/*
 * actions.c  -  functions for dealing with monster actions
 *
 * Advanced Rogue
 * Copyright (C) 1984, 1985, 1986 Michael Morgan, Ken Dalka and AT&T
 * All rights reserved.
 *
 * Based on "Rogue: Exploring the Dungeons of Doom"
 * Copyright (C) 1980, 1981 Michael Toy, Ken Arnold and Glenn Wichman
 * All rights reserved.
 *
 * See the file LICENSE.TXT for full copyright and licensing information.
 */

#include <ctype.h>
#include <limits.h>
#include "curses.h"
#include "rogue.h"
#define	MAXINT	INT_MAX
#define	MININT	INT_MIN
/* 
 * Did we disrupt a spell? 
 */
dsrpt_monster(tp, always, see_him)
register struct thing *tp;
bool always, see_him;
{
    switch (tp->t_action) {
    case A_SUMMON:
    case A_MISSILE:
    case A_SLOW:
	tp->t_action = A_NIL; /* Just make the old fellow start over again */
	tp->t_no_move = movement(tp);
	tp->t_using = NULL;/* Just to be on the safe side */
	turn_on(*tp, WASDISRUPTED);
	if (see_him)
	    msg("%s's spell has been disrupted.",prname(monster_name(tp),TRUE));
	/*
	 * maybe choose something else to do next time since player
	 * is disrupting us
	 */
	tp->t_summon *= 2;
	tp->t_cast /= 2;
	return;
    }

    /* We may want to disrupt other actions, too */
    if (always) {
	tp->t_action = A_NIL; /* Just make the old fellow start over again */
	tp->t_no_move = movement(tp);
	tp->t_using = NULL;/* Just to be on the safe side */
    }
}

dsrpt_player()
{
    int which, action;
    struct linked_list *item;
    struct object *obj;
    
    action = player.t_action;
    which = player.t_selection;

    switch (action) {
    case C_CAST: /* Did we disrupt a spell? */
    case C_PRAY:
    case C_CHANT:
    {
	msg("Your %s was disrupted!", action == C_CAST ? "spell" : "prayer");

	/* Charge him anyway */
	if (action == C_CAST)
	    spell_power += magic_spells[which].s_cost;
	else if (action == C_PRAY)
	    pray_time += cleric_spells[which].s_cost;
	else if (action == C_CHANT)
	    chant_time += druid_spells[which].s_cost;
    }
    when C_COUNT: /* counting of gold? */
    {
	if (purse > 0) {
	    msg("Your gold goes flying everywhere!");
	    do {
		item = spec_item(GOLD, NULL, NULL, NULL);
		obj = OBJPTR(item);
		obj->o_count = min(purse, rnd(10)+1);
		purse -= obj->o_count;
		obj->o_pos = hero;
		fall(item, FALSE);
	    } while (purse > 0 && rnd(10) != 1);
	}
    }
    when C_EAT:
	msg("You gag on your food for a moment.");
	del_pack(player.t_using);
	
    when A_PICKUP:
	msg("You drop what you are picking up!");

    when C_SEARCH:	/* searching for traps and secret doors... */
	msg("Oww....You decide to stop searching.");
	count = 0;	/* don't search again */

    when C_SETTRAP:
	msg("Oww....You can't get a trap set.");

    when A_NIL:
    default:
	return;
    }
    player.t_no_move = movement(&player); /* disoriented for a while */
    player.t_action = A_NIL;
    player.t_selection = 0;
    player.t_using = NULL;
}

/*
 * m_act:
 *	If the critter isn't doing anything, choose an action for it.
 *	Otherwise, let it perform its chosen action.
 */

m_act(tp)
register struct thing *tp;
{
    struct object *obj;
    bool flee;	/* Are we scared? */

    /* What are we planning to do? */
    switch (tp->t_action) {
	default:
	    /* An unknown action! */
	    msg("Unknown monster action (%d)", tp->t_action);

