/*
 * $Id$
 */

/*
 * 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, 6,
                  hb_paramError (1), hb_paramError (2),
                  hb_paramError (3), hb_paramError (4),
                  hb_paramError (5), hb_paramError (6));
      }
      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, 6,
                  hb_paramError (1), hb_paramError (2),
                  hb_paramError (3), hb_paramError (4),
                  hb_paramError (5), hb_paramError (6));
      }
      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 = 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);

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

        /* 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 (pcRetStr, sRetStrLen);
        hb_xfree (pcRetStr);

      }
    }

  }
  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, 6,
                               hb_paramError (1), hb_paramError (2),
                               hb_paramError (3), hb_paramError (4),
                               hb_paramError (5), hb_paramError (6));
    }
     
    if (pSubst != NULL)
    {
      hb_itemReturn (pSubst);
      hb_itemRelease (pSubst);
    }
    else
    {
      if (ISCHAR (2))
        hb_retclen (hb_parc (2), hb_parclen (2));
      else
        hb_retc ("");
    }
  }

  return;

}