<?php
/**
 * Joomla! Content Management System
 *
 * @copyright  Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved.
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\CMS\Log\Logger;

defined('JPATH_PLATFORM') or die;

use Joomla\CMS\Log\LogEntry;
use Joomla\CMS\Log\Logger;

\JLoader::import('joomla.filesystem.file');
\JLoader::import('joomla.filesystem.folder');

/**
 * Joomla! Formatted Text File Log class
 *
 * This class is designed to use as a base for building formatted text files for output. By
 * default it emulates the Syslog style format output. This is a disk based output format.
 *
 * @since  1.7.0
 */
class FormattedtextLogger extends Logger
{
	/**
	 * The format which each entry follows in the log file.
	 *
	 * All fields must be named in all caps and be within curly brackets eg. {FOOBAR}.
	 *
	 * @var    string
	 * @since  1.7.0
	 */
	protected $format = '{DATETIME}	{PRIORITY} {CLIENTIP}	{CATEGORY}	{MESSAGE}';

	/**
	 * The parsed fields from the format string.
	 *
	 * @var    array
	 * @since  1.7.0
	 */
	protected $fields = array();

	/**
	 * The full filesystem path for the log file.
	 *
	 * @var    string
	 * @since  1.7.0
	 */
	protected $path;

	/**
	 * If true, all writes will be deferred as long as possible.
	 * NOTE: Deferred logs may never be written if the application encounters a fatal error.
	 *
	 * @var    boolean
	 * @since  3.9.0
	 */
	protected $defer = false;

	/**
	 * If deferring, entries will be stored here prior to writing.
	 *
	 * @var    array
	 * @since  3.9.0
	 */
	protected $deferredEntries = array();

	/**
	 * Constructor.
	 *
	 * @param   array  &$options  Log object options.
	 *
	 * @since   1.7.0
	 */
	public function __construct(array &$options)
	{
		// Call the parent constructor.
		parent::__construct($options);

		// The name of the text file defaults to 'error.php' if not explicitly given.
		if (empty($this->options['text_file']))
		{
			$this->options['text_file'] = 'error.php';
		}

		// The name of the text file path defaults to that which is set in configuration if not explicitly given.
		if (empty($this->options['text_file_path']))
		{
			$this->options['text_file_path'] = \JFactory::getConfig()->get('log_path');
		}

		// False to treat the log file as a php file.
		if (empty($this->options['text_file_no_php']))
		{
			$this->options['text_file_no_php'] = false;
		}

		// Build the full path to the log file.
		$this->path = $this->options['text_file_path'] . '/' . $this->options['text_file'];

		// Use the default entry format unless explicitly set otherwise.
		if (!empty($this->options['text_entry_format']))
		{
			$this->format = (string) $this->options['text_entry_format'];
		}

		// Wait as long as possible before writing logs
		if (!empty($this->options['defer']))
		{
			$this->defer = (boolean) $this->options['defer'];
		}

		// Build the fields array based on the format string.
		$this->parseFields();
	}

	/**
	 * If deferred, write all pending logs.
	 *
	 * @since  3.9.0
	 */
	public function __destruct()
	{
		// Nothing to do
		if (!$this->defer || empty($this->deferredEntries))
		{
			return;
		}

		// Initialise the file if not already done.
		$this->initFile();

		// Format all lines and write to file.
		$lines = array_map(array($this, 'formatLine'), $this->deferredEntries);

		if (!\JFile::append($this->path, implode("\n", $lines) . "\n"))
		{
			throw new \RuntimeException('Cannot write to log file.');
		}
	}

	/**
	 * Method to add an entry to the log.
	 *
	 * @param   LogEntry  $entry  The log entry object to add to the log.
	 *
	 * @return  void
	 *
	 * @since   1.7.0
	 * @throws  \RuntimeException
	 */
	public function addEntry(LogEntry $entry)
	{
		// Store the entry to be written later.
		if ($this->defer)
		{
			$this->deferredEntries[] = $entry;
		}
		// Write it immediately.
		else
		{
			// Initialise the file if not already done.
			$this->initFile();

