/*
 * event.C: Event subsystem.
 *
 * Copyright © 2007 Pippijn van Steenhoven / The Ermyth Team
 * Rights to this code are as documented in COPYING.
 *
 *
 * Portions of this file were derived from sources bearing the following license:
 * Rights to this code are documented in doc/pod/license.pod.
 * Copyright © 2005-2007 Atheme Project (http://www.atheme.org)           
 */

static char const rcsid[] = "$Id: event.C,v 1.6 2007/09/22 14:27:30 pippijn Exp $";

#include "atheme.h"
#include <libermyth.h>
#include <ermyth/system.h>
#include "internal.h"

char const *last_event_ran = NULL;
struct ev_entry event_table[MAX_EVENTS];
static time_t event_time_min = -1;

/* add an event to the table to be continually ran */
unsigned int
event_add (char const * const name, EVH * func, void *arg, time_t when)
{
  unsigned int i;

  /* find the first inactive index */
  for (i = 0; i < MAX_EVENTS; i++)
    {
      if (!event_table[i].active)
	{
	  event_table[i].func = func;
	  event_table[i].name = name;
	  event_table[i].arg = arg;
	  event_table[i].when = NOW + when;
	  event_table[i].frequency = when;
	  event_table[i].active = true;

	  if ((event_table[i].when < event_time_min) || (event_time_min == -1))
	    event_time_min = event_table[i].when;

	  slog (LG_DEBUG, "event_add(): \"%s\"", name);

	  system_state.event++;

	  return i;
	}
    }

  /* failed to add it... */
  slog (LG_DEBUG, "event_add(): failed to add \"%s\" to event table", name);

  return UINT_MAX;
}

/* adds an event to the table to be ran only once */
unsigned int
event_add_once (char const * const name, EVH * func, void *arg, time_t when)
{
  unsigned int i;

  /* find the first inactive index */
  for (i = 0; i < MAX_EVENTS; i++)
    {
      if (!event_table[i].active)
	{
	  event_table[i].func = func;
	  event_table[i].name = name;
	  event_table[i].arg = arg;
	  event_table[i].when = NOW + when;
	  event_table[i].frequency = 0;
	  event_table[i].active = true;

	  if ((event_table[i].when < event_time_min) || (event_time_min == -1))
	    event_time_min = event_table[i].when;

	  slog (LG_DEBUG, "event_add_once(): \"%s\"", name);

	  system_state.event++;

	  return i;
	}
    }

  /* failed to add it... */
  slog (LG_DEBUG, "event_add(): failed to add \"%s\" to event table", name);

  return UINT_MAX;
}

/* delete an event from the table */
void
event_delete (EVH * func, void *arg)
{
  int i = event_find (func, arg);

  if (i == -1)
    return;

  slog (LG_DEBUG, "event_delete(): removing \"%s\"", event_table[i].name);

  event_table[i].name = NULL;
  event_table[i].func = NULL;
  event_table[i].arg = NULL;
  event_table[i].active = false;

  system_state.event--;
}

/* checks all pending events */
void
event_run (void)
{
  unsigned int i;

  for (i = 0; i < MAX_EVENTS; i++)
    {
      if (event_table[i].active && (event_table[i].when <= NOW))
	{
	  /* now we call it */
	  last_event_ran = event_table[i].name;
	  event_table[i].func (event_table[i].arg);
	  event_time_min = -1;

	  /* event is scheduled more than once */
	  if (event_table[i].frequency)
	    event_table[i].when = NOW + event_table[i].frequency;
	  else
	    {
	      event_table[i].name = NULL;
	      event_table[i].func = NULL;
	      event_table[i].arg = NULL;
	      event_table[i].active = false;

	      system_state.event--;
	    }
	}
    }
}

/* returns the time the next event_run() should happen */
time_t
event_next_time (void)
{
  unsigned int i;

  if (event_time_min == -1)
    {
      for (i = 0; i < MAX_EVENTS; i++)
	{
	  if (event_table[i].active && ((event_table[i].when < event_time_min) || event_time_min == -1))
	    event_time_min = event_table[i].when;
	}
    }

  return event_time_min;
}

/* initializes event system */
void
event_init (void)
{
  last_event_ran = NULL;
  memset ((void *) event_table, 0, sizeof (event_table));
}

/* finds an event in the table */
unsigned int
event_find (EVH * func, void *arg)
{
  unsigned int i;

  for (i = 0; i < MAX_EVENTS; i++)
    {
      if ((event_table[i].func == func) && (event_table[i].arg == arg))
	return i;
    }

  return UINT_MAX;
}