/*
 * Copyright (C) 2008 Search Solution Corporation. All rights reserved by Search Solution. 
 *
 *   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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
 *
 */

/*
 * set_scan.c - Routines to implement set based derived tables.
 */

#ident "$Id$"

#include "config.h"

#include <string.h>

#include "fetch.h"
#include "set_scan.h"

/*
 * qproc_next_set_scan () -
 *   return: SCAN_CODE 
 *   s_id(in)   : s_id: Scan identifier
 * 
 * Note: Move the current element to the next element in the set. Signal
 * scan end if at the end of the set.
 */
SCAN_CODE
qproc_next_set_scan (THREAD_ENTRY * thread_p, SCAN_ID * s_id)
{
  SET_SCAN_ID *set_id = &s_id->s.ssid;
  REGU_VARIABLE *func;
  DB_SET *setp;

  func = set_id->set_ptr;
  if (func->type == TYPE_FUNC && func->value.funcp->ftype == F_SEQUENCE)
    {
      /* if its the empty set, return end of scan */
      if (set_id->operand == NULL)
	{
	  return S_END;
	}

      if (s_id->position == S_BEFORE)
	{
	  s_id->position = S_ON;
	  set_id->cur_index = 0;

	  db_value_clear (s_id->val_list->valp->val);
	  if (fetch_copy_dbval
	      (thread_p, &set_id->operand->value, s_id->vd, NULL, NULL, NULL,
	       s_id->val_list->valp->val) != NO_ERROR)
	    {
	      return S_ERROR;
	    }
	  return S_SUCCESS;
	}
      else if (s_id->position == S_ON)
	{
	  set_id->cur_index++;
	  if (set_id->cur_index == set_id->set_card)
	    {
	      return S_END;
	    }
	  set_id->operand = set_id->operand->next;

	  db_value_clear (s_id->val_list->valp->val);
	  if (fetch_copy_dbval
	      (thread_p, &set_id->operand->value, s_id->vd, NULL, NULL, NULL,
	       s_id->val_list->valp->val) != NO_ERROR)
	    {
	      return S_ERROR;
	    }
	  return S_SUCCESS;
	}
      else if (s_id->position == S_AFTER)
	{
	  return S_END;
	}
      else
	{
	  er_set (ER_ERROR_SEVERITY, ARG_FILE_LINE, ER_QPROC_UNKNOWN_CRSPOS,
		  0);
	  return S_ERROR;
	}
    }
  else
    {
      /* if its the empty set, return end of scan */
      if (DB_IS_NULL (&set_id->set))
	{
	  return S_END;
	}
      setp = DB_GET_SET (&set_id->set);
      if (!setp)
	{
	  return S_END;
	}
      set_id->set_card = db_set_size (setp);
      if (set_id->set_card == 0)
	{
	  return S_END;
	}

      if (s_id->position == S_BEFORE)
	{
	  s_id->position = S_ON;
	  set_id->cur_index = 0;

	  db_value_clear (s_id->val_list->valp->val);
	  if (db_set_get (setp, set_id->cur_index,
			  s_id->val_list->valp->val) != NO_ERROR)
	    {
	      return S_ERROR;
	    }
	  return S_SUCCESS;
	}
      else if (s_id->position == S_ON)
	{
	  set_id->cur_index++;
	  if (set_id->cur_index == set_id->set_card)
	    {
	      return S_END;
	    }

	  db_value_clear (s_id->val_list->valp->val);
	  if (db_set_get (setp, set_id->cur_index,
			  s_id->val_list->valp->val) != NO_ERROR)
	    {
	      return S_ERROR;
	    }
	  return S_SUCCESS;
	}
      else if (s_id->position == S_AFTER)
	{
	  return S_END;
	}
      else
	{
	  er_set (ER_ERROR_SEVERITY, ARG_FILE_LINE, ER_QPROC_UNKNOWN_CRSPOS,
		  0);
	  return S_ERROR;
	}
    }				/* else */

}