	    /* Fall through */

	case A_NIL:
	    /* If the monster is fairly intelligent and about to die, it
	     * may turn tail and run.  But if we are a FRIENDLY creature
	     * in the hero's service, don't run.
	     */
	    if (off(*tp, ISFLEE)					&&
		tp->t_stats.s_hpt < tp->maxstats.s_hpt			&&
		tp->t_stats.s_hpt < max(10, tp->maxstats.s_hpt/6)	&&
		(off(*tp, ISFRIENDLY) || tp->t_dest != &hero)		&&
		rnd(25) < tp->t_stats.s_intel) {
		    turn_on(*tp, ISFLEE);

		    /* It is okay to turn tail */
		    tp->t_oldpos = tp->t_pos;
		}

	    /* Should the monster run away? */
	    flee = on(*tp, ISFLEE) ||
		((tp->t_dest == &hero) && on(player, ISINWALL) &&
		 off(*tp, CANINWALL));

	    m_select(tp, flee);	/* Select an action */
	    return;

	when A_ATTACK:
	    /* 
	     * We're trying to attack the player or monster at t_newpos 
	     * if the prey moved, do nothing
	     */
	    obj = tp->t_using ? OBJPTR(tp->t_using) : NULL;
	    if (ce(tp->t_newpos, hero)) {
		attack(tp, obj, FALSE);
	    }
	    else if (mvwinch(mw, tp->t_newpos.y, tp->t_newpos.x) &&
		     step_ok(tp->t_newpos.y, tp->t_newpos.x, FIGHTOK, tp)) {
		skirmish(tp, &tp->t_newpos, obj, FALSE);
	    }

	when A_SELL:
	    /* Is the player still next to us? */
	    if (ce(tp->t_newpos, hero)) sell(tp);

	    /* The darned player moved away */
	    else if (off(player, ISBLIND) &&
		cansee(unc(tp->t_pos)) &&
		(off(*tp, ISINVIS)     || on(player, CANSEE)) &&
		(off(*tp, ISSHADOW)    || on(player, CANSEE)) &&
		(off(*tp, CANSURPRISE) || ISWEARING(R_ALERT)))
		msg("%s grunts with frustration",prname(monster_name(tp),TRUE));

	when A_MOVE:
	    /* Let's try to move */
	    do_chase(tp);

	    /* If t_no_move > 0, we found that we have to fight! */
	    if (tp->t_no_move > 0) return;

	when A_BREATHE:
	    /* Breathe on the critter */
	    m_breathe(tp);

	when A_SLOW:
	    /* make him move slower */
	    add_slow();
	    turn_off(*tp, CANSLOW);

	when A_MISSILE:
	    /* Start up a magic missile spell */
	    m_spell(tp);

	when A_SONIC:
	    /* Let out a sonic blast! */
	    m_sonic(tp);

	when A_THROW:
	    /* We're throwing something (like an arrow) */
	    missile(tp->t_newpos.y, tp->t_newpos.x, tp->t_using, tp);

	when A_SUMMON:
	    /* We're summoning help */
	    m_summon(tp);

	when A_USERELIC:
	    /* Use our relic */
	    m_use_relic(tp);

	when A_USEWAND:
	    /* use the wand we have */
	    m_use_wand(tp);
    }

    /* No action now */
    tp->t_action = A_NIL;
    tp->t_using = NULL;
}

/*
 * m_breathe:
 *	Breathe in the chosen direction.
 */

m_breathe(tp)
register struct thing *tp;
{
    register int damage;
    register char *breath = "";

    damage = tp->t_stats.s_hpt;
    turn_off(*tp, CANSURPRISE);

    /* Will it breathe at random */
    if (on(*tp, CANBRANDOM)) {
	/* Turn off random breath */
	turn_off(*tp, CANBRANDOM);

