/*
 * monsters.c  -  File with various monster functions in it
 *
 * 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.
 */

/*
 * File with various monster functions in it
 *
 */

#include "curses.h"
#include "rogue.h"
#include <ctype.h>
#include <string.h>
#include <stdlib.h>


/*
 * Check_residue takes care of any effect of the monster 
 */
void
check_residue(struct thing *tp)
{
    /*
     * Take care of special abilities
     */
    if (on(*tp, DIDHOLD) && (--hold_count == 0)) {
	turn_off(player, ISHELD);
        turn_off(*tp, DIDHOLD);
    }

    /* If frightened of this monster, stop */
    if (on(player, ISFLEE) &&
	player.t_dest == &tp->t_pos) turn_off(player, ISFLEE);

    /* If monster was suffocating player, stop it */
    if (on(*tp, DIDSUFFOCATE)) {
	extinguish(suffocate);
	turn_off(*tp, DIDSUFFOCATE);
    }

    /* If something with fire, may darken */
    if (on(*tp, HASFIRE)) {
	register struct room *rp=roomin(&tp->t_pos);
	register struct linked_list *fire_item;

	if (rp) {
	    for (fire_item = rp->r_fires; fire_item != NULL;
		 fire_item = next(fire_item)) {
		if (THINGPTR(fire_item) == tp) {
		    detach(rp->r_fires, fire_item);
		    destroy_item(fire_item);
		    if (rp->r_fires == NULL) {
			rp->r_flags &= ~HASFIRE;
			if (cansee(tp->t_pos.y, tp->t_pos.x)) light(&hero);
		    }
		    break;
		}
	    }
	}
    }
}

/*
 * Creat_mons creates the specified monster -- any if 0 
 * person: Where to create next to
 */

bool
creat_mons(struct thing *person, short monster, bool report)
{
    struct linked_list *nitem;
    register struct thing *tp;
    struct room *rp;
    coord *mp;

    if (levtype == POSTLEV)
	return(FALSE);
    if ((mp = fallpos(&(person->t_pos), FALSE, 2)) != NULL) {
	nitem = new_item(sizeof (struct thing));
	new_monster(nitem,
		    monster == 0 ? randmonster(FALSE, FALSE)
				 : monster,
		    mp,
		    TRUE);
	tp = THINGPTR(nitem);
	runto(tp, &hero);
	carry_obj(tp, monsters[tp->t_index].m_carry/2); /* only half chance */

	/* since it just got here, it is disoriented */
	tp->t_no_move = 2 * movement(tp);

	if (on(*tp, HASFIRE)) {
	    rp = roomin(&tp->t_pos);
	    if (rp) {
		register struct linked_list *fire_item;

		/* Put the new fellow in the room list */
		fire_item = creat_item();
		ldata(fire_item) = (char *) tp;
		attach(rp->r_fires, fire_item);

		rp->r_flags |= HASFIRE;
	    }
	}

	/* 
	 * If we can see this monster, set oldch to ' ' to make light()
	 * think the creature used to be invisible (ie. not seen here)
	 */
	if (cansee(tp->t_pos.y, tp->t_pos.x)) tp->t_oldch = ' ';
	return(TRUE);
    }
    if (report) msg("You hear a faint cry of anguish in the distance.");
    return(FALSE);
}

/*
 * Genmonsters:
 *	Generate at least 'least' monsters for this single room level.
 *	'Treas' indicates whether this is a "treasure" level.
 */

void
genmonsters(int least, bool treas)
{
    reg int i;
    reg struct room *rp = &rooms[0];
    reg struct linked_list *item;
    reg struct thing *mp;
    coord tp;

    for (i = 0; i < level + least; i++) {
	    if (!treas && rnd(100) < 50)	/* put in some little buggers */
		    continue;
	    /*
	     * Put the monster in
	     */
	    item = new_item(sizeof *mp);
	    mp = THINGPTR(item);
	    do {
		    rnd_pos(rp, &tp);
	    } until(mvwinch(stdscr, tp.y, tp.x) == FLOOR);

	    new_monster(item, randmonster(FALSE, FALSE), &tp, FALSE);
	    /*
	     * See if we want to give it a treasure to carry around.
	     */
	    carry_obj(mp, monsters[mp->t_index].m_carry);

