/*
	cvar.c

	dynamic variable tracking

	Copyright (C) 1996-1997  Id Software, Inc.
	Copyright (C) 1999,2000  contributors of the QuakeForge project
	Please see the file "AUTHORS" for a list of contributors

	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
	along with this program; if not, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif

#include <stdio.h>
#include <stdlib.h>

#include "QF/cmd.h"
#include "QF/cvar.h"
#include "QF/hash.h"
#include "QF/mathlib.h"
#include "QF/qargs.h"
#include "QF/quakefs.h"
#include "QF/sys.h"
#include "QF/va.h"

#include "compat.h"

#define USER_RO_CVAR "User-created READ-ONLY Cvar"
#define USER_CVAR "User-created cvar"

VISIBLE cvar_t          *developer;
VISIBLE cvar_t			*cvar_vars;
static const char		*cvar_null_string = "";
static cvar_alias_t		*calias_vars;
static hashtab_t		*cvar_hash;
static hashtab_t		*calias_hash;


VISIBLE cvar_t *
Cvar_FindVar (const char *var_name)
{
	return (cvar_t*) Hash_Find (cvar_hash, var_name);
}

VISIBLE cvar_t *
Cvar_FindAlias (const char *alias_name)
{
	cvar_alias_t *alias;

	alias = (cvar_alias_t *) Hash_Find (calias_hash, alias_name);
	if (alias)
		return alias->cvar;
	return 0;
}

cvar_t *
Cvar_MakeAlias (const char *name, cvar_t *cvar)
{
	cvar_alias_t *alias;
	cvar_t			*var;

	if (Cmd_Exists (name)) {
		Sys_Printf ("Cvar_MakeAlias: %s is a command\n", name);
		return 0;
	}
	if (Cvar_FindVar (name)) {
		Sys_Printf ("Cvar_MakeAlias: %s is a cvar\n",
					name);
		return 0;
	}
	var = Cvar_FindAlias (name);
	if (var && var != cvar) {
		Sys_Printf ("Cvar_MakeAlias: %s is an alias to %s\n",
					name, var->name);
		return 0;
	}
	if (!var) {
		alias = (cvar_alias_t *) calloc (1, sizeof (cvar_alias_t));

		alias->next = calias_vars;
		calias_vars = alias;
		alias->name = strdup (name);
		alias->cvar = cvar;
		Hash_Add (calias_hash, alias);
	}
	return cvar;
}

cvar_t *
Cvar_RemoveAlias (const char *name)
{
	cvar_alias_t *alias;
	cvar_t      *var;

	alias = (cvar_alias_t *) Hash_Find (calias_hash, name);
	if (!alias) {
		Sys_Printf ("Cvar_RemoveAlias: %s is not an alias\n", name);
		return 0;
	}
	var = alias->cvar;
	Hash_Free (calias_hash, Hash_Del (calias_hash, name));
	return var;
}

VISIBLE float
Cvar_VariableValue (const char *var_name)
{
	cvar_t     *var;

	var = Cvar_FindVar (var_name);
	if (!var)
		var = Cvar_FindAlias (var_name);
	if (!var)
		return 0;
	return atof (var->string);
}

VISIBLE const char *
Cvar_VariableString (const char *var_name)
{
	cvar_t     *var;

	var = Cvar_FindVar (var_name);
	if (!var)
		var = Cvar_FindAlias (var_name);
	if (!var)
		return cvar_null_string;
	return var->string;
}

VISIBLE const char *
Cvar_CompleteVariable (const char *partial)
{
	cvar_t     *cvar;
	cvar_alias_t *alias;
	int         len;

	len = strlen (partial);

	if (!len)
		return NULL;

	// check exact match
	for (cvar = cvar_vars; cvar; cvar = cvar->next)
		if (!strcmp (partial, cvar->name))
			return cvar->name;

	// check aliases too :)
	for (alias = calias_vars; alias; alias = alias->next)
		if (!strcmp (partial, alias->name))
			return alias->name;

	// check partial match
	for (cvar = cvar_vars; cvar; cvar = cvar->next)
		if (!strncmp (partial, cvar->name, len))
			return cvar->name;

	// check aliases too :)
	for (alias = calias_vars; alias; alias = alias->next)
		if (!strncmp (partial, alias->name, len))
			return alias->name;

	return NULL;
}

/*
	CVar_CompleteCountPossible

	New function for tab-completion system
	Added by EvilTypeGuy
	Thanks to Fett erich@heintz.com
*/
VISIBLE int
Cvar_CompleteCountPossible (const char *partial)
{
	cvar_t	*cvar;
	int		len;
	int		h;

	h = 0;
	len = strlen(partial);

	if (!len)
		return	0;

