/*
 * $Id$
 */

/*
 * Harbour Project source code:
 *   TABEXPAND(), TABPACK() CT3 string functions
 *
 * Copyright 2002 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"


/*  $DOC$
 *  $FUNCNAME$
 *      TABEXPAND()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Replace tabulator control characters with fill characters
 *  $SYNTAX$
 *      TABEXPAND (<cString>, [<nTabWidth>], [<cFillChar|nFillChar>],
 *                 [<cNewLineCharacters>], [<cTabChar|nTabChar>],
 *                 [<lIgnore141>]) -> cExpandedString
 *  $ARGUMENTS$
 *      <cString>
 *      <nTabWidth>
 *      <cFillChar|nFillChar>
 *      <cNewLineCharacters>      string indicating new line,
 *                                default is the string returned by
 *                                hb_osnewline()
 *      <cTabChar|nTabChar>       character indicating a tab stop,
 *                                default is chr(9)
 *      <lIgnore141>              .T., if the soft-CR used by MEMOEDIT()
 *                                should be ignored as a newline indicator,
 *                                default is .F. (functions uses chr(141))
 *  $RETURNS$
 *  $DESCRIPTION$
 *      TODO: add documentation
 *  $EXAMPLES$
 *  $TESTS$
 *      tabexpand("-"+chr(9)+"!")             == "-       !" 
 *      tabexpand("----"+chr(9) +"!")         == "----    !" 
 *      tabexpand("-"+chr(9)+"!",, "+")       == "-+++++++!" 
 *      tabexpand("-"+chr(9)+ "!", 4)         == "-   !"     
 *      tabexpand("----"+chr(9)+ "!", 8)      == "----    !" 
 *      tabexpand("----"+chr(9)+ "!", 8, "+") == "----++++!" 
 *      tabexpand("-"+chr(9)+"!"+hb_osnewline()+"----"+chr(9)+ "!",, "+") == "-+++++++!"+hb_osnewline()+"----++++!" 
 *  $STATUS$
 *      Started
 *  $COMPLIANCE$
 *      TABEXPAND() is compatible with CT3's TABEXPAND(), but there are
 *      three new parameters for a better fine control of the function's
 *      behaviour.
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is tab.c, library is libct.
 *  $SEEALSO$
 *      TABPACK()
 *  $END$
 */

HB_FUNC( TABEXPAND )
{
   if( ISCHAR( 1 ) )
   {
      char *pcString = ( char * ) hb_parc( 1 );
      size_t sStrLen = ( size_t ) hb_parclen( 1 );
      char *pcRet;
      size_t sRetLen;
      size_t sTabWidth = 0;
      char cFill, cTab, cCR;
      char *pcNewLine;
      size_t sNewLineLen;
      int iIgnore141;
      size_t sIndex, sLineIndex;
      size_t sTabCnt = 0;

      if( ISNUM( 2 ) )
         sTabWidth = hb_parnl( 2 );
      if( ( signed ) sTabWidth <= 0 )
         sTabWidth = 8;

      if( ISNUM( 3 ) )
         cFill = ( char ) ( hb_parnl( 3 ) % 256 );
      else if( hb_parclen( 3 ) > 0 )
         cFill = hb_parc( 3 )[0];
      else
         cFill = 0x20;

      if( ISCHAR( 4 ) && hb_parclen( 4 ) > 0 )
      {
         pcNewLine = ( char * ) hb_parc( 4 );
         sNewLineLen = hb_parclen( 4 );
      }
      else
      {
         pcNewLine = hb_conNewLine();
         sNewLineLen = 0;
         while( *( pcNewLine + sNewLineLen ) != 0x00 )
            sNewLineLen++;
      }
      if( sNewLineLen > 0 )
         cCR = *( pcNewLine );
      else
         cCR = 13;

      if( ISNUM( 5 ) )
         cTab = ( char ) ( hb_parnl( 5 ) % 256 );
      else if( hb_parclen( 5 ) > 0 )
         cTab = hb_parc( 5 )[0];
      else
         cTab = 0x09;

      if( ISLOG( 6 ) )
         iIgnore141 = hb_parl( 6 );
      else
         iIgnore141 = 0;

      /* estimate maximum return length by assuming that EVERY tab char
         can be replaced by at most <nTabWidth> characters */
      for( sIndex = 0; sIndex < sStrLen; sIndex++ )
      {
         if( *( pcString + sIndex ) == cTab )
            sTabCnt++;
      }
      if( sTabCnt == 0 )
      {
         hb_retclen( pcString, sStrLen );
         return;
      }
      pcRet = ( char * ) hb_xgrab( sStrLen + ( sTabCnt * ( sTabWidth - 1 ) ) );

