/*
 * $Id$
 */

/*
 * Harbour Project source code: 
 *   CT3 string function CHARMIRR()
 *
 * Copyright 2001 IntTec GmbH, Neunlindenstr 32, 79106 Freiburg, Germany
 *        Author: Martin Vogel <vogel@inttec.de>
 *
 * www - http://www.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.  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 "ct.h"


/*  $DOC$
 *  $FUNCNAME$
 *      CHARMIRR()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Mirror a string
 *  $SYNTAX$
 *      CHARMIRR (<[@]cString>, [<lDontMirrorSpaces>]) -> cMirroredString
 *  $ARGUMENTS$
 *      <[@]cString>            is the string that should be mirrored
 *      [<lDontMirrorSpaces>]   if set to .T., spaces at the end of
 *                              <cString> will not be mirrored but kept at the end
 *                              Default: .F., mirror the whole string
 *  $RETURNS$
 *      <cMirroredString>       the mirrored string
 *  $DESCRIPTION$
 *      The CHARMIRR() function mirrors a string, i.e. the first character
 *      will be put at the end, the second at the last but one position etc..
 *      One can use this function for index searches, but then, the spaces
 *      at the end of the string should not be mirrored.
 *      One can omit the return value of the function by setting the CSETREF()
 *      switch to .T., but <cString> must then be passed by reference to get
 *      a result.
 *  $EXAMPLES$
 *      ? charmirr ("racecar")        // "racecar" 
 *      ? charmirr ("racecar  ", .T.) // "racecar  "
 *      ? charmirr ("racecar  ", .F.) // "  racecar"
 *  $TESTS$
 *      charmirr ("racecar") == "racecar" 
 *      charmirr ("racecar  ", .T.) == "racecar  "
 *      charmirr ("racecar  ", .F.) == "  racecar"
 *  $STATUS$
 *      Ready
 *  $COMPLIANCE$
 *      CHARMIRR() is compatible with CT3's CHARMIRR().
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is charmirr.c, library is ct3.
 *  $SEEALSO$
 *      CSETREF()
 *  $END$
 */

HB_FUNC( CHARMIRR )
{
   int iNoRet;

   /* suppressing return value ? */
   iNoRet = ct_getref() && ISBYREF( 1 );

   /* param check */
   if( ISCHAR( 1 ) )
   {

      char *pcString = hb_parc( 1 );
      size_t sStrLen = ( size_t ) hb_parclen( 1 );
      char *pcRet, *pc1, *pc2;
      int iDontMirrorSpaces;

      if( ISLOG( 2 ) )
         iDontMirrorSpaces = hb_parl( 2 );
      else
         iDontMirrorSpaces = 0;

      if( sStrLen == 0 )
      {
         int iArgErrorMode = ct_getargerrormode();

         if( iArgErrorMode != CT_ARGERR_IGNORE )
         {
            ct_error( ( USHORT ) iArgErrorMode, EG_ARG, CT_ERROR_CHARMIRR, NULL,
                      "CHARMIRR", 0, EF_CANDEFAULT, HB_ERR_ARGS_BASEPARAMS );
         }
         if( iNoRet )
            hb_retl( 0 );
         else
            hb_retc( NULL );
         return;
      }

      pcRet = ( char * ) hb_xgrab( sStrLen + 1 );

      pc1 = pcString + sStrLen - 1;
      if( iDontMirrorSpaces )
      {
         pc2 = pcRet + sStrLen - 1;
         while( ( pc1 >= pcString ) && ( *pc1 == 0x20 ) )
         {
            *pc2 = 0x20;
            pc1--;
            pc2--;
         }
      }

      pc2 = pcRet;
      for( ; pc1 >= pcString; pc1-- )
      {
         *pc2 = *pc1;
         pc2++;
      }

      /* return string */
      if( ISBYREF( 1 ) )
         hb_storclen( pcRet, sStrLen, 1 );

      if( iNoRet )
      {
         hb_retl( 0 );
         hb_xfree( pcRet );
      }
      else
         hb_retclen_buffer( pcRet, sStrLen );
   }
   else /* if( ISCHAR( 1 ) ) */
   {
      PHB_ITEM pSubst = NULL;
      int iArgErrorMode = ct_getargerrormode();

      if( iArgErrorMode != CT_ARGERR_IGNORE )
      {
         pSubst = ct_error_subst( ( USHORT ) iArgErrorMode, EG_ARG,
                                  CT_ERROR_CHARMIRR, NULL, "CHARMIRR", 0,
                                  EF_CANSUBSTITUTE, HB_ERR_ARGS_BASEPARAMS );
      }

      if( pSubst != NULL )
         hb_itemReturnRelease( pSubst );
      else if( iNoRet )
         hb_retl( 0 );
      else
         hb_retc( NULL );
   }
}
