/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * String manipulation dialplan functions
 * 
 * Copyright (C) 2005, Digium, Inc.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */

#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <regex.h>

#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/logger.h"
#include "asterisk/utils.h"
#include "asterisk/app.h"

static char *function_fieldqty(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len)
{
	char *varname, *varval, workspace[256];
	char *delim = ast_strdupa(data);
	int fieldcount = 0;

	if (delim) {
		varname = strsep(&delim, "|");
		pbx_retrieve_variable(chan, varname, &varval, workspace, sizeof(workspace), NULL);
		while (strsep(&varval, delim))
			fieldcount++;
		snprintf(buf, len, "%d", fieldcount);
	} else {
		ast_log(LOG_ERROR, "Out of memory\n");
		strncpy(buf, "1", len);
	}
	return buf;
}

#ifndef BUILTIN_FUNC
static
#endif
struct ast_custom_function fieldqty_function = {
	.name = "FIELDQTY",
	.synopsis = "Count the fields, with an arbitrary delimiter",
	.syntax = "FIELDQTY(<varname>,<delim>)",
	.read = function_fieldqty,
};

static char *builtin_function_regex(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len) 
{
	char *ret_true = "1", *ret_false = "0", *ret;
	char *arg, *earg, *tmp, errstr[256] = "";
	int errcode;
	regex_t regexbuf;

	ret = ret_false; /* convince me otherwise */
	tmp = ast_strdupa(data);
	if (tmp) {
		/* Regex in quotes */
		arg = strchr(tmp, '"');
		if (arg) {
			arg++;
			earg = strrchr(arg, '"');
			if (earg) {
				*earg = '\0';
			}
		} else {
			arg = tmp;
		}

		if ((errcode = regcomp(&regexbuf, arg, REG_EXTENDED | REG_NOSUB))) {
			regerror(errcode, &regexbuf, errstr, sizeof(errstr));
			ast_log(LOG_WARNING, "Malformed input %s(%s): %s\n", cmd, data, errstr);
			ret = NULL;
		} else {
			ret = regexec(&regexbuf, data, 0, NULL, 0) ? ret_false : ret_true;
		}
		regfree(&regexbuf);
	} else {
		ast_log(LOG_ERROR, "Out of memory in %s(%s)\n", cmd, data);
	}

	return ret;
}

#ifndef BUILTIN_FUNC
static
#endif
struct ast_custom_function regex_function = {
	.name = "REGEX",
	.synopsis = "Regular Expression: Returns 1 if data matches regular expression.",
	.syntax = "REGEX(\"<regular expression>\" <data>)",
	.read = builtin_function_regex,
};

static char *builtin_function_len(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len) 
{
	int length = 0;
	if (data) {
		length = strlen(data);
	}
	snprintf(buf, len, "%d", length);
	return buf;
}

#ifndef BUILTIN_FUNC
static
#endif
struct ast_custom_function len_function = {
	.name = "LEN",
	.synopsis = "Returns the length of the argument given",
	.syntax = "LEN(<string>)",
	.read = builtin_function_len,
};