        null_value= true;

        char buff[DRIZZLE_MAX_LENGTH_DATETIME_AS_STRING];

        String tmp(buff,sizeof(buff), &my_charset_utf8_bin);

        String *res;

        res= args[0]->val_str(&tmp);

        my_error(ER_INVALID_DATETIME_VALUE, MYF(0), res->c_ptr());

        return 0;

      }

  }

  /* @TODO This ODBC thing is a complete hack. Fix it. */

  bool sunday_first= odbc_type;

  int64_t julian_day= julian_day_number_from_gregorian_date(temporal.years(), temporal.months(), temporal.days());

  return (int64_t) day_of_week(julian_day, sunday_first) + test(odbc_type);

}

} /* namespace drizzled */