	/* Select type of breath */
	switch (rnd(10)) {
	    case 0: breath = "acid";
		    turn_on(*tp, NOACID);
	    when 1: breath = "flame";
		    turn_on(*tp, NOFIRE);
	    when 2: breath = "lightning bolt";
		    turn_on(*tp, NOBOLT);
	    when 3: breath = "chlorine gas";
		    turn_on(*tp, NOGAS);
	    when 4: breath = "ice";
		    turn_on(*tp, NOCOLD);
	    when 5: breath = "nerve gas";
		    turn_on(*tp, NOPARALYZE);
	    when 6: breath = "sleeping gas";
		    turn_on(*tp, NOSLEEP);
	    when 7: breath = "slow gas";
		    turn_on(*tp, NOSLOW);
	    when 8: breath = "confusion gas";
		    turn_on(*tp, ISCLEAR);
	    when 9: breath = "fear gas";
		    turn_on(*tp, NOFEAR);
	}
    }

    /* Or can it breathe acid? */
    else if (on(*tp, CANBACID)) {
	turn_off(*tp, CANBACID);
	breath = "acid";
    }

    /* Or can it breathe fire */
    else if (on(*tp, CANBFIRE)) {
	turn_off(*tp, CANBFIRE);
	breath = "flame";
    }

    /* Or can it breathe electricity? */
    else if (on(*tp, CANBBOLT)) {
	turn_off(*tp, CANBBOLT);
	breath = "lightning bolt";
    }

    /* Or can it breathe gas? */
    else if (on(*tp, CANBGAS)) {
	turn_off(*tp, CANBGAS);
	breath = "chlorine gas";
    }

    /* Or can it breathe ice? */
    else if (on(*tp, CANBICE)) {
	turn_off(*tp, CANBICE);
	breath = "ice";
    }

    else if (on(*tp, CANBPGAS)) {
	turn_off(*tp, CANBPGAS);
	breath = "nerve gas";
    }

    /* can it breathe sleeping gas */
    else if (on(*tp, CANBSGAS)) {
	turn_off(*tp, CANBSGAS);
	breath = "sleeping gas";
    }

    /* can it breathe slow gas */
    else if (on(*tp, CANBSLGAS)) {
	turn_off(*tp, CANBSLGAS);
	breath = "slow gas";
    }

    /* can it breathe confusion gas */
    else if (on(*tp, CANBCGAS)) {
	turn_off(*tp, CANBCGAS);
	breath = "confusion gas";
    }

    /* can it breathe fear gas */
    else {
	turn_off(*tp, CANBFGAS);
	breath = "fear gas";
    }

    /* Now breathe -- sets "monst_dead" if it kills someone */
    shoot_bolt(tp, tp->t_pos, tp->t_newpos, FALSE, 
		    tp->t_index, breath, damage);

    running = FALSE;
    if (fight_flush) md_flushinp();
}

/*
 * m_select:
 *	Select an action for the monster.
 */

m_select(th, flee)
register struct thing *th;
register bool flee; /* True if running away or player is inaccessible in wall */
{
    register struct room *rer, *ree;	/* room of chaser, room of chasee */
    int dist = MININT;
    int mindist = MAXINT, maxdist = MININT;
    bool rundoor;			/* TRUE means run to a door */
    char sch;
    coord *last_door=0,			/* Door we just came from */
	   this;			/* Temporary destination for chaser */

    rer = roomin(&th->t_pos);	/* Find room of chaser */
    ree = roomin(th->t_dest);	/* Find room of chasee */

    /* First see if we want to use an ability or weapon */
    if (m_use_it(th, flee, rer, ree)) return;

    /*
     * We don't count monsters on doors as inside rooms here because when
     * a monster is in a room and the player is not in that room, the
     * monster looks for the best door out.  If we counted doors as part
     * of the room, the monster would already be on the best door out;
     * so he would never move.
     */
    if ((sch = CCHAR( mvwinch(stdscr, th->t_pos.y, th->t_pos.x) )) == DOOR ||
	sch == SECRETDOOR || sch == PASSAGE) {
	rer = NULL;
    }
    this = *th->t_dest;

