/*
 * Copyright (C) 2004, 2006-2009  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1998-2001, 2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: time.c,v 1.52 2009-08-14 07:51:08 marka Exp $ */

#include <config.h>

#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include <windows.h>

#include <isc/assertions.h>
#include <isc/time.h>
#include <isc/util.h>

/*
 * struct FILETIME uses "100-nanoseconds intervals".
 * NS / S = 1000000000 (10^9).
 * While it is reasonably obvious that this makes the needed
 * conversion factor 10^7, it is coded this way for additional clarity.
 */
#define NS_PER_S 	1000000000
#define NS_INTERVAL	100
#define INTERVALS_PER_S (NS_PER_S / NS_INTERVAL)
#define UINT64_MAX	_UI64_MAX

/***
 *** Absolute Times
 ***/

static isc_time_t epoch = { { 0, 0 } };
LIBISC_EXTERNAL_DATA isc_time_t *isc_time_epoch = &epoch;

/***
 *** Intervals
 ***/

static isc_interval_t zero_interval = { 0 };
LIBISC_EXTERNAL_DATA isc_interval_t *isc_interval_zero = &zero_interval;

void
isc_interval_set(isc_interval_t *i, unsigned int seconds,
		 unsigned int nanoseconds)
{
	REQUIRE(i != NULL);
	REQUIRE(nanoseconds < NS_PER_S);

	/*
	 * This rounds nanoseconds up not down.
	 */
	i->interval = (LONGLONG)seconds * INTERVALS_PER_S
		+ (nanoseconds + NS_INTERVAL - 1) / NS_INTERVAL;
}

isc_boolean_t
isc_interval_iszero(const isc_interval_t *i) {
	REQUIRE(i != NULL);
	if (i->interval == 0)
		return (ISC_TRUE);

	return (ISC_FALSE);
}

void
isc_time_set(isc_time_t *t, unsigned int seconds, unsigned int nanoseconds) {
	SYSTEMTIME epoch = { 1970, 1, 4, 1, 0, 0, 0, 0 };
	FILETIME temp;
	ULARGE_INTEGER i1;

	REQUIRE(t != NULL);
	REQUIRE(nanoseconds < NS_PER_S);

	SystemTimeToFileTime(&epoch, &temp);

	i1.LowPart = t->absolute.dwLowDateTime;
	i1.HighPart = t->absolute.dwHighDateTime;

	i1.QuadPart += (unsigned __int64)nanoseconds/100;
	i1.QuadPart += (unsigned __int64)seconds*10000000;

	t->absolute.dwLowDateTime = i1.LowPart;
	t->absolute.dwHighDateTime = i1.HighPart;
}

void
isc_time_settoepoch(isc_time_t *t) {
	REQUIRE(t != NULL);

	t->absolute.dwLowDateTime = 0;
	t->absolute.dwHighDateTime = 0;
}

isc_boolean_t
isc_time_isepoch(const isc_time_t *t) {
	REQUIRE(t != NULL);

	if (t->absolute.dwLowDateTime == 0 &&
	    t->absolute.dwHighDateTime == 0)
		return (ISC_TRUE);

	return (ISC_FALSE);
}

isc_result_t
isc_time_now(isc_time_t *t) {
	REQUIRE(t != NULL);

	GetSystemTimeAsFileTime(&t->absolute);

	return (ISC_R_SUCCESS);
}

isc_result_t
isc_time_nowplusinterval(isc_time_t *t, const isc_interval_t *i) {
	ULARGE_INTEGER i1;

	REQUIRE(t != NULL);
	REQUIRE(i != NULL);

	GetSystemTimeAsFileTime(&t->absolute);

	i1.LowPart = t->absolute.dwLowDateTime;
	i1.HighPart = t->absolute.dwHighDateTime;

	if (UINT64_MAX - i1.QuadPart < (unsigned __int64)i->interval)
		return (ISC_R_RANGE);

	i1.QuadPart += i->interval;

	t->absolute.dwLowDateTime  = i1.LowPart;
	t->absolute.dwHighDateTime = i1.HighPart;

	return (ISC_R_SUCCESS);
}

int
isc_time_compare(const isc_time_t *t1, const isc_time_t *t2) {
	REQUIRE(t1 != NULL && t2 != NULL);

	return ((int)CompareFileTime(&t1->absolute, &t2->absolute));
}

isc_result_t
isc_time_add(const isc_time_t *t, const isc_interval_t *i, isc_time_t *result)
{
	ULARGE_INTEGER i1;

	REQUIRE(t != NULL && i != NULL && result != NULL);

	i1.LowPart = t->absolute.dwLowDateTime;
	i1.HighPart = t->absolute.dwHighDateTime;

	if (UINT64_MAX - i1.QuadPart < (unsigned __int64)i->interval)
		return (ISC_R_RANGE);

	i1.QuadPart += i->interval;

	result->absolute.dwLowDateTime = i1.LowPart;
	result->absolute.dwHighDateTime = i1.HighPart;

	return (ISC_R_SUCCESS);
}

isc_result_t
isc_time_subtract(const isc_time_t *t, const isc_interval_t *i,
		  isc_time_t *result) {
	ULARGE_INTEGER i1;

