/*************************************************************************
*									 *
*	 YAP Prolog 							 *
*									 *
*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
*									 *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
*									 *
**************************************************************************
*									 *
* File:		myddas_sqlite3.c						 *
* Last rev:	22/03/05						 *
* mods:									 *
* comments:	Predicates for comunicating with a sqlite3 database system *
*									 *
*************************************************************************/

#if MYDDAS_SQLITE3

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sqlite3.h>
#include "Yap.h"
#include "Yatom.h"
#include "YapText.h"
#include "cut_c.h"
#include "eval.h"
#include "myddas.h"
#ifdef MYDDAS_STATS
#include "myddas_structs.h"
#include "myddas_statistics.h"
#endif
#include "myddas_wkb2prolog.h"

#define CALL_SQLITE(f)                                          \
{                                                           \
	int i;                                                  \
	i = sqlite3_ ## f;                                      \
	if (i != SQLITE_OK) {                                   \
		fprintf (stderr, "%s failed with status %d: %s\n",  \
		#f, i, sqlite3_errmsg (db));               \
		exit (1);                                           \
	}                                                       \
}                                                           \

#define CALL_SQLITE_EXPECT(f,x)                                 \
{                                                           \
	int i;                                                  \
	i = sqlite3_ ## f;                                      \
	if (i != SQLITE_ ## x) {                                \
		fprintf (stderr, "%s failed with status %d: %s\n",  \
		#f, i, sqlite3_errmsg (db));               \
		exit (1);                                           \
	}                                                       \
}					\

static Int null_id = 0;

typedef struct result_set {
  sqlite3_stmt *stmt;
  sqlite3 *db;
  char **res_set;
  int nrows;
  int length;
} resultSet;

void Yap_InitMYDDAS_SQLITE3Preds(void);
void Yap_InitBackMYDDAS_SQLITE3Preds(void);


static Int c_sqlite3_connect( USES_REGS1 );
static Int c_sqlite3_disconnect( USES_REGS1 );
static Int c_sqlite3_number_of_fields( USES_REGS1 );
static Int c_sqlite3_get_attributes_types( USES_REGS1 );
static Int c_sqlite3_query( USES_REGS1 );
static Int c_sqlite3_table_write( USES_REGS1 );
static Int c_sqlite3_row( USES_REGS1 );
static Int c_sqlite3_row_cut( USES_REGS1 );
static Int c_sqlite3_get_fields_properties( USES_REGS1 );
static Int c_sqlite3_get_next_result_set( USES_REGS1 );
static Int c_sqlite3_get_database( USES_REGS1 );
static Int c_sqlite3_change_database( USES_REGS1 );

void Yap_InitMYDDAS_SQLITE3Preds(void)
{
  /* db_dbect: Host x User x Passwd x Database x dbection x ERROR_CODE */
  Yap_InitCPred("c_sqlite3_connect", 4, c_sqlite3_connect,  0);

  /* db_number_of_fields: Relation x connection x NumberOfFields */
  Yap_InitCPred("c_sqlite3_number_of_fields",3, c_sqlite3_number_of_fields, 0);

  /* db_get_attributes_types: Relation x TypesList */
  Yap_InitCPred("c_sqlite3_get_attributes_types", 3, c_sqlite3_get_attributes_types,  0);

  /* db_query: SQLQuery x ResultSet x conection */
  Yap_InitCPred("c_sqlite3_query", 5, c_sqlite3_query, 0);

  /* db_disconnect: connection */
  Yap_InitCPred("c_sqlite3_disconnect", 1,c_sqlite3_disconnect, 0);

  /* db_table_write: Result Set */
  Yap_InitCPred("c_sqlite3_table_write", 1, c_sqlite3_table_write,  0);

  /* db_get_fields_properties: PredName x connection x PropertiesList*/
  Yap_InitCPred("c_sqlite3_get_fields_properties",3,c_sqlite3_get_fields_properties,0);

  Yap_InitCPred("c_sqlite3_get_next_result_set",2,c_sqlite3_get_next_result_set,0);

