nexus/ai.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "ai.h"
#include "attack.h"
#include "defs.h"
#include "flag.h"
#include "io.h"
#include "lf.h"
#include "map.h"
#include "move.h"
#include "nexus.h"
#include "objects.h"
#include "spell.h"
#include "text.h"

extern lifeform_t *player;
extern enum ERROR reason;

int wantdb = B_TRUE;

void aiattack(lifeform_t *lf, lifeform_t *victim, int timelimit) {
	int db = B_FALSE;
	flag_t *f;

	if (lfhasflag(lf, F_DEBUG)) {
		db = B_TRUE;
	}

	// already targetting this lf?
	f = lfhasflagval(lf, F_TARGET, victim->id, NA, NA, NULL);
	if (f) {
		if ((f->lifetime > 0) && (f->lifetime < timelimit)) {
			f->lifetime = timelimit;
		}
		return;
	}

	if (db) {
		char lfname[BUFLEN],vicname[BUFLEN];
		getlfname(lf, lfname);
		getlfname(victim, vicname);
		dblog(".oO { %s settings new target:  %s }", lfname, vicname);
	}

	killflagsofid(lf->flags, F_TARGET);
	killflagsofid(lf->flags, F_TARGETCELL);


	if ((timelimit == PERMENANT) || (timelimit == UNLIMITED)) {
		addflag(lf->flags, F_TARGET, victim->id, victim->cell->x,  victim->cell->y, NULL);
	} else {
		addtempflag(lf->flags, F_TARGET, victim->id , victim->cell->x ,  victim->cell->y, NULL,timelimit);
	}
	// tell the player
	if (cansee(player, lf)) {
		makenoise(lf, N_GETANGRY);
	}

	// change allegience ?
	if (!areenemies(lf, victim)) {
		if (getallegiance(victim) == AL_FRIENDLY) {
			if (!hasflag(lf->flags, F_HOSTILE)) {
				addflag(lf->flags, F_HOSTILE, B_TRUE, NA, NA, NULL);
			}
		}
	}

}

enum OBTYPE aigetattackspell(lifeform_t *lf, lifeform_t *victim) {
	flag_t *f;
	enum OBTYPE poss[MAXPILEOBS];
	int nposs = 0;
	int db = B_FALSE;

	if (lfhasflag(lf, F_DEBUG)) {
		db = B_TRUE;
	}

	for (f = lf->flags->first ; f ; f = f->next) {
		if ((f->id == F_CANCAST) || (f->id == F_CANWILL)) {
			if (aispellok(lf, f->val[0], victim, F_AICASTTOATTACK)) {
				poss[nposs] = f->val[0];
				nposs++;
			}
		}
	}

	// select a random one
	if (nposs > 0) {
		int sel;
		sel = rnd(0,nposs-1);
		return poss[sel];
	}
	
	return OT_NONE;
}

enum OBTYPE aigetfleespell(lifeform_t *lf) {
	flag_t *f;
	enum OBTYPE poss[MAXPILEOBS];
	int nposs = 0;
	int db = B_FALSE;
	lifeform_t *fleefrom;

	if (lfhasflag(lf, F_DEBUG)) {
		db = B_TRUE;
	}

	f = lfhasflag(lf, F_FLEEFROM);
	if (f) {
		fleefrom = findlf(lf->cell->map, f->val[0]);
	}
	

	for (f = lf->flags->first ; f ; f = f->next) {
		if ((f->id == F_CANCAST) || (f->id == F_CANWILL)) {
			if (aispellok(lf, f->val[0], fleefrom, F_AICASTTOFLEE)) {
				poss[nposs] = f->val[0];
				nposs++;
			}
		}
	}

	// select a random one
	if (nposs > 0) {
		int sel;
		sel = rnd(0,nposs-1);
		return poss[sel];
	}
	
	return OT_NONE;
}

void aigetspelltarget(lifeform_t *lf, objecttype_t *spelltype, lifeform_t *victim, lifeform_t **spelllf, cell_t **spellcell, object_t **spellob, enum FLAG purpose) {
	int specialcase = B_FALSE;
	flag_t *f;

	// default - at victim.
	if (spelllf) *spelllf = victim;
	if (spellcell) *spellcell = victim->cell;
	if (spellob) *spellob = NULL;

	f = hasflag(spelltype->flags, purpose);
	if (f) {
		switch (f->val[0]) {
			case ST_VICTIM:
				// at victim.
				if (spelllf) *spelllf = victim;
				if (spellcell) *spellcell = victim->cell;
				if (spellob) *spellob = NULL;
				break;
			case ST_ADJSELF: // cast at myself when next to victim
				if (getcelldist(lf->cell, victim->cell) <= 1) {
					if (spelllf) *spelllf = lf;
					if (spellcell) *spellcell = lf->cell;
					if (spellob) *spellob = NULL;
				}
				break;
			case ST_ADJVICTIM: // cast at victim when next to victim
				if (getcelldist(lf->cell, victim->cell) <= 1) {
					if (spelllf) *spelllf = victim;
					if (spellcell) *spellcell = victim->cell;
					if (spellob) *spellob = NULL;
				}
				break;
			case ST_SELF:
				if (spelllf) *spelllf = lf;
				if (spellcell) *spellcell = lf->cell;
				if (spellob) *spellob = NULL;
				break;
			case ST_ANYWHERE:
				if (spelllf) *spelllf = NULL;
				if (spellcell) *spellcell = NULL;
				if (spellob) *spellob = NULL;
				break;
			case ST_SPECIAL:
				specialcase = B_TRUE;
				break;
		}
		
