/* $Header: predicates.c,v 1.1 90/04/14 14:56:49 lachesis Exp $
 * $Log:	predicates.c,v $
 * Revision 1.1  90/04/14  14:56:49  lachesis
 * Initial revision
 * 
 */
#include "copyright.h"

/* Predicates for testing various conditions */

#include <ctype.h>

#include "db.h"
#include "interface.h"
#include "config.h"
#include "externs.h"

int can_link_to(dbref who, dbref where)
{
    return(where >= 0
	   && where < db_top
	   && (controls(who, where) || (db[where].flags & LINK_OK)));
}

int could_doit(dbref player, dbref thing)
{
    if(Typeof(thing) == TYPE_EXIT && db[thing].sp.exit.ndest == 0) {
	return 0;
    }
    return(eval_boolexp (player, db[thing].key));
}

int can_doit(dbref player, dbref thing, const char *default_fail_msg)
{
    dbref loc;
    char buf[BUFFER_LEN];

    if((loc = getloc(player)) == NOTHING) return 0;

    if(!could_doit(player, thing)) {
	/* can't do it */
	if(db[thing].fail_message) {
	    notify(player, db[thing].fail_message);
	} else if(default_fail_msg) {
	    notify(player, default_fail_msg);
	}
	
	if(db[thing].ofail && !Dark(player)) {
#ifdef GENDER
	    pronoun_substitute(buf, player, db[thing].ofail, 1);
#else
	    sprintf(buf, "%s %s", db[player].name, db[thing].ofail);
#endif /* GENDER */
	    notify_except(db[loc].contents, player, buf);
	}

	return 0;
    } else {
	/* can do it */
	if(db[thing].succ_message) {
	    notify(player, db[thing].succ_message);
	}

	if(db[thing].osuccess && !Dark(player)) {
#ifdef GENDER
            pronoun_substitute(buf, player, db[thing].osuccess, 1);
#else
            sprintf(buf, "%s %s", db[player].name, db[thing].osuccess);
#endif /* GENDER */
            notify_except(db[loc].contents, player, buf);
	}

	return 1;
    }
}

int can_see(dbref player, dbref thing, int can_see_loc)
{
    if(player == thing || Typeof(thing) == TYPE_EXIT) {
	return 0;
    } else if(can_see_loc) {
	return(!Dark(thing) || controls(player, thing));
    } else {
	/* can't see loc */
	return(controls(player, thing));
    }
}

int controls(dbref who, dbref what)
{
    /* Wizard controls everything */
    /* owners control their stuff */
    if (what < 0 || what >= db_top) return 0;
#ifdef RECYCLE
    /* No one controls garbage */
    if (Typeof(what) == TYPE_GARBAGE) return 0;
#endif    
    if (Wizard(who)) return 1;
    switch(Typeof(what)) {
      case TYPE_ROOM:
	return (who == db[what].sp.room.owner);
	/*NOTREACHED*/
	break;
      case TYPE_PLAYER:
	return (who == what);
	/*NOTREACHED*/
	break;
      case TYPE_EXIT:
	return (who == db[what].sp.exit.owner);
	/*NOTREACHED*/
	break;
      case TYPE_THING:
	return (who == db[what].sp.thing.owner);
	/*NOTREACHED*/
	break;
    }
    return 0;
}

int can_link(dbref who, dbref what)
{
    return((Typeof(what) == TYPE_EXIT && db[what].sp.exit.ndest == 0)
	   || controls(who, what));
}

int payfor(dbref who, int cost)
{
    if(Wizard(who)) {
	return 1;
    } else if(db[who].sp.player.pennies >= cost) {
	db[who].sp.player.pennies -= cost;
	return 1;
    } else {
	return 0;
    }
}
int word_start (const char *str, const char let)
{
    int chk;

    for (chk = 1; *str; str++) {
	if (chk && *str == let) return 1;
	chk = *str == ' ';
    }
    return 0;
}

int ok_name(const char *name)
{
    return (name
	    && *name
	    && *name != LOOKUP_TOKEN
	    && *name != NUMBER_TOKEN
	    && !index(name, ARG_DELIMITER)
	    && !index(name, AND_TOKEN)
	    && !index(name, OR_TOKEN)
	    && !word_start(name, NOT_TOKEN)
	    && string_compare(name, "me")
	    && string_compare(name, "home")
	    && string_compare(name, "here"));
}

int ok_player_name(const char *name)
{
    const char *scan;

    if(!ok_name(name) || strlen(name) > PLAYER_NAME_LIMIT) return 0;

    for(scan = name; *scan; scan++) {
	if(!(isprint(*scan) && !isspace(*scan))) { /* was isgraph(*scan) */
	    return 0;
	}
    }

    /* lookup name to avoid conflicts */
    return (lookup_player(name) == NOTHING);
}

int ok_password(const char *password)
{
    const char *scan;

    if(*password == '\0') return 0;

    for(scan = password; *scan; scan++) {
	if(!(isprint(*scan) && !isspace(*scan))) {
	    return 0;
	}
    }

    return 1;
}