	    /* Calculate a movement rate */
	    mp->t_no_move = movement(mp);

	    /* Is it going to give us some light? */
	    if (on(*mp, HASFIRE)) {
		register struct linked_list *fire_item;

		fire_item = creat_item();
		ldata(fire_item) = (char *) mp;
		attach(rp->r_fires, fire_item);
		rp->r_flags |= HASFIRE;
	    }
    }
}

/*
 * id_monst returns the index of the monster given its letter
 */

short
id_monst(char monster)
{
    register short result;

    result = NLEVMONS*vlevel;
    if (result > NUMMONST) result = NUMMONST;

    for(; result>0; result--)
	if (monsters[result].m_appear == monster) return(result);
    for (result=(NLEVMONS*vlevel)+1; result <= NUMMONST; result++)
	if (monsters[result].m_appear == monster) return(result);
    return(0);
}


/*
 * new_monster:
 *	Pick a new monster and add it to the list
 */

void
new_monster(struct linked_list *item, short type, coord *cp, bool max_monster)
{
    register struct thing *tp;
    register struct monster *mp;
    register char *ip, *hitp;
    register int i, min_intel, max_intel;
    register int num_dice, num_sides=8, num_extra=0;

    attach(mlist, item);
    tp = THINGPTR(item);
    tp->t_pack = NULL;
    tp->t_index = type;
    tp->t_wasshot = FALSE;
    tp->t_type = monsters[type].m_appear;
    tp->t_ctype = C_MONSTER;
    tp->t_action = A_NIL;
    tp->t_doorgoal = 0;
    tp->t_quiet = 0;
    tp->t_dest = NULL;
    tp->t_name = NULL;
    tp->t_pos = tp->t_oldpos = *cp;
    tp->t_oldch = CCHAR( mvwinch(cw, cp->y, cp->x) );
    mvwaddch(mw, cp->y, cp->x, tp->t_type);
    mp = &monsters[tp->t_index];

    /* Figure out monster's hit points */
    hitp = mp->m_stats.s_hpt;
    num_dice = atoi(hitp);
    if ((hitp = strchr(hitp, 'd')) != NULL) {
	num_sides = atoi(++hitp);
	if ((hitp = strchr(hitp, '+')) != NULL)
	    num_extra = atoi(++hitp);
    }

    tp->t_stats.s_lvladj = 0;
    tp->t_stats.s_lvl = mp->m_stats.s_lvl;
    tp->t_stats.s_arm = mp->m_stats.s_arm;
    strncpy(tp->t_stats.s_dmg, mp->m_stats.s_dmg, sizeof(tp->t_stats.s_dmg));
    tp->t_stats.s_str = mp->m_stats.s_str;
    tp->t_stats.s_dext = mp->m_stats.s_dex;
    tp->t_movement = mp->m_stats.s_move;
    if (vlevel > HARDER) { /* the deeper, the meaner we get */
	 tp->t_stats.s_lvl += (vlevel - HARDER);
	 num_dice += (vlevel - HARDER)/2;
	 tp->t_stats.s_arm -= (vlevel - HARDER) / 4;
    }
    if (max_monster)
	tp->t_stats.s_hpt = num_dice * num_sides + num_extra;
    else
	tp->t_stats.s_hpt = roll(num_dice, num_sides) + num_extra;
    tp->t_stats.s_exp = mp->m_stats.s_exp + mp->m_add_exp*tp->t_stats.s_hpt;

    /*
     * just initailize others values to something reasonable for now
     * maybe someday will *really* put these in monster table
     */
    tp->t_stats.s_wisdom = 8 + rnd(4);
    tp->t_stats.s_const = 8 + rnd(4);
    tp->t_stats.s_charisma = 8 + rnd(4);