  /* c_sqlite3_get_database: connection x DataBaseName */
  Yap_InitCPred("c_sqlite3_get_database",2,c_sqlite3_get_database,0);

  /* c_sqlite3_change_database: connection x DataBaseName */
  Yap_InitCPred("c_sqlite3_change_database",2,c_sqlite3_change_database,0);


}

void Yap_InitBackMYDDAS_SQLITE3Preds(void)
{
	/* db_row: ResultSet x Arity x ListOfArgs */
  Yap_InitCPredBackCut("c_sqlite3_row", 3, sizeof(Int),
		    c_sqlite3_row,
		    c_sqlite3_row,
		    c_sqlite3_row_cut, 0);

}

static Int
c_sqlite3_connect( USES_REGS1 ) {

  Term arg_file = Deref(ARG1);
  Term arg_db = ARG4;

  MYDDAS_UTIL_CONNECTION new = NULL;
  sqlite3 *db;

  char *file = AtomName(AtomOfTerm(arg_file));

  CALL_SQLITE( open(file, &db) );

  if (!Yap_unify(arg_db, MkAddressTerm(db)))
	return FALSE;
  else
    {
      /* Criar um novo no na lista de ligacoes*/
      new = myddas_util_add_connection(db,NULL,API_SQLITE3);

      if (new == NULL){
#ifdef DEBUG
	fprintf(stderr, "ERROR: ** c_db_my_connect ** Error allocating memory\n");
#endif
	return FALSE;
      }
      return TRUE;
    }

}

static MYDDAS_STATS_TIME
myddas_stat_init_query( sqlite3 *db )
{
#ifdef MYDDAS_STATS
  MYDDAS_UTIL_connecTION node = myddas_util_search_connection(db);
  MyddasULInt count = 0;

  /* Count the number of querys made to the server */
  MyddasULInt number_querys;
  MYDDAS_STATS_CON_GET_NUMBER_QUERIES_MADE(node,number_querys);
  MYDDAS_STATS_CON_SET_NUMBER_QUERIES_MADE(node,++number_querys);
  MYDDAS_STATS_CON_GET_NUMBER_QUERIES_MADE_COUNT(node,count);
  MYDDAS_STATS_CON_SET_NUMBER_QUERIES_MADE_COUNT(node,++count);
  /* Measure time spent by the sqlite3 Server
     processing the SQL Query */
  return myddas_stats_walltime();
#else
  return NULL;
#endif
}


static MYDDAS_STATS_TIME
myddas_stat_end_query( MYDDAS_STATS_TIME start )
{
  MYDDAS_STATS_TIME diff = NULL;
#ifdef MYDDAS_STATS
  /* Measure time spent by the sqlite3 Server
     processing the SQL Query */
  end = myddas_stats_walltime();

  MYDDAS_STATS_INITIALIZE_TIME_STRUCT(diff,time_copy);
  myddas_stats_subtract_time(diff,end,start);
  diff = myddas_stats_time_copy_to_final(diff);

  MYDDAS_FREE(end,struct myddas_stats_time_struct);
  MYDDAS_FREE(start,struct myddas_stats_time_struct);

  MYDDAS_STATS_CON_GET_TOTAL_TIME_DBSERVER(node,total_time);
  /* Automacally updates the MYDDAS_STRUCTURE */
  myddas_stats_add_time(total_time,diff,total_time);
  MYDDAS_STATS_CON_GET_TOTAL_TIME_DBSERVER_COUNT(node,count);
  MYDDAS_STATS_CON_SET_TOTAL_TIME_DBSERVER_COUNT(node,++count);

  MYDDAS_STATS_TIME time = NULL;
  MYDDAS_STATS_CON_GET_LAST_TIME_DBSERVER(node,time);
  myddas_stats_move_time(diff,time);
  MYDDAS_STATS_CON_GET_LAST_TIME_DBSERVER_COUNT(node,count);
  MYDDAS_STATS_CON_SET_LAST_TIME_DBSERVER_COUNT(node,++count);
#endif
  return diff;
}