		if (specialcase) {
			if (spelltype->id == OT_S_TELEKINESIS) {
				float maxweight;
				object_t *poss[MAXPILEOBS];
				int nposs;
				int i;
				// find nearest object which can be picked up 

				// this is copied out of the telekenesis spell code!
				maxweight = getlfweight(lf, B_NOOBS) + 
					(getlfweight(lf, B_NOOBS) * (getstatmod(lf, A_IQ) / 100));

				nposs = 0;
				for (i = 0; i < lf->nlos; i++) {
					object_t *o;
					for (o = lf->los[i]->obpile->first ; o ; o = o->next) {
						if (!hasflag(o->flags, F_NOPICKUP) &&
							getobweight(o) <= maxweight) {
							poss[nposs] = o;
							nposs++;
							if (nposs >= MAXPILEOBS) break;
						}
					}
					if (nposs >= MAXPILEOBS) break;
				}
				// should always be true since we check this in aispellok
				if (nposs > 0) {
					if (spellob) *spellob = poss[rnd(0,nposs-1)];
				}

				// cast spell at the victim
				if (spelllf) *spelllf = victim;
				if (spellcell) *spellcell = victim->cell;
			} else if (spelltype->id == OT_S_CHARM) {
				lifeform_t *l;
				l = getnearbypeaceful(lf);
				if (l) {
					if (spelllf) *spelllf = l;
					if (spellcell) *spellcell = l->cell;
					if (spellob) *spellob = NULL;
				}
			}
		}
	}
}

object_t *aigetwand(lifeform_t *lf, enum FLAG purpose) {
	object_t *o;
	object_t *poss[MAXPILEOBS];
	int nposs = 0;
	for (o = lf->pack->first ; o ; o = o->next) {
		// wand with charges left?
		if ((o->type->obclass->id == OC_WAND) && (getcharges(o) > 0)) {
			// do we know how to use it? 
			if (hasflag(o->flags, purpose)) {
				// TODO: if castatself, check whether we actually need to (ie. healing, invis, etc)
				poss[nposs] = o;
				nposs++;
			}
		}
	}
	if (nposs > 0) {
		return poss[rnd(0,nposs-1)];
	}
	return NULL;
}

void aigoto(lifeform_t *lf, cell_t *c, int timelimit) {
	int db = B_FALSE;

	if (lfhasflag(lf, F_DEBUG)) {
		db = B_TRUE;
	}

	if (db) {
		char lfname[BUFLEN];
		getlfname(lf, lfname);
		dblog(".oO { %s going to targecell:  %d, %d }", lfname, c->x, c->y);
	}

	killflagsofid(lf->flags, F_TARGET);
	killflagsofid(lf->flags, F_TARGETCELL);


	if ((timelimit == PERMENANT) || (timelimit == UNLIMITED)) {
		addflag(lf->flags, F_TARGETCELL, c->x, c->y, NA, NULL);
	} else {
		addtempflag(lf->flags, F_TARGETCELL, c->x, c->y, NA, NULL,timelimit);
	}
}

void aimove(lifeform_t *lf) {
	int db = B_FALSE;
	object_t *curwep,*bestwep, *o;
	object_t *curgun,*bestgun;
	flag_t *f;
	//flag_t *nextf;
	// lifeform_t *fleefrom = NULL;
	lifeform_t *target;
	enum BODYPART bp;
	int x,y;
	cell_t *c;
	obpile_t *unarmedpile = NULL;
	flag_t *unarmedflag = NULL;



	/*
	if (wantdb && haslos(player, lf->cell)) {
		db = B_TRUE;
	} else {
		db = B_FALSE;
	}
	*/

	if (wantdb && lfhasflag(lf, F_DEBUG)) {
		db = B_TRUE;
	} else {
		db = B_FALSE;
	}

	if (db) {
		char lfname[BUFLEN];
		real_getlfname(lf, lfname, B_FALSE);
		dblog("AIMOVE:  %s", lfname);
	}

	/*
	// if lifeform isn't alive, skip turn
	if (isdead(lf)) {
		if (db) dblog(".oO { i am not alive, skipping turn. }");
		taketime(lf, SPEED_DEAD);
		return;
	}
	*/



	// do we have a better weapon we could use?
	curwep = getweapon(lf);
	bestwep = getbestweapon(lf);

	if (curwep != bestwep) {
		if (db) dblog(".oO { i have a better weapon than my current one (%s > %s) }",bestwep->type->name, curwep ? curwep->type->name : "nothing");
		// weild better one
		if (!weild(lf, bestwep)) return;
	}