	// Loop through the cvars and count all possible matches
	for (cvar = cvar_vars; cvar; cvar = cvar->next)
		if (!strncmp(partial, cvar->name, len))
			h++;

	return h;
}

/*
	CVar_CompleteBuildList

	New function for tab-completion system
	Added by EvilTypeGuy
	Thanks to Fett erich@heintz.com
	Thanks to taniwha
*/
VISIBLE const char	**
Cvar_CompleteBuildList (const char *partial)
{
	cvar_t	*cvar;
	int		len = 0;
	int		bpos = 0;
	int		sizeofbuf = (Cvar_CompleteCountPossible (partial) + 1) *
						 sizeof (char *);
	const char	**buf;

	len = strlen(partial);
	buf = malloc(sizeofbuf + sizeof (char *));
	SYS_CHECKMEM (buf);
	// Loop through the alias list and print all matches
	for (cvar = cvar_vars; cvar; cvar = cvar->next)
		if (!strncmp(partial, cvar->name, len))
			buf[bpos++] = cvar->name;

	buf[bpos] = NULL;
	return buf;
}

VISIBLE void
Cvar_Set (cvar_t *var, const char *value)
{
	int     changed;
	int     vals;

	if (!var)
		return;

	if (var->flags & CVAR_ROM) {
		Sys_MaskPrintf (SYS_DEV, "Cvar \"%s\" is read-only, cannot modify\n",
						var->name);
		return;
	}

	changed = !strequal (var->string, value);
	free ((char*)var->string);					// free the old value string

	var->string = strdup (value);
	var->value = atof (var->string);
	var->int_val = atoi (var->string);
	VectorZero (var->vec);
	vals = sscanf (var->string, "%f %f %f",
				   &var->vec[0], &var->vec[1], &var->vec[2]);
	if (vals == 1)
		var->vec[2] = var->vec[1] = var->vec[0];

	if (changed && var->callback)
		var->callback (var);
}

VISIBLE void
Cvar_SetValue (cvar_t *var, float value)
{
	Cvar_Set (var, va ("%g", value));
}

/*
	Cvar_Command

	Handles variable inspection and changing from the console
*/
VISIBLE qboolean
Cvar_Command (void)
{
	cvar_t     *v;

	// check variables
	v = Cvar_FindVar (Cmd_Argv (0));
	if (!v)
		v = Cvar_FindAlias (Cmd_Argv (0));
	if (!v)
		return false;

	// perform a variable print or set
	if (Cmd_Argc () == 1) {
		Sys_Printf ("\"%s\" is \"%s\"\n", v->name, v->string);
		return true;
	}

	Cvar_Set (v, Cmd_Argv (1));
	return true;
}

/*
	Cvar_WriteVariables

	Writes lines containing "seta variable value" for all variables
	with the archive flag set to true.
*/
VISIBLE void
Cvar_WriteVariables (QFile *f)
{
	cvar_t     *var;

	for (var = cvar_vars; var; var = var->next)
		if (var->flags & CVAR_ARCHIVE)
			Qprintf (f, "seta %s \"%s\"\n", var->name, var->string);
}

static void
set_cvar (const char *cmd, int orflags)
{
	cvar_t     *var;
	const char *value;
	const char *var_name;

	if (Cmd_Argc () != 3) {
		Sys_Printf ("usage: %s <cvar> <value>\n", cmd);
		return;
	}

	var_name = Cmd_Argv (1);
	value = Cmd_Argv (2);
	var = Cvar_FindVar (var_name);

	if (!var)
		var = Cvar_FindAlias (var_name);

	if (var) {
		if (var->flags & CVAR_ROM) {
			Sys_MaskPrintf (SYS_DEV,
							"Cvar \"%s\" is read-only, cannot modify\n",
							var_name);
		} else {
			Cvar_Set (var, value);
			Cvar_SetFlags (var, var->flags | orflags);
		}
	} else {
		var = Cvar_Get (var_name, value, CVAR_USER_CREATED | orflags, NULL,
						USER_CVAR);
	}
}

static void
Cvar_Set_f (void)
{
	set_cvar ("set", CVAR_NONE);
}

static void
Cvar_Setrom_f (void)
{
	set_cvar ("setrom", CVAR_ROM);
}

static void
Cvar_Seta_f (void)
{
	set_cvar ("seta", CVAR_ARCHIVE);
}

static void
Cvar_Inc_f (void)
{
	cvar_t     *var;
	float       inc = 1;
	const char *name;

