/*
 * $Id$
 */

/*
 * Harbour Project source code: 
 *   internal and switch functions for CT3 string 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"


/* -------------- */
/* initialization */
/* -------------- */
int ct_str_init( void )
{
   HB_TRACE( HB_TR_DEBUG, ( "ctstr_init()" ) );
   return 1;
}

int ct_str_exit( void )
{
   HB_TRACE( HB_TR_DEBUG, ( "ctstr_exit()" ) );
   return 1;
}


/* -------------------------- */
/* search for exact substring */
/* -------------------------- */
char *ct_at_exact_forward( char *pcString, size_t sStrLen,
                           char *pcMatch, size_t sMatchLen, size_t * psMatchStrLen )
{

   size_t sPos;

   HB_TRACE( HB_TR_DEBUG, ( "ct_at_exact_forward (\"%s\", %u, \"%s\", %u, %p)",
                            pcString, sStrLen, pcMatch, sMatchLen, psMatchStrLen ) );

   if( ( sMatchLen == 0 ) || ( sStrLen < sMatchLen ) )
      return NULL;

   sPos = hb_strAt( pcMatch, sMatchLen, pcString, sStrLen );
   if( sPos == 0 )
   {
      return NULL;
   }
   else
   {
      if( psMatchStrLen != NULL )
         *psMatchStrLen = sMatchLen;
      return pcString + sPos - 1;
   }

}


/* ------------------------------------------------ */
/* search for exact substring in backward direction */
/* ------------------------------------------------ */
char *ct_at_exact_backward( char *pcString, size_t sStrLen,
                            char *pcMatch, size_t sMatchLen, size_t * psMatchStrLen )
{

   size_t sIndex;
   char *pcRet;

   HB_TRACE( HB_TR_DEBUG, ( "ct_at_exact_backward (\"%s\", %u, \"%s\", %u, %p)",
                            pcString, sStrLen, pcMatch, sMatchLen, psMatchStrLen ) );

   if( ( sMatchLen == 0 ) || ( sStrLen < sMatchLen ) )
      return NULL;

   for( pcRet = pcString + sStrLen - sMatchLen; pcRet >= pcString; pcRet-- )
   {
      for( sIndex = 0; sIndex < sMatchLen; sIndex++ )
         if( *( pcRet + sIndex ) != *( pcMatch + sIndex ) )
            break;
      if( sIndex == sMatchLen )
      {
         /* last match found */
         if( psMatchStrLen != NULL )
            *psMatchStrLen = sMatchLen;
         return pcRet;
      }
   }

   return NULL;
}


/* ----------------------------------- */
/* search for substring using wildcard */
/* ----------------------------------- */
char *ct_at_wildcard_forward( char *pcString, size_t sStrLen,
                              char *pcMatch, size_t sMatchLen,
                              char cWildCard, size_t * psMatchStrLen )
{

   size_t sIndex;
   char *pcRet, *pcStop;

   HB_TRACE( HB_TR_DEBUG, ( "ct_at_wildcard_forward (\"%s\", %u, \"%s\", %u, \'%c\', %p)",
                            pcString, sStrLen, pcMatch, sMatchLen, cWildCard, psMatchStrLen ) );

   if( ( sMatchLen == 0 ) || ( sStrLen < sMatchLen ) )
      return NULL;

   pcStop = pcString + sStrLen - sMatchLen;
   for( pcRet = pcString; pcRet < pcStop; pcRet++ )
   {
      for( sIndex = 0; sIndex < sMatchLen; sIndex++ )
      {
         char c = *( pcMatch + sIndex );

         if( ( c != cWildCard ) && ( c != *( pcRet + sIndex ) ) )
            break;
      }
      if( sIndex == sMatchLen )
      {
         if( psMatchStrLen != NULL )
            *psMatchStrLen = sMatchLen;
         return pcRet;
      }
   }

   return NULL;
}


/* --------------------------------------------------------- */
/* search for substring using wildcard in backward direction */
/* --------------------------------------------------------- */
char *ct_at_wildcard_backward( char *pcString, size_t sStrLen,
                               char *pcMatch, size_t sMatchLen,
                               char cWildCard, size_t * psMatchStrLen )
{

   size_t sIndex;
   char *pcRet;

