/*
 * $Id$
 */

/*
 * Harbour Project source code: 
 *   ATADJUST() CT3 string function
 *
 * 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"


/*  $DOC$
 *  $FUNCNAME$
 *      ATADJUST()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Adjusts a sequence within a string to a specified position
 *  $SYNTAX$
 *      ATADJUST (<cStringToMatch>, <cString>, <nAdjustPosition>,
 *                [<nCounter>], [<nIgnore>],
 *                [<nFillChar|cFillChar>]) -> cString
 *  $ARGUMENTS$
 *      <cStringToMatch>        is the sequence to be adjusted within <cString>
 *      <cString>               is the string that contains <cStringToMatch>
 *      <nAdjustPosition>       specifies the position to that <cStringToMatch>
 *                              will be adjusted
 *      [<nCounter>]            specifies which occurence of <cStringToMatch>
 *                              in <cString> is to be adjusted
 *                              Default: last occurence
 *      [<nIgnore>]             specifies how many characters should be omitted
 *                              in the scan
 *      [<nFillChar|cFillChar>] specifies the character that is used for the
 *                              adjustment
 *  $RETURNS$
 *      cString                 the changed string
 *  $DESCRIPTION$
 *      <TODO: add a description, some examples and tests here>
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Ready
 *  $COMPLIANCE$
 *      ATADJUST() works like CT3's ATADJUST()
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is atadjust.c, library is ct3.
 *  $SEEALSO$
 *      SETATLIKE(),CSETATMUPA()
 *  $END$
 */

HB_FUNC( ATADJUST )
{
   if( ISCHAR( 1 ) && ISCHAR( 2 ) && ISNUM( 3 ) )
   {
      char *pcStringToMatch = hb_parc( 1 );
      size_t sStrToMatchLen = ( size_t ) hb_parclen( 1 );
      char *pcString = hb_parc( 2 );
      size_t sStrLen = ( size_t ) hb_parclen( 2 );
      size_t sAdjustPosition = hb_parnl( 3 );

      int iMultiPass = ct_getatmupa();
      int iAtLike = ct_getatlike();
      char cAtLike = ct_getatlikechar();
      size_t sIgnore, sMatchStrLen;
      ULONG ulCounter;
      char *pc = NULL;

      char cFillChar;
      char *pcRetStr, *pcCheckFill;
      size_t sRetStrLen;

      /* eventually ignore some characters */
      if( ISNUM( 5 ) )
         sIgnore = ( size_t ) hb_parnl( 5 );
      else
         sIgnore = 0;

      if( sIgnore >= sStrLen )
      {
         int iArgErrorMode = ct_getargerrormode();

         if( iArgErrorMode != CT_ARGERR_IGNORE )
         {
            ct_error( ( USHORT ) iArgErrorMode, EG_ARG, CT_ERROR_ATADJUST, NULL, "ATADJUST", 0,
                      EF_CANDEFAULT, HB_ERR_ARGS_BASEPARAMS );
         }
         hb_retclen( pcString, sStrLen );
         return;
      }
      else
      {
         pcString += sIgnore;
         sStrLen -= sIgnore;
      }

      /* check for wrong adjust position */
      if( sAdjustPosition == 0 )
      {
         int iArgErrorMode = ct_getargerrormode();

         if( iArgErrorMode != CT_ARGERR_IGNORE )
         {
            ct_error( ( USHORT ) iArgErrorMode, EG_ARG, CT_ERROR_ATADJUST, NULL, "ATADJUST", 0,
                      EF_CANDEFAULT, HB_ERR_ARGS_BASEPARAMS );
         }
         hb_retclen( pcString, sStrLen );
         return;
      }
      else
         sAdjustPosition--;     /* makes live easier since C indices start at zero ! */

      /* nth match or last match ? */
      if( ISNUM( 4 ) && ( ulCounter = hb_parnl( 4 ) ) != 0 )
      {
         /* find the <ulCounter>th match */
         char *pcSubStr;
         size_t sSubStrLen;
         ULONG ulMatchCounter = 0;

         pcSubStr = pcString;
         sSubStrLen = sStrLen;

         while( ulMatchCounter < ulCounter )
         {
            switch ( iAtLike )
            {
               case CT_SETATLIKE_EXACT:
                  pc = ct_at_exact_forward( pcSubStr, sSubStrLen, pcStringToMatch,
                                            sStrToMatchLen, &sMatchStrLen );
                  break;

