/*
 * $Id$
 */

/*
 * Harbour Project source code:
 * Math functions
 *
 * Copyright 1999 {list of individual authors and e-mail addresses}
 * 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 of the License, or
 * (at your option) any later version, with one exception:
 *
 * The exception is that if you link the Harbour Runtime Library (HRL)
 * and/or the Harbour Virtual Machine (HVM) 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 HRL
 * and/or HVM code into it.
 *
 * 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 program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA (or visit
 * their web site at http://www.gnu.org/).
 *
 */

/*
 * The following parts are Copyright of the individual authors.
 * www - http://www.harbour-project.org
 *
 * Copyright 1999 David G. Holm <dholm@jsd-llc.com>
 *    HB_ROUND()
 *
 * See doc/license.txt for licensing terms.
 *
 */

#include <math.h>
#include "extend.h"
#include "itemapi.h"
#include "errorapi.h"

#if defined( __WATCOMC__ )

static int s_internal_math_error = 0;

/* define harbour specific error handler for math errors
 */
int matherr( struct exception * err )
{
   HB_TRACE(HB_TR_DEBUG, ("matherr(%p)", err));

   switch( err->type )
   {
      case DOMAIN:
         /* a domain error has occured, such as sqrt( -1 ) */
         s_internal_math_error = EG_ARG;
         break;
      case SING:
         /* a singularity will result, such as pow( 0, -2 ) */
         s_internal_math_error = EG_ARG;
         break;
      case OVERFLOW:
         /* an overflow will result, such as pow( 10, 100 ) */
         s_internal_math_error = EG_NUMOVERFLOW;
         break;
      case UNDERFLOW:
         /* an underflow will result, such as pow( 10, -100 ) */
         s_internal_math_error = EG_NUMOVERFLOW;
         break;
      case TLOSS:
         /* total loss of significance will result, such as exp( 1000 ) */
         s_internal_math_error = EG_NUMERR;
         break;
      case PLOSS:
         /* partial loss of significance will result, such as sin( 10e70 ) */
         s_internal_math_error = EG_NUMERR;
         break;
      default:
         s_internal_math_error = EG_NUMERR;
         break;
   }

   err->retval = 0.0;

   return 1;   /* don't print any message and don't set errno */
}
#endif

HARBOUR HB_ABS( void )
{
   PHB_ITEM pNumber = hb_param( 1, IT_NUMERIC );

   if( pNumber )
   {
      int iWidth;
      int iDec;

      hb_itemGetNLen( pNumber, &iWidth, &iDec );

      if( IS_INTEGER( pNumber ) )
      {
         int iNumber = hb_itemGetNI( pNumber );

         if( iNumber >= 0 )
            hb_retnilen( iNumber, iWidth );
         else
            hb_retni( -iNumber );
      }
      else if( IS_LONG( pNumber ) )
      {
         long lNumber = hb_itemGetNL( pNumber );

         if( lNumber >= 0 )
            hb_retnllen( lNumber, iWidth );
         else
            hb_retnl( -lNumber );
      }
      else if( IS_DOUBLE( pNumber ) )
      {
         double dNumber = hb_itemGetND( pNumber );

         hb_retndlen( dNumber >= 0.0 ? dNumber : -dNumber, 0, iDec );
      }
   }
   else
   {
      PHB_ITEM pResult = hb_errRT_BASE_Subst( EG_ARG, 1089, NULL, "ABS" );

      if( pResult )
      {
         hb_itemReturn( pResult );
         hb_itemRelease( pResult );
      }
   }
}

HARBOUR HB_EXP( void )
{
   if( ISNUM( 1 ) )
   {
#if defined( __WATCOMC__ )
      double dResult = exp( hb_parnd( 1 ) );

      if( s_internal_math_error )
      {
         PHB_ITEM pResult = hb_errRT_BASE_Subst( s_internal_math_error, 1096, NULL, "EXP" );

         s_internal_math_error = 0;

         if( pResult )
         {
            hb_itemReturn( pResult );
            hb_itemRelease( pResult );
         }
      }
      else
         hb_retnd( dResult );
#else
      hb_retnd( exp( hb_parnd( 1 ) ) );
#endif
   }
   else
   {
      PHB_ITEM pResult = hb_errRT_BASE_Subst( EG_ARG, 1096, NULL, "EXP" );

      if( pResult )
      {
         hb_itemReturn( pResult );
         hb_itemRelease( pResult );
      }
   }
}