   HB_TRACE( HB_TR_DEBUG, ( "ct_at_wildcard_backward (\"%s\", %u, \"%s\", %u, \'%c\', %p)",
                            pcString, sStrLen, pcMatch, sMatchLen, cWildCard, psMatchStrLen ) );

   if( ( sMatchLen == 0 ) || ( sStrLen < sMatchLen ) )
      return NULL;

   for( pcRet = pcString + sStrLen - sMatchLen; pcRet >= pcString; pcRet-- )
   {
      for( sIndex = 0; sIndex < sMatchLen; sIndex++ )
      {
         char c = *( pcMatch + sIndex );

         if( ( c != cWildCard ) && ( c != *( pcRet + sIndex ) ) )
            break;
      }
      if( sIndex == sMatchLen )
      {
         /* last match found */
         if( psMatchStrLen != NULL )
            *psMatchStrLen = sMatchLen;
         return pcRet;
      }
   }

   return NULL;
}


/* ------------------------------- */
/* search for character from a set */
/* ------------------------------- */
char *ct_at_charset_forward( char *pcString, size_t sStrLen,
                             char *pcCharSet, size_t sCharSetLen, size_t * psMatchedCharPos )
{

   char *pcRet, *pcSet, *pcStop1, *pcStop2;

   HB_TRACE( HB_TR_DEBUG, ( "ct_at_charset_forward (\"%s\", %u, \"%s\", %u, %p)",
                            pcString, sStrLen, pcCharSet, sCharSetLen, psMatchedCharPos ) );

   *( psMatchedCharPos ) = sCharSetLen;

   if( ( sCharSetLen == 0 ) || ( sStrLen == 0 ) )
      return NULL;

   pcStop1 = pcString + sStrLen;
   pcStop2 = pcCharSet + sCharSetLen;
   for( pcRet = pcString; pcRet < pcStop1; pcRet++ )
   {
      for( pcSet = pcCharSet; pcSet < pcStop2; pcSet++ )
         if( *pcSet == *pcRet )
         {
            if( psMatchedCharPos != NULL )
               *( psMatchedCharPos ) = pcSet - pcCharSet;
            return pcRet;
         }
   }

   return NULL;
}


/* ----------------------------------------------------- */
/* search for character from a set in backward direction */
/* ----------------------------------------------------- */
char *ct_at_charset_backward( char *pcString, size_t sStrLen,
                              char *pcCharSet, size_t sCharSetLen, size_t * psMatchedCharPos )
{

   char *pcRet, *pcSet, *pcStop;

   HB_TRACE( HB_TR_DEBUG, ( "ct_at_charset_backward (\"%s\", %u, \"%s\", %u, %p)",
                            pcString, sStrLen, pcCharSet, sCharSetLen, psMatchedCharPos ) );

   *( psMatchedCharPos ) = sCharSetLen;

   if( ( sCharSetLen == 0 ) || ( sStrLen == 0 ) )
      return NULL;

   pcStop = pcCharSet + sCharSetLen;
   for( pcRet = pcString + sStrLen - 1; pcRet >= pcString; pcRet-- )
   {
      for( pcSet = pcCharSet; pcSet < pcStop; pcSet++ )
         if( *pcSet == *pcRet )
         {
            if( psMatchedCharPos != NULL )
               *( psMatchedCharPos ) = pcSet - pcCharSet;
            return pcRet;
         }
   }

   return NULL;
}


/*  
 *  CSETREF() stuff
 */

static int siRefSwitch = 0;     /* TODO: make this tread safe */

void ct_setref( int iNewSwitch )
{
   HB_TRACE( HB_TR_DEBUG, ( "ct_setref(%i)", iNewSwitch ) );
   siRefSwitch = iNewSwitch;
}


int ct_getref( void )
{
   HB_TRACE( HB_TR_DEBUG, ( "ct_getref()" ) );
   return siRefSwitch;
}