    /*
     * If we are in a room heading for the player and the player is not
     * in the room with us, we run to the "best" door.
     * If we are in a room fleeing from the player, then we run to the
     * "best" door if he IS in the same room.
     *
     * Note:  We don't bother with doors in mazes or if we can walk
     * through walls.
     */
    if (rer != NULL && levtype != MAZELEV && off(*th, CANINWALL)) {
	if (flee) rundoor = (rer == ree);
	else rundoor = (rer != ree);
    }
    else rundoor = FALSE;

    if (rundoor) {
	register struct linked_list *exitptr;	/* For looping through exits */
	coord *exit,				/* A particular door */
	      *entrance;			/* Place just inside doorway */
	int exity, exitx;			/* Door's coordinates */
	char dch='\0';				/* Door character */

	if (th->t_doorgoal)
	    dch = CCHAR( mvwinch(stdscr, th->t_doorgoal->y, th->t_doorgoal->x) );
	    
	/* Do we have a valid goal? */
	if ((dch == PASSAGE || dch == DOOR) &&  /* A real door */
	    (!flee || !ce(*th->t_doorgoal, *th->t_dest))) { /* Prey should not
						             * be at door if
							     * we are running
							     * away
							     */
	    /* Make sure the player is not in the doorway, either */
	    entrance = doorway(rer, th->t_doorgoal);
	    if (!flee || entrance == NULL || !ce(*entrance, *th->t_dest)) {
		this = *th->t_doorgoal;
		dist = 0;	/* Indicate that we have our door */
	    }
	}

	/* Go through all the doors */
	else for (exitptr = rer->r_exit; exitptr; exitptr = next(exitptr)) {
	    exit = DOORPTR(exitptr);
	    exity = exit->y;
	    exitx = exit->x;

	    /* Make sure it is a real door */
	    dch = CCHAR( mvwinch(stdscr, exity, exitx) );
	    if (dch == PASSAGE || dch == DOOR) {
		/* Don't count a door if we are fleeing from someone and
		 * he is standing on it.  Also, don't count it if he is
		 * standing in the doorway.
		 */
		if (flee) {
		    if (ce(*exit, *th->t_dest)) continue;

		    entrance = doorway(rer, exit);
		    if (entrance != NULL && ce(*entrance, *th->t_dest))
			continue;
		}
		
		/* Were we just on this door? */
		if (ce(*exit, th->t_oldpos)) last_door = exit;

		else {
		    dist = DISTANCE(th->t_dest->y, th->t_dest->x, exity, exitx);

		    /* If fleeing, we want to maximize distance from door to
		     * what we flee, and minimize distance from door to us.
		     */
		    if (flee)
		       dist -= DISTANCE(th->t_pos.y, th->t_pos.x, exity, exitx);

		    /* Maximize distance if fleeing, otherwise minimize it */
		    if ((flee && (dist > maxdist)) ||
			(!flee && (dist < mindist))) {
			th->t_doorgoal = exit;	/* Use this door */
			this = *exit;
			mindist = maxdist = dist;
		    }
		}
	    }
	}

	/* Could we not find a door? */
	if (dist == MININT) {
	    /* If we were on a door, go ahead and use it */
	    if (last_door) {
		th->t_doorgoal = last_door;
		this = th->t_oldpos;
		dist = 0;	/* Indicate that we found a door */
	    }
	    else th->t_doorgoal = NULL;	/* No more door goal */
	}

	/* Indicate that we do not want to flee from the door */
	if (dist != MININT) flee = FALSE;
    }
    else th->t_doorgoal = 0;	/* Not going to any door */

    /* Now select someplace to go and start the action */
    chase(th, &this, rer, ree, flee);
}

