/*
 * CallWeaver -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 * Portions Copyright (C) 2005, Anthony Minessale II
 *
 * See http://www.callweaver.org for more information about
 * the CallWeaver project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 * 
 * \brief Conditional logic dialplan functions
 * 
 */
#ifdef HAVE_CONFIG_H
#include "confdefs.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <ctype.h>

#include "callweaver.h"

CALLWEAVER_FILE_VERSION("$HeadURL$", "$Revision$")

#include "callweaver/module.h"
#include "callweaver/channel.h"
#include "callweaver/pbx.h"
#include "callweaver/logger.h"
#include "callweaver/utils.h"
#include "callweaver/app.h"
#include "callweaver/config.h"		/* for cw_true */

static void *isnull_function;
static const char *isnull_func_name = "ISNULL";
static const char *isnull_func_synopsis = "NULL Test: Returns 1 if NULL or 0 otherwise";
static const char *isnull_func_syntax = "ISNULL(data)";
static const char *isnull_func_desc = "";

static void *set_function;
static const char *set_func_name = "SET";
static const char *set_func_synopsis = "SET assigns a value to a channel variable";
static const char *set_func_syntax = "SET(varname=[value])";
static const char *set_func_desc = "";

static void *exists_function;
static const char *exists_func_name = "EXISTS";
static const char *exists_func_synopsis = "Existence Test: Returns 1 if exists, 0 otherwise";
static const char *exists_func_syntax = "EXISTS(data)";
static const char *exists_func_desc = "";

static void *if_function;
static const char *if_func_name = "IF";
static const char *if_func_synopsis = "Conditional: Returns the data following '?' if true else the data following ':'";
static const char *if_func_syntax = "IF(expr ? [true] [: false])";
static const char *if_func_desc =
"Returns the value of [true] if expr evaluates to true, otherwise returns\n"
"the value of [false]\n"
"NOTE: Both true and false are evaluated regardless of which is to be returned\n\n"
"DEPRECATED\n"
"This will fail if the true and/or false values evaluate to a string containing\n"
"a comma, colon or question mark.\n\n"
"Replace IF( A ? B : C ) with $[ A ? B :: C ]\n"
"e.g. for ${IF($[ ${A} = \"debug\" ] ? ${B} : ${C})}\n"
"     use $[ $[ \"${A}\" = \"debug\" ] ? \"${B}\" :: \"${C}\" ]\n";

static void *if_time_function;
static const char *if_time_func_name = "IFTIME";
static const char *if_time_func_synopsis = "Temporal Conditional: Returns the data following '?' if true else the data following ':'";
static const char *if_time_func_syntax = "IFTIME(timespec ? [true] [: false])";
static const char *if_time_func_desc = "";


static char *builtin_function_isnull(struct cw_channel *chan, int argc, char **argv, char *buf, size_t len) 
{
	return (argc > 0 && argv[0][0] ? "0" : "1");
}

static char *builtin_function_exists(struct cw_channel *chan, int argc, char **argv, char *buf, size_t len) 
{
	return (argc > 0 && argv[0][0] ? "1" : "0");
}

static char *builtin_function_iftime(struct cw_channel *chan, int argc, char **argv, char *buf, size_t len) 
{
	struct cw_timing timing;
	char *s, *q;  

	if (argc < 4 || argc > 6 || !(s = strchr(argv[3], '?'))) {
		cw_log(LOG_ERROR, "Syntax: %s\n", if_time_func_syntax);
		return NULL;
	}
	/* Trim trailing space from the timespec */
	q = s;
	do { *(q--) = '\0'; } while (q >= argv[3] && isspace(*q));
	pbx_extract_timing_fromargv(&timing, argc, argv);
	s++; // Move pointer after the '?' sign

