/**

 * @file enc_syslog.c

 * Encoder for syslog format.

 * This file contains code from all related objects that is required in

 * order to encode syslog format. The core idea of putting all of this into

 * a single file is that this makes it very straightforward to write

 * encoders for different encodings, as all is in one place.

 */

/*

 * liblognorm - a fast samples-based log normalization library

 * Copyright 2010-2016 by Rainer Gerhards and Adiscon GmbH.

 *

 * Modified by Pavel Levshin (pavel@levshin.spb.ru) in 2013

 *

 * This file is part of liblognorm.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 *

 * A copy of the LGPL v2.1 can be found in the file "COPYING" in this distribution.

 */

#include "config.h"

#include <stdlib.h>

#include <stdio.h>

#include <stdarg.h>

#include <assert.h>

#include <string.h>

#include <libestr.h>

#include "internal.h"

#include "liblognorm.h"

#include "enc.h"

static int

ln_addValue_Syslog(const char *value, es_str_t **str)

{

	int r;

	es_size_t i;

	assert(str != NULL);

	assert(*str != NULL);

	assert(value != NULL);

	for(i = 0; i < strlen(value); i++) {

		switch(value[i]) {

		case '\0':

			es_addChar(str, '\\');

			es_addChar(str, '0');

			break;

		case '\n':

			es_addChar(str, '\\');

			es_addChar(str, 'n');

			break;

		/* TODO : add rest of control characters here... */

		case ',': /* comma is CEE-reserved for lists */

			es_addChar(str, '\\');

			es_addChar(str, ',');

			break;

#if 0 /* alternative encoding for discussion */

		case '^': /* CEE-reserved for lists */

			es_addChar(str, '\\');

			es_addChar(str, '^');

			break;

#endif

		/* at this layer ... do we need to think about transport

		 * encoding at all? Or simply leave it to the transport agent?

		 */

		case '\\': /* RFC5424 reserved */

			es_addChar(str, '\\');

			es_addChar(str, '\\');

			break;

		case ']': /* RFC5424 reserved */

			es_addChar(str, '\\');

			es_addChar(str, ']');

			break;

		case '\"': /* RFC5424 reserved */

			es_addChar(str, '\\');

			es_addChar(str, '\"');

			break;

		default:

			es_addChar(str, value[i]);

			break;

		}

	}

	r = 0;

	return r;

}

static int

ln_addField_Syslog(char *name, struct json_object *field, es_str_t **str)

{

	int r;

	const char *value;

	int needComma = 0;

	struct json_object *obj;

	int i;

	assert(field != NULL);

	assert(str != NULL);

	assert(*str != NULL);

	CHKR(es_addBuf(str, name, strlen(name)));

	CHKR(es_addBuf(str, "=\"", 2));

	switch(json_object_get_type(field)) {

	case json_type_array:

		for (i = json_object_array_length(field) - 1; i >= 0; i--) {

			if(needComma)

				es_addChar(str, ',');

			else

				needComma = 1;

			CHKN(obj = json_object_array_get_idx(field, i));

			CHKN(value = json_object_get_string(obj));

			CHKR(ln_addValue_Syslog(value, str));

		}

		break;

	case json_type_string:

	case json_type_int:

		CHKN(value = json_object_get_string(field));

		CHKR(ln_addValue_Syslog(value, str));

		break;

	case json_type_null:

	case json_type_boolean:

	case json_type_double:

	case json_type_object:

		CHKR(es_addBuf(str, "***unsupported type***", sizeof("***unsupported type***")-1));

		break;

	default:

		CHKR(es_addBuf(str, "***OBJECT***", sizeof("***OBJECT***")-1));

	}

	CHKR(es_addChar(str, '\"'));

	r = 0;

done:

	return r;

}

static inline int

ln_addTags_Syslog(struct json_object *taglist, es_str_t **str)

{

	int r = 0;

	struct json_object *tagObj;

	int needComma = 0;

	const char *tagCstr;

	int i;

	assert(json_object_is_type(taglist, json_type_array));

	CHKR(es_addBuf(str, " event.tags=\"", 13));

	for (i = json_object_array_length(taglist) - 1; i >= 0; i--) {

		if(needComma)

			es_addChar(str, ',');

		else

			needComma = 1;

		CHKN(tagObj = json_object_array_get_idx(taglist, i));

		CHKN(tagCstr = json_object_get_string(tagObj));

		CHKR(es_addBuf(str, (char*)tagCstr, strlen(tagCstr)));

	}

	es_addChar(str, '"');

done:	return r;

}

int

ln_fmtEventToRFC5424(struct json_object *json, es_str_t **str)

{

	int r = -1;

	struct json_object *tags;

	assert(json != NULL);

	assert(json_object_is_type(json, json_type_object));

	if((*str = es_newStr(256)) == NULL)

		goto done;

	es_addBuf(str, "[cee@115", 8);

	if(json_object_object_get_ex(json, "event.tags", &tags)) {

		CHKR(ln_addTags_Syslog(tags, str));

	}

	struct json_object_iterator it = json_object_iter_begin(json);

	struct json_object_iterator itEnd = json_object_iter_end(json);

	while (!json_object_iter_equal(&it, &itEnd)) {

		char *const name = (char*)json_object_iter_peek_name(&it);

		if (strcmp(name, "event.tags")) {

			es_addChar(str, ' ');

			ln_addField_Syslog(name, json_object_iter_peek_value(&it), str);

		}

		json_object_iter_next(&it);

	}

	es_addChar(str, ']');

done:

	return r;

}