	REQUIRE(t != NULL && i != NULL && result != NULL);

	i1.LowPart = t->absolute.dwLowDateTime;
	i1.HighPart = t->absolute.dwHighDateTime;

	if (i1.QuadPart < (unsigned __int64) i->interval)
		return (ISC_R_RANGE);

	i1.QuadPart -= i->interval;

	result->absolute.dwLowDateTime = i1.LowPart;
	result->absolute.dwHighDateTime = i1.HighPart;

	return (ISC_R_SUCCESS);
}

isc_uint64_t
isc_time_microdiff(const isc_time_t *t1, const isc_time_t *t2) {
	ULARGE_INTEGER i1, i2;
	LONGLONG i3;

	REQUIRE(t1 != NULL && t2 != NULL);

	i1.LowPart  = t1->absolute.dwLowDateTime;
	i1.HighPart = t1->absolute.dwHighDateTime;
	i2.LowPart  = t2->absolute.dwLowDateTime;
	i2.HighPart = t2->absolute.dwHighDateTime;

	if (i1.QuadPart <= i2.QuadPart)
		return (0);

	/*
	 * Convert to microseconds.
	 */
	i3 = (i1.QuadPart - i2.QuadPart) / 10;

	return (i3);
}

isc_uint32_t
isc_time_seconds(const isc_time_t *t) {
	SYSTEMTIME epoch = { 1970, 1, 4, 1, 0, 0, 0, 0 };
	FILETIME temp;
	ULARGE_INTEGER i1, i2;
	LONGLONG i3;

	SystemTimeToFileTime(&epoch, &temp);

	i1.LowPart  = t->absolute.dwLowDateTime;
	i1.HighPart = t->absolute.dwHighDateTime;
	i2.LowPart  = temp.dwLowDateTime;
	i2.HighPart = temp.dwHighDateTime;

	i3 = (i1.QuadPart - i2.QuadPart) / 10000000;

	return ((isc_uint32_t)i3);
}

isc_uint32_t
isc_time_nanoseconds(const isc_time_t *t) {
	ULARGE_INTEGER i;

	i.LowPart  = t->absolute.dwLowDateTime;
	i.HighPart = t->absolute.dwHighDateTime;
	return ((isc_uint32_t)(i.QuadPart % 10000000) * 100);
}

void
isc_time_formattimestamp(const isc_time_t *t, char *buf, unsigned int len) {
	FILETIME localft;
	SYSTEMTIME st;
	char DateBuf[50];
	char TimeBuf[50];

	static const char badtime[] = "99-Bad-9999 99:99:99.999";

	REQUIRE(len > 0);
	if (FileTimeToLocalFileTime(&t->absolute, &localft) &&
	    FileTimeToSystemTime(&localft, &st)) {
		GetDateFormat(LOCALE_USER_DEFAULT, 0, &st, "dd-MMM-yyyy",
			      DateBuf, 50);
		GetTimeFormat(LOCALE_USER_DEFAULT, TIME_NOTIMEMARKER|
			      TIME_FORCE24HOURFORMAT, &st, NULL, TimeBuf, 50);

		snprintf(buf, len, "%s %s.%03u", DateBuf, TimeBuf,
			 st.wMilliseconds);

	} else
		snprintf(buf, len, badtime);
}

void
isc_time_formathttptimestamp(const isc_time_t *t, char *buf, unsigned int len) {
	SYSTEMTIME st;
	char DateBuf[50];
	char TimeBuf[50];

/* strftime() format: "%a, %d %b %Y %H:%M:%S GMT" */

	REQUIRE(len > 0);
	if (FileTimeToSystemTime(&t->absolute, &st)) {
		GetDateFormat(LOCALE_USER_DEFAULT, 0, &st,
			      "ddd',', dd-MMM-yyyy", DateBuf, 50);
		GetTimeFormat(LOCALE_USER_DEFAULT,
			      TIME_NOTIMEMARKER | TIME_FORCE24HOURFORMAT,
			      &st, "hh':'mm':'ss", TimeBuf, 50);

		snprintf(buf, len, "%s %s GMT", DateBuf, TimeBuf);
	} else {
		buf[0] = 0;
	}
}

void
isc_time_formatISO8601(const isc_time_t *t, char *buf, unsigned int len) {
	SYSTEMTIME st;
	char DateBuf[50];
	char TimeBuf[50];

/* strtime() format: "%Y-%m-%dT%H:%M:%SZ" */

	REQUIRE(len > 0);
	if (FileTimeToSystemTime(&t->absolute, &st)) {
		GetDateFormat(LOCALE_NEUTRAL, 0, &st, "yyyy-MM-dd",
			      DateBuf, 50);
		GetTimeFormat(LOCALE_NEUTRAL,
			      TIME_NOTIMEMARKER | TIME_FORCE24HOURFORMAT,
			      &st, "hh':'mm':'ss", TimeBuf, 50);
		snprintf(buf, len, "%s%sZ", DateBuf, TimeBuf);
	} else {
		buf[0] = 0;
	}
}