/*
 * $Id$
 */

/*
 * Harbour Project source code:
 * The Date API (C level)
 *
 * Copyright 1999 David G. Holm <dholm@jsd-llc.com>
 * 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.
 *
 */

/*
 * 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_dateFormat()
 *    hb_dateUnformat()
 *
 * See doc/license.txt for licensing terms.
 *
 */

#include <ctype.h>

#include "hbapi.h"
#include "hbdate.h"
#include "hbset.h"

HB_EXPORT char * hb_dateFormat( const char * szDate, char * szFormattedDate, const char * szDateFormat )
{
   /*
    * NOTE: szFormattedDate must point to a buffer of at least 11 bytes.
    *       szDateFormat must point to a buffer holding the date format to use.
    */
   int format_count, digit_count, size;

   HB_TRACE(HB_TR_DEBUG, ("hb_dateFormat(%s, %p, %s)", szDate, szFormattedDate, szDateFormat));

   /*
    * Determine the maximum size of the formatted date string
    */
   size = strlen( szDateFormat );
   if( size > 10 ) size = 10;

   if( szDate && szFormattedDate && strlen( szDate ) == 8 ) /* A valid date is always 8 characters */
   {
      const char * szPtr;
      int digit;
      BOOL used_d, used_m, used_y;

      format_count = 0;
      used_d = used_m = used_y = FALSE;
      szPtr = szDateFormat;

      while( format_count < size )
      {
         digit = toupper( ( UCHAR ) *szPtr );
         szPtr++;
         digit_count = 1;
         while( toupper( ( UCHAR ) *szPtr ) == digit && format_count < size )
         {
            szPtr++;
            if( format_count + digit_count < size ) digit_count++;
         }
         switch( digit )
         {
            case 'D':
               switch( digit_count )
               {
                  case 4:
                     if( ! used_d && format_count < size )
                     {
/*                        szFormattedDate[ format_count++ ] = '0'; */
                        szFormattedDate[ format_count++ ] = szDate[ 6 ];
                        digit_count--;
                     }
                  case 3:
                     if( ! used_d && format_count < size )
                     {
/*                        szFormattedDate[ format_count++ ] = '0'; */
                        szFormattedDate[ format_count++ ] = szDate[ 6 ];
                        digit_count--;
                     }
                  case 2:
                     if( ! used_d && format_count < size )
                     {
                        szFormattedDate[ format_count++ ] = szDate[ 6 ];
                        digit_count--;
                     }
                  default:
                     if( ! used_d && format_count < size )
                     {
                        szFormattedDate[ format_count++ ] = szDate[ 7 ];
                        digit_count--;
                     }
                     while( digit_count-- > 0 && format_count < size ) szFormattedDate[ format_count++ ] = digit;
               }
               used_d = TRUE;
               break;

            case 'M':
               switch( digit_count )
               {
                  case 4:
                     if( ! used_m && format_count < size )
                     {
                        /* szFormattedDate[ format_count++ ] = '0'; */
                        szFormattedDate[ format_count++ ] = szDate[ 4 ];
                        digit_count--;
                     }
                  case 3:
                     if( ! used_m && format_count < size )
                     {
                        /* szFormattedDate[ format_count++ ] = '0'; */
                        szFormattedDate[ format_count++ ] = szDate[ 4 ];
                        digit_count--;
                     }
                  case 2:
                     if( ! used_m && format_count < size )
                     {
                        szFormattedDate[ format_count++ ] = szDate[ 4 ];
                        digit_count--;
                     }
                  default:
                     if( ! used_m && format_count < size )
                     {
                        szFormattedDate[ format_count++ ] = szDate[ 5 ];
                        digit_count--;
                     }
                     while( digit_count-- > 0 && format_count < size ) szFormattedDate[ format_count++ ] = digit;
               }
               used_m = TRUE;
               break;

            case 'Y':
               switch( digit_count )
               {
                  case 4:
                     if( ! used_y && format_count < size )
                     {
                        szFormattedDate[ format_count++ ] = szDate[ 0 ];
                        digit_count--;
                     }