#ifdef MYDDAS_STATS
/* measure transfer time */
static void
myddas_stat_transfer_query( MYDDAS_STATS_TIME diff )
{
  /* Measure time spent by the sqlite3 Server
     transferring the result of the last query
     back to the client */
  start = myddas_stats_walltime();
  /* Measure time spent by the sqlite3 Server
     transferring the result of the last query
     back to the client */
  end = myddas_stats_walltime();

  MYDDAS_STATS_INITIALIZE_TIME_STRUCT(diff,time_copy);
  myddas_stats_subtract_time(diff,end,start);
  diff = MYDDAS_STATS_TIME_copy_to_final(diff);

  MYDDAS_FREE(end,struct myddas_stats_time_struct);
  MYDDAS_FREE(start,struct myddas_stats_time_struct);

  MYDDAS_STATS_CON_GET_TOTAL_TIME_TRANSFERING(node,total_time);
  /* Automacally updates the MYDDAS_STRUCTURE */
  myddas_stats_add_time(total_time,diff,total_time);
  MYDDAS_STATS_CON_GET_TOTAL_TIME_TRANSFERING_COUNT(node,count);
  MYDDAS_STATS_CON_SET_TOTAL_TIME_TRANSFERING_COUNT(node,++count);

  time = NULL;
  MYDDAS_STATS_CON_GET_LAST_TIME_TRANSFERING(node,time);
  MYDDAS_STATS_CON_GET_LAST_TIME_TRANSFERING_COUNT(node,count);
  MYDDAS_STATS_CON_SET_LAST_TIME_TRANSFERING_COUNT(node,++count);
  myddas_stats_move_time(diff,time);

  /* Measure the number of Rows returned from the server */
  if (res_set != NULL)
    {
      /* With an INSERT statement, sqlite3_(use or store)_result()
         returns a NULL pointer*/

      /* This is only works if we use sqlite3_store_result */
      MyddasUInt numberRows = sqlite3_num_rows(res_set);
      MyddasUInt rows;
      myddas_stat_transfer_query( diff );

      MYDDAS_STATS_CON_GET_TOTAL_ROWS(node,rows);
      numberRows = numberRows + rows;
      MYDDAS_STATS_CON_SET_TOTAL_ROWS(node,numberRows);
      MYDDAS_STATS_CON_GET_TOTAL_ROWS_COUNT(node,count);
      MYDDAS_STATS_CON_SET_TOTAL_ROWS_COUNT(node,++count);

      /* Calculate the ammount of data sent by the server */
      MyddasUInt total,number_fields = sqlite3_num_fields(res_set);
      sqlite3_ROW row;
      MyddasULInt i;
      total=0;
      while ((row = sqlite3_fetch_row(res_set)) != NULL){
        sqlite3_field_seek(res_set,0);

        for(i=0;i<number_fields;i++){
          if (row[i] != NULL)
            total = total + strlen(row[i]);
        }
      }
      MYDDAS_STATS_CON_SET_LAST_BYTES_TRANSFERING_FROM_DBSERVER(node,total);
      MYDDAS_STATS_CON_GET_LAST_BYTES_TRANSFERING_FROM_DBSERVER_COUNT(node,count);
      MYDDAS_STATS_CON_SET_LAST_BYTES_TRANSFERING_FROM_DBSERVER_COUNT(node,++count);

      MyddasUInt bytes = 0;
      MYDDAS_STATS_CON_GET_TOTAL_BYTES_TRANSFERING_FROM_DBSERVER(node,bytes);
      total = total + bytes;
      MYDDAS_STATS_CON_SET_TOTAL_BYTES_TRANSFERING_FROM_DBSERVER(node,total);
      MYDDAS_STATS_CON_GET_TOTAL_BYTES_TRANSFERING_FROM_DBSERVER_COUNT(node,count);
      MYDDAS_STATS_CON_SET_TOTAL_BYTES_TRANSFERING_FROM_DBSERVER_COUNT(node,++count);
    }
}
#endif

