/*****************************************************************************
*
* MODULE:       DBF driver 
*   	    	
* AUTHOR(S):    Radim Blazek
*
* PURPOSE:      Simple driver for reading and writing dbf files     
*
* COPYRIGHT:    (C) 2000 by the GRASS Development Team
*
*               This program is free software under the GNU General Public
*   	    	License (>=v2). Read the file COPYING that comes with GRASS
*   	    	for details.
*
*****************************************************************************/

#include <grass/dbmi.h>
#include <grass/datetime.h>
#include <grass/shapefil.h>
#include "globals.h"
#include "proto.h"

int
db__driver_describe_table  (dbString *table_name, dbTable **table)

{
    int         tab;	
    char        *name;

    name = db_get_string (table_name);
    
    tab = find_table ( name );
    if ( tab == -1 ) {
	append_error("Table '%s' doesn't exist", db_get_string(table_name)); 
	report_error();
	return DB_FAILED;
    }
    describe_table ( tab, NULL, 0, table );

    return DB_OK;
}

/* scols is array of indexes selected columns or null,
 * if nscols == 0 => describe all columns */
int
describe_table (int tab, int *scols, int nscols, dbTable **table)
{
    int         i, col, ncols, dbtype, precision, scale;
    dbColumn    *column;
    COLUMN      *dcol;

    load_table_head ( tab );
    ncols = db.tables[tab].ncols;

    if ( nscols > 0 )
        ncols = nscols;
    
    if (!(*table = db_alloc_table(ncols))) {
        return DB_FAILED;
    }
    
    for (i=0; i < ncols; i++)
      {
        if ( nscols > 0 )
	    col = scols[i];
        else
	    col = i;

	dcol = &(db.tables[tab].cols[col]);
        column = db_get_table_column (*table, i);
	
        db_set_column_name (column, dcol->name);
        db_set_column_length (column, dcol->width);
	db_set_column_host_type (column, dcol->type);
	
        switch ( dcol->type )
          {  
            case DBF_INT:
                dbtype = DB_SQL_TYPE_INTEGER;
                precision = dcol->width - 1;  /* one char for sign */
                scale = 0;  
		break;
            case DBF_DOUBLE:
                dbtype = DB_SQL_TYPE_DOUBLE_PRECISION;
                precision = dcol->width - 2;  /* one char for sign second for decimal point */
                scale = dcol->decimals;  
                break;
            case DBF_CHAR:
                dbtype = DB_SQL_TYPE_CHARACTER;
                precision = 0;
                scale = 0; 
	        break;

            default:
                dbtype = DB_SQL_TYPE_UNKNOWN;
                break;
          }

        db_set_column_sqltype (column, dbtype);

	/* precision is number of digits */
        db_set_column_precision (column, precision);
	/* scale is number of digits to the right of decimal point */
	db_set_column_scale (column, scale);
	
	db_set_column_null_allowed (column);
        db_set_column_has_undefined_default_value(column);
        db_unset_column_use_default_value(column);
	
        db_set_column_select_priv_granted (column);
	
        if ( db.tables[tab].write )
            db_set_column_update_priv_granted (column);
	else
            db_set_column_update_priv_not_granted (column); 

	
      }
    
    /* set the table name */
    db_set_table_name (*table, db.tables[tab].name);

    /* set the table description */
    db_set_table_description(*table, "");
    
    if ( db.tables[tab].write )
      {	    
        db_set_table_delete_priv_granted (*table);
        db_set_table_insert_priv_granted (*table);
      } 
    else 
      {
        db_set_table_delete_priv_not_granted (*table);
        db_set_table_insert_priv_not_granted (*table);
      }
	
    return DB_OK;
}