/*
 * $Id$
 */

/*
 * Harbour Project source code:
 *   POSCHAR(), POSDEL(), POSINS() and POSREPL() CT3 functions
 *
 * 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"


/*  $DOC$
 *  $FUNCNAME$
 *      POSCHAR()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Replace character at a certain position within a string
 *  $SYNTAX$
 *      POSCHAR (<[@]cString>, <cCharacter|nCharacter>, [<nPosition>]) -> cString
 *  $ARGUMENTS$
 *  $RETURNS$
 *  $DESCRIPTION$
 *      TODO: add documentation
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Started
 *  $COMPLIANCE$
 *      POSCHAR() is compatible with CT3's POSCHAR().
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is pos2.c, library is libct.
 *  $SEEALSO$
 *      POSDEL(),POSINS(),POSREPL(),CSETREF()
 *  $END$
 */

HB_FUNC( POSCHAR )
{
   int iNoRet;

   iNoRet = ct_getref() && ISBYREF( 1 );

   if( hb_parclen( 1 ) > 0 )
   {
      if( ( hb_parclen( 2 ) > 0 ) || ISNUM( 2 ) )
      {
         char *pcString = hb_parc( 1 );
         size_t sStrLen = hb_parclen( 1 );
         char *pcRet;
         char cReplace;
         size_t sPosition;

         if( ISCHAR( 2 ) )
            cReplace = *( hb_parc( 2 ) );
         else
            cReplace = ( char ) ( hb_parnl( 2 ) % 256 );

         if( ISNUM( 3 ) )
         {
            sPosition = hb_parnl( 3 );
            if( sPosition == 0 )
               sPosition = sStrLen;
         }
         else
            sPosition = sStrLen;

         pcRet = ( char * ) hb_xgrab( sStrLen + 1 );
         hb_xmemcpy( pcRet, pcString, sStrLen );
         *( pcRet + sPosition - 1 ) = cReplace;

         if( ISBYREF( 1 ) )
            hb_storclen( pcRet, sStrLen, 1 );

         if( iNoRet )
         {
            hb_ret();
            hb_xfree( pcRet );
         }
         else
            hb_retclen_buffer( pcRet, sStrLen );
      }
      else  /* ( hb_parclen( 2 ) > 0 ) || ISNUM( 2 ) */
      {
         PHB_ITEM pSubst = NULL;
         int iArgErrorMode = ct_getargerrormode();

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

         if( pSubst != NULL )
            hb_itemReturnRelease( pSubst );
         else if( iNoRet )
            hb_ret();
         else
            hb_retclen( hb_parc( 1 ), hb_parclen( 1 ) );
      }
   }
   else  /* hb_parclen( 1 ) > 0 */
   {
      PHB_ITEM pSubst = NULL;
      int iArgErrorMode = ct_getargerrormode();

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

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


/*  $DOC$
 *  $FUNCNAME$
 *      POSDEL()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Delete characters at a certain position within a string
 *  $SYNTAX$
 *      POSDEL (<cString>, [<nStartPosition>], <nLength>) -> cString
 *  $ARGUMENTS$
 *  $RETURNS$
 *  $DESCRIPTION$
 *      TODO: add documentation
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Started
 *  $COMPLIANCE$
 *      POSDEL() is compatible with CT3's POSDEL().
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is pos2.c, library is libct.
 *  $SEEALSO$
 *      POSCHAR(),POSINS(),POSREPL()
 *  $END$
 */

HB_FUNC( POSDEL )
{
   if( ISCHAR( 1 ) )
   {
      char *pcString = hb_parc( 1 );
      size_t sStrLen = hb_parclen( 1 );
      size_t sStartPos, sDelLen;
      char *pcRet;

      if( ISNUM( 3 ) )
         sDelLen = hb_parnl( 3 );
      else
         sDelLen = 1;           /* set new standard behavior */

      if( ISNUM( 2 ) )
      {
         sStartPos = hb_parnl( 2 );
         if( sStartPos == 0 || sStartPos > sStrLen - sDelLen + 1 )
            sStartPos = sStrLen - sDelLen + 1;
      }
      else
         sStartPos = sStrLen - sDelLen + 1;

      if( sStrLen <= sDelLen )
      {
         hb_retc( NULL );
         return;
      }

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

      /* copy first part */
      if( sStartPos > 1 )
      {
         hb_xmemcpy( pcRet, pcString, sStartPos - 1 );
      }

      /* copy second part */
      if( sStrLen > ( sStartPos - 1 + sDelLen ) )
      {
         hb_xmemcpy( pcRet + sStartPos - 1, pcString + sStartPos - 1 + sDelLen,
                     sStrLen - ( sStartPos - 1 + sDelLen ) );
      }

      hb_retclen_buffer( pcRet, sStrLen - sDelLen );
   }
   else  /* 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_POSDEL, NULL, "POSDEL", 0,
                                  EF_CANSUBSTITUTE, HB_ERR_ARGS_BASEPARAMS );
      }

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


/*  $DOC$
 *  $FUNCNAME$
 *      POSINS()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Insert characters at a certain position within a string
 *  $SYNTAX$
 *      POSINS (<cString>, <cInsert>, [<nPosition>]) -> cString
 *  $ARGUMENTS$
 *  $RETURNS$
 *  $DESCRIPTION$
 *      TODO: add documentation
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Started
 *  $COMPLIANCE$
 *      POSINS() is compatible with CT3's POSINS().
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is pos2.c, library is libct.
 *  $SEEALSO$
 *      POSCHAR,POSDEL(),POSREPL()
 *  $END$
 */

