<?php

/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/

namespace Symfony\Component\Console\Output;

use Symfony\Component\Console\Exception\InvalidArgumentException;
use Symfony\Component\Console\Formatter\OutputFormatterInterface;

/**
* A BufferedOutput that keeps only the last N chars.
*
* @author Jérémy Derussé <jeremy@derusse.com>
*/
class TrimmedBufferOutput extends Output
{
private $maxLength;
private $buffer = '';

public function __construct(int $maxLength, ?int $verbosity = self::VERBOSITY_NORMAL, bool $decorated = false, OutputFormatterInterface $formatter = null)
{
if ($maxLength <= 0) {
throw new InvalidArgumentException(sprintf('"%s()" expects a strictly positive maxLength. Got %d.', __METHOD__, $maxLength));
}

parent::__construct($verbosity, $decorated, $formatter);
$this->maxLength = $maxLength;
}

/**
* Empties buffer and returns its content.
*
* @return string
*/
public function fetch()
{
$content = $this->buffer;
$this->buffer = '';

return $content;
}

/**
* {@inheritdoc}
*/
protected function doWrite($message, $newline)
{
$this->buffer .= $message;

if ($newline) {
$this->buffer .= \PHP_EOL;
}

$this->buffer = substr($this->buffer, 0 - $this->maxLength);
}
}