/*
 * m_sonic:
 *	The monster is sounding a sonic blast.
 */

m_sonic(tp)
register struct thing *tp;
{
    register int damage;
    static struct object blast =
    {
	MISSILE, {0, 0}, "", 0, "", "150" , NULL, 0, 0, 0, 0
    };

    turn_off(*tp, CANSONIC);
    turn_off(*tp, CANSURPRISE);
    do_motion(&blast, tp->t_newpos.y, tp->t_newpos.x, tp);
    damage = 150;
    if (save(VS_BREATH, &player, -3))
	damage /= 2;
    msg ("%s's sonic blast hits you", prname(monster_name(tp), TRUE));
    if ((pstats.s_hpt -= damage) <= 0)
	death(tp->t_index);

    running = FALSE;
    if (fight_flush) md_flushinp();
    dsrpt_player();
}

/*
 * m_spell:
 *	The monster casts a spell.  Currently this is limited to
 *	magic missile.
 */
m_spell(tp)
register struct thing *tp;
{
    static struct object missile =
    {
	MISSILE, {0, 0}, "", 0, "", "0d4 " , NULL, 0, WS_MISSILE, 100, 1
    };

    sprintf(missile.o_hurldmg, "%dd4", tp->t_stats.s_lvl);
    do_motion(&missile, tp->t_newpos.y, tp->t_newpos.x, tp);
    hit_monster(unc(missile.o_pos), &missile, tp);
    turn_off(*tp, CANMISSILE);
    turn_off(*tp, CANSURPRISE);

    running = FALSE;
    if (fight_flush) md_flushinp();
}

/*
 * m_summon:
 *	Summon aid.
 */

m_summon(tp)
register struct thing *tp;
{
    register char *helpname, *mname;
    int fail, numsum;
    register int which, i;

    /* Let's make sure our prey is still here */
    if (!cansee(unc(tp->t_pos)) || fallpos(&hero, FALSE, 2) == NULL) return;

    /*
     * Non-uniques can only summon once.  Uniques get fewer
     * creatures with each successive summoning. Also, the
     * probability of summoning goes down
     */
    if (off(*tp, ISUNIQUE))
	    turn_off(*tp, CANSUMMON);

    turn_off(*tp, CANSURPRISE);
    mname = monster_name(tp);
    helpname = monsters[tp->t_index].m_typesum;
    which = findmindex(helpname);

    if ((off(*tp, ISINVIS)     || on(player, CANSEE)) &&
	(off(*tp, ISSHADOW)    || on(player, CANSEE)) &&
	(off(*tp, CANSURPRISE) || ISWEARING(R_ALERT))) {
	if (monsters[which].m_normal == FALSE) { /* genocided? */
	    msg("%s appears dismayed", prname(mname, TRUE));
	    monsters[tp->t_index].m_numsum = 0;
	}
	else {
	    msg("%s summons %ss for help", prname(mname, TRUE), helpname);
	}
    }
    else {
	if (monsters[which].m_normal == FALSE) /* genocided? */
	    monsters[tp->t_index].m_numsum = 0;
	else {
	    msg("%ss seem to appear from nowhere!", helpname);
	}
    }
    numsum = monsters[tp->t_index].m_numsum;
    if (numsum && on(*tp, ISUNIQUE)) {   /* UNIQUEs summon less each time */
	monsters[tp->t_index].m_numsum--; 
	tp->t_summon *= 2; /* cut probability in half */
    }

    /*
     * try to make all the creatures around player but remember
     * if unsuccessful
     */
    for (i=0, fail=0; i<numsum; i++) {
	 if (!creat_mons(&player, which, FALSE))
	     fail++;	/* remember the failures */
    }

    /*
     * try once again to make the buggers
     */
    for (i=0; i<fail; i++)
	 creat_mons(tp, which, FALSE);
    
    /* Now let the poor fellow see all the trouble */
    light(&hero);
    turn_on(*tp, HASSUMMONED);
}

/*
 * m_use_it:
 *	See if the monster (tp) has anything useful it can do
 *	(ie. an ability or a weapon) other than just move.
 */

bool
m_use_it(tp, flee, rer, ree)
register struct thing *tp;
bool flee;
register struct room *rer, *ree;
{
    int dist;
    register coord *ee = tp->t_dest, *er = &tp->t_pos; 
    coord *shoot_dir;
    struct linked_list *weapon;
    struct thing *prey;
    bool dest_player;	/* Are we after the player? */