	// do we have a better firearm ?
	curgun = getfirearm(lf);
	bestgun = getbestfirearm(lf);

	if (curgun != bestgun) {
		if (db) dblog(".oO { i have a better gun than my current one (%s > %s) }",bestgun->type->name, curgun ? curgun->type->name : "nothing");
		// weild better one
		if (!weild(lf, bestgun)) return;
	}

	// do we have better ammo?
	if (curgun) {
		object_t *curammo;
		curammo = getammo(lf);
		if (!curammo) {
			for (o = lf->pack->first ; o ; o = o->next) {
				testammo(lf, o); // doesn't take any time.
				if (getammo(lf)) break;
			}
		}
	}

	// do we have better armour?
	for (bp = BP_RIGHTHAND ; bp < MAXBODYPARTS; bp++) {
		object_t *curarm;
		curarm = getarmour(lf, bp);
		// do we have a better one?
		for (o = lf->pack->first ; o ; o = o->next) {
			if (canwear(lf, o, BP_NONE) && isbetterarmourthan(o, curarm)) {
				// wear this armour instead
				if (!wear(lf, o)) return;
			} 
		}
	}


	// now check whetehr we have ANY weapon
	curwep = getattackwep(lf, &unarmedpile, &unarmedflag);
	if (unarmedpile) killobpile(unarmedpile);

	// before attacking targets, 
	// look for any object which we _covet_.
	// ie. if we covet something, we will pick it up
	// instead of attacking our target.
	if (db) dblog(".oO { looking for covetted objects... }");
	if (lookforobs(lf, B_COVETS)) {
		if (db) dblog(".oO { found covetted object. returning. }");
		return;
	}
	
	// do we already have a target we are attacking?
	f = hasflag(lf->flags, F_TARGET);
	if (f) {
		int targid;
		int lastx,lasty;
		if (db) dblog(".oO { i have a target... }");
		targid = f->val[0];
		lastx = f->val[1];
		lasty = f->val[2];
		target = findlf(lf->cell->map, targid);
		if (target) { 
			if (db) dblog(".oO { my target is lfid %d (%s). }", targid, target->race->name);
			if (cansee(lf, target)) {
				int goingtomove = B_TRUE;
				enum OBTYPE spell;
				object_t *gun;

				// reset F_TARGET lifetime to full.
				f->lifetime = AI_FOLLOWTIME;
				if (db) dblog(".oO { i can see my target (at %d,%d). might move towards it. }",target->cell->x,target->cell->y);
				// remember last known loc
				f->val[1] = target->cell->x;
				f->val[2] = target->cell->y;

				goingtomove = B_TRUE;


				// drink boost potions
				if (!useitemwithflag(lf, F_AIBOOSTITEM)) {
					return;
				}



				if (goingtomove && (getcelldist(lf->cell, target->cell) == 1)) {
				}

				// can we attack with spells (ie. ones which target the victim)?
				// if target is adjacent, we will normally just attack rather than try a spell. 
				spell = aigetattackspell(lf, target);
				if ( (spell != OT_NONE) &&  // found a valid spell/ability to use
                                     ((getcelldist(lf->cell, target->cell) != 1) || (rnd(1,3) == 1))  
					) {
					int spellfailed = B_FALSE;
					lifeform_t *spelllf = NULL;
					cell_t *spellcell = NULL;
					object_t *spellob = NULL;
					objecttype_t *st;
					st = findot(spell);
					if (db) {
						dblog(".oO { will cast attack spell: %s }", st->name);
					}

					// special cases: eg. spells like telekenesis
					if (spell == OT_S_TELEKINESIS) {
						float maxweight;
						object_t *poss[MAXPILEOBS];
						int nposs;
						int i;
						// find nearest object which can be picked up 

						// this is copied out of the telekenesis spell code!
						maxweight = getlfweight(lf, B_NOOBS) + 
							(getlfweight(lf, B_NOOBS) * (getstatmod(lf, A_IQ) / 100));

						nposs = 0;
						for (i = 0; i < lf->nlos; i++) {
							object_t *o;
							for (o = lf->los[i]->obpile->first ; o ; o = o->next) {
								if (!hasflag(o->flags, F_NOPICKUP) &&
									getobweight(o) <= maxweight) {
									poss[nposs] = o;
									nposs++;
									if (nposs >= MAXPILEOBS) break;
								}
							}
							if (nposs >= MAXPILEOBS) break;
						}
						if (nposs > 0) {
							spellob = poss[rnd(0,nposs-1)];
						} else {
							spellfailed = B_TRUE;
						}

						// cast spell at the player
						spelllf = target;
						spellcell = target->cell;
					} else {
						// pick targets based on spell flags
						aigetspelltarget(lf, st, target, &spelllf, &spellcell, &spellob, F_AICASTTOATTACK);
					}

					if (spellfailed) {
						if (db) dblog(".oO { cast spell/ability failed (1)! }");
					} else {
						if (getschool(spell) == SS_ABILITY) {
							spellfailed = useability(lf, spell, spelllf, spellcell);
						} else {
							spellfailed = castspell(lf, spell, spelllf, spellob, spellcell);
						}
					}
					if (spellfailed) {
						if (db) dblog(".oO { cast spell/ability tried but failed (2)! reason = %d }", reason);
					} else {
						// spell succesful
						return;
					}
				}

