/*
 * Harbour Project source code:
 * hb_StrShrink() function
 *
 * Copyright 2007-2012 Viktor Szakats (vszakats.net/harbour)
 * www - http://harbour-project.org
 *
 * 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; either version 2, 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software; see the file COPYING.txt.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA (or visit the web site http://www.gnu.org/).
 *
 * As a special exception, the Harbour Project gives permission for
 * additional uses of the text contained in its release of Harbour.
 *
 * The exception is that, if you link the Harbour libraries with other
 * files to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the Harbour library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the Harbour
 * Project under the name Harbour.  If you copy code from other
 * Harbour Project or Free Software Foundation releases into a copy of
 * Harbour, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for Harbour, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.
 *
 */

#include "hbapi.h"
#include "hbapicdp.h"
#include "hbapiitm.h"

HB_FUNC( HB_STRSHRINK )
{
   PHB_ITEM pText = hb_param( 1, HB_IT_STRING );

   if( pText )
   {
      HB_ISIZ nShrinkBy = hb_parnldef( 2, 1 );

      if( nShrinkBy > 0 )
      {
         const char * pszText = hb_itemGetCPtr( pText );
         HB_ISIZ nText = hb_itemGetCLen( pText );
         HB_ISIZ nLen;
         PHB_CODEPAGE cdp = hb_vmCDP();

         if( HB_CDP_ISCHARIDX( cdp ) )
            nLen = hb_cdpTextLen( cdp, pszText, nText );
         else
            nLen = nText;

         if( nShrinkBy < nLen )
         {
            if( HB_CDP_ISCHARIDX( cdp ) )
               nLen = hb_cdpTextPos( cdp, pszText, nText, nLen - nShrinkBy );
            else
               nLen -= nShrinkBy;
         }
         else
            nLen = 0;

         hb_retclen( pszText, nLen );
      }
      else
         hb_itemReturn( pText );
   }
   else
      hb_retc_null();
}