      /* now copy the string */
      sIndex = 0;
      sRetLen = 0;
      sLineIndex = 0;
      while( sTabCnt > 0 )
      {
         char cChar = ( char ) *( pcString + sIndex );

         if( cChar == cTab )
         {
            /* tab character */
            size_t sFillIndex;

            for( sFillIndex = sTabWidth - ( sLineIndex % sTabWidth ); sFillIndex > 0; sFillIndex-- )
            {
               *( pcRet + sRetLen ) = cFill;
               sRetLen++;
               sLineIndex++;
            }
            sTabCnt--;
            sIndex++;
         }
         else if( ( unsigned char ) cChar == 141 )
         {
            /* soft carriage return */
            *( pcRet + sRetLen ) = ( char ) 141;
            sRetLen++;
            sIndex++;
            if( iIgnore141 )
               sLineIndex++;
            else
               sLineIndex = 0;
         }
         else if( cChar == cCR )
         {
            /* newline string ? */
            if( sNewLineLen > 0 &&
                sIndex + sNewLineLen <= sStrLen &&
                ct_at_exact_forward( pcString + sIndex, sNewLineLen, pcNewLine,
                                     sNewLineLen, NULL ) == pcString + sIndex )
            {
               hb_xmemcpy( pcRet + sRetLen, pcString + sIndex, sNewLineLen );
               sRetLen += sNewLineLen;
               sIndex += sNewLineLen;
               sLineIndex = 0;
            }
            else
            {
               *( pcRet + sRetLen ) = cCR;
               sRetLen++;
               sIndex++;
               sLineIndex++;
            }
         }
         else
         {
            *( pcRet + sRetLen ) = *( pcString + sIndex );
            sRetLen++;
            sIndex++;
            sLineIndex++;
         }
      }
      /* copy rest */
      hb_xmemcpy( pcRet + sRetLen, pcString + sIndex, sStrLen - sIndex );
      sRetLen += sStrLen - sIndex;
      hb_retclen( pcRet, sRetLen );
      hb_xfree( pcRet );
   }
   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_TABEXPAND, NULL, "TABEXPAND", 0,
                                  EF_CANSUBSTITUTE, HB_ERR_ARGS_BASEPARAMS );
      }
      if( pSubst != NULL )
         hb_itemReturnRelease( pSubst );
      else
         hb_retc( NULL );
   }
}


/*  $DOC$
 *  $FUNCNAME$
 *      TABPACK()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Pack fill characters to appropriate tab characters
 *  $SYNTAX$
 *      TABPACK (<cString>, [<nTabWidth>], [<cFillChar|nFillChar>], 
 *               [<cNewLineCharacters>], [<cTabChar|nTabChar>],
 *               [<lIgnore141>]) -> cPackedString
 *  $ARGUMENTS$
 *      <cString>
 *      <nTabWidth>
 *      <cFillChar|nFillChar>
 *      <cNewLineCharacters>      string indicating new line,
 *                                default is the string returned by
 *                                hb_osnewline()
 *      <cTabChar|nTabChar>       character indicating a tab stop,
 *                                default is chr(9)
 *      <lIgnore141>              .T., if the soft-CR used by MEMOEDIT()
 *                                should be ignored as a newline indicator,
 *                                default is .F. (functions uses chr(141))
 *  $RETURNS$
 *  $DESCRIPTION$
 *      TODO: add documentation
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Started
 *  $COMPLIANCE$
 *      TABPACK() is compatible with CT3's TABPACK(), but there are
 *      three new parameters for a better fine control of the function's
 *      behaviour.
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is tab.c, library is libct.
 *  $SEEALSO$
 *      TABEXPAND()
 *  $END$
 */

HB_FUNC( TABPACK )
{
   if( ISCHAR( 1 ) )
   {
      char *pcString = ( char * ) hb_parc( 1 );
      size_t sStrLen = ( size_t ) hb_parclen( 1 );
      char *pcRet;
      size_t sRetLen;
      size_t sTabWidth = 0;
      char cFill, cTab, cCR;
      char *pcNewLine;
      size_t sNewLineLen;
      int iIgnore141;
      size_t sIndex, sTabIndex, sFillCount;

      if( ISNUM( 2 ) )
         sTabWidth = hb_parnl( 2 );
      if( ( signed ) sTabWidth <= 0 )
         sTabWidth = 8;

      if( ISNUM( 3 ) )
         cFill = ( char ) ( hb_parnl( 3 ) % 256 );
      else if( hb_parclen( 3 ) > 0 )
         cFill = hb_parc( 3 )[0];
      else
         cFill = 0x20;

