set.h

/********************************************************************\
  * BitlBee -- An IRC to other IM-networks gateway                     *
  *                                                                    *
  * Copyright 2002-2006 Wilmer van der Gaast and others                *
  \********************************************************************/

/* Some stuff to register, handle and save user preferences             */

/*
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License with
  the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
  if not, write to the Free Software Foundation, Inc., 51 Franklin St.,
  Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef __SET_H__
#define __SET_H__

struct set;

/* This used to be specific to irc_t structures, but it's more generic now
   (so it can also be used for account_t structs). It's pretty simple, but
   so far pretty useful.

   In short, it just keeps a linked list of settings/variables and it also
   remembers a default value for every setting. And to prevent the user
   from setting invalid values, you can write an evaluator function for
   every setting, which can check a new value and block it by returning
   NULL, or replace it by returning a new value. See struct set.eval. */

typedef char *(*set_eval) (struct set *set, char *value);

extern char *SET_INVALID;

typedef enum {
	SET_NOSAVE = 0x0001,   /* Don't save this setting (i.e. stored elsewhere). */
	SET_NULL_OK = 0x0100,  /* set->value == NULL is allowed. */
	SET_HIDDEN = 0x0200,   /* Don't show up in setting lists. Mostly for internal storage. */
	SET_PASSWORD = 0x0400, /* Value shows up in settings list as "********". */
	SET_HIDDEN_DEFAULT = 0x0800, /* Hide unless changed from default. */
	SET_LOCKED = 0x1000    /* Setting is locked, don't allow changing it */
} set_flags_t;

typedef struct set {
	void *data;     /* Here you can save a pointer to the
	                   object this settings belongs to. */

	char *key;
	char *old_key;  /* Previously known as; for smooth upgrades. */
	char *value;
	char *def;      /* Default value. If the set_setstr() function
	                   notices a new value is exactly the same as
	                   the default, value gets set to NULL. So when
	                   you read a setting, don't forget about this!
	                   In fact, you should only read values using
	                   set_getstr/int(). */

	set_flags_t flags; /* Mostly defined per user. */

	/* Eval: Returns SET_INVALID if the value is incorrect, exactly
	   the passed value variable, or a corrected value. In case of
	   the latter, set_setstr() will free() the returned string! */
	set_eval eval;
	void *eval_data;
	struct set *next;
} set_t;

#define set_value(set) ((set)->value) ? ((set)->value) : ((set)->def)

/* Should be pretty clear. */
set_t *set_add(set_t **head, const char *key, const char *def, set_eval eval, void *data);

/* Returns the raw set_t. Might be useful sometimes. */
set_t *set_find(set_t **head, const char *key);

/* Returns a pointer to the string value of this setting. Don't modify the
   returned string, and don't free() it! */
G_MODULE_EXPORT char *set_getstr(set_t **head, const char *key);

/* Get an integer. In previous versions set_getint() was also used to read
   boolean values, but this SHOULD be done with set_getbool() now! */
G_MODULE_EXPORT int set_getint(set_t **head, const char *key);
G_MODULE_EXPORT int set_getbool(set_t **head, const char *key);

/* set_setstr() strdup()s the given value, so after using this function
   you can free() it, if you want. */
int set_setstr(set_t **head, const char *key, char *value);
int set_setint(set_t **head, const char *key, int value);
void set_del(set_t **head, const char *key);
int set_reset(set_t **head, const char *key);

/* returns true if a setting shall be shown to the user */
int set_isvisible(set_t *set);

/* Two very useful generic evaluators. */
char *set_eval_int(set_t *set, char *value);
char *set_eval_bool(set_t *set, char *value);

/* Another more complicated one. */
char *set_eval_list(set_t *set, char *value);

/* Some not very generic evaluators that really shouldn't be here... */
char *set_eval_to_char(set_t *set, char *value);
char *set_eval_oauth(set_t *set, char *value);

#endif /* __SET_H__ */