HB_FUNC( POSINS )
{
   if( ISCHAR( 1 ) )
   {
      char *pcString = hb_parc( 1 );
      size_t sStrLen = hb_parclen( 1 );
      char *pcInsert;
      size_t sInsLen;

      if( ( sInsLen = hb_parclen( 2 ) ) > 0 )
      {
         size_t sStartPos;
         char *pcRet;

         pcInsert = hb_parc( 2 );

         if( ISNUM( 3 ) )
         {
            sStartPos = hb_parnl( 3 );
            if( sStartPos == 0 )
               sStartPos = sStrLen;
         }
         else
            sStartPos = sStrLen;

         /* check for false sStartPos */
         if( sStartPos > sStrLen + 1 )
         {
            int iArgErrorMode = ct_getargerrormode();

            if( iArgErrorMode != CT_ARGERR_IGNORE )
            {
               ct_error( ( USHORT ) iArgErrorMode, EG_ARG, CT_ERROR_POSINS,
                         NULL, "POSINS", 0, EF_CANDEFAULT,
                         HB_ERR_ARGS_BASEPARAMS );
            }
            hb_retclen( pcString, sStrLen );
            return;
         }

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

         /* copy first part */
         if( sStartPos > 1 )
            hb_xmemcpy( pcRet, pcString, sStartPos - 1 );

         /* insert string */
         hb_xmemcpy( pcRet + sStartPos - 1, pcInsert, sInsLen );

         /* copy second part */
         if( sStrLen > ( sStartPos - 1 ) )
         {
            hb_xmemcpy( pcRet + sStartPos - 1 + sInsLen, pcString + sStartPos - 1,
                        sStrLen - ( sStartPos - 1 ) );
         }

         hb_retclen_buffer( pcRet, sStrLen + sInsLen );
      }
      else  /* hb_parclen( 2 ) > 0 */
         hb_retclen( pcString, sStrLen );
   }
   else  /* 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_POSINS, NULL, "POSINS", 0,
                                  EF_CANSUBSTITUTE, HB_ERR_ARGS_BASEPARAMS );
      }

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


/*  $DOC$
 *  $FUNCNAME$
 *      POSREPL()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Replace characters at a certain position within a string
 *  $SYNTAX$
 *      POSREPL (<[@]cString>, <cReplacement>, [<nStartPosition>]) -> cString
 *  $ARGUMENTS$
 *  $RETURNS$
 *  $DESCRIPTION$
 *      TODO: add documentation
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Started
 *  $COMPLIANCE$
 *      POSREPL() is compatible with CT3's POSREPL().
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is pos2.c, library is libct.
 *  $SEEALSO$
 *      POSCHAR(),POSDEL(),POSINS(),CSETREF()
 *  $END$
 */

HB_FUNC( POSREPL )
{
   int iNoRet;

   iNoRet = ct_getref() && ISBYREF( 1 );

   if( ISCHAR( 1 ) )
   {
      char *pcString = hb_parc( 1 );
      size_t sStrLen = hb_parclen( 1 );
      char *pcReplace;
      size_t sReplLen;

      if( ( sReplLen = hb_parclen( 2 ) ) > 0 )
      {

         size_t sStartPos;
         char *pcRet;
         size_t sRetLen;

         pcReplace = hb_parc( 2 );

         if( ISNUM( 3 ) )
         {
            sStartPos = hb_parnl( 3 );
            if( sStartPos == 0 )
            {
               if( sReplLen > sStrLen )
                  sStartPos = 1;
               else
                  sStartPos = sStrLen - sReplLen + 1;
            }
         }
         else
         {
            if( sReplLen > sStrLen )
               sStartPos = 1;
            else
               sStartPos = sStrLen - sReplLen + 1;
         }

         /* check for false sStartPos */
         if( sStartPos > sStrLen + 1 )
         {
            int iArgErrorMode = ct_getargerrormode();

            if( iArgErrorMode != CT_ARGERR_IGNORE )
            {
               ct_error( ( USHORT ) iArgErrorMode, EG_ARG, CT_ERROR_POSREPL,
                         NULL, "POSREPL", 0, EF_CANDEFAULT,
                         HB_ERR_ARGS_BASEPARAMS );
            }

            if( iNoRet )
               hb_ret();
            else
               hb_retclen( pcString, sStrLen );
            return;
         }

         if( sStrLen > ( sStartPos + sReplLen - 1 ) )
            sRetLen = sStrLen;
         else
            sRetLen = sStartPos + sReplLen - 1;

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

         /* copy first part */
         if( sStartPos > 1 )
            hb_xmemcpy( pcRet, pcString, sStartPos - 1 );

         /* insert replacement string */
         hb_xmemcpy( pcRet + sStartPos - 1, pcReplace, sReplLen );

         /* copy second part */
         if( sStrLen > ( sStartPos - 1 + sReplLen ) )
            hb_xmemcpy( pcRet + sStartPos - 1 + sReplLen, pcString + sStartPos - 1 + sReplLen,
                        sStrLen - ( sStartPos - 1 + sReplLen ) );

         if( ISBYREF( 1 ) )
         {
            hb_storclen( pcRet, sRetLen, 1 );
         }

         if( iNoRet )
         {
            hb_xfree( pcRet );
            hb_ret();
         }
         else
            hb_retclen_buffer( pcRet, sRetLen );

      }
      else  /* hb_parclen( 2 ) > 0 */
      {
         PHB_ITEM pSubst = NULL;
         int iArgErrorMode = ct_getargerrormode();

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

         if( pSubst != NULL )
            hb_itemReturnRelease( pSubst );
         else if( iNoRet )
            hb_ret();
         else
            hb_retclen( pcString, sStrLen );
      }
   }
   else  /* 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_POSREPL, NULL, "POSREPL", 0,
                                  EF_CANSUBSTITUTE, HB_ERR_ARGS_BASEPARAMS );
      }

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