/* db_query: SQLQuery x ResultSet x connection */
static Int
c_sqlite3_query( USES_REGS1 ) {
  Term arg_sql_query = Deref(ARG1);
  Term arg_result_set = Deref(ARG2);
  Term arg_db = Deref(ARG3);
  Term arg_mode = Deref(ARG4);
  Term arg_arity = Deref(ARG5);

  char *sql = AtomName(AtomOfTerm(arg_sql_query));
  char *mode = AtomName(AtomOfTerm(arg_mode));
  sqlite3 *db = AddressOfTerm(arg_db);
  sqlite3_stmt *stmt;

  MYDDAS_STATS_TIME start, end;
  int length=strlen(sql);
  struct result_set *rs = malloc(sizeof( struct result_set));
  if (!rs)
    return FALSE;
  rs->db = db;

  start = myddas_stat_init_query( db );

   /* Send query to server and process it */
  if (strcmp(mode,"store_result")!=0) {
    // Leave data for extraction
    printf(" SQL 0: %s\n", sql);
    CALL_SQLITE (prepare_v2(db, sql, -1, &stmt, NULL) );
    rs->stmt = stmt;
    rs->res_set = NULL;
    rs->nrows = -1;
    rs->length = sqlite3_column_count( stmt );
    if (!Yap_unify(arg_arity, MkIntegerTerm(rs->length)))
      {
	free(rs);
	return FALSE;
      }
   if (!Yap_unify(arg_result_set, MkAddressTerm( rs)))
      {
        free(rs);
        return FALSE;
      }
    return TRUE;
  } else{
    // construct an intermediate table, res_set
    char **res_set;
    char *msg;
    int nrows;

    CALL_SQLITE (get_table(db, sql, &res_set, &nrows, &length, &msg) );

    //end = myddas_stat_end_query( start );
    if (res_set == NULL)
      {
#ifdef DEBUG
        printf("Empty Query!\n");
#endif
        return TRUE;
      }
    //INSERT statements don't return any res_set
    if (nrows == 0) {
      return TRUE;
    }
    if (!Yap_unify(arg_arity, MkIntegerTerm(nrows))){
      free(rs);
      sqlite3_free_table(res_set);
      return FALSE;
    }
    rs->stmt = NULL;
    rs->res_set = res_set;
    rs->nrows = nrows;
    rs->length = length;
    if (!Yap_unify(arg_result_set, MkAddressTerm( rs)))
      {
	free(rs);
	sqlite3_free_table(res_set);
	return FALSE;
      }
  }
  return TRUE;
}


static Int
c_sqlite3_number_of_fields( USES_REGS1 ) {
  Term arg_relation = Deref(ARG1);
  Term arg_db = Deref(ARG2);
  Term arg_fields = ARG3;

  char *relation = AtomName(AtomOfTerm(arg_relation));
  sqlite3 *db = AddressOfTerm(arg_db);
  sqlite3_stmt *stmt;

  char sql[256];

  sprintf(sql,"SELECT * FROM `%s`",relation);

  /* executar a query SQL */
  printf(" SQL 1: %s\n", sql);
CALL_SQLITE (prepare_v2(db, sql, -1, &stmt, NULL) );

  int fields = sqlite3_column_count( stmt );

  CALL_SQLITE (finalize( stmt ) );

  return Yap_unify(arg_fields, MkIntegerTerm( fields ));
}


/* db_get_attributes_types: RelName x connection -> TypesList */
static Int
c_sqlite3_get_attributes_types( USES_REGS1 ) {
  Term arg_relation = Deref(ARG1);
  Term arg_db = Deref(ARG2);
  Term arg_types_list = Deref(ARG3);
  Term list, head;

  char *relation = AtomName(AtomOfTerm(arg_relation));
  sqlite3 *db = (sqlite3 *) IntegerOfTerm(arg_db);
  char sql[256];
  int row;

  sqlite3_stmt *stmt;
  Int rc = TRUE;

  sprintf(sql,"SELECT * FROM `%s`",relation);

