/* ****************************************************************************
 * utils/timer.c -- timer internals.
 * Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
 *
 * This file is part of libcasio.
 * libcasio 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; either version 3.0 of the License,
 * or (at your option) any later version.
 *
 * libcasio 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 libcasio; if not, see <http://www.gnu.org/licenses/>.
 * ************************************************************************* */
#include "../internals.h"

/* ---
 * Default functions for UNIX.
 * --- */

#if _POSIX_C_SOURCE >= 199309L
# include <time.h>

struct casio_timer_s {
	clockid_t clk_id;
	struct timespec initial;
};

CASIO_LOCAL int default_get_timer(casio_timer_t **timerp)
{
	casio_timer_t *timer;

	if (!(timer = casio_alloc(sizeof(*timer), 1)))
		return (casio_error_alloc);

#ifdef __linux__
	timer->clk_id = CLOCK_MONOTONIC_COARSE;
#else
	timer->clk_id = CLOCK_MONOTONIC;
#endif

	if (clock_gettime(timer->clk_id, &timer->initial) < 0) {
		casio_free(timer);
		return (casio_error_unknown);
	}

	*timerp = timer;
	return (0);
}

CASIO_LOCAL void default_free_timer(casio_timer_t *timer)
{
	casio_free(timer);
}

CASIO_LOCAL int default_get_spent_time(casio_timer_t *timer,
	unsigned long *spent)
{
	struct timespec ts;

	if (clock_gettime(timer->clk_id, &ts) < 0)
		return (casio_error_unknown);

	*spent = (ts.tv_sec - timer->initial.tv_sec) * 1000
		+ (ts.tv_nsec - timer->initial.tv_nsec) / 1000000;
	return (0);
}

#else
# define NO_DEFAULTS 1
#endif

/* ---
 * Public API functions.
 * --- */

#if NO_DEFAULTS
CASIO_LOCAL casio_get_timer_t *gettimer = NULL;
CASIO_LOCAL casio_get_spent_time_t *getspenttime = NULL;
#else
CASIO_LOCAL casio_get_timer_t *gettimer = &default_get_timer;
CASIO_LOCAL casio_get_spent_time_t *getspenttime = &default_get_spent_time;
#endif

#if NO_DEFAULTS || NO_TIMERFREE
CASIO_LOCAL casio_free_timer_t *freetimer = NULL;
#else
CASIO_LOCAL casio_free_timer_t *freetimer = &default_free_timer;
#endif

int CASIO_EXPORT casio_get_timer(casio_timer_t **timerp)
{
	if (!gettimer)
		return (casio_error_op);
	return ((*gettimer)(timerp));
}

void CASIO_EXPORT casio_free_timer(casio_timer_t *timer)
{
	if (!freetimer)
		return ;
	(*freetimer)(timer);
}

int CASIO_EXPORT casio_get_spent_time(casio_timer_t *timer,
	unsigned long *spent)
{
	if (!getspenttime)
		return (casio_error_op);
	return ((*getspenttime)(timer, spent));
}