    /* Set the initial flags */
    for (i=0; i<16; i++) tp->t_flags[i] = 0;
    for (i=0; i<MAXFLAGS; i++)
	turn_on(*tp, mp->m_flags[i]);

    /*
     * these are the base chances that a creatures will do something
     * assuming it can. These are(or can be) modified at runtime
     * based on what the creature experiences
     */
    tp->t_breathe = 75;		/* base chance of breathing */
    tp->t_artifact = 90;	/* base chance of using artifact */
    tp->t_summon = 40;		/* base chance of summoning */
    tp->t_cast = 75;		/* base chance of casting a spell */
    tp->t_wand = on(*tp, ISUNIQUE) ? 35 : 50;	/* base chance of using wands */

    /* suprising monsters don't always surprise you */
    if (!max_monster		&& on(*tp, CANSURPRISE) && 
	off(*tp, ISUNIQUE)	&& rnd(100) < 20)
	    turn_off(*tp, CANSURPRISE);

    /* If this monster is unique, gen it */
    if (on(*tp, ISUNIQUE)) mp->m_normal = FALSE;

    /* 
     * If it is the quartermaster, then compute his level and exp pts
     * based on the level. This will make it fair when thieves try to
     * steal and give them reasonable experience if they succeed.
     * Then fill his pack with his wares.
     */
    if (on(*tp, CANSELL)) {	
	tp->t_stats.s_exp = vlevel * 100;
	tp->t_stats.s_lvl = vlevel/2 + 1;
	make_sell_pack(tp);
    }

    /* Normally scared monsters have a chance to not be scared */
    if (on(*tp, ISFLEE) && (rnd(4) == 0)) turn_off(*tp, ISFLEE);

    /* Figure intelligence */
    min_intel = atoi(mp->m_intel);
    if ((ip = (char *) strchr(mp->m_intel, '-')) == NULL)
	tp->t_stats.s_intel = min_intel;
    else {
	max_intel = atoi(++ip);
	if (max_monster)
	    tp->t_stats.s_intel = max_intel;
	else
	    tp->t_stats.s_intel = min_intel + rnd(max_intel - min_intel);
    }
    if (vlevel > HARDER) 
	 tp->t_stats.s_intel += ((vlevel - HARDER)/2);
    tp->maxstats = tp->t_stats;

    /* If the monster can shoot, it may have a weapon */
    if (on(*tp, CANSHOOT) && ((rnd(100) < (22 + vlevel)) || max_monster)) {
	struct linked_list *item1;
	register struct object *cur, *cur1;

	item = new_item(sizeof *cur);
	item1 = new_item(sizeof *cur1);
	cur = OBJPTR(item);
	cur1 = OBJPTR(item1);
	cur->o_hplus = (rnd(4) < 3) ? 0
				    : (rnd(3) + 1) * ((rnd(3) < 2) ? 1 : -1);
	cur->o_dplus = (rnd(4) < 3) ? 0
				    : (rnd(3) + 1) * ((rnd(3) < 2) ? 1 : -1);
	cur1->o_hplus = (rnd(4) < 3) ? 0
				    : (rnd(3) + 1) * ((rnd(3) < 2) ? 1 : -1);
	cur1->o_dplus = (rnd(4) < 3) ? 0
				    : (rnd(3) + 1) * ((rnd(3) < 2) ? 1 : -1);

        strncpy(cur->o_damage, "0d0", sizeof(cur->o_damage));  
	strncpy(cur->o_hurldmg, "0d0", sizeof(cur->o_hurldmg));  
	strncpy(cur1->o_damage, "0d0", sizeof(cur1->o_damage));  
	strncpy(cur1->o_hurldmg, "0d0", sizeof(cur1->o_hurldmg));  

	cur->o_ac = cur1->o_ac = 11;
	cur->o_count = cur1->o_count = 1;
	cur->o_group = cur1->o_group = 0;
	cur->contents = cur1->contents = NULL;
	if ((cur->o_hplus <= 0) && (cur->o_dplus <= 0)) cur->o_flags = ISCURSED;
	if ((cur1->o_hplus <= 0) && (cur1->o_dplus <= 0))
	    cur1->o_flags = ISCURSED;
	cur->o_flags = cur1->o_flags = 0;
	cur->o_type = cur1->o_type = WEAPON;
	cur->o_mark[0] = cur1->o_mark[0] = '\0';

