<?php
/*
** Zabbix
** Copyright (C) 2001-2021 Zabbix SIA
**
** 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 the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
**/


/**
 * A converted for converting 1.8 trigger expressions.
 */
class C10TriggerConverter extends CConverter {

	/**
	 * A parser for function macros.
	 *
	 * @var CFunctionMacroParser
	 */
	protected $function_macro_parser;

	/**
	 * Converted used to convert simple check item keys.
	 *
	 * @var CConverter
	 */
	protected $itemKeyConverter;

	public function __construct() {
		$this->function_macro_parser = new CFunctionMacroParser(['18_simple_checks' => true]);
		$this->itemKeyConverter = new C10ItemKeyConverter();
	}

	/**
	 * Converts simple check item keys used in trigger expressions.
	 *
	 * @param string $expression
	 *
	 * @return string
	 */
	public function convert($expression) {
		$new_expression = '';

		for ($pos = 0; isset($expression[$pos]); $pos++) {
			if ($this->function_macro_parser->parse($expression, $pos) != CParser::PARSE_FAIL) {
				$new_expression .= '{'.
					$this->function_macro_parser->getHost().':'.
					$this->itemKeyConverter->convert($this->function_macro_parser->getItem()).'.'.
					$this->function_macro_parser->getFunction().
				'}';

				$pos += $this->function_macro_parser->getLength() - 1;
			}
			else {
				$new_expression .= $expression[$pos];
			}
		}

		return $new_expression;
	}
}
