/*
 * timer.c -- handles timers in ircII
 * Copyright 1993, 1996 Matthew Green
 * This file organized/adapted by Jeremy Nelson
 *
 * This used to be in edit.c, and it used to only allow you to
 * register ircII commands to be executed later.  I needed more
 * generality then that, specifically the ability to register
 * any function to be called, so i pulled it all together into
 * this file and called it timer.c
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "irc.h"
#include "ircaux.h"
#include "lastlog.h"
#include "timer.h"
#include "hook.h"
#include "output.h"
#include "commands.h"
#include "misc.h"
#include "vars.h"
#include "fset.h"
#include "tcommand.h"

static void show_timer (char *command);
void delete_all_timers (void);

/*
 * timercmd: the bit that handles the TIMER command.  If there are no
 * arguements, then just list the currently pending timers, if we are
 * give a -DELETE flag, attempt to delete the timer from the list.  Else
 * consider it to be a timer to add, and add it.
 */
void
cmd_timer (struct command *cmd, char *args)
{
	char *waittime, *flag;
	char *want = empty_string;
	char *ptr;
	int repeat = 0;
	long events = 1;

	if (*args == '-' || *args == '/')
	{
		flag = next_arg (args, &args);

		if (!my_strnicmp (flag + 1, "D", 1))	/* DELETE */
		{
			if (!(ptr = next_arg (args, &args)))
				say ("%s: Need a timer reference number for -DELETE", cmd->name);
			else
			{
				if (!my_strnicmp (ptr, "A", 1))
					delete_all_timers ();
				else
					delete_timer (ptr);
			}

			return;
		}
		else if (!my_strnicmp (flag + 1, "REP", 3))
		{
			char *na = next_arg (args, &args);
			repeat = 0;
			if (!na || !*na)
			{
				say ("%s: Missing arguement to -REPEAT", cmd->name);
				return;
			}
			if (!strcmp (na, "*") || !strcmp (na, "-1"))
				repeat = -1, events = -1;
			else if ((events = my_atol (na)) == 0)
				return;
		}
		else if (!my_strnicmp (flag + 1, "REF", 3))	/* REFNUM */
		{
			want = next_arg (args, &args);
			if (!want || !*want)
			{
				say ("%s: Missing argument to -REFNUM", cmd->name);
				return;
			}
		}
		else
		{
			say ("%s: %s no such flag", cmd->name, flag);
			return;
		}
	}

	/* else check to see if we have no args -> list */

	if (!(waittime = next_arg (args, &args)))
		show_timer (cmd->name);
	else
		add_timer (want, atol (waittime), events, NULL, args, NULL);
	return;
}

/*
 * This is put here on purpose -- we dont want any of the above functions
 * to have any knowledge of this struct.
 */
static TimerList *PendingTimers;
static char *schedule_timer (TimerList * ntimer);


static char *current_exec_timer = empty_string;

/*
 * ExecuteTimers:  checks to see if any currently pending timers have
 * gone off, and if so, execute them, delete them, etc, setting the
 * current_exec_timer, so that we can't remove the timer while its
 * still executing.
 *
 * changed the behavior: timers will not hook while we are waiting.
 */
extern void 
ExecuteTimers (void)
{
	time_t now;
	TimerList *current;
	int old_in_on_who;
	static int parsingtimer = 0;

	/* We do NOT want to parse timers while waiting
	 * cause it gets icky recursive
	 */
	if (waiting_out > waiting_in || parsingtimer || !PendingTimers)
		return;

	parsingtimer = 1;
	time (&now);
	while (PendingTimers && PendingTimers->time <= now)
	{
		current = PendingTimers;
		PendingTimers = PendingTimers->next;
		old_in_on_who = in_on_who;

		/* 
		 * If a callback function was registered, then
		 * we use it.  If no callback function was registered,
		 * then we use ''parse_line''.
		 */
		current_exec_timer = current->ref;
		if (current->callback)
			(*current->callback) (current->command);
		else
			parse_line ("TIMER", (char *) current->command, current->subargs, 0, 0);

		current_exec_timer = empty_string;
		in_on_who = old_in_on_who;


		/*
		 * Clean up or reschedule the timer
		 */
		if (current->events < 0 || (current->events != 1))
		{
			if (current->events != -1)
				current->events--;
			current->time += current->interval;
			schedule_timer (current);
		}
		else
		{
			if (!current->callback)
			{
				new_free ((char **) &current->command);
				new_free ((char **) &current->subargs);
			}
			new_free ((char **) &current);
		}
	}
	parsingtimer = 0;
}


/*
 * show_timer:  Display a list of all the TIMER commands that are
 * pending to be executed.
 */
static void 
show_timer (char *command)
{
	TimerList *tmp;
	time_t current, time_left;
	int count = 0;

	for (tmp = PendingTimers; tmp; tmp = tmp->next)
		if (!tmp->callback)
			count++;

	if (count == 0)
	{
		say ("%s: No commands pending to be executed", command);
		return;
	}

	time (&current);
	put_it ("%s", convert_output_format (get_fset_var (FORMAT_TIMER_FSET), "%s %s %s %s", "Timer", "Seconds", "Events", "Command"));
	for (tmp = PendingTimers; tmp; tmp = tmp->next)
	{
		time_left = tmp->time - current;
		if (time_left < 0)
			time_left = 0;
#if 0
		if (tmp->callback)
			continue;
#endif
		put_it ("%s", convert_output_format (get_fset_var (FORMAT_TIMER_FSET), "%s %l %d %s", tmp->ref, time_left, tmp->events, tmp->callback ? "(internal callback)" : (tmp->command ? tmp->command : "")));
	}
}