	/* The monster may use a crossbow, sling, or an arrow */
	i = rnd(100);
	if (i < 10) {
	    cur->o_which = CROSSBOW;
	    cur1->o_which = BOLT;
	    init_weapon(cur, CROSSBOW);
	    init_weapon(cur1, BOLT);
	}
	else if (i < 70) {
	    cur->o_which = BOW;
	    cur1->o_which = ARROW;
	    init_weapon(cur, BOW);
	    init_weapon(cur1, ARROW);
	}
	else {
	    cur->o_which = SLING;
	    cur1->o_which = ROCK;
	    init_weapon(cur, SLING);
	    init_weapon(cur1, ROCK);
	}

	attach(tp->t_pack, item);
	attach(tp->t_pack, item1);
    }


    /* Calculate the initial movement rate */
    updpack(TRUE, tp);
    tp->t_no_move = movement(tp);

    if (ISWEARING(R_AGGR))
	runto(tp, &hero);
    if (on(*tp, ISDISGUISE))
    {
	char mch;

	if (tp->t_pack != NULL)
	    mch = (OBJPTR(tp->t_pack))->o_type;
	else
	    switch (rnd(10)) {
		case 0: mch = GOLD;
		when 1: mch = POTION;
		when 2: mch = SCROLL;
		when 3: mch = FOOD;
		when 4: mch = WEAPON;
		when 5: mch = ARMOR;
		when 6: mch = RING;
		when 7: mch = STICK;
		when 8: mch = monsters[randmonster(FALSE, FALSE)].m_appear;
		when 9: mch = MM;
	    }
	tp->t_disguise = mch;
    }
}

/*
 * randmonster:
 *	Pick a monster to show up.  The lower the level,
 *	the meaner the monster.
 */

short
randmonster(bool wander, bool no_unique)
{
    register int d, cur_level, range, i; 

    /* 
     * Do we want a merchant? Merchant is always in place 'NUMMONST' 
     */
    if (wander && monsters[NUMMONST].m_wander && rnd(100) < pstats.s_charisma/4)
	return NUMMONST;

    cur_level = vlevel;
    range = 4*NLEVMONS;
    i = 0;
    do
    {
	if (i++ > range*10) { /* just in case all have be genocided */
	    i = 0;
	    if (--cur_level <= 0)
		fatal("Rogue could not find a monster to make");
	}
	d = NLEVMONS*(cur_level - 1) + (rnd(range) - (range - 1 - NLEVMONS));
	if (d < 1)
	    d = rnd(NLEVMONS) + 1;
	if (d > NUMMONST - NUMUNIQUE - 1) {
	    if (no_unique)
		d = rnd(range) + (NUMMONST - NUMUNIQUE - 1) - (range - 1);
	    else if (d > NUMMONST - 1)
		d = rnd(range+NUMUNIQUE) + (NUMMONST-1) - (range+NUMUNIQUE-1);
	}
    }
    while  (wander ? !monsters[d].m_wander || !monsters[d].m_normal 
		   : !monsters[d].m_normal);
    return d;
}

/* Sell displays a menu of goods from which the player may choose
 * to purchase something.
 */

void
sell(struct thing *tp)
{
    register struct linked_list *item, *seller;
    register struct linked_list *sellpack;
    register struct object *obj;
    register int worth, min_worth;
    char buffer[LINELEN];


    /*
     * Get a linked_list pointer to the seller.  We need this in case
     * he disappears so we can set monst_dead.
     */
    seller = find_mons(tp->t_pos.y, tp->t_pos.x);

    sellpack = tp->t_pack;
    if (sellpack == NULL) {
	msg("%s looks puzzled and departs.", prname(monster_name(tp), TRUE));