  /* executar a query SQL */
  printf(" SQL 3: %s\n", sql);
  CALL_SQLITE (prepare_v2(db, sql, -1, &stmt, NULL) );

  int fields = sqlite3_column_count( stmt );

  list = arg_types_list;

  for (row = 0; row < fields; row++)
  {
    const char *tm;


    head = HeadOfTerm(list);
    rc = (
	  rc && Yap_unify(head, MkAtomTerm(Yap_LookupAtom(sqlite3_column_name(stmt, row))) ) );
    list = TailOfTerm(list);
    head = HeadOfTerm(list);
    list = TailOfTerm(list);

    int type = sqlite3_column_type(stmt,row );
    switch(type) {
      case SQLITE_INTEGER:
	tm = "integer";
      break;
    case SQLITE_FLOAT:
      tm = "real";
      break;
    case SQLITE_TEXT:
      tm = "string";
      break;
    case SQLITE_BLOB:
      tm = "blob";
      break;
    case SQLITE_NULL:
    default:
      tm = "";
      break;
    }
    if (!Yap_unify(head, MkAtomTerm(Yap_LookupAtom(tm))) )
      rc = FALSE;
  }

  CALL_SQLITE (finalize( stmt ) );

  return rc;

}

/* db_disconnect */
static Int
c_sqlite3_disconnect( USES_REGS1 ) {
  Term arg_db = Deref(ARG1);

  sqlite3 *db = (sqlite3 *) IntegerOfTerm(arg_db);

  if ((myddas_util_search_connection(db)) != NULL)
    {
      myddas_util_delete_connection(db);
      sqlite3_close(db);
      return TRUE;
    }
  else
    {
      return FALSE;
    }
}

/* db_table_write: Result Set */
static Int
c_sqlite3_table_write( USES_REGS1 ) {
  /*
    Term arg_res_set = Deref(ARG1);
    sqlite3_RES *res_set = (sqlite3_RES *) IntegerOfTerm(arg_res_set);

    mydas_util_table_write(res_set);
    sqlite3_free_result(res_set);
  */
  return TRUE;
}

static Int
c_sqlite3_get_fields_properties( USES_REGS1 ) {
  Term nome_relacao = Deref(ARG1);
  Term arg_db = Deref(ARG2);
  Term fields_properties_list = Deref(ARG3);
  Term head, list;

  char *relation = AtomName(AtomOfTerm(nome_relacao));
  char sql[256];
  Int num_fields,i;
  sqlite3 *db = (sqlite3 *) (IntegerOfTerm(arg_db));

  sqlite3_stmt *stmt;

  sprintf(sql,"SELECT * FROM `%s`",relation);

  /* executar a query SQL */
  printf(" SQL 4: %s\n", sql);
  CALL_SQLITE (prepare_v2(db, sql, -1, &stmt, NULL) );

  Functor functor = Yap_MkFunctor(Yap_LookupAtom("property"),4);

  Term properties[4];

  list = fields_properties_list;

  num_fields = sqlite3_column_count( stmt );

  for (i=0;i<num_fields;i++)
    {
      int not_null, prim, auto_inc;

      head = HeadOfTerm(list);

      const char *col = sqlite3_column_name(stmt, i);
      properties[0] = MkAtomTerm(Yap_LookupAtom(col));

