/*
 * Copyright (c) 2003-2004 MontaVista Software, Inc.
 * Copyright (c) 2006 Red Hat, Inc.
 *
 * All rights reserved.
 *
 * Author: Steven Dake (sdake@mvista.com)
 *
 * This software licensed under BSD license, the text of which follows:
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * - Neither the name of the MontaVista Software, Inc. nor the names of its
 *   contributors may be used to endorse or promote products derived from this
 *   software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef TLIST_H_DEFINED
#define TLIST_H_DEFINED

#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>

#include "../include/list.h"

typedef void * timer_handle;

struct timerlist {
	struct list_head timer_head;
	struct list_head *timer_iter;
};

struct timerlist_timer {
	struct list_head list;
	struct timeval tv;
	void (*timer_fn)(void *data);
	void *data;
	timer_handle handle_addr;
};

static inline void timerlist_init (struct timerlist *timerlist)
{
	list_init (&timerlist->timer_head);
}

static inline void timeval_adjust_to_msec (struct timeval *tv) {
        tv->tv_usec = (tv->tv_usec / 1000) * 1000;
}


static inline void timerlist_add (struct timerlist *timerlist, struct timerlist_timer *timer)
{
	struct list_head *timer_list = 0;
	struct timerlist_timer *timer_from_list;
	int found;

	timeval_adjust_to_msec (&timer->tv);
//printf ("Adding timer %d %d\n", timer->tv.tv_sec, timer->tv.tv_usec);
	for (found = 0, timer_list = timerlist->timer_head.next;
		timer_list != &timerlist->timer_head;
		timer_list = timer_list->next) {

		timer_from_list = list_entry (timer_list,
			struct timerlist_timer, list);

		if ((timer_from_list->tv.tv_sec > timer->tv.tv_sec) ||
			((timer_from_list->tv.tv_sec == timer->tv.tv_sec) &&
			(timer_from_list->tv.tv_usec > timer->tv.tv_usec))) {
			list_add (&timer->list, timer_list->prev);
			found = 1;
			break; /* for timer iteration */
		}
	}
	if (found == 0) {
		list_add (&timer->list, timerlist->timer_head.prev);
	}
}

static inline int timerlist_add_future (struct timerlist *timerlist,
	void (*timer_fn) (void *data),
	void *data,
	unsigned int msec_in_future,
	timer_handle *handle)
{
	struct timerlist_timer *timer;
	struct timeval current_time;
	unsigned int seconds;
	unsigned int mseconds;

	timer = (struct timerlist_timer *)malloc (sizeof (struct timerlist_timer));
	if (timer == 0) {
		errno = ENOMEM;
		return (-1);
	}
	
	seconds = msec_in_future / 1000;
	mseconds = msec_in_future % 1000;

	gettimeofday (&current_time, 0);
	timeval_adjust_to_msec (&current_time);
	timer->tv.tv_sec = current_time.tv_sec + seconds;
	timer->tv.tv_usec = current_time.tv_usec + mseconds * 1000;
	if (timer->tv.tv_usec >= 1000000) {
		timer->tv.tv_sec++;
		timer->tv.tv_usec -= 1000000;
	}
	timer->data = data;
	timer->timer_fn = timer_fn;
	timer->handle_addr = handle;
	timerlist_add (timerlist, timer);

	*handle = timer;
	return (0);
}

static inline void timerlist_del (struct timerlist *timerlist, timer_handle timer_handle)
{
	struct timerlist_timer *timer = (struct timerlist_timer *)timer_handle;

	memset (timer->handle_addr, 0, sizeof (struct timerlist_timer *));
	/*
	 * If the next timer after the currently expiring timer because
	 * timerlist_del is called from a timer handler, get to the enxt
	 * timer
	 */
	if (timerlist->timer_iter == &timer->list) {
		timerlist->timer_iter = timerlist->timer_iter->next;
	}
	list_del (&timer->list);
	list_init (&timer->list);
	free (timer);
}

static inline void timerlist_del_data (struct timerlist *timerlist, timer_handle timer_handle)
{
	struct timerlist_timer *timer = (struct timerlist_timer *)timer_handle;

	if (timer->data) {
		free (timer->data);
	}
	timerlist_del(timerlist,timer_handle);
}

static inline void timerlist_pre_dispatch (struct timerlist *timerlist, timer_handle timer_handle)
{
	struct timerlist_timer *timer = (struct timerlist_timer *)timer_handle;

