<?php
/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *	   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @package log4php
 */

/**
 * Returns the date/time of the logging request.
 * 
 * Option: the datetime format, as used by the date() function. If 
 * the option is not given, the default format 'c' will be used.
 * 
 * There are several "special" values which can be given for this option:
 * 'ISO8601', 'ABSOLUTE' and 'DATE'.
 * 
 * @package log4php
 * @subpackage pattern
 * @version $Revision$
 * @since 2.3
 */
class LoggerPatternConverterDate extends LoggerPatternConverter {

	const DATE_FORMAT_ISO8601 = 'c';
	
	const DATE_FORMAT_ABSOLUTE = 'H:i:s';
	
	const DATE_FORMAT_DATE = 'd M Y H:i:s.u';
	
	private $format = self::DATE_FORMAT_ISO8601;
	
	private $specials = array(
		'ISO8601' => self::DATE_FORMAT_ISO8601,
		'ABSOLUTE' => self::DATE_FORMAT_ABSOLUTE,
		'DATE' => self::DATE_FORMAT_DATE,
	);
	
	private $useLocalDate = false;
	
	public function activateOptions() {
		
		// Parse the option (date format)
		if (!empty($this->option)) {
			if(isset($this->specials[$this->option])) {
				$this->format = $this->specials[$this->option];
			} else {
				$this->format = $this->option;
			}
		}
		
		// Check whether the pattern contains milliseconds (u)
		if (preg_match('/(?<!\\\\)u/', $this->format)) {
			$this->useLocalDate = true;
		}
	}
	
	public function convert(LoggerLoggingEvent $event) {
		if ($this->useLocalDate) {
			return $this->date($this->format, $event->getTimeStamp());
		}
		return date($this->format, $event->getTimeStamp());
	}
	
	/**
	 * Currently, PHP date() function always returns zeros for milliseconds (u)
	 * on Windows. This is a replacement function for date() which correctly 
	 * displays milliseconds on all platforms. 
	 * 
	 * It is slower than PHP date() so it should only be used if necessary. 
	 */
	private function date($format, $utimestamp) {
		$timestamp = floor($utimestamp);
		$ms = floor(($utimestamp - $timestamp) * 1000);
		$ms = str_pad($ms, 3, '0', STR_PAD_LEFT);
	
		return date(preg_replace('`(?<!\\\\)u`', $ms, $format), $timestamp);
	}
}