				// if not adjacent, check for guns, wands, throwing
				if (goingtomove && (getcelldist(lf->cell, target->cell) > 1) && haslof(lf, target->cell, B_FALSE, NULL)) {
					// can we attack by firing a weapon?
					gun = getfirearm(lf);
					if (goingtomove && gun && getammo(lf)) {
						if (db) {
							char gunname[BUFLEN];
							getobname(gun, gunname, gun->amt);
							dblog(".oO { will fire my gun (%s) at target. }",gunname);
						}
						setguntarget(lf, target);
						if (!shoot(lf)) {
							// succesful
							return;
						} else {
							if (db) dblog(".oO { shoot gun failed! reason = %d }", reason);
						}
					} else {
						if (db) dblog(".oO { not firing out gun  }");
					}

					// can we attack by throwing something?
					if (goingtomove && hasbp(lf, BP_HANDS)) {
						o = getbestthrowmissile(lf);
						if (o) {
							if (db) dblog(".oO { will throw %s at my target instead of moving }", o->type->name);
							// try to throw it!
							if (!throwat(lf, o, target->cell)) {
								// succesful
								goingtomove = B_FALSE;
							} else {
								if (db) dblog(".oO { throw failed! }");
							}
						} 
					}

					// do we have a wand we can zap?
					if (lfhasflag(lf, F_HUMANOID) || hasbp(lf, BP_HANDS)) {
						if (lfhasflag(lf, F_FLEEFROM)) {
							o = aigetwand(lf, F_AICASTTOFLEE);
						} else {
							o = aigetwand(lf, F_AICASTTOATTACK);
						}
						if (o) {
							objecttype_t *st;
							cell_t *zapcell = NULL;

							st = getlinkspell(o);
							if (st) {
								enum FLAG purpose;
								if (lfhasflag(lf, F_FLEEFROM)) {
									purpose = F_AICASTTOFLEE;
								} else {
									purpose = F_AICASTTOATTACK;
								}
								aigetspelltarget(lf, st, target, NULL, &zapcell, NULL, purpose);
							} else {
								// no linkspell - just zap it.
								zapcell = NULL;
							}

							// zap it
							if (db) dblog(".oO { will zap %s instead of moving }", o->type->name);

							if (!operate(lf, o, zapcell)) {
								// succesful
								goingtomove = B_FALSE;
							} else {
								if (db) dblog(".oO { zap failed! }");
							}
						}
					}
				}

				// do we have a valid melee attack?
				if (!curwep) {
					if (db) dblog(".oO { won't move towards target - i have no weapon. }");
					goingtomove = B_FALSE;
				}

				if (goingtomove) {
					if (!movetowards(lf, target->cell, DT_ORTH)) {
						// success
						return;
					} else {
						if (db) dblog(".oO { move towards failed! - reason = %d }",reason);
					}
				}
			} else {
				cell_t *targcell;
				if (db) dblog(".oO { i cannot see my target. moving to last known loc %d/%d }",lastx,lasty);

				// can't see target. 
				// move towards their last known location instead
				targcell = getcellat(lf->cell->map, lastx, lasty);
				if (targcell) {
					aigoto(lf, targcell, PERMENANT);
				} else {
					if (db) dblog(".oO { go to target's last known loc failed! }");
				}

				/*
				// just try to move in a random direction
				if (db) dblog(".oO { will move randomly }");
				// dorandommove will call taketime() if it fails,
				// so it's safe to just return
				dorandommove(lf, B_NOBADMOVES);
				return;
				*/
			}
		}
	} 

	// do we have a target cell?
	f = hasflag(lf->flags, F_TARGETCELL);
	if (f) {
		// if so, move towards it
		x = f->val[0];
		y = f->val[1];
		if (db) dblog(".oO { walking from %d,%d towards f_targetcell (%d,%d) ... }", lf->cell->x, lf->cell->y, x, y);
		c = getcellat(lf->cell->map, x, y);
		if (c) {
			if (movetowards(lf, c, DT_ORTH)) {
				// couldn't move towards it for some reason.
				// so stop trying.
				if (db) dblog(".oO { couldn't walk towards f_targetcell. abandoning it. }");
				killflag(f);
				// remember NOT to target this one.
				lf->ignorecell = c;
			} else {
				if (db) dblog(".oO { successfully walked towards f_targetcell. arrived at %d,%d }",lf->cell->x, lf->cell->y);
				// moved towards it.
				// reset lifetime
				f->lifetime = AI_FOLLOWTIME;