	/* Get rid of the monster */
	killed(seller, FALSE, FALSE, FALSE);
	return;
    }

    /* See how much the minimum pack item is worth */
    min_worth = 100000;
    for (item = sellpack; item != NULL; item = next(item)) {
	obj = OBJPTR(item);
	obj->o_flags |= ISPOST;	/* Force a long description of the item */
	worth = get_worth(obj);
	if (worth < min_worth) min_worth = worth;
    }

    /* See if player can afford an item */
    if (min_worth > purse) {
	msg("%s eyes your small purse and departs.", 
	    prname(monster_name(tp), TRUE));

	/* Get rid of the monster */
	killed(seller, FALSE, FALSE, FALSE);
	return;
    }

    /* Announce our intentions */
    msg("%s opens his pack.--More--", prname(monster_name(tp), TRUE));
    wait_for(' ');

    /* Try to sell something */
    sprintf(buffer, "You got %d gold pieces.  Buy", purse);
    item = get_item(sellpack, buffer, ALL, TRUE, TRUE);

    /* Get rid of the monster */
    if (item != NULL) detach(tp->t_pack, item);	/* Take it out of the pack */
    killed(seller, FALSE, FALSE, FALSE);

    if (item == NULL) return;

    /* Can he afford the selected item? */
    obj = OBJPTR(item);

    worth = get_worth(obj);
    if (worth > purse) {
	msg("You cannot afford it.");
	o_discard(item);
	return;
    }

    /* Charge him through the nose */
    purse -= worth;

    /* If a stick or ring, let player know the type */
    switch (obj->o_type) {
	case RING:  r_know[obj->o_which] = TRUE;
	when POTION:p_know[obj->o_which] = TRUE;
	when SCROLL:s_know[obj->o_which] = TRUE;
	when STICK: ws_know[obj->o_which] = TRUE;
	when MM:    m_know[obj->o_which] = TRUE;

    }

    /* Remove the POST flag that we used for get_item() */
    obj->o_flags &= ~ISPOST;

    if (add_pack(item, FALSE, NULL) == FALSE) {
	obj->o_pos = hero;
	fall(item, TRUE);
    }
}



/*
 * what to do when the hero steps next to a monster
 */
struct linked_list *
wake_monster(int y, int x)
{
    register struct thing *tp;
    register struct linked_list *it;
    register struct room *trp;
    register char *mname;
    bool nasty;	/* Will the monster "attack"? */

    if ((it = find_mons(y, x)) == NULL) {
	msg("Wake:  can't find monster in show (%d, %d)", y, x);
	return (NULL);
    }
    tp = THINGPTR(it);
    if (on(*tp, ISSTONE)) /* if stoned, don't do anything */
	return it;

    /*
     * For now, if we are a friendly monster, we won't do any of
     * our special effects.
     */
    if (on(*tp, ISFRIENDLY)) return it;

    trp = roomin(&tp->t_pos); /* Current room for monster */

    /*
     * Let greedy ones in a room guard gold
     * (except in a maze where lots of creatures would all go for the 
     * same piece of gold)
     */
    if (on(*tp, ISGREED)	&& off(*tp, ISRUN)	&& 
	levtype != MAZELEV	&& trp != NULL		&&
	lvl_obj != NULL) {
	    register struct linked_list *item;
	    register struct object *cur;

	    for (item = lvl_obj; item != NULL; item = next(item)) {
		cur = OBJPTR(item);
		if ((cur->o_type == GOLD) && (roomin(&cur->o_pos) == trp)) {
		    /* Run to the gold */
		    runto(tp, &cur->o_pos);

		    /* Make it worth protecting */
		    cur->o_count += GOLDCALC + GOLDCALC;
		    break;
		}
	    }
    }

