/*
 * $Id$
 */

/*
 * Harbour Project source code:
 * Additional date functions
 *
 * Copyright 1999 Jose Lalin <dezac@corevia.com>
 * www - http://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://harbour-project.org
 *
 * Copyright 1999 Jon Berg <jmberg@pnh10.med.navy.mil>
 *    DateTime()
 *
 * See COPYING for licensing terms.
 *
 */

#include <time.h>

#include "hbapi.h"
#include "hbapiitm.h"
#include "hbapilng.h"
#include "hbdate.h"

static int s_daysinmonth[ 12 ] =
{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

static HB_BOOL hb_isleapyear( int iYear )
{
   HB_TRACE(HB_TR_DEBUG, ("hb_isleapyear(%d)", iYear));

   return ( iYear % 4 == 0 && iYear % 100 != 0 ) || ( iYear % 400 == 0 );
}

static int hb_daysinmonth( int iYear, int iMonth )
{
   HB_TRACE(HB_TR_DEBUG, ("hb_daysinmonth(%d, %d)", iYear, iMonth));

   if( iMonth > 0 && iMonth < 13 )
      return s_daysinmonth[ iMonth - 1 ] +
             ( ( iMonth == 2 && hb_isleapyear( iYear ) ) ? 1 : 0 );
   else
      return 0;
}

static int hb_doy( int iYear, int iMonth, int iDay )
{
   int i;
   int iDoy = 0;

   HB_TRACE(HB_TR_DEBUG, ("hb_doy(%d, %d, %d)", iYear, iMonth, iDay));

   for( i = 1; i < iMonth; i++ )
      iDoy += hb_daysinmonth( iYear, i );

   return iDoy + iDay;
}

static int hb_woy( int iYear, int iMonth, int iDay, HB_BOOL bISO )
{
   int iWeek, n;

   HB_TRACE(HB_TR_DEBUG, ("hb_woy(%d, %d, %d, %d)", iYear, iMonth, iDay, (int) bISO));

   iDay = hb_doy( iYear, iMonth, iDay );
   n = ( ( ( 1 - ( bISO ? 1 : 0 ) ) % 7 ) ) - 1;
   iDay += ( n > 0 ) ? 1 : 0;
   iWeek = iDay / 7;
   if( bISO )
      iWeek += ( n < 4 ) ? 1 : 0;
   else
      ++iWeek;

   return iWeek;
}

HB_FUNC( AMONTHS )
{
   PHB_ITEM pReturn = hb_itemArrayNew( 12 );    /* Create array */
   int i;

   for( i = 0; i < 12; i++ )
      hb_arraySetC( pReturn, i + 1, hb_langDGetItem( HB_LANG_ITEM_BASE_MONTH + i ) );

   hb_itemReturnRelease( pReturn );
}

HB_FUNC( ADAYS )
{
   PHB_ITEM pReturn = hb_itemArrayNew( 7 );    /* Create array */
   int i;

   for( i = 0; i < 7; i++ )
      hb_arraySetC( pReturn, i + 1, hb_langDGetItem( HB_LANG_ITEM_BASE_DAY + i ) );

   hb_itemReturnRelease( pReturn );
}

HB_FUNC( ISLEAPYEAR )
{
   PHB_ITEM pDate = hb_param( 1, HB_IT_DATETIME );

   if( pDate )
   {
      int iYear, iMonth, iDay;

      hb_dateDecode( hb_itemGetDL( pDate ), &iYear, &iMonth, &iDay );
      hb_retl( hb_isleapyear( iYear ) );
   }
   else
      hb_retl( HB_FALSE );
}

HB_FUNC( HBMISC_DAYSINMONTH )
{
   PHB_ITEM pDate = hb_param( 1, HB_IT_DATETIME );

   if( pDate )
   {
      int iYear, iMonth, iDay;

      hb_dateDecode( hb_itemGetDL( pDate ), &iYear, &iMonth, &iDay );
      hb_retni( hb_daysinmonth( iYear, iMonth ) );
   }
   else
      hb_retni( 0 );
}

/* Return the nWeek of the year (1 - 52, 0 - 52 if ISO) */

HB_FUNC( WOY )
{
   PHB_ITEM pDate = hb_param( 1, HB_IT_DATETIME );

   if( pDate )
   {
      int iYear, iMonth, iDay;

      hb_dateDecode( hb_itemGetDL( pDate ), &iYear, &iMonth, &iDay );
      hb_retni( hb_woy( iYear, iMonth, iDay, hb_parldef( 2, HB_TRUE ) ) );
   }
   else
      hb_retni( 0 );
}