	memset (timer->handle_addr, 0, sizeof (struct timerlist_timer *));
	list_del (&timer->list);
	list_init (&timer->list);
}

static inline void timerlist_post_dispatch (struct timerlist *timerlist, timer_handle timer_handle)
{
	struct timerlist_timer *timer = (struct timerlist_timer *)timer_handle;

	free (timer);
}

#ifdef CODE_COVERAGE_COMPILE_OUT
static inline int timer_expire_get_tv (struct timerlist *timerlist, struct timeval *tv)
{
	struct timeval current_time;
	struct timerlist_timer *timer_from_list;

	/*
	 * empty list, no expire
	 */
	if (timerlist->timer_head.next == &timerlist->timer_head) {
		return (-1);
	}
	
	timer_from_list = list_entry (timerlist->timer_head.next,
		struct timerlist_timer, list);

	gettimeofday (&current_time, 0);
	timeval_adjust_to_msec (&current_time);

	/*
	 * timer at head of list is expired, zero msecs required
	 */
	if ((timer_from_list->tv.tv_sec < current_time.tv_sec) ||
		((timer_from_list->tv.tv_sec == current_time.tv_sec) &&
		(timer_from_list->tv.tv_usec <= current_time.tv_usec))) {
		
		tv->tv_sec = 0;
		tv->tv_usec = 0;
	}

	tv->tv_sec = timer_from_list->tv.tv_sec - current_time.tv_sec;
	tv->tv_usec = timer_from_list->tv.tv_usec - current_time.tv_usec;
	if (tv->tv_usec < 0) {
		tv->tv_sec -= 1;
		tv->tv_usec += 1000000;
	}
	if (tv->tv_sec < 0) {
		tv->tv_sec = 0;
		tv->tv_usec = 0;
	}

	timeval_adjust_to_msec (tv);
	return (0);
}
#endif /* CODE_COVERAGE_COMPILE_OUT */

static inline unsigned int timerlist_timeout_msec (struct timerlist *timerlist)
{
	struct timeval current_time;
	struct timerlist_timer *timer_from_list;
	int time_in_msec;

	/*
	 * empty list, no expire
	 */
	if (timerlist->timer_head.next == &timerlist->timer_head) {
		return (-1);
	}
	
	timer_from_list = list_entry (timerlist->timer_head.next,
		struct timerlist_timer, list);

	gettimeofday (&current_time, 0);
	timeval_adjust_to_msec (&current_time);

	/*
	 * timer at head of list is expired, zero msecs required
	 */
	if ((timer_from_list->tv.tv_sec < current_time.tv_sec) ||
		((timer_from_list->tv.tv_sec == current_time.tv_sec) &&
		(timer_from_list->tv.tv_usec <= current_time.tv_usec))) {
		return (0);
	}
	time_in_msec = ((timer_from_list->tv.tv_sec - current_time.tv_sec) * 1000) + ((timer_from_list->tv.tv_usec - current_time.tv_usec) / 1000);

	if (time_in_msec < 0) {
		return (0);
	}
	return time_in_msec;
}

static inline void timerlist_expire (struct timerlist *timerlist)
{
	struct timerlist_timer *timer_from_list;
	struct timeval current_time;

	gettimeofday (&current_time, 0);
	timeval_adjust_to_msec (&current_time);

	for (timerlist->timer_iter = timerlist->timer_head.next;
		timerlist->timer_iter != &timerlist->timer_head;) {

		timer_from_list = list_entry (timerlist->timer_iter,
			struct timerlist_timer, list);

		if ((timer_from_list->tv.tv_sec < current_time.tv_sec) ||
			((timer_from_list->tv.tv_sec == current_time.tv_sec) &&
			(timer_from_list->tv.tv_usec <= current_time.tv_usec))) {
//printf ("Executing timer %d %d\n", timer_from_list->tv.tv_sec, timer_from_list->tv.tv_usec);
			timerlist->timer_iter = timerlist->timer_iter->next;

			timerlist_pre_dispatch (timerlist, timer_from_list);

			timer_from_list->timer_fn (timer_from_list->data);

			timerlist_post_dispatch (timerlist, timer_from_list);
		} else {
			break; /* for timer iteration */
		}
	}
	timerlist->timer_iter = 0;
}
#endif /* TLIST_H_DEFINED */