HARBOUR HB_INT( void )
{
   PHB_ITEM pNumber = hb_param( 1, IT_NUMERIC );

   if( pNumber )
   {
      double dNumber = hb_itemGetND( pNumber );
      int iWidth;

      hb_itemGetNLen( pNumber, &iWidth, NULL );

      hb_retndlen( dNumber >= 0 ? floor( dNumber ) : ceil( dNumber ), iWidth, 0 );
   }
   else
   {
      PHB_ITEM pResult = hb_errRT_BASE_Subst( EG_ARG, 1090, NULL, "INT" );

      if( pResult )
      {
         hb_itemReturn( pResult );
         hb_itemRelease( pResult );
      }
   }
}

HARBOUR HB_LOG( void )
{
   if( ISNUM( 1 ) )
   {
#if defined( __WATCOMC__ )
      double dResult = log( hb_parnd( 1 ) );

      if( s_internal_math_error )
      {
         PHB_ITEM pResult = hb_errRT_BASE_Subst( s_internal_math_error, 1095, NULL, "LOG" );

         s_internal_math_error = 0;

         if( pResult )
         {
            hb_itemReturn( pResult );
            hb_itemRelease( pResult );
         }
      }
      else
         hb_retnd( dResult );
#else
      double dNumber = hb_parnd( 1 );

      if( dNumber <= 0.0 )
         /* Indicate overflow if called with an invalid argument */
         hb_retndlen( log( dNumber ), 99, -1 );
      else
         hb_retnd( log( dNumber ) );
#endif
   }
   else
   {
      PHB_ITEM pResult = hb_errRT_BASE_Subst( EG_ARG, 1095, NULL, "LOG" );

      if( pResult )
      {
         hb_itemReturn( pResult );
         hb_itemRelease( pResult );
      }
   }
}

/* returns the maximum of two date or numerics */
HARBOUR HB_MAX( void )
{
   PHB_ITEM p1 = hb_param( 1, IT_ANY );
   PHB_ITEM p2 = hb_param( 2, IT_ANY );

   if( IS_NUMERIC( p1 ) && IS_NUMERIC( p2 ) )
   {
      /* NOTE: The order of these if() branches is significant, */
      /*       Please, don't change it. */

      if( IS_DOUBLE( p1 ) || IS_DOUBLE( p2 ) )
      {
         double d1 = hb_itemGetND( p1 );
         double d2 = hb_itemGetND( p2 );

         int iDec1;
         int iDec2;

         hb_itemGetNLen( p1, NULL, &iDec1 );
         hb_itemGetNLen( p2, NULL, &iDec2 );

         if( d1 >= d2 )
            hb_retndlen( d1, 0, iDec1 );
         else
            hb_retndlen( d2, 0, iDec2 );
      }
      else if( IS_LONG( p1 ) || IS_LONG( p2 ) )
      {
         long l1 = hb_itemGetNL( p1 );
         long l2 = hb_itemGetNL( p2 );

         hb_retnl( l1 >= l2 ? l1 : l2 );
      }
      else
      {
         int i1 = hb_itemGetNI( p1 );
         int i2 = hb_itemGetNI( p2 );

         hb_retni( i1 >= i2 ? i1 : i2 );
      }
   }
   else if( IS_DATE( p1 ) && IS_DATE( p2 ) )
   {
      char szDate[ 9 ];

      hb_retds( hb_itemGetNL( p1 ) >= hb_itemGetNL( p2 ) ? hb_pardsbuff( szDate, 1 ) : hb_pardsbuff( szDate, 2 ) );
   }
   else
   {
      PHB_ITEM pResult = hb_errRT_BASE_Subst( EG_ARG, 1093, NULL, "MAX" );

      if( pResult )
      {
         hb_itemReturn( pResult );
         hb_itemRelease( pResult );
      }
   }
}

/* returns the minimum of two date or numerics */
HARBOUR HB_MIN( void )
{
   PHB_ITEM p1 = hb_param( 1, IT_ANY );
   PHB_ITEM p2 = hb_param( 2, IT_ANY );

   if( IS_NUMERIC( p1 ) && IS_NUMERIC( p2 ) )
   {
      /* NOTE: The order of these if() branches is significant, */
      /*       Please, don't change it. */

      if( IS_DOUBLE( p1 ) || IS_DOUBLE( p2 ) )
      {
         double d1 = hb_itemGetND( p1 );
         double d2 = hb_itemGetND( p2 );

         int iDec1;
         int iDec2;

         hb_itemGetNLen( p1, NULL, &iDec1 );
         hb_itemGetNLen( p2, NULL, &iDec2 );

         if( d1 <= d2 )
            hb_retndlen( d1, 0, iDec1 );
         else
            hb_retndlen( d2, 0, iDec2 );
      }
      else if( IS_LONG( p1 ) || IS_LONG( p2 ) )
      {
         long l1 = hb_itemGetNL( p1 );
         long l2 = hb_itemGetNL( p2 );

