/*
 * The Rin Library – time module
 *
 * Copyright (C) 2017 Gediminas Jakutis
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; version 2.1
 * of the License.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "rin/time.h"
#include "time_private.h"

struct timespec rin_time_add(const struct timespec * const a, const struct timespec * const b)
{
	struct timespec ret;

	ret.tv_sec = a->tv_sec + b->tv_sec;
	ret.tv_nsec = a->tv_nsec + b->tv_nsec;

	return rin_time_normalize(&ret);
}

struct timespec rin_time_sub(const struct timespec * const a, const struct timespec * const b)
{
	struct timespec ret;

	ret.tv_sec = a->tv_sec - b->tv_sec;
	ret.tv_nsec = a->tv_nsec - b->tv_nsec;

	return rin_time_normalize(&ret);
}

struct timespec rin_time_normalize(const struct timespec * const t)
{
	struct timespec ret;

	ret = *t;

	if (ret.tv_nsec >= 0 && ret.tv_nsec <= tv_nsec_max) {
		return ret;
	}

	if (ret.tv_nsec > 0) {
		ret.tv_sec += ret.tv_nsec / (tv_nsec_max + 1);
		ret.tv_nsec = ret.tv_nsec % (tv_nsec_max + 1);
	} else {
		ret.tv_sec += ret.tv_nsec / (tv_nsec_max + 1) - 1;
		ret.tv_nsec = (tv_nsec_max + 1) - (-ret.tv_nsec) % (tv_nsec_max + 1);
	}

	return ret;
}

long int rin_time_cmp(const struct timespec * const a, const struct timespec * const b)
{
	if (a->tv_sec != b->tv_sec) {
		return a->tv_sec - b->tv_sec;
	} else {
		return a->tv_nsec - b->tv_nsec;
	}
}

unsigned int rin_time_cmp_less(const struct timespec * const a, const struct timespec * const b)
{
	if (a->tv_sec > b->tv_sec) {
		return 0;
	} else if (a->tv_sec < b->tv_sec) {
		return 1;
	} else {
		return a->tv_nsec < b->tv_nsec;
	}
}

unsigned int rin_time_cmp_more(const struct timespec * const a, const struct timespec * const b)
{
	if (a->tv_sec < b->tv_sec) {
		return 0;
	} else if (a->tv_sec > b->tv_sec) {
		return 1;
	} else {
		return a->tv_nsec > b->tv_nsec;
	}
}

unsigned int rin_time_cmp_lessequal(const struct timespec * const a, const struct timespec * const b)
{
	if (a->tv_sec > b->tv_sec) {
		return 0;
	} else if (a->tv_sec < b->tv_sec) {
		return 1;
	} else {
		return a->tv_nsec <= b->tv_nsec;
	}
}

unsigned int rin_time_cmp_moreequal(const struct timespec * const a, const struct timespec * const b)
{
	if (a->tv_sec < b->tv_sec) {
		return 0;
	} else if (a->tv_sec > b->tv_sec) {
		return 1;
	} else {
		return a->tv_nsec >= b->tv_nsec;
	}
}

unsigned int rin_time_cmp_equal(const struct timespec * const a, const struct timespec * const b)
{
	return a->tv_sec == b->tv_sec && a->tv_nsec == b->tv_nsec;
}

unsigned int rin_time_cmp_nonequal(const struct timespec * const a, const struct timespec * const b)
{
	return a->tv_sec != b->tv_sec || a->tv_nsec != b->tv_nsec;
}