    /*
     * If we are fleeing, there's a chance, depending on our
     * intelligence, that we'll just run in terror.
     */
    if (flee && rnd(25) >= tp->t_stats.s_intel) return(FALSE);

    /*
     * Make sure that we have a living destination, and record whether
     * it is the player.
     */
    if (ee != NULL) {
        if (ce(*ee, hero)) {
	    dest_player = TRUE;
	    prey = &player;
	}
	else {
	    struct linked_list *item;

	    dest_player = FALSE;

	    /* What is the monster we're chasing? */
	    item = find_mons(ee->y, ee->x);
	    if (item != NULL) prey = THINGPTR(item);
	    else return(FALSE);
	}
    }
    else return(FALSE);

    /*
     * If we are friendly to the hero, we don't do anything.
     */
    if (on(*tp, ISFRIENDLY) && dest_player) return(FALSE);

    /*
     * Also, for now, if our prey is in a wall, we won't do
     * anything.  The prey must be in the same room as we are OR
     * we must have a straight shot at him.  Note that
     * shoot_dir must get set before rer is checked so
     * that we get a valid value.
     */
    if (on(*prey, ISINWALL) ||
	((shoot_dir = can_shoot(er, ee)) == NULL &&
	(rer == NULL || rer != ree)))
	return(FALSE);

    /*
     * If we can't see the prey then forget it
     */
    if (on(*prey, ISINVIS) && off(*tp, CANSEE))
	return(FALSE);

    /* How far are we from our prey? */
    dist = DISTANCE(er->y, er->x, ee->y, ee->x);

    /* 
     * Shall we summon aid so we don't have to get our hands dirty? 
     * For now, we will only summon aid against the player.
     * We'll wait until he's within 2 dots of a missile length.
     */
    if (on(*tp, CANSUMMON) && dest_player 			&&
	dist < (BOLT_LENGTH+2)*(BOLT_LENGTH+2)			&&
	rnd(tp->t_summon) < tp->t_stats.s_lvl			&&
	monsters[tp->t_index].m_numsum > 0			&&
	fallpos(&hero, FALSE, 2) != NULL) {
	tp->t_action = A_SUMMON;	/* We're going to summon help */
	tp->t_no_move = movement(tp); /* It takes time! */
	return(TRUE);
    }

    /*
     * If the creature can cast a slow spell and if the prey is within
     * 2 dots of a missile fire, then see whether we will cast it.
     * if next to player, lessen chance because we don't like being
     * disrupted
     */
    if (on(*tp, CANSLOW) && dest_player			&& 
	dist < (BOLT_LENGTH+5)*(BOLT_LENGTH+5)		&&
	rnd(100) < (dist > 3 ? tp->t_cast : tp->t_cast/2)) {
	    tp->t_action = A_SLOW;		/* We're going to slow him */
	    tp->t_no_move = 3 * movement(tp);	/* Takes time! */
	    debug("casting slow spell!");
	    return(TRUE);
    }

    /*
     * If we have a special magic item, we might use it.  We will restrict
     * this options to uniques with relics and creatures with wands for now.  
     * Also check for the quartermaster. Don't want him shooting wands....
     */
    if ((on(*tp, ISUNIQUE) || on(*tp, CARRYSTICK)) && 
	off(*tp, CANSELL) && dest_player	   &&
	m_use_pack(tp, er, ee, dist, shoot_dir)) {
	    return(TRUE);
    }

    /* From now on, we must have a direct shot at the prey */
    if (shoot_dir == NULL) return(FALSE);

    /* We may use a sonic blast if we can, only on the player */
    if (on(*tp, CANSONIC)		&& 
	dest_player			&&
	(dist < BOLT_LENGTH*2)		&&
	(rnd(100) < tp->t_breathe)) {
	tp->t_newpos = *shoot_dir;	/* Save the direction */
	tp->t_action = A_SONIC;	/* We're going to sonic blast */
	tp->t_no_move = 2 * movement(tp); /* Takes 2 movement periods */
    }

