<?php

/**
 * This file is part of the ramsey/uuid library
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * @copyright Copyright (c) Ben Ramsey <ben@benramsey.com>
 * @license http://opensource.org/licenses/MIT MIT
 * @link https://benramsey.com/projects/ramsey-uuid/ Documentation
 * @link https://packagist.org/packages/ramsey/uuid Packagist
 * @link https://github.com/ramsey/uuid GitHub
 */
namespace PixelCaffeine\Dependencies\Ramsey\Uuid\Provider\Node;

use Exception;
use PixelCaffeine\Dependencies\Ramsey\Uuid\Provider\NodeProviderInterface;
/**
 * RandomNodeProvider provides functionality to generate a random node ID, in
 * the event that the node ID could not be obtained from the host system
 *
 * @link http://tools.ietf.org/html/rfc4122#section-4.5
 */
class RandomNodeProvider implements \PixelCaffeine\Dependencies\Ramsey\Uuid\Provider\NodeProviderInterface
{
    /**
     * Returns the system node ID
     *
     * @return string System node ID as a hexadecimal string
     * @throws Exception if it was not possible to gather sufficient entropy
     */
    public function getNode()
    {
        $nodeBytes = \random_bytes(6);
        // Split the node bytes for math on 32-bit systems.
        $nodeMsb = \substr($nodeBytes, 0, 3);
        $nodeLsb = \substr($nodeBytes, 3);
        // Set the multicast bit; see RFC 4122, section 4.5.
        $nodeMsb = \hex2bin(\str_pad(\dechex(\hexdec(\bin2hex($nodeMsb)) | 0x10000), 6, '0', \STR_PAD_LEFT));
        // Recombine the node bytes.
        $node = $nodeMsb . $nodeLsb;
        return \str_pad(\bin2hex($node), 12, '0', \STR_PAD_LEFT);
    }
}
