#include "copyright.h"

#ifndef __DB_H
#define __DB_H
#include <stdio.h>

typedef int dbref;              /* offset into db */

#define TYPE_ROOM 	0x0
#define TYPE_THING 	0x1
#define TYPE_EXIT 	0x2
#define TYPE_PLAYER 	0x3
#define NOTYPE		0x7     /* no particular type */
#define TYPE_MASK 	0x7     /* room for expansion */
#define ANTILOCK	0x8     /* if present, makes key cause failure */
#define WIZARD		0x10    /* gets automatic control */
#define LINK_OK		0x20    /* anybody can link to this room */
#define DARK		0x40    /* contents of room are not printed */
#define TEMPLE		0x80    /* objects dropped in this room go home */
#define STICKY		0x100   /* this object goes home when dropped */

#ifdef RESTRICTED_BUILDING
#define BUILDER		0x200   /* this player can use construction commands */
#endif /* RESTRICTED_BUILDING */

typedef int object_flag_type;

#define Typeof(x) (db[(x)].flags & TYPE_MASK)
#define Wizard(x) ((db[(x)].flags & WIZARD) != 0)
#define Dark(x) ((db[(x)].flags & DARK) != 0)

#ifdef RESTRICTED_BUILDING
#define Builder(x) ((db[(x)].flags & (WIZARD|BUILDER)) != 0)
#endif /* RESTRICTED_BUILDING */

/* special dbref's */
#define NOTHING (-1)            /* null dbref */
#define AMBIGUOUS (-2)          /* multiple possibilities, for matchers */
#define HOME (-3)               /* virtual room, represents mover's home */

struct object {
  char *name;
  char *description;
  dbref location;               /* pointer to container */
  /* for exits, pointer to destination */
  dbref contents;               /* pointer to first item */
  dbref exits;                  /* pointer to first exit for rooms */
  /* pointer to home for things and players */
  dbref next;                   /* pointer to next in contents/exits chain */

  /* the following are used for pickups for things, entry for exits */
  dbref key;                    /* if not NOTHING, must have this to do op */
  char *fail_message;           /* what you see if op fails */
  char *succ_message;           /* what you see if op succeeds */
  /* other messages get your name prepended, so if your name is "Foo", */
  /* and osuccess = "disappears in a blast of gamma radiation." */
  /* then others see "Foo disappears in a blast of gamma radiation." */
  /* (At some point I may put in Maven-style %-substitutions.) */
  char *ofail;                  /* what others see if op fails */
  char *osuccess;               /* what others see if op succeeds */

  dbref owner;                  /* who controls this object */
  int pennies;                  /* number of pennies object contains */
  object_flag_type flags;
  char *password;               /* password for players */
};

extern struct object *db;
extern dbref db_top;

extern char *alloc_string (const char *s);

extern dbref new_object (void); /* return a new object */

extern int db_write_object (FILE *, dbref);     /* write one object to file */

extern dbref db_write (FILE * f);       /* write db to file, return # of objects */

extern dbref db_read (FILE * f);        /* read db from file, return # of objects */
                                /* Warning: destroys existing db contents! */

extern void db_free (void);

extern dbref parse_dbref (const char *);        /* parse a dbref */

#define DOLIST(var, first) \
  for((var) = (first); (var) != NOTHING; (var) = db[(var)].next)
#define PUSH(thing, locative) \
    ((db[(thing)].next = (locative)), (locative) = (thing))
#define getloc(thing) (db[thing].location)

/*
  Usage guidelines:

  To refer to objects use db[object_ref].  Pointers to objects may 
  become invalid after a call to new_object().

  The programmer is responsible for managing storage for string
  components of entries; db_read will produce malloc'd strings.  The
  alloc_string routine is provided for generating malloc'd strings
  duplicates of other strings.  Note that db_free and db_read will
  attempt to free any non-NULL string that exists in db when they are
  invoked.  
*/
#endif /* __DB_H */