	switch (Cmd_Argc ()) {
		default:
		case 1:
			Sys_Printf ("inc <cvar> [amount] : increment cvar\n");
			return;
		case 3:
			inc = atof (Cmd_Argv (2));
		case 2:
			name = Cmd_Argv (1);
			var = Cvar_FindVar (name);
			if (!var)
				var = Cvar_FindAlias (name);
			if (!var)
				Sys_Printf ("Unknown variable \"%s\"\n", name);
			break;
	}
	Cvar_SetValue (var, var->value + inc);
}

static void
Cvar_Toggle_f (void)
{
	cvar_t     *var;

	if (Cmd_Argc () != 2) {
		Sys_Printf ("toggle <cvar> : toggle a cvar on/off\n");
		return;
	}

	var = Cvar_FindVar (Cmd_Argv (1));
	if (!var)
		var = Cvar_FindAlias (Cmd_Argv (1));
	if (!var) {
		Sys_Printf ("Unknown variable \"%s\"\n", Cmd_Argv (1));
		return;
	}

	Cvar_Set (var, var->int_val ? "0" : "1");
}

static void
Cvar_Cycle_f (void)
{
	int         i;
	const char *name;
	cvar_t     *var;

	if (Cmd_Argc () < 3) {
		Sys_Printf ("cycle <cvar> <value list>: cycle cvar through a list of "
					"values\n");
		return;
	}

	name = Cmd_Argv (1);
	var = Cvar_FindVar (name);
	if (!var)
		var = Cvar_FindAlias (name);
	if (!var) {
		var = Cvar_Get (name, Cmd_Argv (Cmd_Argc () - 1), CVAR_USER_CREATED,
						0, USER_CVAR);
	}

	// loop through the args until you find one that matches the current cvar
	// value. yes, this will get stuck on a list that contains the same value
	// twice. it's not worth dealing with, and i'm not even sure it can be
	// dealt with -- johnfitz
	for (i = 2; i < Cmd_Argc (); i++) {
		// zero is assumed to be a string, even though it could actually be
		// zero. The worst case is that the first time you call this command,
		// it won't match on zero when it should, but after that, it will be
		// comparing string that all had the same source (the user) so it will
		// work.
		if (atof (Cmd_Argv (i)) == 0) {
			if (!strcmp (Cmd_Argv (i), var->string))
				break;
		} else {
			if (atof (Cmd_Argv (i)) == var->value)
				break;
		}
	}

	if (i == Cmd_Argc ())
		Cvar_Set (var, Cmd_Argv (2));	// no match
	else if (i + 1 == Cmd_Argc ())
		Cvar_Set (var, Cmd_Argv (2));	// matched last value in list
	else
		Cvar_Set (var, Cmd_Argv (i + 1));	// matched earlier in list
}

static void
Cvar_Reset (cvar_t *var)
{
	Cvar_Set (var, var->default_string);
}

static void
Cvar_Reset_f (void)
{
	cvar_t     *var;
	const char *name;

	switch (Cmd_Argc ()) {
		default:
		case 1:
			Sys_Printf ("reset <cvar> : reset cvar to default\n");
			break;
		case 2:
			name = Cmd_Argv (1);
			var = Cvar_FindVar (name);
			if (!var)
				var = Cvar_FindAlias (name);
			if (!var)
				Sys_Printf ("Unknown variable \"%s\"\n", name);
			else
				Cvar_Reset (var);
			break;
	}
}

static void
Cvar_ResetAll_f (void)
{
	cvar_t     *var;

	for (var = cvar_vars; var; var = var->next)
		if (!(var->flags & CVAR_ROM))
			Cvar_Reset (var);
}

static void
Cvar_CvarList_f (void)
{
	cvar_t     *var;
	int         i;
	int         showhelp = 0;
	const char *flags;

	if (Cmd_Argc () > 1) {
		showhelp = 1;
		if (strequal (Cmd_Argv (1), "cfg"))
			showhelp++;
	}
	for (var = cvar_vars, i = 0; var; var = var->next, i++) {
		flags = va ("%c%c%c%c",
					var->flags & CVAR_ROM ? 'r' : ' ',
					var->flags & CVAR_ARCHIVE ? '*' : ' ',
					var->flags & CVAR_USERINFO ? 'u' : ' ',
					var->flags & CVAR_SERVERINFO ? 's' : ' ');
		if (showhelp == 2)
			Sys_Printf ("//%s %s\n%s \"%s\"\n\n", flags, var->description,
						var->name, var->string);
		else if (showhelp)
			Sys_Printf ("%s %-20s : %s\n", flags, var->name, var->description);
		else
			Sys_Printf ("%s %s\n", flags, var->name);
	}