			// Write the new entry to the file.
			$line = $this->formatLine($entry);
			$line .= "\n";

			if (!\JFile::append($this->path, $line))
			{
				throw new \RuntimeException('Cannot write to log file.');
			}
		}
	}

	/**
	 * Format a line for the log file.
	 *
	 * @param   JLogEntry  $entry  The log entry to format as a string.
	 *
	 * @return  String
	 *
	 * @since  3.9.0
	 */
	protected function formatLine(LogEntry $entry)
	{
		// Set some default field values if not already set.
		if (!isset($entry->clientIP))
		{
			// Check for proxies as well.
			if (isset($_SERVER['REMOTE_ADDR']))
			{
				$entry->clientIP = $_SERVER['REMOTE_ADDR'];
			}
			elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR']))
			{
				$entry->clientIP = $_SERVER['HTTP_X_FORWARDED_FOR'];
			}
			elseif (isset($_SERVER['HTTP_CLIENT_IP']))
			{
				$entry->clientIP = $_SERVER['HTTP_CLIENT_IP'];
			}
		}

		// If the time field is missing or the date field isn't only the date we need to rework it.
		if ((strlen($entry->date) != 10) || !isset($entry->time))
		{
			// Get the date and time strings in GMT.
			$entry->datetime = $entry->date->toISO8601();
			$entry->time = $entry->date->format('H:i:s', false);
			$entry->date = $entry->date->format('Y-m-d', false);
		}

		// Get a list of all the entry keys and make sure they are upper case.
		$tmp = array_change_key_case(get_object_vars($entry), CASE_UPPER);

		// Decode the entry priority into an English string.
		$tmp['PRIORITY'] = $this->priorities[$entry->priority];

		// Fill in field data for the line.
		$line = $this->format;

		foreach ($this->fields as $field)
		{
			$line = str_replace('{' . $field . '}', (isset($tmp[$field])) ? $tmp[$field] : '-', $line);
		}

		return $line;
	}

	/**
	 * Method to generate the log file header.
	 *
	 * @return  string  The log file header
	 *
	 * @since   1.7.0
	 */
	protected function generateFileHeader()
	{
		$head = array();

		// Build the log file header.

		// If the no php flag is not set add the php die statement.
		if (empty($this->options['text_file_no_php']))
		{
			// Blank line to prevent information disclose: https://bugs.php.net/bug.php?id=60677
			$head[] = '#';
			$head[] = '#<?php die(\'Forbidden.\'); ?>';
		}

		$head[] = '#Date: ' . gmdate('Y-m-d H:i:s') . ' UTC';
		$head[] = '#Software: ' . \JPlatform::getLongVersion();
		$head[] = '';

		// Prepare the fields string
		$head[] = '#Fields: ' . strtolower(str_replace('}', '', str_replace('{', '', $this->format)));
		$head[] = '';

		return implode("\n", $head);
	}

	/**
	 * Method to initialise the log file.  This will create the folder path to the file if it doesn't already
	 * exist and also get a new file header if the file doesn't already exist.  If the file already exists it
	 * will simply open it for writing.
	 *
	 * @return  void
	 *
	 * @since   1.7.0
	 * @throws  \RuntimeException
	 */
	protected function initFile()
	{
		// We only need to make sure the file exists
		if (\JFile::exists($this->path))
		{
			return;
		}

		// Make sure the folder exists in which to create the log file.
		\JFolder::create(dirname($this->path));

		// Build the log file header.
		$head = $this->generateFileHeader();

		if (!\JFile::write($this->path, $head))
		{
			throw new \RuntimeException('Cannot write to log file.');
		}
	}

	/**
	 * Method to parse the format string into an array of fields.
	 *
	 * @return  void
	 *
	 * @since   1.7.0
	 */
	protected function parseFields()
	{
		$this->fields = array();
		$matches = array();

		// Get all of the available fields in the format string.
		preg_match_all('/{(.*?)}/i', $this->format, $matches);

		// Build the parsed fields list based on the found fields.
		foreach ($matches[1] as $match)
		{
			$this->fields[] = strtoupper($match);
		}
	}
}