/*  $DOC$
 *  $FUNCNAME$
 *      CSETREF()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Determine return value of reference sensitive CT3 string functions
 *  $SYNTAX$
 *      CSETREF ([<lNewSwitch>]) -> lOldSwitch
 *  $ARGUMENTS$
 *      [<lNewSwitch>]  .T. -> suppress return value
 *                      .F. -> do not suppress return value
 *  $RETURNS$
 *      lOldSwitch      old (if lNewSwitch is a logical value) or
 *                      current state of the switch
 *  $DESCRIPTION$
 *      Within the CT3 functions, the following functions do not
 *      change the length of a string passed as parameter while
 *      transforming this string:
 *
 *      ADDASCII()   BLANK()       CHARADD()
 *      CHARAND()    CHARMIRR()    CHARNOT()
 *      CHAROR()     CHARRELREP()  CHARREPL()
 *      CHARSORT()   CHARSWAP()    CHARXOR()
 *      CRYPT()      JUSTLEFT()    JUSTRIGHT()
 *      POSCHAR()    POSREPL()     RANGEREPL()
 *      REPLALL()    REPLLEFT()    REPLRIGHT()
 *      TOKENLOWER() TOKENUPPER()  WORDREPL()
 *      WORDSWAP()
 *
 *      Thus, these functions allow to pass the string by reference [@] to
 *      the function so that it may not be necessary to return the transformed
 *      string. By calling CSETREF (.T.), the above mentioned functions return
 *      the value .F. instead of the transformed string if the string is
 *      passed by reference to the function.
 *      The switch is turned off (.F.) by default.
 *
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Ready
 *  $COMPLIANCE$
 *      This function is fully CT3 compatible.
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is ctstr.c, library is ct3.
 *  $SEEALSO$
 *      ADDASCII()   BLANK()       CHARADD()
 *      CHARAND()    CHARMIRR()    CHARNOT()
 *      CHAROR()     CHARRELREP()  CHARREPL()
 *      CHARSORT()   CHARSWAP()    CHARXOR()
 *      CRYPT()      JUSTLEFT()    JUSTRIGHT()
 *      POSCHAR()    POSREPL()     RANGEREPL()
 *      REPLALL()    REPLLEFT()    REPLRIGHT()
 *      TOKENLOWER() TOKENUPPER()  WORDREPL()
 *      WORDSWAP()
 *  $END$
 */

HB_FUNC( CSETREF )
{
   hb_retl( ct_getref() );

   if( ISLOG( 1 ) )
   {
      ct_setref( hb_parl( 1 ) );
   }
   else if( hb_pcount() > 0 ) /* 1 params, but is not logical ! */
   {
      int iArgErrorMode = ct_getargerrormode();

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


/*
 * CSETATMUPA() stuff
 */

static int siAtMupaSwitch = 0;  /* TODO: make this tread safe */

void ct_setatmupa( int iNewSwitch )
{
   HB_TRACE( HB_TR_DEBUG, ( "ct_setatmupa(%i)", iNewSwitch ) );
   siAtMupaSwitch = iNewSwitch;
}


int ct_getatmupa( void )
{
   HB_TRACE( HB_TR_DEBUG, ( "ct_getatmupa()" ) );
   return siAtMupaSwitch;
}


/*  $DOC$
 *  $FUNCNAME$
 *      CSETATMUPA()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Determine "multi-pass" behaviour in some string functions
 *  $SYNTAX$
 *      CSETATMUPA ([<lNewSwitch>]) -> lOldSwitch
 *  $ARGUMENTS$
 *      [<lNewSwitch>]  .T. -> turn "multi-pass" on
 *                      .F. -> turn "multi-pass" off
 *  $RETURNS$
 *      lOldSwitch      old (if lNewSwitch is a logical value) or
 *                      current state of the switch
 *  $DESCRIPTION$
 *      CSETATMUPA determines how the following CT3 string functions
 *      
 *      ATNUM()       AFTERATNUM()  BEFORATNUM()
 *      ATREPL()      NUMAT()       ATADJUST()
 *      WORDTOCHAR()  WORDREPL()
 *
 *      perform their work. See the respective function documentation for a
 *      further description how the switch influences these functions.
 *
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Ready
 *  $COMPLIANCE$
 *      This function is fully CT3 compatible.
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is ctstr.c, library is ct3.
 *  $SEEALSO$
 *      ATNUM()       AFTERATNUM()  BEFORATNUM()
 *      ATREPL()      NUMAT()       ATADJUST()
 *      WORDTOCHAR()  WORDREPL()
 *  $END$
 */


HB_FUNC( CSETATMUPA )
{
   hb_retl( ct_getatmupa() );

   if( ISLOG( 1 ) )
   {
      ct_setatmupa( hb_parl( 1 ) );
   }
   else if( hb_pcount() > 0 ) /* 1 params, but is not logical ! */
   {
      int iArgErrorMode = ct_getargerrormode();