      sNewLineLen = hb_parclen( 4 );
      if( sNewLineLen > 0 )
         pcNewLine = ( char * ) hb_parc( 4 );
      else
      {
         pcNewLine = hb_conNewLine();
         sNewLineLen = strlen( pcNewLine );
      }
      if( sNewLineLen > 0 )
         cCR = *( pcNewLine );
      else
         cCR = 13;

      if( ISNUM( 5 ) )
         cTab = ( char ) ( hb_parnl( 5 ) % 256 );
      else if( hb_parclen( 5 ) > 0 )
         cTab = hb_parc( 5 )[0];
      else
         cTab = 0x09;

      if( ISLOG( 6 ) )
         iIgnore141 = hb_parl( 6 );
      else
         iIgnore141 = 0;

      if( sStrLen == 0 )
      {
         hb_retc( NULL );
         return;
      }
      /* estimate maximum return length by assuming that there's
         nothing to pack */
      pcRet = ( char * ) hb_xgrab( sStrLen );

      /* now copy the string */
      sIndex = 0;
      sRetLen = 0;
      sTabIndex = 0;
      sFillCount = 0;

      while( sIndex < sStrLen )
      {
         char cChar = ( char ) *( pcString + sIndex );

         if( cChar == cFill )
         {
            if( sTabIndex == sTabWidth - 1 )
            {
               /* we have just found the last character of a tabstopp */
               *( pcRet + sRetLen ) = cTab;
               sRetLen++;
               sFillCount = 0;
               sTabIndex = 0;
               sIndex++;
            }
            else
            {
               sFillCount++;
               sTabIndex++;
               sIndex++;
            }
         }
         else if( cChar == cTab )
         {
            *( pcRet + sRetLen ) = cTab;
            sRetLen++;
            /* discard any fill characters before the tabstopp */
            sFillCount = 0;
            sTabIndex = 0;
            sIndex++;
         }
         else if( ( unsigned char ) cChar == 141 && !iIgnore141 )
         {
            /* soft carriage return */

            /* eventually not enough fill chars to fill a tab,
               so copy them verbatim */
            for( ; sFillCount > 0; sFillCount-- )
            {
               *( pcRet + sRetLen ) = cFill;
               sRetLen++;
            }
            *( pcRet + sRetLen ) = ( char ) 141;
            sRetLen++;
            sTabIndex = 0;
            sIndex++;
         }
         else if( cChar == cCR )
         {
            /* newline string ? */
            if( sNewLineLen > 0 &&
                sIndex + sNewLineLen <= sStrLen &&
                ct_at_exact_forward( pcString + sIndex, sNewLineLen, pcNewLine,
                                     sNewLineLen, NULL ) == pcString + sIndex )
            {
               /* eventually not enough fill chars to fill a tab,
                  so copy them verbatim */
               for( ; sFillCount > 0; sFillCount-- )
               {
                  *( pcRet + sRetLen ) = cFill;
                  sRetLen++;
               }
               hb_xmemcpy( pcRet + sRetLen, pcString + sIndex, sNewLineLen );
               sRetLen += sNewLineLen;
               sIndex += sNewLineLen;
               sTabIndex = 0;
            }
            else
            {
               *( pcRet + sRetLen ) = cCR;
               sRetLen++;
               sIndex++;
               sTabIndex = 0;
            }
         }
         else
         {
            /* eventually not enough fill chars to fill a tab,
               so copy them verbatim */
            for( ; sFillCount > 0; sFillCount-- )
            {
               *( pcRet + sRetLen ) = cFill;
               sRetLen++;
               sTabIndex++;
               if( sTabIndex == sTabWidth - 1 )
               {
                  sTabIndex = 0;
               }
            }
            *( pcRet + sRetLen ) = *( pcString + sIndex );
            sRetLen++;
            sIndex++;
            sTabIndex++;
            if( sTabIndex == sTabWidth - 1 )
               sTabIndex = 0;
         }
      }
      /* copy rest */
      for( ; sFillCount > 0; sFillCount-- )
      {
         *( pcRet + sRetLen ) = cFill;
         sRetLen++;
      }
      hb_retclen( pcRet, sRetLen );
      hb_xfree( pcRet );
   }
   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_TABPACK, NULL, "TABPACK", 0,
                                  EF_CANSUBSTITUTE, HB_ERR_ARGS_BASEPARAMS );
      }
      if( pSubst != NULL )
         hb_itemReturnRelease( pSubst );
      else
         hb_retc( NULL );
   }
}