	Sys_Printf ("------------\n%d variables\n", i);
}

static void
cvar_free (void *c, void *unused)
{
	cvar_t *cvar = (cvar_t*)c;
	free ((char*)cvar->name);
	free ((char*)cvar->string);
	free (cvar);
}

static const char *
cvar_get_key (const void *c, void *unused)
{
	cvar_t *cvar = (cvar_t*)c;
	return cvar->name;
}

static void
calias_free (void *c, void *unused)
{
	cvar_alias_t *calias = (cvar_alias_t *) c;
	free (calias->name);
	free (calias);
}

static const char *
calias_get_key (const void *c, void *unused)
{
	cvar_alias_t *calias = (cvar_alias_t *) c;
	return calias->name;
}

VISIBLE void
Cvar_Init_Hash (void)
{
	cvar_hash = Hash_NewTable (1021, cvar_get_key, cvar_free, 0);
	calias_hash = Hash_NewTable (1021, calias_get_key, calias_free, 0);
}

VISIBLE void
Cvar_Init (void)
{
	developer = Cvar_Get ("developer", "0", CVAR_NONE, NULL,
			"set to enable extra debugging information");

	Cmd_AddCommand ("set", Cvar_Set_f, "Set the selected variable, useful on "
					"the command line (+set variablename setting)");
	Cmd_AddCommand ("setrom", Cvar_Setrom_f, "Set the selected variable and "
					"make it read-only, useful on the command line. "
					"(+setrom variablename setting)");
	Cmd_AddCommand ("seta", Cvar_Seta_f, "Set the selected variable, and make "
					"it archived, useful on the command line (+seta "
					"variablename setting)");
	Cmd_AddCommand ("toggle", Cvar_Toggle_f, "Toggle a cvar on or off");
	Cmd_AddCommand ("cvarlist", Cvar_CvarList_f, "List all cvars");
	Cmd_AddCommand ("cycle", Cvar_Cycle_f,
					"Cycle a cvar through a list of values");
	Cmd_AddCommand ("inc", Cvar_Inc_f, "Increment a cvar");
	Cmd_AddCommand ("reset", Cvar_Reset_f, "Reset a cvar");
	Cmd_AddCommand ("resetall", Cvar_ResetAll_f, "Reset all cvars");
}

VISIBLE cvar_t *
Cvar_Get (const char *name, const char *string, int cvarflags,
		  void (*callback)(cvar_t*), const char *description)
{

	cvar_t     *var;

	if (Cmd_Exists (name)) {
		Sys_Printf ("Cvar_Get: %s is a command\n", name);
		return NULL;
	}
	var = Cvar_FindVar (name);
	if (!var) {
		cvar_t    **v;
		var = (cvar_t *) calloc (1, sizeof (cvar_t));

		// Cvar doesn't exist, so we create it
		var->name = strdup (name);
		var->string = strdup (string);
		var->default_string = strdup (string);
		var->flags = cvarflags;
		var->callback = callback;
		var->description = description;
		var->value = atof (var->string);
		var->int_val = atoi (var->string);
		sscanf (var->string, "%f %f %f",
				&var->vec[0], &var->vec[1], &var->vec[2]);
		Hash_Add (cvar_hash, var);

		for (v = &cvar_vars; *v; v = &(*v)->next)
			if (strcmp ((*v)->name, var->name) >= 0)
				break;
		var->next = *v;
		*v = var;
	} else {
		// Cvar does exist, so we update the flags and return.
		var->flags &= ~CVAR_USER_CREATED;
		var->flags |= cvarflags;
		if (!var->callback)
			var->callback = callback;
		if (!var->description
			|| strequal (var->description, USER_RO_CVAR)
			|| strequal (var->description, USER_CVAR))
			var->description = description;
		if (!var->default_string)
			var->default_string = strdup (string);
	}
	if (var->callback)
		var->callback (var);

	return var;
}

/*
	Cvar_SetFlags

	sets a Cvar's flags simply and easily
*/
VISIBLE void
Cvar_SetFlags (cvar_t *var, int cvarflags)
{
	if (var == NULL)
		return;

	var->flags = cvarflags;
}