    /* If we can breathe, we may do so */
    else if (on(*tp, CANBREATHE)		&&
	 (dist < BOLT_LENGTH*BOLT_LENGTH)	&&
	 (rnd(100) < tp->t_breathe)) {
	    tp->t_newpos = *shoot_dir;	/* Save the direction */
	    tp->t_action = A_BREATHE;	/* We're going to breathe */
	    tp->t_no_move = movement(tp); /* It takes 1 movement period */
    }

    /* 
     * We may shoot missiles if we can 
     * if next to player, lessen chance so we don't get disrupted as often
     */
    else if (on(*tp,CANMISSILE) && 
	     rnd(100) < (dist > 3 ? tp->t_cast : tp->t_cast/2)){
	    tp->t_newpos = *shoot_dir;	/* Save the direction */
	    tp->t_action = A_MISSILE;	/* We're going to shoot MM's */
	    tp->t_no_move = 3 * movement(tp); /* Takes time! */
    }

    /* 
     * If we can shoot or throw something, we might do so.
     * If next to player, then forget it
     */
    else if ((on(*tp,CANSHOOT)		|| on(*tp,CARRYWEAPON) || 
	      on(*tp,CARRYDAGGER)	|| on(*tp, CARRYAXE))		&&
	      dist > 3							&&
	      off(*tp, CANSELL)						&&
	     (weapon = get_hurl(tp))) {
	    tp->t_newpos = *shoot_dir;	/* Save the direction */
	    tp->t_action = A_THROW;	/* We're going to throw something */
	    tp->t_using = weapon;	/* Save our weapon */
	    tp->t_no_move = 2 * movement(tp); /* Takes 2 movement periods */
    }
    
    /* We couldn't find anything to do */
    else return(FALSE);

    return(TRUE);

}

/*
 * runners:
 *	Make all the awake monsters try to do something.
 */

runners(segments)
int segments;    /* Number of segments since last called */
{
    register struct linked_list *item;
    register struct thing *tp = NULL;
    register min_time = 20;	/* Minimum time until a monster can act */

    /*
     * loop thru the list of running (wandering) monsters and see what
     * each one will do this time. 
     *
     * Note: the special case that one of this buggers kills another.
     *	     if this happens than we have to see if the monster killed
     *	     himself or someone else. In case its himself we have to get next
     *	     one immediately. If it wasn't we have to get next one at very
     *	     end in case he killed the next one.
     */

    for (item = mlist; item != NULL; item = next(item))	{
	tp = THINGPTR(item);
	turn_on(*tp, ISREADY);
    }

    for (;;) {

	for (item = mlist; item != NULL; item = next(item)) {
	    tp = THINGPTR(item);

	    if (on(*tp, ISREADY))
		break;
	}

	if (item == NULL)
	    break;

	turn_off(*tp, ISREADY);

	/* If we are not awake, just skip us */
	if (off(*tp, ISRUN) && off(*tp, ISHELD)) continue;

	/* See if it's our turn */
	tp->t_no_move -= segments;
	if (tp->t_no_move > 0) {
	    if (tp->t_no_move < min_time) min_time = tp->t_no_move;
	    continue;
	}

	/* If we were frozen, we're moving now */
	if (tp->t_action == A_FREEZE) tp->t_action = A_NIL;

	if (on(*tp, ISHELD)) {
	    /* Make sure the action and using are nil */
	    tp->t_action = A_NIL;
	    tp->t_using = NULL;

	    /* Can we break free? */
	    if (rnd(tp->t_stats.s_lvl) > 11) {
		turn_off(*tp, ISHELD);
		runto(tp, &hero);
		if (cansee(tp->t_pos.y, tp->t_pos.x))
		    msg("%s breaks free from the hold spell", 
			prname(monster_name(tp), TRUE));
	    }