	// Move pointer after ':' sign
	if ((q = strchr(s, ':'))) {
		*(q) = '\0';
		q++;
	}
	if (cw_check_timing(&timing)) {
		/* True: we want everything between '?' and ':' */
		cw_copy_string(buf, s, len);
	} else if (q && *(q) != '\0') {
		// False: we want everything after ':' (if anything) //
		cw_copy_string(buf, q, len);
	}
	return buf;
}

static char *builtin_function_if(struct cw_channel *chan, int argc, char **argv, char *buf, size_t len) 
{
	char *s, *q, **a;
	int i, n, l, first;

	static int deprecation_warning = 0;

	if (!deprecation_warning) {
		cw_log(LOG_WARNING, "IF(... ? ... : ...) is deprecated, please use $[ ... ? ... :: ... ] instead.\n");
		deprecation_warning = 1;
	}

	/* First argument is "<condition ? ..." */
	if (argc < 1 || !(s = strchr(argv[0], '?'))) {
		cw_log(LOG_ERROR, "Syntax: %s\n", if_func_syntax);
		return NULL;
	}

	/* Trim trailing space from the condition */
	q = s;
	do { *(q--) = '\0'; } while (q >= argv[0] && isspace(*q));

	do { *(s++) = '\0'; } while (isspace(*s));

	n = 0;
	if (cw_true(argv[0])) {
		/* True: we want everything between '?' and ':' */
		argv[0] = s;
		a = argv;
		for (i = 0; i < argc; i++) {
			if ((s = strchr(argv[i], ':'))) {
				do { *(s--) = '\0'; } while (s >= argv[i] && isspace(*s));
				n = i + 1;
				break;
			}
		}
	} else {
		/* False: we want everything after ':' (if anything) */
		argv[0] = s;
		for (i = 0; i < argc; i++) {
			if ((s = strchr(argv[i], ':'))) {
				do { *(s++) = '\0'; } while (isspace(*s));
				argv[i] = s;
				a = argv + i;
				n = argc - i;
				break;
			}
		}
		/* No ": ..." so we just drop through */
	}

	first = 1;
	len--; /* one for the terminating null */
	q = buf;
	for (i = 0; len && i < n; i++) {
		if (!first) {
			*(q++) = ',';
			len--;
		} else
			first = 0;
		l = strlen(a[i]);
		if (l > len)
			l = len;
		memcpy(q, a[i], l);
		q += l;
		len -= l;
	}
	*q = '\0';

	return buf;
}

static char *builtin_function_set(struct cw_channel *chan, int argc, char **argv, char *buf, size_t len) 
{
	char *p;

	if (argc != 1 || !argv[0][0] || !(p = strchr(argv[0], '='))) {
		cw_log(LOG_ERROR, "Syntax: %s\n", set_func_syntax);
		return NULL;
	}

	*(p++) = '\0';

	pbx_builtin_setvar_helper(chan, argv[0], p);
	cw_copy_string(buf, p, len);

	return buf;
}


static char *tdesc = "logic functions";

int unload_module(void)
{
        int res = 0;

	res |= cw_unregister_function(isnull_function);
	res |= cw_unregister_function(set_function);
	res |= cw_unregister_function(exists_function);
	res |= cw_unregister_function(if_function);
	res |= cw_unregister_function(if_time_function);
        return res;
}

int load_module(void)
{
	isnull_function = cw_register_function(isnull_func_name, builtin_function_isnull, NULL, isnull_func_synopsis, isnull_func_syntax, isnull_func_desc);
        set_function = cw_register_function(set_func_name, builtin_function_set, NULL, set_func_synopsis, set_func_syntax, set_func_desc);
        exists_function = cw_register_function(exists_func_name, builtin_function_exists, NULL, exists_func_synopsis, exists_func_syntax, exists_func_desc);
        if_function = cw_register_function(if_func_name, builtin_function_if, NULL, if_func_synopsis, if_func_syntax, if_func_desc);
        if_time_function = cw_register_function(if_time_func_name, builtin_function_iftime, NULL, if_time_func_synopsis, if_time_func_syntax, if_time_func_desc);
        return 0;
}

char *description(void)
{
	return tdesc;
}

int usecount(void)
{
	return 0;
}

/*
Local Variables:
mode: C
c-file-style: "linux"
indent-tabs-mode: nil
End:
*/