<?php

declare(strict_types=1);

namespace App\Domain\Entity;

abstract class AEntity
{
    protected string $id;

    public function __construct()
    {
        $this->id = $this->generateUUIDv4();
    }

    /**
     * @author Grégoire Pineau <lyrixx@lyrixx.info>
     *
     * https://github.com/symfony/polyfill-uuid/blob/a41886c1c81dc075a09c71fe6db5b9d68c79de23/Uuid.php#L378-L438
     */
    private function generateUUIDv4(): string
    {
        $timeOffsetInt = 0x01B21DD213814000;

        $time = microtime(false);
        $time = substr($time, 11) . substr($time, 2, 7);

        $time = str_pad(dechex((int) $time + $timeOffsetInt), 16, '0', \STR_PAD_LEFT);

        // https://tools.ietf.org/html/rfc4122#section-4.1.5
        // We are using a random data for the sake of simplicity: since we are
        // not able to get a super precise timeOfDay as a unique sequence
        $clockSeq = random_int(0, 0x3FFF);

        static $node;
        if (null === $node) {
            if (\function_exists('apcu_fetch')) {
                $node = apcu_fetch('__symfony_uuid_node');
                if (false === $node) {
                    $node = sprintf(
                        '%06x%06x',
                        random_int(0, 0xFFFFFF) | 0x010000,
                        random_int(0, 0xFFFFFF)
                    );
                    apcu_store('__symfony_uuid_node', $node);
                }
            } else {
                $node = sprintf(
                    '%06x%06x',
                    random_int(0, 0xFFFFFF) | 0x010000,
                    random_int(0, 0xFFFFFF)
                );
            }
        }

        return sprintf(
            '%08s-%04s-1%03s-%04x-%012s',
            // 32 bits for "time_low"
            substr($time, -8),

            // 16 bits for "time_mid"
            substr($time, -12, 4),

            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 1
            substr($time, -15, 3),

            // 16 bits:
            // * 8 bits for "clk_seq_hi_res",
            // * 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            $clockSeq | 0x8000,

            // 48 bits for "node"
            $node
        );
    }
}