      CALL_SQLITE (table_column_metadata(db, NULL, relation, col, NULL,  NULL,
					      &not_null, &prim, &auto_inc) );
      properties[1] = MkIntegerTerm(not_null); //Can't be NULL

      properties[2] = MkIntegerTerm(prim); //It''s a primary key

      properties[3] = MkIntegerTerm(auto_inc);

      list = TailOfTerm(list);
      if (!Yap_unify(head, Yap_MkApplTerm(functor,4,properties))){
      	return FALSE;
      }
    }

  sqlite3_finalize(stmt);

  return TRUE;
}

/* c_sqlite3_get_next_result_set: connection * NextResSet */
static Int
c_sqlite3_get_next_result_set( USES_REGS1 ) {
  Term arg_db = Deref(ARG1);
  Term arg_next_res_set = Deref(ARG2);

  sqlite3 *db = (sqlite3 *) (IntegerOfTerm(arg_db));
  sqlite3_stmt *stmt;

  if ((stmt = sqlite3_next_stmt(db, NULL)) != NULL){
    struct result_set *rs = malloc(sizeof( struct result_set));
    if (!rs)
      return FALSE;
    rs->stmt = stmt;
    rs->res_set = NULL;
    rs->nrows = -1;
    rs->length = sqlite3_column_count( stmt );
    rs->db = db;
    Yap_unify(arg_next_res_set, MkAddressTerm(rs));
  }
  return TRUE;
}

static Int
c_sqlite3_get_database( USES_REGS1 ) {
  Term arg_con = Deref(ARG1);
  Term arg_database = Deref(ARG2);

  if (!Yap_unify(arg_database,arg_con))
    return FALSE;

  return TRUE;

}

static Int
c_sqlite3_change_database( USES_REGS1 ) {
  /* no-op for now */
  return TRUE;
}

static Int
c_sqlite3_row_cut( USES_REGS1 ) {
  struct result_set *res_set=NULL;

  res_set = AddressOfTerm(CBACK_CUT_ARG(1));
  sqlite3 *db = res_set->db;
    CALL_SQLITE( finalize( res_set->stmt ) );
  free(res_set);
  return TRUE;
}

#define cvt( s ) cvt__( s PASS_REGS )

static Term
cvt__(const char *s USES_REGS) {
  return Yap_CharsToTDQ( s, CurrentModule PASS_REGS);
}

/* db_row: ResultSet x Arity_ListOfArgs x ListOfArgs -> */
static Int
c_sqlite3_row( USES_REGS1 ) {
#ifdef MYDDAS_STATS
  /*   Measure time used by the  */
  /*      c_sqlite3_row function */
  //MYDDAS_STATS_TIME start,end,total_time,diff;
  MyddasULInt count = 0;
  start = myddas_stats_walltime();
#endif
  Term arg_result_set = Deref(ARG1);
  Term arg_arity = Deref(ARG2);
  Term arg_list_args = Deref(ARG3);
  Int rc = TRUE;

  if (IsVarTerm( arg_result_set ) ) {
    if (!c_sqlite3_query( PASS_REGS1 ) ) {
      cut_fail();
    }
    arg_result_set = Deref(ARG1);
    EXTRA_CBACK_ARG(3,1)= arg_result_set ;
    EXTRA_CBACK_ARG(3,2)= MkIntegerTerm(0) ;
  }
  struct result_set *res_set = AddressOfTerm(arg_result_set);

  Term head, list, null_atom[1];
  Int i, arity;
  list = arg_list_args;
  arity = IntegerOfTerm(arg_arity);
  sqlite3 *db = res_set->db;
  if (res_set->stmt == NULL ) {
    CACHE_REGS
    Int indx = IntegerOfTerm(EXTRA_CBACK_ARG(3,2));
    Int rc = true;
    // data needs to be copied to Prolog
    // row by row
#ifdef MYDDAS_STATS
    MYDDAS_STATS_TIME diff;

    MYDDAS_STATS_INITIALIZE_TIME_STRUCT(diff,time_copy);
#endif
     while (indx/arity < res_set->nrows)
      {
	for (i = 0; i < arity; i++)
	  {
	    /* Ts -> List */
	    const char *field = res_set->res_set[indx++];
	    head = HeadOfTerm(list);
	    list = TailOfTerm(list);
	    rc = (rc && Yap_unify(head, cvt( field  )) );
	  }
	if (rc)
	  return rc;
      }
#ifdef MYDDAS_STATS
     myddas_stat_transfer_query( diff );
#endif
    cut_fail();
  }
  // busy-waiting
  int res;
  while((res = sqlite3_step(res_set->stmt)) == SQLITE_BUSY);
  if (res == SQLITE_DONE) {
    // no more data
    CALL_SQLITE (finalize( res_set->stmt ) );
    free(res_set);
#ifdef MYDDAS_STATS
    end = myddas_stats_walltime();

