// swad_figure_cache.c: figures (global stats) cached in database

/*
    SWAD (Shared Workspace At a Distance),
    is a web platform developed at the University of Granada (Spain),
    and used to support university teaching.

    This file is part of SWAD core.
    Copyright (C) 1999-2020 Antonio Caņas Vargas

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    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 Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
/*****************************************************************************/
/********************************* Headers ***********************************/
/*****************************************************************************/

//#define _GNU_SOURCE 		// For asprintf
#include <stdio.h>		// For sscanf
//#include <stdlib.h>		// For system, getenv, etc.
//#include <string.h>		// For string functions

#include "swad_database.h"
#include "swad_figure_cache.h"
#include "swad_scope.h"

/*****************************************************************************/
/************** External global variables from others modules ****************/
/*****************************************************************************/

// extern struct Globals Gbl;

/*****************************************************************************/
/***************************** Private constants *****************************/
/*****************************************************************************/

#define FigCch_TIME_CACHE	((time_t)(1UL * 60UL * 60UL))	// Past these seconds, update cached value

/*****************************************************************************/
/******************************* Private types *******************************/
/*****************************************************************************/

/*****************************************************************************/
/***************************** Private variables *****************************/
/*****************************************************************************/

/*****************************************************************************/
/****************************** Private prototypes ***************************/
/*****************************************************************************/

/*****************************************************************************/
/************** Get number of users who have chosen an option ****************/
/*****************************************************************************/

void FigCch_UpdateFigureIntoCache (FigCch_FigureCached_t Figure,
                                   Hie_Level_t Scope,long Cod,
                                   unsigned Value)
  {
   /***** Trivial check *****/
   if (Figure == FigCch_UNKNOWN)
      return;

   /***** Update figure's value in database *****/
   DB_QueryREPLACE ("can not update cached figure value",
		    "REPLACE INTO figures"
		    " (Figure,Scope,Cod,Value)"
		    " VALUES"
		    " (%u,'%s',%ld,%u)",
		    (unsigned) Figure,Sco_GetDBStrFromScope (Scope),Cod,Value);
  }

/*****************************************************************************/
/************** Get number of users who have chosen an option ****************/
/*****************************************************************************/
// Return true is figure is found (if figure is cached and recently updated)

bool FigCch_GetFigureFromCache (FigCch_FigureCached_t Figure,
                                Hie_Level_t Scope,long Cod,
                                unsigned *Value)
  {
   MYSQL_RES *mysql_res;
   MYSQL_ROW row;
   bool Found = false;

   *Value = 0;	// Default value when not found

   /***** Trivial check *****/
   if (Figure == FigCch_UNKNOWN)
      return Found;

   /***** Get figure's value if cached and recent *****/
   if (DB_QuerySELECT (&mysql_res,"can not get cached figure value",
		       "SELECT Value"
		       " FROM figures"
		       " WHERE Figure=%u AND Scope='%s' AND Cod=%ld"
		       " AND LastUpdate>FROM_UNIXTIME(UNIX_TIMESTAMP()-%lu)",
		       (unsigned) Figure,Sco_GetDBStrFromScope (Scope),Cod,
		       FigCch_TIME_CACHE))
     {
      /* Get row */
      row = mysql_fetch_row (mysql_res);

      /* Get value (row[0]) */
      if (row[0])
	 if (sscanf (row[0],"%u",Value) == 1)
            Found = true;
     }

   /***** Free structure that stores the query result *****/
   DB_FreeMySQLResult (&mysql_res);

   return Found;
  }