/***********************************************************************

*                                                                      *

*               This software is part of the ast package               *

*          Copyright (c) 1985-2011 AT&T Intellectual Property          *

*                      and is licensed under the                       *

*                 Eclipse Public License, Version 1.0                  *

*                    by AT&T Intellectual Property                     *

*                                                                      *

*                A copy of the License is available at                 *

*          http://www.eclipse.org/org/documents/epl-v10.html           *

*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *

*                                                                      *

*              Information and Software Systems Research               *

*                            AT&T Research                             *

*                           Florham Park NJ                            *

*                                                                      *

*                 Glenn Fowler <gsf@research.att.com>                  *

*                  David Korn <dgk@research.att.com>                   *

*                   Phong Vo <kpv@research.att.com>                    *

*                                                                      *

***********************************************************************/

#pragma prototyped

/*

 * Glenn Fowler

 * AT&T Research

 *

 * Time_t conversion support

 */

#include <tmx.h>

#include "FEATURE/tmlib"

/*

 * return Tm_t for t

 * time zone and leap seconds accounted for in return value

 */

Tm_t*

tmxtm(register Tm_t* tm, Time_t t, Tm_zone_t* zone)

{

	register struct tm*	tp;

	register Tm_leap_t*	lp;

	Time_t			x;

	time_t			now;

	int			leapsec;

	int			y;

	uint32_t		n;

	int32_t			o;

#if TMX_FLOAT

	Time_t			z;

	uint32_t		i;

#endif

	tmset(tm_info.zone);

	leapsec = 0;

	if ((tm_info.flags & (TM_ADJUST|TM_LEAP)) == (TM_ADJUST|TM_LEAP) && (n = tmxsec(t)))

	{

		for (lp = &tm_data.leap[0]; n < lp->time; lp++);

		if (lp->total)

		{

			if (n == lp->time && (leapsec = (lp->total - (lp+1)->total)) < 0)

				leapsec = 0;

			t = tmxsns(n - lp->total, tmxnsec(t));

		}

	}

	x = tmxsec(t);

	if (!(tm->tm_zone = zone))

	{

		if (tm_info.flags & TM_UTC)

			tm->tm_zone = &tm_data.zone[2];

		else

			tm->tm_zone = tm_info.zone;

	}

	if ((o = 60 * tm->tm_zone->west) && x > o)

	{

		x -= o;

		o = 0;

	}

#if TMX_FLOAT

	i = x / (24 * 60 * 60);

	z = i;

	n = x - z * (24 * 60 * 60);

	tm->tm_sec = n % 60 + leapsec;

	n /= 60;

	tm->tm_min = n % 60;

	n /= 60;

	tm->tm_hour = n % 24;

#define x	i

#else

	tm->tm_sec = x % 60 + leapsec;

	x /= 60;

	tm->tm_min = x % 60;

	x /= 60;

	tm->tm_hour = x % 24;

	x /= 24;

#endif

	tm->tm_wday = (x + 4) % 7;

	tm->tm_year = (400 * (x + 25202)) / 146097 + 1;

	n = tm->tm_year - 1;

	x -= n * 365 + n / 4 - n / 100 + (n + (1900 - 1600)) / 400 - (1970 - 1901) * 365 - (1970 - 1901) / 4;

	tm->tm_mon = 0;

	tm->tm_mday = x + 1;

	tm->tm_nsec = tmxnsec(t);

	tmfix(tm);

	n += 1900;

	tm->tm_isdst = 0;

	if (tm->tm_zone->daylight)

	{

		if ((y = tmequiv(tm) - 1900) == tm->tm_year)

			now = tmxsec(t);

		else

		{

			Tm_t	te;

			te = *tm;

			te.tm_year = y;

			now = tmxsec(tmxtime(&te, tm->tm_zone->west));

		}

		if ((tp = tmlocaltime(&now)) && ((tm->tm_isdst = tp->tm_isdst) || o))

		{

			tm->tm_min -= o / 60 + (tm->tm_isdst ? tm->tm_zone->dst : 0);

			tmfix(tm);

		}

	}

	return tm;

}

/*

 * return Tm_t for t

 * time zone and leap seconds accounted for in return value

 */

Tm_t*

tmxmake(Time_t t)

{

	static Tm_t		ts;

	return tmxtm(&ts, t, NiL);

}