				// are we there yet?
				if (lf->cell == c) {
					if (db) dblog(".oO { arrived at f_targetcell.  removing. }");
					killflag(f);
				}
			}
		} else {
			if (db) dblog(".oO { f_targetcell doesn't exist.  abandoning. }");
			// destination doesn't exist!
			killflag(f);
			// remember NOT to target this one.
			lf->ignorecell = c;
		} 
		return;
	}

	// look for any object which we want
	if (db) dblog(".oO { looking for any ob which i want. }");
	if (lookforobs(lf, B_ANY)) {
		if (db) dblog(".oO { found ob that i want. returning. }");
		return;
	}


	// not attacking anyone in particular
	if (db) dblog(".oO { i do not have a target or can't move towards it. }");
	// are we hostile?  if so, look for a target
	switch (getallegiance(lf)) {
		int i;
		int x,y;
		case AL_HOSTILE:
			if (db) dblog(".oO { i am hostile. looking for a target. }");

			// look around for a target
			for (i = 0; i < lf->nlos; i++) {
				cell_t *c;
				c = lf->los[i];
			
				if (c->lf && cansee(lf, c->lf)) {
					if (isplayer(c->lf)) { // TODO: change to if isenemy ?
						if (db) dblog(".oO { found a target - lfid %d (%s) ! }",c->lf->id, c->lf->race->name);
						
						aiattack(lf, c->lf, AI_FOLLOWTIME);
						// then move towards them...
						if (db) dblog(".oO { moving towards my new target }");

						if (curwep) {
							if (!movetowards(lf, c, DT_ORTH)) return;
						} else {
							if (db) dblog(".oO { won't move towards target - i have no weapon. }");
						} 
						break;
					}
				}
			}
			break;
		case AL_FRIENDLY: // are we friendly?  if so, look for a target
			if (db) dblog(".oO { i am friendly to the player. looking for a target. }");
			// look around for a target
			// TODO: use our vis rang einstead of 10!
			for (y = lf->cell->y - 10; y <= lf->cell->y + 10; y++) {
				for (x = lf->cell->x - 10; x <= lf->cell->x + 10; x++) {
					c = getcellat(lf->cell->map, x, y);
					// cell exists and we can see it?
					if (c && c->lf && (c->lf != lf) && cansee(lf, c->lf)) {
						// player there?
						if (!isplayer(c->lf)) {
							if (db) dblog(".oO { found a target - lfid %d (%s) ! }",c->lf->id, c->lf->race->name);
							// target them!
							addtempflag(lf->flags, F_TARGET, c->lf->id, c->x, c->y, NULL, AI_FOLLOWTIME);
							// then move towards them...
							if (db) dblog(".oO { moving towards my new target }");
							if (!movetowards(lf, c, DT_ORTH)) return;
						}
					}
				}
			}
			break;
		default:
			break;
	}


	// need to heal?
	if ((lf->hp < lf->maxhp) || 
	   ((lf->mp < getmaxmp(lf)) && lfhasflag(lf, F_RESTHEALMPAMT)) ) {
		if (lf->hp < (lf->maxhp/2)) {
			if (!useitemwithflag(lf, F_AIHEALITEM)) {
				return;
			}
		}

		if (db) dblog(".oO { resting }");
		rest(lf, B_TRUE);
	}

	// need to train skills?
	if (lf->skillpoints || lfhasflag(lf, F_STATGAINREADY)) {
		if (canrest(lf)) {
			// special case - monsters don't need to actually rest to gain
			// skills, although they DO still need to wait until the player
			// is out of sight.
			enhanceskills(lf);
		}
	}

	// just try to move in a random direction
	if (db) dblog(".oO { default - moving randomly }");
	dorandommove(lf, B_NOBADMOVES);
	return;
	
	// if we get this far, just wait
	rest(lf, B_TRUE);
}

int aipickup(lifeform_t *lf, object_t *o) {
	if (isedible(o)) {
		return eat(lf, o);
	} else {
		return pickup(lf, o, o->amt, B_TRUE);
	}
	return B_FALSE;
}

int aiobok(lifeform_t *lf, object_t *o, lifeform_t *target) {
	switch (o->type->id) {
		case OT_POT_INVIS:
		case OT_WAND_INVIS:
			if (lfhasflag(target, F_INVISIBLE)) {
				return B_FALSE;
			}
			break;
		case OT_POT_INVULN:
			if (lfhasflag(target, F_INVULNERABLE)) {
				return B_FALSE;
			}
			break;
		default:
			break;
	}
	return B_TRUE;
}

// is the spell 'spellid' okay for AI lifeform 'lf' to cast at 'victim', for given purpose.
// 	purpose could be F_AICASTTOFLEE or F_ATCASTTOATTACK
int aispellok(lifeform_t *lf, enum OBTYPE spellid, lifeform_t *victim, enum FLAG purpose) {
	objecttype_t *ot;
	flag_t *f;
	int db = B_FALSE;
	int ok = B_FALSE;
	int specialcase = B_FALSE;
	int specificcheckok = B_FALSE;

	if (lfhasflag(lf, F_DEBUG)) {
		db = B_TRUE;
	}
	ot = findot(spellid);

