#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
    && Typeof (where) == TYPE_ROOM
    && (controls (who, where) || (db[where].flags & LINK_OK)));
}

int could_doit (dbref player, dbref thing)
{
  dbref key;
  int status;

  if (Typeof (thing) != TYPE_ROOM && db[thing].location == NOTHING)
    return 0;
  if ((key = db[thing].key) == NOTHING)
    return 1;
  status = (player == key || member (key, db[player].contents));
  return ((db[thing].flags & ANTILOCK) ? !status : status);
}

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) {
      sprintf (buf, "%s %s", db[player].name, db[thing].ofail);
      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) {
      sprintf (buf, "%s %s", db[player].name, db[thing].osuccess);
      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 */
  return (what >= 0 && what < db_top && (Wizard (who)
      || who == db[what].owner));
}

int can_link (dbref who, dbref what)
{
  return ((Typeof (what) == TYPE_EXIT && db[what].location == NOTHING)
    || controls (who, what));
}

int payfor (dbref who, int cost)
{
  if (Wizard (who)) {
    return 1;
  } else if (db[who].pennies >= cost) {
    db[who].pennies -= cost;
    return 1;
  } else {
    return 0;
  }
}

int ok_name (const char *name)
{
  return (name
    && *name
    && *name != LOOKUP_TOKEN
    && *name != NUMBER_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))
    return 0;

  for (scan = name; *scan; scan++) {
    if (!isgraph (*scan)) {
      return 0;
    }
  }

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