/*
 * create_timer_ref:  returns the lowest unused reference number for a timer
 *
 * This will never return 0 for a refnum because that is what atol() returns
 * on case of error, so that it can never happen that a timer has a refnum
 * of zero which would be tripped if the user did say,
 *      /TIMER -refnum foobar 3 blah blah blah
 * which should elicit an error, not be silently punted.
 */
static int 
create_timer_ref (char *refnum_want, char *refnum_gets)
{
	TimerList *tmp;
	int refnum = 0;

	/* Max of 10 characters. */
	if (strlen (refnum_want) > REFNUM_MAX)
		refnum_want[REFNUM_MAX] = 0;

	/* If the user doesnt care */
	if (!strcmp (refnum_want, empty_string))
	{
		/* Find the lowest refnum available */
		for (tmp = PendingTimers; tmp; tmp = tmp->next)
		{
			if (refnum < my_atol (tmp->ref))
				refnum = my_atol (tmp->ref);
		}
		strmcpy (refnum_gets, ltoa (refnum + 1), REFNUM_MAX);
	}
	else
	{
		/* See if the refnum is available */
		for (tmp = PendingTimers; tmp; tmp = tmp->next)
		{
			if (!my_stricmp (tmp->ref, refnum_want))
				return -1;
		}
		strmcpy (refnum_gets, refnum_want, REFNUM_MAX);
	}

	return 0;
}

/*
 * Deletes a refnum.  This does cleanup only if the timer is a 
 * user-defined timer, otherwise no clean up is done (the caller
 * is responsible to handle it)  This shouldnt output an error,
 * it should be more general and return -1 and let the caller
 * handle it.  Probably will be that way in a future release.
 */
extern int 
delete_timer (char *ref)
{
	TimerList *tmp, *prev;

	if (current_exec_timer != empty_string)
	{
		say ("You may not remove a TIMER from itself");
		return -1;
	}

	for (prev = tmp = PendingTimers; tmp; prev = tmp, tmp = tmp->next)
	{
		/* can only delete user created timers */
		if (!my_stricmp (tmp->ref, ref))
		{
			if (tmp == prev)
				PendingTimers = PendingTimers->next;
			else
				prev->next = tmp->next;
			if (!tmp->callback)
			{
				new_free ((char **) &tmp->command);
				new_free ((char **) &tmp->subargs);
			}
			new_free ((char **) &tmp);
			return 0;
		}
	}
	say ("TIMER: Can't delete %s, no such refnum", ref);
	return -1;
}

void 
delete_all_timers (void)
{
	while (PendingTimers)
		delete_timer (PendingTimers->ref);
	return;
}

/*
 * You call this to register a timer callback.
 *
 * The arguments:
 *  refnum_want: The refnum requested.  This should only be sepcified
 *               by the user, functions wanting callbacks should specify
 *               the value -1 which means "dont care".
 * The rest of the arguments are dependant upon the value of "callback"
 *      -- if "callback" is NULL then:
 *  callback:    NULL
 *  what:        some ircII commands to run when the timer goes off
 *  subargs:     what to use to expand $0's, etc in the 'what' variable.
 *
 *      -- if "callback" is non-NULL then:
 *  callback:    function to call when timer goes off
 *  what:        argument to pass to "callback" function.  Should be some
 *               non-auto storage, perhaps a struct or a malloced char *
 *               array.  The caller is responsible for disposing of this
 *               area when it is called, since the timer mechanism does not
 *               know anything of the nature of the argument.
 * subargs:      should be NULL, its ignored anyhow.
 */
char *
add_timer (char *refnum_want, long when, long events, int (callback) (void *), char *what, char *subargs)
{
	TimerList *ntimer;
	char refnum_got[REFNUM_MAX + 1] = "";

	if (when == 0)
		return NULL;
	ntimer = (TimerList *) new_malloc (sizeof (TimerList));
	ntimer->in_on_who = in_on_who;
	ntimer->time = time (NULL) + when;
	ntimer->interval = when;
	ntimer->events = events;
	if (create_timer_ref (refnum_want, refnum_got) == -1)
	{
		say ("TIMER: Refnum %s already exists", refnum_want);
		new_free ((char **) &ntimer);
		return NULL;
	}

	strcpy (ntimer->ref, refnum_got);
	ntimer->callback = callback;
	if (callback)
	{
		ntimer->command = (void *) what;
		ntimer->subargs = (void *) NULL;
	}
	else
	{
		ntimer->command = m_strdup (what);
		ntimer->subargs = m_strdup (subargs);
	}

	/* we've created it, now put it in order */
	return schedule_timer (ntimer);
}

static char *
schedule_timer (TimerList * ntimer)
{
	TimerList **slot;

	/* we've created it, now put it in order */
	for (slot = &PendingTimers; *slot; slot = &(*slot)->next)
	{
		if ((*slot)->time > ntimer->time)
			break;
	}
	ntimer->next = *slot;
	*slot = ntimer;
	return ntimer->ref;
}

/*
 * TimerTimeout:  Called from irc_io to help create the timeout
 * part of the call to select.
 */
time_t 
TimerTimeout (void)
{
	time_t current;
	time_t timeout_in;

	if (!PendingTimers)
		return 100000;	/* Just larger than the maximum of 60 */
	time (&current);
	timeout_in = PendingTimers->time - current;
	return (timeout_in < 0) ? 0 : timeout_in;
}