	    /* Too bad -- try again later */
	    else tp->t_no_move = movement(tp);
	}

	/* Heal the creature if it's not in the middle of some action */
	if (tp->t_action == A_NIL) doctor(tp);

	while (off(*tp,ISELSEWHERE) &&
	    off(*tp,ISDEAD) &&
	       tp->t_no_move <= 0 && off(*tp, ISHELD) && on(*tp, ISRUN)) {
	    /* Let's act (or choose an action if t_action = A_NIL) */
	    m_act(tp);
	}

	if (off(*tp,ISELSEWHERE) && off(*tp,ISDEAD)) {
	    if (tp->t_no_move < min_time) min_time = tp->t_no_move;
	    if (tp->t_quiet < 0) tp->t_quiet = 0;
	}
    }
    return(min_time);
}

/*
 * See if a monster has some magic it can use.  Return TRUE if so.
 * Only care about relics and wands for now.
 */
bool
m_use_pack(monster, monst_pos, defend_pos, dist, shoot_dir)
register struct thing *monster;
register coord *monst_pos, *defend_pos;
register int dist;
register coord *shoot_dir;
{
    register struct object *obj;
    register struct linked_list *pitem, *relic, *stick;
    register int units = -1;

    relic = stick = NULL;

    for (pitem=monster->t_pack; pitem; pitem=next(pitem)) {
	obj = OBJPTR(pitem);
	if (obj->o_flags & ISCURSED) continue;
	if (obj->o_type == RELIC) {
	    switch (obj->o_which) {
		case MING_STAFF:
		    if (shoot_dir != NULL) {
			units = 2;	/* Use 2 time units */
			relic = pitem;
		    }

		when EMORI_CLOAK:
		    if (obj->o_charges != 0	&& 
			shoot_dir != NULL) {
			    units = 2;	/* Use 2 time units */
			    relic = pitem;
		    }

		when ASMO_ROD:
		    /* The bolt must be able to reach the defendant */
		    if (shoot_dir != NULL			&& 
			dist < BOLT_LENGTH * BOLT_LENGTH) {
			units = 2;	/* Use 2 time units */
			relic = pitem;
		    }

		when BRIAN_MANDOLIN:
		    /* The defendant must be the player and within 4 spaces */
		    if (ce(*defend_pos, hero)		&& 
			dist < 25			&&
			player.t_action != A_FREEZE) {
			units = 4;
			relic = pitem;
		    }

		when GERYON_HORN:
		    /* The defendant must be the player and within 5 spaces */
		    if (ce(*defend_pos, hero)				     &&
			dist < 25					     &&
			(off(player,ISFLEE)|| player.t_dest!=&monster->t_pos)) {
			units = 3;
			relic = pitem;
		    }
	    }
	}
	if (obj->o_type == STICK) {
	    if (obj->o_charges < 1) continue;
	    switch(obj->o_which) {
		case WS_ELECT:
		case WS_FIRE:
		case WS_COLD:
		    /* The bolt must be able to reach the defendant */
		    if (shoot_dir != NULL			&& 
			dist < BOLT_LENGTH * BOLT_LENGTH) {
			    units = 3;
			    stick = pitem;
		    }

		when WS_MISSILE:
		case WS_SLOW_M:
		case WS_CONFMON:
		case WS_PARALYZE:
		case WS_MDEG:
		case WS_FEAR:
		    if (shoot_dir != NULL) {
			units = 3;
			stick = pitem;
		    }
		
		otherwise:
		    break;
	    }
	}
    }

    /* use relics in preference to all others */
    if (relic) debug("chance to use relic = %d%%", monster->t_artifact);
    if (stick) debug("chance to use stick = %d%%", monster->t_wand);
    if (relic && rnd(100) < monster->t_artifact)  {
	monster->t_action = A_USERELIC;
	pitem = relic;
    }
    else if (stick && rnd(100) < monster->t_wand) {
	/*
	 * see if the monster will use the wand 
	 */
	pitem = stick;
	monster->t_action = A_USEWAND;
    }
    else {
	return(FALSE);
    }

    monster->t_no_move = units * movement(monster);
    monster->t_using = pitem;
    monster->t_newpos = *shoot_dir;
    return(TRUE);
}