/**
 * @file clock.h
 * @note Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
 *
 * 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 of the License, 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 program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef HAVE_CLOCK_H
#define HAVE_CLOCK_H

#include "ds.h"
#include "transport.h"

#define MAX_PORTS 8

/** Defines a network interface, with PTP options. */
struct interface {
	char *name;
	enum transport_type transport;
	enum timestamp_type timestamping;
};

/** Opaque type. */
struct clock;

/**
 * Obtains a reference to the best foreign master of a clock.
 * @param c  The clock instance.
 * @return   A pointer to the data set of the foreign master,
 *           or NULL if none has been yet discovered.
 */
struct dataset *clock_best_foreign(struct clock *c);

/**
 * Obtains a reference to the port with the best foreign master.
 * @param c  The clock instance.
 * @return   A pointer to the port with the best foreign master,
 *           or NULL if none has been yet discovered.
 */
struct port *clock_best_port(struct clock *c);

/**
 * Obtain the clockClass attribute from a clock.
 * @param c  The clock instance.
 * @return   The value of the clock's class.
 */
UInteger8 clock_class(struct clock *c);

/**
 * Create a clock instance. There can only be one clock in any system,
 * so subsequent calls will destroy the previous clock instance.
 *
 * @param phc         PTP hardware clock device to use.
 *                    Pass NULL to select CLOCK_REALTIME.
 * @param interface   An array of network interfaces.
 * @param count       The number of elements in @a interfaces.
 * @param ds          A pointer to a default data set for the clock.
 * @return            A pointer to the single global clock instance.
 */
struct clock *clock_create(char *phc, struct interface *iface, int count,
			   struct defaultDS *ds);

/**
 * Obtains a clock's default data set.
 * @param c  The clock instance.
 * @return   A pointer to the data set of the clock.
 */
struct dataset *clock_default_ds(struct clock *c);

/**
 * Poll for events and dispatch them.
 * @param c A pointer to a clock instance obtained with clock_create().
 * @return  Zero on success, non-zero otherwise.
 */
int clock_poll(struct clock *c);

#endif