	// enough mp etc?
	if (!cancast(lf, spellid, NULL)) {
		if (db) {
			char why[BUFLEN];
			if (reason == E_NOMP) {
				strcpy(why, "not enough mp");
			} else if (reason == E_TOOPOWERFUL) {
				strcpy(why, "spell too powerful");
			} else if (reason == E_NOTREADY) {
				strcpy(why, "abil not ready");
			} else if (reason == E_NEEDGRAB) {
				strcpy(why, "needs grab");
			} else {
				strcpy(why, "unknown reason");
			}
			if (db) {
				if (ot) {
					dblog(".oO { can't cast %s right now (%s) (mpcost=%d, i have %d) }", 
						ot ? ot->name : "?unkownspell?", why,
						getmpcost(lf, ot->id), lf->mp);
				} else {
					dblog(".oO { can't cast ?unknownspell? right now }");
				}
			}
		}
		return B_FALSE;
	}

	// boost spell already active?
	if (hasflag(ot->flags, F_ONGOING)) {
		if (lfhasflagval(lf, F_BOOSTSPELL, ot->id, NA, NA, NULL)) {
			if (db) {
				dblog(".oO { can't cast %s - it is already active.", ot ? ot->name : "?unkownspell?");
			}
			return B_FALSE;
		}
	}

	f = hasflag(ot->flags, purpose);
	if (f) {
		int range;
		switch (f->val[0]) {
			case ST_VICTIM:
				range = getspellrange(spellid, getspellpower(lf, spellid));
				if ((range == UNLIMITED) || (getcelldist(lf->cell, victim->cell) <= range)) {
					if (db) {
						dblog(".oO { spell possibility: %s }", ot ? ot->name : "?unkownspell?");
					}
					ok = B_TRUE;
				}
				break;
			case ST_SELF:
			case ST_ANYWHERE:
				if (db) {
					dblog(".oO { spell possibility: %s }", ot ? ot->name : "?unkownspell?");
				}
				ok = B_TRUE;
				break;
			case ST_ADJVICTIM:
				if (getcelldist(lf->cell,victim->cell) == 1) {
					if (ot->id == OT_A_GRAB) {
						if (lfhasflag(lf, F_GRABBING) || lfhasflag(lf, F_GRABBEDBY) || 
						    lfhasflag(victim, F_GRABBING) || lfhasflag(victim, F_GRABBEDBY)) {
						} else {
							ok = B_TRUE;
						}
					} else if (ot->id == OT_A_CRUSH) {
						// can only crush if you first grab something
						if (lfhasflag(lf, F_GRABBING)) {
							ok = B_TRUE;
						}
					} else {
						ok = B_TRUE;
					}
				}
				break;
			case ST_ADJSELF:
				if (getcelldist(lf->cell,victim->cell) == 1) {
					ok = B_TRUE;
				}
				break;
			case ST_SPECIAL:
				specialcase = B_TRUE;
				break;
		}
	} else {
		// invalid spell for this purpose
		dblog(".oO { cant cast %s - not valid for given purpose }", ot ? ot->name : "?unkownspell?");
		return B_FALSE;
	}


	if (specialcase) {
		if (ot->id == OT_S_TELEKINESIS) {
			int i,nposs;
			float maxweight;
			maxweight = getlfweight(lf, B_NOOBS) + 
				(getlfweight(lf, B_NOOBS) * (getstatmod(lf, A_IQ) / 100));

			nposs = 0;
			for (i = 0; i < lf->nlos; i++) {
				object_t *o;
				for (o = lf->los[i]->obpile->first ; o ; o = o->next) {
					if (!hasflag(o->flags, F_NOPICKUP) &&
						getobweight(o) <= maxweight) {
						ok = B_TRUE;
						break;
					}
					if (ok) break;
				}
			}
		} else if (ot->id == OT_S_CHARM) {
			if (getnearbypeaceful(lf)) {
				ok = B_TRUE;
			}
		} else {
			dblog(".oO { cant cast %s - specialcase conditions not yet coded }", ot ? ot->name : "?unkownspell?");
			return B_FALSE;
		}
	}

	if (!ok) {
		dblog(".oO { cant cast %s - targetting conditions cannot be met }", ot ? ot->name : "?unkownspell?");
		return B_FALSE;
	}

	// now check whether it meets specific spell conditions
	specificcheckok = B_TRUE;
	if (ot->id == OT_S_ANIMATEMETAL) {
		object_t *wep;
		wep = getweapon(lf);
		if (!wep || !ismetal(wep->material->id)) {
			specificcheckok = B_TRUE;
		}
	}
	if ((ot->id == OT_S_BLINDNESS) && isblind(victim)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_DRAINLIFE) && isimmuneto(victim->flags, DT_NECROTIC)) {
		specificcheckok = B_FALSE;
	}
	if (ot->id == OT_A_SWOOP) {
		flag_t *srflag;
		int srange = 5;
		srflag = lfhasflag(lf, F_SWOOPRANGE);
		if (srflag) {
			srange = srflag->val[0];
		}
		
