/*
This file is part of CanFestival, a library implementing CanOpen Stack. 

Copyright (C): Edouard TISSERANT and Francis DUPIN

See COPYING file for copyrights details.

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; either
version 2.1 of the License, or (at your option) any later version.

This library 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
/*!
** @file   timer.c
** @author Edouard TISSERANT and Francis DUPIN
** @date   Tue Jun  5 09:32:32 2007
**
** @brief
**
**
*/

/* #define DEBUG_WAR_CONSOLE_ON */
/* #define DEBUG_ERR_CONSOLE_ON */

#include <applicfg.h>
#include "timer.h"

/*  ---------  The timer table --------- */
s_timer_entry timers[MAX_NB_TIMER] = {{TIMER_FREE, NULL, NULL, 0, 0, 0},};

TIMEVAL total_sleep_time = TIMEVAL_MAX;
TIMER_HANDLE last_timer_raw = -1;

#define min_val(a,b) ((a<b)?a:b)

/*!                                                                                                
** -------  Use this to declare a new alarm ------                                                                                                
**                                                                                                 
** @param d                                                                                        
** @param id                                                                                       
** @param callback                                                                                 
** @param value                                                                                    
** @param period                                                                                   
**                                                                                                 
** @return                                                                                         
**/   
TIMER_HANDLE SetAlarm(CO_Data* d, UNS32 id, TimerCallback_t callback, TIMEVAL value, TIMEVAL period)
{
	/*printf("SetAlarm(UNS32 id=%d, TimerCallback_t callback=%x, TIMEVAL value=%d, TIMEVAL period=%d)\n", id, callback, value, period); */
	TIMER_HANDLE i;
	TIMER_HANDLE row_number = TIMER_NONE;

	/* in order to decide new timer setting we have to run over all timer rows */
	for(i=0; i <= last_timer_raw + 1 && i < MAX_NB_TIMER; i++)
	{
		s_timer_entry *row = (timers+i);

		if (callback && 	/* if something to store */
		   row->state == TIMER_FREE) /* and empty row */
		{	/* just store */
			row->callback = callback;
			row->d = d;
			row->id = id;
			row->val = value;
			row->interval = period;
			row->state = TIMER_ARMED;
			row_number = i;
			break;
		}
	}
	
	if (row_number != TIMER_NONE) /* if successfull **/
	{
		TIMEVAL real_timer_value;
		TIMEVAL elapsed_time;
		
		if (row_number == last_timer_raw + 1) last_timer_raw++;
		
		/* set next wakeup alarm if new entry is sooner than others, or if it is alone */
		real_timer_value = min_val(value, TIMEVAL_MAX);
		elapsed_time = getElapsedTime();

		/*printf("elapsed_time=%d real_timer_value=%d total_sleep_time=%d\n", elapsed_time, real_timer_value, total_sleep_time); */
		if (total_sleep_time > elapsed_time && total_sleep_time - elapsed_time > real_timer_value)
		{
			total_sleep_time = elapsed_time + real_timer_value;
			setTimer(real_timer_value);
		}
		/*printf("SetAlarm() return %d\n", row_number); */
		return row_number;
	}
	return TIMER_NONE;
}

/*!                                                                                                
**  -----  Use this to remove an alarm ----                                                                                             
**                                                                                                 
** @param handle                                                                                   
**                                                                                                 
** @return                                                                                         
**/  
TIMER_HANDLE DelAlarm(TIMER_HANDLE handle)
{
	/* Quick and dirty. system timer will continue to be trigged, but no action will be preformed. */
	MSG_WAR(0x3320, "DelAlarm. handle = ", handle);
	if(handle != TIMER_NONE)
	{
		if(handle == last_timer_raw) 
			last_timer_raw--;
		timers[handle].state = TIMER_FREE; 		
	}
	else {
	}
	return TIMER_NONE;
}

/*!                                                                                                
** ------  TimeDispatch is called on each timer expiration ----                                                                                                
**                                                                                                 
**/  
void TimeDispatch()
{
	TIMER_HANDLE i;
	TIMEVAL next_wakeup = TIMEVAL_MAX; /* used to compute when should normaly occur next wakeup */
	/* First run : change timer state depending on time */
	/* Get time since timer signal */
	TIMEVAL overrun = getElapsedTime();
	
	TIMEVAL real_total_sleep_time = total_sleep_time + overrun;
	/*printf("total_sleep_time %d + overrun %d\n", total_sleep_time , overrun); */

	for(i=0; i <= last_timer_raw; i++)
	{
		s_timer_entry *row = (timers+i);

		if (row->state & TIMER_ARMED) /* if row is active */
		{
			if (row->val <= real_total_sleep_time) /* to be trigged */
			{
				/*printf("row->val(%d) <= (%d)real_total_sleep_time\n", row->val, real_total_sleep_time); */
				if (!row->interval) /* if simply outdated */
				{
					row->state = TIMER_TRIG; /* ask for trig */
				}
				else /* or period have expired */
				{
					/* set val as interval, with overrun correction */
					row->val = row->interval - (overrun % row->interval);
					row->state = TIMER_TRIG_PERIOD; /* ask for trig, periodic */
					/* Check if this new timer value is the soonest */
					next_wakeup = min_val(row->val,next_wakeup);
				}
			}
			else
			{
				/* Each armed timer value in decremented. */
				row->val -= real_total_sleep_time;

				/* Check if this new timer value is the soonest */
				next_wakeup = min_val(row->val,next_wakeup);
			}
		}
	}
	
	/* Remember how much time we should sleep. */
	total_sleep_time = next_wakeup;

	/* Set timer to soonest occurence */
	setTimer(next_wakeup);

	/* Then trig them or not. */
	for(i=0; i<=last_timer_raw; i++)
	{
		s_timer_entry *row = (timers+i);

		if (row->state & TIMER_TRIG)
		{
			row->state &= ~TIMER_TRIG; /* reset trig state (will be free if not periodic) */
			if(row->callback)
				(*row->callback)(row->d, row->id); /* trig ! */
		}
	}
}