               case CT_SETATLIKE_WILDCARD:
                  pc = ct_at_wildcard_forward( pcSubStr, sSubStrLen, pcStringToMatch,
                                               sStrToMatchLen, cAtLike, &sMatchStrLen );
                  break;

               default:
                  pc = NULL;
            }

            if( pc == NULL )
            {
               /* no match found; if this happens at this point,
                  there are no <ulCounter> matches, so return */
               hb_retclen( pcString, sStrLen );
               return;
            }

            ulMatchCounter++;
            if( iMultiPass )
               pcSubStr = pc + 1;
            else
               pcSubStr = pc + sMatchStrLen;
            sSubStrLen = sStrLen - ( pcSubStr - pcString );
         }
      }
      else /* ( ISNUM( 4 ) && ( (ulCounter = hb_parnl( 4 ) ) != 0 ) */
      {
         /* we have to find the last match */
         switch ( iAtLike )
         {
            case CT_SETATLIKE_EXACT:
               pc = ct_at_exact_backward( pcString, sStrLen, pcStringToMatch,
                                          sStrToMatchLen, &sMatchStrLen );
               break;

            case CT_SETATLIKE_WILDCARD:
               pc = ct_at_wildcard_backward( pcString, sStrLen, pcStringToMatch,
                                             sStrToMatchLen, cAtLike, &sMatchStrLen );
               break;

            default:
               pc = NULL;
         }

         if( pc == NULL )
         {
            /* no matches found */
            hb_retclen( pcString, sStrLen );
            return;
         }
      }

      /* adjust string */
      if( ISCHAR( 6 ) )
      {
         if( hb_parclen( 6 ) > 0 )
            cFillChar = *( hb_parc( 6 ) );
         else
            cFillChar = 0x20;
      }
      else if( ISNUM( 6 ) )
         cFillChar = ( char ) ( hb_parnl( 6 ) % 256 );
      else
         cFillChar = 0x20;

      /* position of pc == adjust position ? */
      if( pc == pcString + sAdjustPosition )
      {
         /* do nothing */
         hb_retclen( pcString, sStrLen );
      }
      else
      {
         if( pc > pcString + sAdjustPosition )
         {
            /* adjust to left */
            /* check if we only delete cFillChar characters */
            for( pcCheckFill = pcString + sAdjustPosition; pcCheckFill < pc; pcCheckFill++ )
               if( *pcCheckFill != cFillChar )
               {
                  /* no -> return string unchanged */
                  hb_retclen( pcString, sStrLen );
                  return;
               }

            /* ok -> calculate new string size */
            sRetStrLen = sStrLen - ( pc - ( pcString + sAdjustPosition ) );
            pcRetStr = ( char * ) hb_xgrab( sRetStrLen + 1 );

            /* copy first portion of string */
            if( sAdjustPosition > 0 )
               hb_xmemcpy( pcRetStr, pcString, sAdjustPosition );

            /* copy second portion of string */
            if( sRetStrLen > sAdjustPosition )
               hb_xmemcpy( pcRetStr + sAdjustPosition, pc, sRetStrLen - sAdjustPosition );

            hb_retclen_buffer( pcRetStr, sRetStrLen );
         }
         else
         {
            /* adjust to right */
            sRetStrLen = sStrLen + ( pcString + sAdjustPosition ) - pc;
            pcRetStr = ( char * ) hb_xgrab( sRetStrLen + 1 );

            /* copy first portion of string */
            if( pc > pcString )
               hb_xmemcpy( pcRetStr, pcString, pc - pcString );

            /* fill characters */
            hb_xmemset( pcRetStr + ( pc - pcString ), cFillChar,
                        sAdjustPosition - ( pc - pcString ) );

            /* copy second portion of string */
            if( sRetStrLen > sAdjustPosition )
               hb_xmemcpy( pcRetStr + sAdjustPosition, pc, sRetStrLen - sAdjustPosition );

            hb_retclen_buffer( pcRetStr, sRetStrLen );
         }
      }
   }
   else                         /* ((ISCHAR (1)) && (ISCHAR (2)) && (ISNUM (3))) */
   {
      PHB_ITEM pSubst = NULL;
      int iArgErrorMode = ct_getargerrormode();

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

      if( pSubst != NULL )
         hb_itemReturnRelease( pSubst );
      else if( ISCHAR( 2 ) )
         hb_retclen( hb_parc( 2 ), hb_parclen( 2 ) );
      else
         hb_retc( NULL );
   }
}
