<?php



/*

 * This file is part of the Monolog package.

 *

 * (c) Jordi Boggiano <j.boggiano@seld.be>

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */



namespace Monolog\Handler;



use Monolog\Logger;



/**

 * Stores logs to files that are rotated every day and a limited number of files are kept.

 *

 * This rotation is only intended to be used as a workaround. Using logrotate to

 * handle the rotation is strongly encouraged when you can use it.

 *

 * @author Christophe Coevoet <stof@notk.org>

 * @author Jordi Boggiano <j.boggiano@seld.be>

 */

class RotatingFileHandler extends StreamHandler

{

    const FILE_PER_DAY = 'Y-m-d';

    const FILE_PER_MONTH = 'Y-m';

    const FILE_PER_YEAR = 'Y';



    protected $filename;

    protected $maxFiles;

    protected $mustRotate;

    protected $nextRotation;

    protected $filenameFormat;

    protected $dateFormat;



    /**

     * @param string   $filename

     * @param int      $maxFiles       The maximal amount of files to keep (0 means unlimited)

     * @param int      $level          The minimum logging level at which this handler will be triggered

     * @param Boolean  $bubble         Whether the messages that are handled can bubble up the stack or not

     * @param int|null $filePermission Optional file permissions (default (0644) are only for owner read/write)

     * @param Boolean  $useLocking     Try to lock log file before doing any writes

     */

    public function __construct($filename, $maxFiles = 0, $level = Logger::DEBUG, $bubble = true, $filePermission = null, $useLocking = false)

    {

        $this->filename = $filename;

        $this->maxFiles = (int) $maxFiles;

        $this->nextRotation = new \DateTime('tomorrow');

        $this->filenameFormat = '{filename}-{date}';

        $this->dateFormat = 'Y-m-d';



        parent::__construct($this->getTimedFilename(), $level, $bubble, $filePermission, $useLocking);

    }



    /**

     * {@inheritdoc}

     */

    public function close()

    {

        parent::close();



        if (true === $this->mustRotate) {

            $this->rotate();

        }

    }



    public function setFilenameFormat($filenameFormat, $dateFormat)

    {

        if (!preg_match('{^Y(([/_.-]?m)([/_.-]?d)?)?$}', $dateFormat)) {

            trigger_error(

                'Invalid date format - format must be one of '.

                'RotatingFileHandler::FILE_PER_DAY ("Y-m-d"), RotatingFileHandler::FILE_PER_MONTH ("Y-m") '.

                'or RotatingFileHandler::FILE_PER_YEAR ("Y"), or you can set one of the '.

                'date formats using slashes, underscores and/or dots instead of dashes.',

                E_USER_DEPRECATED

            );

        }

        if (substr_count($filenameFormat, '{date}') === 0) {

            trigger_error(

                'Invalid filename format - format should contain at least `{date}`, because otherwise rotating is impossible.',

                E_USER_DEPRECATED

            );

        }

        $this->filenameFormat = $filenameFormat;

        $this->dateFormat = $dateFormat;

        $this->url = $this->getTimedFilename();

        $this->close();

    }



    /**

     * {@inheritdoc}

     */

    protected function write(array $record)

    {

        // on the first record written, if the log is new, we should rotate (once per day)

        if (null === $this->mustRotate) {

            $this->mustRotate = !file_exists($this->url);

        }



        if ($this->nextRotation < $record['datetime']) {

            $this->mustRotate = true;

            $this->close();

        }



        parent::write($record);

    }



    /**

     * Rotates the files.

     */

    protected function rotate()

    {

        // update filename

        $this->url = $this->getTimedFilename();

        $this->nextRotation = new \DateTime('tomorrow');



        // skip GC of old logs if files are unlimited

        if (0 === $this->maxFiles) {

            return;

        }



        $logFiles = glob($this->getGlobPattern());

        if ($this->maxFiles >= count($logFiles)) {

            // no files to remove

            return;

        }



        // Sorting the files by name to remove the older ones

        usort($logFiles, function ($a, $b) {

            return strcmp($b, $a);

        });



        foreach (array_slice($logFiles, $this->maxFiles) as $file) {

            if (is_writable($file)) {

                // suppress errors here as unlink() might fail if two processes

                // are cleaning up/rotating at the same time

                set_error_handler(function ($errno, $errstr, $errfile, $errline) {});

                unlink($file);

                restore_error_handler();

            }

        }



        $this->mustRotate = false;

    }



    protected function getTimedFilename()

    {

        $fileInfo = pathinfo($this->filename);

        $timedFilename = str_replace(

            array('{filename}', '{date}'),

            array($fileInfo['filename'], date($this->dateFormat)),

            $fileInfo['dirname'] . '/' . $this->filenameFormat

        );



        if (!empty($fileInfo['extension'])) {

            $timedFilename .= '.'.$fileInfo['extension'];

        }



        return $timedFilename;

    }



    protected function getGlobPattern()

    {

        $fileInfo = pathinfo($this->filename);

        $glob = str_replace(

            array('{filename}', '{date}'),

            array($fileInfo['filename'], '*'),

            $fileInfo['dirname'] . '/' . $this->filenameFormat

        );

        if (!empty($fileInfo['extension'])) {

            $glob .= '.'.$fileInfo['extension'];

        }



        return $glob;

    }

}