		if (!haslof(lf, victim->cell, LOF_NEED,NULL)) {
			specificcheckok = B_FALSE;
		} else if (isimmobile(lf) || !lfhasflag(lf, F_FLYING)) {
			specificcheckok = B_FALSE;
		} else if (getcelldist(lf->cell, victim->cell) > srange) {
			specificcheckok = B_FALSE;
		}
	}
	if ((ot->id == OT_S_HASTE) && lfhasflag(lf, F_FASTACT)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_INVISIBILITY) && lfhasflag(victim, F_INVISIBLE)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_PAIN) && lfhasflag(victim, F_PAIN)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_HEALING) && (lf->hp >= lf->maxhp)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_HEALINGMIN) && (lf->hp >= lf->maxhp)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_PARALYZE) && lfhasflag(victim, F_PARALYZED)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_SLEEP) && lfhasflag(victim, F_ASLEEP)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_SLOW) && lfhasflag(victim, F_SLOWACT)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_A_SPRINT) && lfhasflag(lf, F_SPRINTING)) {
		specificcheckok = B_FALSE;
	}
	if ((ot->id == OT_S_WEAKEN)) {
		flag_t *lff;
		for (lff = lf->flags->first; lff ; lff = lff->next) {
			if ((lff->id == F_ATTRMOD) && (lff->val[0] == A_STR) && (lff->obfrom == OT_S_WEAKEN)) {
				specificcheckok = B_FALSE;
				break;
			}
		}
	}
	if (!specificcheckok) {
		dblog(".oO { cant cast %s - specific spell check failed }", ot ? ot->name : "?unkownspell?");
		return B_FALSE;
	}

	return B_TRUE;
}


object_t *hasbetterarmour(lifeform_t *lf, obpile_t *op) {
	object_t *o;

	for (o = op->first ; o ; o = o->next) {
		if (isarmour(o)) {
			object_t *curarm;
			enum BODYPART bp;
			flag_t *f;
			// where does it go?
			f = hasflag(o->flags, F_GOESON);
			bp = f->val[0];
			// is it better than what we have in that position?
			curarm = getarmour(lf, bp);
			if (isbetterwepthan(o, curarm)) {
				return o;
			}
		}
	}
	return NULL;
}

object_t *hasbetterweapon(lifeform_t *lf, obpile_t *op) {
	object_t *bestwep, *o;

	bestwep = getbestweapon(lf);
	for (o = op->first ; o ; o = o->next) {
		if (isweapon(o) && isbetterwepthan(o, bestwep) && canweild(lf, o)) {
			return o;
		}
	}
	return NULL;
}


// returns B_TRUE if we did something
int lookforobs(lifeform_t *lf, int covetsonly) {
	object_t *o;
	enum OBTYPE oid[MAXPILEOBS];
	int noids = 0;
	enum FLAG wantflag[MAXPILEOBS];
	int nwantflags = 0;
	flag_t *f;
	cell_t *c;
	int n;
	int i;
	int db = B_FALSE;

	if (wantdb && lfhasflag(lf, F_DEBUG)) {
		db = B_TRUE;
	} else {
		db = B_FALSE;
	}

	// construct a list of objects which we want
	noids = 0;
	for (f = lf->flags->first ; f ; f = f->next) {
		if (f->id == F_WANTS) {
			if (!covetsonly || (f->val[1] == B_COVETS)) {
				oid[noids] = f->val[0];
				noids++; 
			}
		} else if (f->id == F_WANTSOBFLAG) {
			if (!covetsonly || (f->val[1] == B_COVETS)) {
				wantflag[nwantflags] = f->val[0];
				nwantflags++; 
			}
		}
	}

	// current cell has an object we want?
	o = hasobmulti(lf->cell->obpile, oid, noids);
	if (o && !isdangerousob(o, lf, B_TRUE) && (canpickup(lf, o, 1) || caneat(lf,o)) ) {
		if (db) dblog(".oO { current cell has ob i want (%s) }",o->type->name);
		// try to pick it up
		if (!aipickup(lf, o)) return B_TRUE;
		if (db) dblog(".oO { pickup of %s failed, trying to eat! }",o->type->name);
		if (!eat(lf, o)) return B_TRUE;
		if (db) dblog(".oO { eating %s failed }",o->type->name);
	} 
	// has an object with a flag we want?
	for (n = 0; n < nwantflags; n++) {
		o = hasobwithflag(lf->cell->obpile, wantflag[n]);
		if (o && !isdangerousob(o, lf, B_TRUE) && (canpickup(lf, o, 1) || caneat(lf,o)) ) {
			if (db) dblog(".oO { current cell has ob with flag i want (%s) }",o->type->name);
			// try to pick it up
			if (!aipickup(lf, o)) return B_TRUE;
			if (db) dblog(".oO { pickup of %s with wantflag failed, trying to eat! }",o->type->name);
			if (!eat(lf, o)) return B_TRUE;
			if (db) dblog(".oO { eating %s with wantflag failed }",o->type->name);