    /*
     * Every time he sees mean monster, it might start chasing him
     */
    if (on(*tp, ISMEAN)							&& 
	off(*tp, ISHELD)						&& 
	off(*tp, ISRUN)							&& 
	rnd(100) > 33							&& 
	(!is_stealth(&player) || (on(*tp, ISUNIQUE) && rnd(100) > 50))	&&
	(off(player, ISINVIS) || on(*tp, CANSEE))			||
	(trp != NULL && (trp->r_flags & ISTREAS))) {
	runto(tp, &hero);
    }

    /*
     * Get the name; we don't want to do it until here because we need to
     * know whether the monster is still sleeping or not.
     */
    mname = monster_name(tp);

    /* See if the monster will bother the player */
    nasty = (on(*tp, ISRUN) && cansee(tp->t_pos.y, tp->t_pos.x));

    /*
     * if the creature is awake and can see the player and the
     * player has the dreaded "eye of vecna" then see if the
     * creature is turned to stone
     */
    if (cur_relic[EYE_VECNA] && nasty && off(*tp, NOSTONE) &&
	(off(player, ISINVIS) || on(*tp, CANSEE))) {
	turn_on(*tp, NOSTONE);	/* only have to save once */
	if (!save(VS_PETRIFICATION, tp, -2)) {
		turn_on(*tp, ISSTONE);
		turn_off(*tp, ISRUN);
		turn_off(*tp, ISINVIS);
		turn_off(*tp, CANSURPRISE);
		turn_off(*tp, ISDISGUISE);
		msg("%s is turned to stone!", prname(mname, TRUE));
		return it;
	}
    }

    /* 
     * Handle monsters that can gaze and do things while running
     * Player must be able to see the monster and the monster must 
     * not be asleep 
     */
    if (nasty && !invisible(tp)) {
	/*
	 * Confusion
	 */
	if (on(*tp, CANHUH)				 &&
	   (off(*tp, ISINVIS)     || on(player, CANSEE)) &&
	   (off(*tp, CANSURPRISE) || ISWEARING(R_ALERT))) {
	    if (!save(VS_MAGIC, &player, 0)) {
		if (off(player, ISCLEAR)) {
		    if (find_slot(unconfuse))
			lengthen(unconfuse, HUHDURATION);
		    else {
			fuse(unconfuse, NULL, HUHDURATION, AFTER);
			msg("%s's gaze has confused you.",prname(mname, TRUE));
			turn_on(player, ISHUH);
		    }
		}
		else msg("You feel dizzy for a moment, but it quickly passes.");
	    }
	    else if (rnd(100) < 67)
		turn_off(*tp, CANHUH); /* Once you save, maybe that's it */
	}

	/* Sleep */
	if(on(*tp, CANSNORE) &&  
	   player.t_action != A_FREEZE && 
	   !save(VS_PARALYZATION, &player, 0)) {
	    if (ISWEARING(R_ALERT))
		msg("You feel slightly drowsy for a moment.");
	    else {
		msg("%s's gaze puts you to sleep.", prname(mname, TRUE));
		player.t_no_move += movement(&player) * SLEEPTIME;
		player.t_action = A_FREEZE;
		if (rnd(100) < 50) turn_off(*tp, CANSNORE);
	    }
	}

	/* Fear */
	if (on(*tp, CANFRIGHTEN) && !on(player, ISFLEE)) {
	    turn_off(*tp, CANFRIGHTEN);
	    if (!ISWEARING(R_HEROISM) && 
		!save(VS_WAND, &player, -(tp->t_stats.s_lvl/10))) {
		    turn_on(player, ISFLEE);
		    player.t_dest = &tp->t_pos;
		    msg("The sight of %s terrifies you.", prname(mname, FALSE));
	    }
	}

	/* blinding creatures */
	if(on(*tp, CANBLIND) && !find_slot(sight)) {
	    turn_off(*tp, CANBLIND);
	    if (!save(VS_WAND, &player, 0)) {
		msg("The gaze of %s blinds you", prname(mname, FALSE));
		turn_on(player, ISBLIND);
		fuse(sight, NULL, rnd(30)+20, AFTER);
		light(&hero);
	    }
	}

