/* ************************************************************************
*   File: mail.h                                        Part of CircleMUD *
*  Usage: header file for mail system                                     *
*                                                                         *
*  All rights reserved.  See license.doc for complete information.        *
*                                                                         *
*  Copyright (C) 1993, 94 by the Trustees of the Johns Hopkins University *
*  CircleMUD is based on DikuMUD, Copyright (C) 1990, 1991.               *
************************************************************************ */

#ifndef _mail_h_
#define _mail_h_
/******* MUD MAIL SYSTEM HEADER FILE *********************
 ***     written by Jeremy Elson (jelson@cs.jhu.edu)   ***
 ********************************************************/

/* INSTALLATION INSTRUCTIONS in MAIL.C */

/* You can modify the following constants to fit your own MUD.  */

/* minimum level a player must be to send mail  */
#define MIN_MAIL_LEVEL 1

/* # of gold coins required to send mail        */
#define STAMP_PRICE 15

/* Maximum size of mail in bytes (arbitrary)    */
#define MAX_MAIL_SIZE 4096

/* size of mail file allocation blocks          */
#define BLOCK_SIZE 100

/*
 * NOTE:  Make sure that your block size is big enough -- if not,
 * HEADER_BLOCK_DATASIZE will end up negative.  This is a bad thing.
 * Check the define below to make sure it is >0 when choosing values
 * for NAME_SIZE and BLOCK_SIZE.  100 is a nice round number for
 * BLOCK_SIZE and is the default ... why bother trying to change it
 * anyway?
 *
 * The mail system will always allocate disk space in chunks of size
 * BLOCK_SIZE.
 */

/* USER CHANGABLE DEFINES ABOVE **
***************************************************************************
**   DON'T TOUCH DEFINES BELOW  */

int     scan_file(void);
int     has_mail(long recipient);
void    store_mail(long to, long from, char *message_pointer);
char    *read_delete(long recipient);


#define HEADER_BLOCK  -1
#define LAST_BLOCK    -2
#define DELETED_BLOCK -3

/*
 * note: next_block is part of header_blk in a data block; we can't combine
 * them here because we have to be able to differentiate a data block from a
 * header block when booting mail system.
 */

struct header_data_type
{
  long next_block;             /* if header block, link to next block  */
  long from;                   /* idnum of the mail's sender           */
  long to;                     /* idnum of mail's recipient            */
  time_t mail_time;            /* when was the letter mailed?          */
};

/* size of the data part of a header block */
#define HEADER_BLOCK_DATASIZE \
        (BLOCK_SIZE - sizeof(long) - sizeof(struct header_data_type) - 1)

/* size of the data part of a data block */
#define DATA_BLOCK_DATASIZE (BLOCK_SIZE - sizeof(long) - 1)

/* note that an extra space is allowed in all string fields for the
   terminating null character.  */

struct header_block_type_d
{
  long block_type;             /* is this a header or data block?      */
  struct header_data_type header_data; /* other header data            */
  char txt[HEADER_BLOCK_DATASIZE+1]; /* actual text plus 1 for null    */
};

struct data_block_type_d
{
  long block_type;             /* -1 if header block, -2 if last data block
                                         in mail, otherwise a link to the next */
  char txt[DATA_BLOCK_DATASIZE+1]; /* actual text plus 1 for null      */
};

typedef struct header_block_type_d header_block_type;
typedef struct data_block_type_d data_block_type;

struct position_list_type_d
{
  long position;
  struct position_list_type_d *next;
};

typedef struct position_list_type_d position_list_type;

struct mail_index_type_d
{
  long recipient;                      /* who is this mail for?        */
  position_list_type *list_start;      /* list of mail positions       */
  struct mail_index_type_d *next;      /* link to next one             */
};

typedef struct mail_index_type_d mail_index_type;

#endif