		}
	}
	// current cell has better weapon?
	if (lfhasflag(lf, F_HUMANOID) && hasbp(lf, BP_WEAPON)) {
		f = hasflag(lf->flags, F_WANTSBETTERWEP);
		if (f) {
			if (!covetsonly || (f->val[1] == B_COVETS)) {
				o = hasbetterweapon(lf, lf->cell->obpile);
				if (o && !isdangerousob(o, lf, B_TRUE) && canpickup(lf, o, 1)) {
					if (db) dblog(".oO { current cell has better weapon (%s) }",o->type->name);
					// try to pick it up
					if (!aipickup(lf, o)) return B_TRUE;
					if (db) dblog(".oO { pickup of better wep %s failed! }",o->type->name);
				}
			}
		}
	}

	if (lfhasflag(lf, F_HUMANOID)) {
		// current cell has better armour?
		f = hasflag(lf->flags, F_WANTSBETTERARM);
		if (f ) {
			if (!covetsonly || (f->val[1] == B_COVETS)) {
				o = hasbetterarmour(lf, lf->cell->obpile);
				if (o && !isdangerousob(o, lf, B_TRUE) && canpickup(lf, o, 1)) {
					if (db) dblog(".oO { current cell has better armour (%s) }",o->type->name);
					// try to pick it up
					if (!aipickup(lf, o)) return B_TRUE;
					if (db) dblog(".oO { pickup of better armour %s failed! }",o->type->name);
				}
			}
		}
	}

	// look around for objects which we want, if we don't already have a targetcell.
	if (!hasflag(lf->flags, F_TARGETCELL)) {
		if (db) dblog(".oO { no targetcell, so looking for remote objects }");
		for (i = 0 ; i < lf->nlos; i++) {
			int gothere = B_FALSE;

			c = lf->los[i];
			if (!c->lf && (c != lf->ignorecell)) {
				o = hasobmulti(c->obpile, oid, noids);
				if (o && !isdangerousob(o, lf, B_TRUE) && (canpickup(lf, o, 1) || caneat(lf,o)) ) {
					if (db) dblog(".oO { remote cell has ob i want (%s). setting f_targetcell. }",o->type->name);
					gothere = B_TRUE;
				} 
				if (!gothere) {
					// has an object with a flag we want?
					for (n = 0; n < nwantflags; n++) {
						o = hasobwithflag(c->obpile, wantflag[n]);
						if (o && !isdangerousob(o, lf, B_TRUE) && (canpickup(lf, o, 1) || caneat(lf, o)) ) {
							if (db) dblog(".oO { remote cell has ob with flag i want (%s) }", o->type->name);
							gothere = B_TRUE;
						}
					}
				}
				if (!gothere) {
					if (lfhasflag(lf, F_HUMANOID) && hasbp(lf, BP_WEAPON)) {
						// remote cell has better weapon?
						f = hasflag(lf->flags, F_WANTSBETTERWEP);
						if (f) {
							if (!covetsonly || (f->val[1] == B_COVETS)) {
							
								o = hasbetterweapon(lf, c->obpile);
								if (o && !isdangerousob(o, lf, B_TRUE) && canpickup(lf, o, 1)) {
									if (db) dblog(".oO { remote cell has better weapon (%s). setting f_targetcell }",o->type->name);
									gothere = B_TRUE;
								}
							}
						}
					}
				}
				if (!gothere) {
					if (lfhasflag(lf, F_HUMANOID)) {
						// remote cell has better armour?
						f = hasflag(lf->flags, F_WANTSBETTERARM);
						if (f) {
							if (!covetsonly || (f->val[1] == B_COVETS)) {
							
								o = hasbetterarmour(lf, c->obpile);
								if (o && !isdangerousob(o, lf, B_TRUE) && canpickup(lf, o, 1)) {
									if (db) dblog(".oO { remote cell has better armour (%s). setting f_targetcell }",o->type->name);
									gothere = B_TRUE;
								}
							}
						}
					}
				}


				if (gothere) {
					// start walking towards target cell
					aigoto(lf, c, AI_FOLLOWTIME);
					return B_TRUE;
				}
			}
		}
	}
	if (db) dblog(".oO { didn't find any obs i want }");
	return B_FALSE;
}

// try to use an item with the given flag on ourself.
// returns B_FALSE if successful
int useitemwithflag(lifeform_t *lf, enum FLAG whichflag) {
	object_t *o;
	for (o = lf->pack->first ; o ; o = o->next) {
		if (hasflag(o->flags, whichflag)) {
			if (aiobok(lf, o, lf)) {
				if (o->type->obclass->id == OC_POTION) {
					if (canquaff(lf, o)) {
						quaff(lf, o);
						return B_FALSE;
					}
				} else if (o->type->obclass->id == OC_SCROLL) {
					if (!readsomething(lf, o)) {
						return B_FALSE;
					}
				} else if ((o->type->obclass->id == OC_WAND) && getcharges(o)) {
					// if wand, use it on ourself
					if (!operate(lf, o, lf->cell)) {
						return B_FALSE;
					}
				}
			}
		}
	}
	// failed to use an item 
	return B_TRUE;
}