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


/*
 * SETATLIKE() stuff
 */

static int siAtLikeMode = 0;    /* TODO: make this tread safe */
static int scAtLikeChar = '?';  /* TODO: make this tread safe */

void ct_setatlike( int iNewMode )
{
   HB_TRACE( HB_TR_DEBUG, ( "ct_setatlike(%i)", iNewMode ) );
   siAtLikeMode = iNewMode;
}


int ct_getatlike( void )
{
   HB_TRACE( HB_TR_DEBUG, ( "ct_getatlike()" ) );
   return siAtLikeMode;
}


void ct_setatlikechar( char cNewChar )
{
   HB_TRACE( HB_TR_DEBUG, ( "ct_setatlikechar(\'%c\')", cNewChar ) );
   scAtLikeChar = cNewChar;
}


char ct_getatlikechar( void )
{
   HB_TRACE( HB_TR_DEBUG, ( "ct_getatlikechar()" ) );
   return scAtLikeChar;
}


/*  $DOC$
 *  $FUNCNAME$
 *      SETATLIKE()
 *  $CATEGORY$
 *      CT3 string functions
 *  $ONELINER$
 *      Determine scan behaviour in some string functions
 *  $SYNTAX$
 *      SETATLIKE ([<nMode>] [, <[@]cWildcard>]) --> nOldMode
 *  $ARGUMENTS$
 *      [<nMode>]   CT_SETATLIKE_EXACT    -> characters are compared exactly
 *                  CT_SETATLIKE_WILDCARD -> characters are compared using
 *                                           a wildcard character
 *                  The default value is CT_SETATLIKE_EXACT.
 *      [<[@]cWildcard>]  determines the character that is subsequently used
 *                        as a wildcard character for substring scanning.
 *                        The default value is "?".
 *                        NEW: If this parameter is passed by reference [@],
 *                        the current wildcard character is stored in
 *                        <cWildcard>.
 *  $RETURNS$
 *      nOldMode          old (if nMode is a numeric value) or
 *                        current state of the switch
 *  $DESCRIPTION$
 *      In the following CT3 functions, strings are compared on a character
 *      base:
 *
 *      ATADJUST()    ATNUM()    AFTERATNUM()
 *      BEFOREATNUM() ATREPL()   NUMAT()
 *      STRDIFF()
 *
 *      With the SETATLIKE function, one can determine when characters are
 *      considered to match within these functions. If CT_SETATLIKE_WILDCARD
 *      is set (e.g. "?"), then "?" matches every other character.
 *
 *      <nMode> can be one of the following values that are defined
 *      in ct.ch
 * 
 *      Definition            | Value
 *      ----------------------|------
 *      CT_SETATLIKE_EXACT    |   0 
 *      CT_SETATLIKE_WILDCARD |   1 
 *
 *  $EXAMPLES$
 *  $TESTS$
 *  $STATUS$
 *      Ready
 *  $COMPLIANCE$
 *      This function is fully CT3 compatible, but allows to pass the
 *      second parameter by reference so that the current wildcard character
 *      can be determined.
 *  $PLATFORMS$
 *      All
 *  $FILES$
 *      Source is ctstr.c, header is ct.ch, library is ct3.
 *  $SEEALSO$
 *  $END$
 */

HB_FUNC( SETATLIKE )
{

   hb_retni( ct_getatlike() );

   /* set new mode if first parameter is CT_SETATLIKE_EXACT (==0)
      or CT_SETATLIKE_WILDCARD (==1) */
   if( ISNUM( 1 ) )
   {
      int iNewMode = hb_parni( 1 );

      if( ( iNewMode == CT_SETATLIKE_EXACT ) || ( iNewMode == CT_SETATLIKE_WILDCARD ) )
      {
         ct_setatlike( iNewMode );
      }
      else
      {
         int iArgErrorMode = ct_getargerrormode();

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

   /* set new wildcard character, if ISCHAR(2) but !ISBYREF(2) */
   if( ISCHAR( 2 ) )
   {
      if( ISBYREF( 2 ) )
      {
         /* new behaviour: store the current wildcard char in second parameter */
         char cResult;

         cResult = ct_getatlikechar();
         hb_storclen( &cResult, 1, 2 );
      }
      else
      {
         char *pcNewChar = hb_parc( 2 );

         if( hb_parclen( 2 ) > 0 )
            ct_setatlikechar( *pcNewChar );
      }
   }
   else if( hb_pcount() > 1 ) /* more than 2 params, but second is not string ! */
   {
      int iArgErrorMode = ct_getargerrormode();

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