         hb_retnl( l1 <= l2 ? l1 : l2 );
      }
      else
      {
         int i1 = hb_itemGetNI( p1 );
         int i2 = hb_itemGetNI( p2 );

         hb_retni( i1 <= i2 ? i1 : i2 );
      }
   }
   else if( IS_DATE( p1 ) && IS_DATE( p2 ) )
   {
      char szDate[ 9 ];

      hb_retds( hb_itemGetNL( p1 ) <= hb_itemGetNL( p2 ) ? hb_pardsbuff( szDate, 1 ) : hb_pardsbuff( szDate, 2 ) );
   }
   else
   {
      PHB_ITEM pResult = hb_errRT_BASE_Subst( EG_ARG, 1092, NULL, "MIN" );

      if( pResult )
      {
         hb_itemReturn( pResult );
         hb_itemRelease( pResult );
      }
   }
}

/* TOFIX: In Clipper this is written in Clipper, see the source below, */
/*        and the error handling is NOT made here, but in the % operator */

HARBOUR HB_MOD( void )
{
/*
FUNCTION MOD(cl_num, cl_base)

   LOCAL cl_result

        cl_result = cl_num % cl_base

        RETURN IF( cl_base = 0, ;
                           cl_num,;
                           IF(cl_result * cl_base < 0, cl_result + cl_base, cl_result) )
*/
   PHB_ITEM pNumber = hb_param( 1, IT_NUMERIC );

   if( pNumber && ISNUM( 2 ) )
   {
      double dNumber = hb_itemGetND( pNumber );
      double dBase = hb_parnd( 2 ); /* dBase! Cool! */

      if( dBase )
      {
         double dResult = dNumber - ( ( long ) ( dNumber / dBase ) * dBase );

         if( dResult * dBase < 0 )
            hb_retnd( dResult + dBase );
         else
            hb_retnd( dResult );
      }
      else
      {
         int iDec;

         hb_itemGetNLen( pNumber, NULL, &iDec );

         hb_retndlen( dNumber, 0, iDec );
      }
   }
   else
      hb_errRT_BASE( EG_ARG, 1085, NULL, "%" );
}

double hb_numRound( double dResult, int iDec )
{
   HB_TRACE(HB_TR_DEBUG, ("hb_numRound(%lf, %d)", dResult, iDec));

   if( dResult != 0.0 )
   {
      if( iDec == 0 )
      {
         if( dResult < 0.0 )
            dResult = ceil( dResult - 0.5 );
         else
            dResult = floor( dResult + 0.5 );
      }
      else if( iDec < 0 )
      {
         double dAdjust = pow( 10, -iDec );

         if( dResult < 0.0 )
            dResult = ceil( ( dResult / dAdjust ) - 0.5 );
         else
            dResult = floor( ( dResult / dAdjust ) + 0.5 );

         dResult *= dAdjust;
      }
      else
      {
         double dAdjust = pow( 10, iDec );

         if( dResult < 0.0 )
            dResult = ceil( ( dResult * dAdjust ) - 0.5 );
         else
            dResult = floor( ( dResult * dAdjust ) + 0.5 );

         dResult /= dAdjust;
      }
   }

   return dResult;
}

HARBOUR HB_ROUND( void )
{
   if( ISNUM( 1 ) && ISNUM( 2 ) )
   {
      int iDec = hb_parni( 2 );

      hb_retndlen( hb_numRound( hb_parnd( 1 ), iDec ), 0, HB_MAX_( iDec, 0 ) );
   }
   else
   {
      PHB_ITEM pResult = hb_errRT_BASE_Subst( EG_ARG, 1094, NULL, "ROUND" );

      if( pResult )
      {
         hb_itemReturn( pResult );
         hb_itemRelease( pResult );
      }
   }
}

HARBOUR HB_SQRT( void )
{
   if( ISNUM( 1 ) )
   {
#if defined( __WATCOMC__ )
      double dResult = sqrt( hb_parnd( 1 ) );

      if( s_internal_math_error )
      {
         PHB_ITEM pResult = hb_errRT_BASE_Subst( s_internal_math_error, 1097, NULL, "SQRT" );

         s_internal_math_error = 0;

         if( pResult )
         {
            hb_itemReturn( pResult );
            hb_itemRelease( pResult );
         }
      }
      else
         hb_retnd( dResult );
#else
      double dNumber = hb_parnd( 1 );

      hb_retnd( dNumber > 0 ? sqrt( dNumber ) : 0 ); /* Clipper doesn't error! */
#endif
   }
   else
   {
      PHB_ITEM pResult = hb_errRT_BASE_Subst( EG_ARG, 1097, NULL, "SQRT" );

      if( pResult )
      {
         hb_itemReturn( pResult );
         hb_itemRelease( pResult );
      }
   }
}