                  case 3:
                     if( ! used_y && format_count < size )
                     {
                        szFormattedDate[ format_count++ ] = szDate[ 1 ];
                        digit_count--;
                     }

                  case 2:
                     if( ! used_y && format_count < size )
                     {
                        szFormattedDate[ format_count++ ] = szDate[ 2 ];
                        digit_count--;
                     }

                  default:
                     if( ! used_y && format_count < size )
                     {
                        szFormattedDate[ format_count++ ] = szDate[ 3 ];
                        digit_count--;
                     }
                     while( digit_count-- > 0 && format_count < size ) szFormattedDate[ format_count++ ] = digit;
               }
               used_y = TRUE;
               break;

            default:
               while( digit_count-- > 0 && format_count < size ) szFormattedDate[ format_count++ ] = digit;
         }
      }
   }
   else
   {
      /* Not a valid date string, so return a blank date with separators */
      format_count = size; /* size is either 8 or 10 */
      strncpy( szFormattedDate, szDateFormat, size );

      for( digit_count = 0; digit_count < size; digit_count++ )
      {
         switch( szFormattedDate[ digit_count ] )
         {
            case 'D':
            case 'd':
            case 'M':
            case 'm':
            case 'Y':
            case 'y':
               szFormattedDate[ digit_count ] = ' ';
         }
      }
   }

   szFormattedDate[ format_count ] = '\0';

   return szFormattedDate;
}

HB_EXPORT long hb_dateUnformat( const char * szDate, const char * szDateFormat )
{
   int d_value = 0, m_value = 0, y_value = 0;

   if( szDate )
   {
      int d_pos = 0, m_pos = 0, y_pos = 0;
      int count, digit, non_digit, size;

      if( ! szDateFormat )
         szDateFormat = hb_set.HB_SET_DATEFORMAT;
      size = strlen( szDateFormat );

      for( count = 0; count < size; count++ )
      {
         switch( szDateFormat[ count ] )
         {
            case 'D':
            case 'd':
               if( d_pos == 0 )
               {
                  if( m_pos == 0 && y_pos == 0 ) d_pos = 1;
                  else if( m_pos == 0 || y_pos == 0 ) d_pos = 2;
                  else d_pos = 3;
               }
               break;
            case 'M':
            case 'm':
               if( m_pos == 0 )
               {
                  if( d_pos == 0 && y_pos == 0 ) m_pos = 1;
                  else if( d_pos == 0 || y_pos == 0 ) m_pos = 2;
                  else m_pos = 3;
               }
               break;
            case 'Y':
            case 'y':
               if( y_pos == 0 )
               {
                  if( m_pos == 0 && d_pos == 0 ) y_pos = 1;
                  else if( m_pos == 0 || d_pos == 0 ) y_pos = 2;
                  else y_pos = 3;
               }
         }
      }

      /* If there are non-digits at the start of the date field,
         they are not to be treated as date field separators */
      non_digit = 1;
      size = strlen( szDate );
      for( count = 0; count < size; count++ )
      {
         digit = szDate[ count ];
         if( isdigit( digit ) )
         {
            /* Process the digit for the current date field */
            if( d_pos == 1 )
               d_value = ( d_value * 10 ) + digit - '0';
            else if( m_pos == 1 )
               m_value = ( m_value * 10 ) + digit - '0';
            else if( y_pos == 1 )
               y_value = ( y_value * 10 ) + digit - '0';
            /* Treat the next non-digit as a date field separator */
            non_digit = 0;
         }
         else if( digit != ' ' )
         {
            /* Process the non-digit */
            if( non_digit++ == 0 )
            {
               /* Only move to the next date field on the first
                  consecutive non-digit that is encountered */
               d_pos--;
               m_pos--;
               y_pos--;
            }
         }
      }

      if( y_value >= 0 && y_value < 100 )
      {
         count = hb_set.HB_SET_EPOCH % 100;
         digit = hb_set.HB_SET_EPOCH / 100;

         if( y_value >= count )
            y_value += ( digit * 100 );
         else
            y_value += ( ( digit * 100 ) + 100 );
      }
   }

   return hb_dateEncode( y_value, m_value, d_value );
}