	/* the sight of the ghost can age you! */
	if (on(*tp, CANAGE)) { 
	    turn_off (*tp, CANAGE);
	    if (!save(VS_MAGIC, &player, 0)) {
		msg ("The sight of %s ages you!", prname(mname, FALSE));
		pstats.s_const--;
		max_stats.s_const--;
		if (pstats.s_const < 0)
		    death (D_CONSTITUTION);
	    }
	}


	/* Turning to stone */
	if (on(*tp, LOOKSTONE)) {
	    turn_off(*tp, LOOKSTONE);

	    if (on(player, CANINWALL))
		msg("The gaze of %s has no effect.", prname(mname, FALSE));
	    else {
		if (!save(VS_PETRIFICATION, &player, 0) && rnd(100) < 5) {
		    pstats.s_hpt = -1;
		    msg("The gaze of %s petrifies you.", prname(mname, FALSE));
		    msg("You are turned to stone !!! --More--");
		    wait_for(' ');
		    death(D_PETRIFY);
		}
		else {
		    msg("The gaze of %s stiffens your limbs.", 
			prname(mname, FALSE));
		    player.t_no_move += movement(&player) * STONETIME;
		    player.t_action = A_FREEZE;
		}
	    }
	}
    }

    return it;
}
/*
 * wanderer:
 *	A wandering monster has awakened and is headed for the player
 */

void
wanderer(void)
{
    register int i;
    register struct room *hr = roomin(&hero);
    register struct linked_list *item;
    register struct thing *tp;
    register long *attr;	/* Points to monsters' attributes */
    int carry;	/* Chance of wanderer carrying anything */
    short rmonst;	/* Our random wanderer */
    bool canteleport = FALSE,	/* Can the monster teleport? */
	 seehim;	/* Is monster within sight? */
    coord cp;

    rmonst = randmonster(TRUE, FALSE);	/* Choose a random wanderer */
    attr = &monsters[rmonst].m_flags[0]; /* Start of attributes */
    for (i=0; i<MAXFLAGS; i++)
	if (*attr++ == CANTELEPORT) {
	    canteleport = TRUE;
	    break;
	}

    /* Find a place for it -- avoid the player's room if can't teleport */
    do {
	do {
	    i = rnd_room();
	} until (canteleport || hr != &rooms[i] || levtype == MAZELEV ||
		 levtype == OUTSIDE || levtype == POSTLEV);

	/* Make sure the monster does not teleport on top of the player */
	do {
	    rnd_pos(&rooms[i], &cp);
	} while (hr == &rooms[i] && ce(cp, hero));
    } until (step_ok(cp.y, cp.x, NOMONST, NULL));

    /* Create a new wandering monster */
    item = new_item(sizeof *tp);
    new_monster(item, rmonst, &cp, FALSE);
    tp = THINGPTR(item);
    runto(tp, &hero);
    tp->t_pos = cp;	/* Assign the position to the monster */
    seehim = cansee(tp->t_pos.y, tp->t_pos.x);
    if (on(*tp, HASFIRE)) {
	register struct room *rp;

	rp = roomin(&tp->t_pos);
	if (rp) {
	    register struct linked_list *fire_item;

	    fire_item = creat_item();
	    ldata(fire_item) = (char *) tp;
	    attach(rp->r_fires, fire_item);

	    rp->r_flags |= HASFIRE;
	    if (seehim && next(rp->r_fires) == NULL)
		light(&hero);
	}
    }

    /* See if we give the monster anything */
    carry = monsters[tp->t_index].m_carry;
    if (off(*tp, ISUNIQUE)) carry /= 2;	/* Non-unique has only a half chance */
    carry_obj(tp, carry);

    /* Calculate its movement rate */
    tp->t_no_move = movement(tp);

    /* Alert the player if a monster just teleported in */
    if (hr == &rooms[i] && canteleport && seehim && !invisible(tp)) {
	msg("A %s just teleported in", monster_name(tp));
	light(&hero);
	running = FALSE;
    }

    if (wizard)
	msg("Started a wandering %s", monster_name(tp));
}
