<?php

/*
* This file is part of Composer.
*
* (c) Nils Adermann <naderman@naderman.de>
* 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 Composer\Util;

/**
* Temporarily suppress PHP error reporting, usually warnings and below.
*
* @author Niels Keurentjes <niels.keurentjes@omines.com>
*/
class Silencer
{
/**
* @var int[] Unpop stack
*/
private static $stack = array();

/**
* Suppresses given mask or errors.
*
* @param int|null $mask Error levels to suppress, default value NULL indicates all warnings and below.
* @return int The old error reporting level.
*/
public static function suppress($mask = null)
{
if (!isset($mask)) {
$mask = E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT;
}
$old = error_reporting();
self::$stack[] = $old;
error_reporting($old & ~$mask);

return $old;
}

/**
* Restores a single state.
*/
public static function restore()
{
if (!empty(self::$stack)) {
error_reporting(array_pop(self::$stack));
}
}

/**
* Calls a specified function while silencing warnings and below.
*
* Future improvement: when PHP requirements are raised add Callable type hint (5.4) and variadic parameters (5.6)
*
* @param callable $callable Function to execute.
* @throws \Exception Any exceptions from the callback are rethrown.
* @return mixed Return value of the callback.
*/
public static function call($callable /*, ...$parameters */)
{
try {
self::suppress();
$result = call_user_func_array($callable, array_slice(func_get_args(), 1));
self::restore();

return $result;
} catch (\Exception $e) {
// Use a finally block for this when requirements are raised to PHP 5.5
self::restore();
throw $e;
}
}
}