    MYDDAS_STATS_INITIALIZE_TIME_STRUCT(diff,time_copy);
    myddas_stats_subtract_time(diff,end,start);
    diff = myddas_stats_time_copy_to_final(diff);

    MYDDAS_FREE(end,struct myddas_stats_time_struct);
    MYDDAS_FREE(start,struct myddas_stats_time_struct);

    MYDDAS_STATS_GET_DB_ROW_FUNCTION(total_time);
    myddas_stats_add_time(total_time,diff,total_time);
    MYDDAS_STATS_GET_DB_ROW_FUNCTION_COUNT(count);
    MYDDAS_STATS_SET_DB_ROW_FUNCTION_COUNT(++count);

    MYDDAS_FREE(diff,struct myddas_stats_time_struct);
#endif /* MYDDAS_STATS */
    cut_fail();  /* This macro already does a return FALSE */

  } else if (res == SQLITE_ROW) {
    list = arg_list_args;
    Term tf;

    for (i = 0; i < arity; i++)
      {
        /* convert data types here */
        head = HeadOfTerm(list);
        list = TailOfTerm(list);

        int type = sqlite3_column_type(res_set->stmt, i);
        switch(type) {
        case SQLITE_INTEGER:
          tf = Yap_Mk64IntegerTerm( sqlite3_column_int64(res_set->stmt, i));
          break;
        case SQLITE_FLOAT:
          tf = MkFloatTerm( sqlite3_column_double(res_set->stmt, i));
          break;
        case SQLITE_TEXT:
          tf = MkAtomTerm( Yap_LookupAtom((const char *)sqlite3_column_text(res_set->stmt, i) ));
          break;
        case SQLITE_BLOB:
	  {
	    size_t bytes = sqlite3_column_bytes(res_set->stmt, i);
	    tf = Yap_AllocExternalDataInStack(EXTERNAL_BLOB, bytes);
	    memcpy( ExternalBlobFromTerm( tf ), sqlite3_column_blob(res_set->stmt, i), bytes );
	  }
          break;
        case SQLITE_NULL:
	  null_atom[0] = MkIntegerTerm(null_id++);
	  tf = Yap_MkApplTerm(Yap_MkFunctor(Yap_LookupAtom("null"),1),1,null_atom);
          break;
        }
        if (!Yap_unify(head, tf))
          rc = FALSE;
      }
#ifdef MYDDAS_STATS
    end = myddas_stats_walltime();

    myddas_stats_subtract_time(diff,end,start);
    diff = myddas_stats_time_copy_to_final(diff);

    MYDDAS_FREE(end,struct myddas_stats_time_struct);
    MYDDAS_FREE(start,struct myddas_stats_time_struct);

    MYDDAS_STATS_GET_DB_ROW_FUNCTION(total_time);
    myddas_stats_add_time(total_time,diff,total_time);
    MYDDAS_STATS_GET_DB_ROW_FUNCTION_COUNT(count);
    MYDDAS_STATS_SET_DB_ROW_FUNCTION_COUNT(++count);

    MYDDAS_FREE(diff,struct myddas_stats_time_struct);
#endif /* MYDDAS_STATS */
  } else
    {
      Yap_Error(SYSTEM_ERROR_INTERNAL, TermNil, "sqlite3: %s", sqlite3_errmsg( db ) );
    }
	return rc;
}

#else


void Yap_InitMYDDAS_SQLITE3Preds(void);
void Yap_InitBackMYDDAS_SQLITE3Preds(void);


void Yap_InitMYDDAS_SQLITE3Preds(void)
{}
void Yap_InitBackMYDDAS_SQLITE3Preds(void)
{}


#endif