<?php

declare(strict_types=1);

namespace Shared\Helpers;

use Ramsey\Uuid\Rfc4122\FieldsInterface as Rfc4122FieldsInterface;
use Ramsey\Uuid\Uuid;
use Ramsey\Uuid\UuidInterface;
use Shared\Exceptions\InvalidUuidException;

final readonly class UuidHelper
{
    private function __construct()
    {
        // Static class
    }

    public static function isV4(UuidInterface $uuid): bool
    {
        return self::version($uuid) === 4;
    }

    public static function isV7(UuidInterface $uuid): bool
    {
        return self::version($uuid) === 7;
    }

    public static function version(UuidInterface $uuid): int
    {
        $fields = $uuid->getFields();

        if ($fields instanceof Rfc4122FieldsInterface) {
            $version = $fields->getVersion();

            if ($version !== null) {
                return $version;
            }
        }

        $uuidString = $uuid->toString();

        if (strlen($uuidString) >= 15) {
            return (int) hexdec($uuidString[14]);
        }

        return 0;
    }

    public static function validateUuid(UuidInterface $uuid): void
    {
        if (! Uuid::isValid($uuid->toString())) {
            throw InvalidUuidException::forValue($uuid->toString());
        }
    }

    public static function toDateTime(UuidInterface $uuid): \DateTimeImmutable
    {
        if (! self::isV7($uuid)) {
            throw new InvalidUuidException("Cannot extract datetime from non-V7 UUID: {$uuid->toString()}");
        }

        $fields = $uuid->getFields();

        if ($fields instanceof Rfc4122FieldsInterface) {
            $timeMsHex = $fields->getTimeLow()->toString() . $fields->getTimeMid()->toString();
        } else {
            $hex       = str_replace('-', '', $uuid->toString());
            $timeMsHex = substr($hex, 0, 12);
        }

        $timeMs = (int) hexdec($timeMsHex);
        $sec    = intdiv($timeMs, 1000);
        $ms     = $timeMs % 1000;

        $dateTime = \DateTimeImmutable::createFromFormat('U.u', sprintf('%d.%06d', $sec, $ms * 1000));

        if ($dateTime === false) {
            throw new InvalidUuidException("Failed to extract datetime from UUID: {$uuid->toString()}");
        }

        return $dateTime->setTimezone(new \DateTimeZone('UTC'));
    }
}