<?php

declare(strict_types=1);

namespace SpomkyLabs\Pki\CryptoTypes\Asymmetric\RFC8410\Curve448;

use function mb_strlen;
use SpomkyLabs\Pki\CryptoTypes\AlgorithmIdentifier\Asymmetric\Ed448AlgorithmIdentifier;
use SpomkyLabs\Pki\CryptoTypes\AlgorithmIdentifier\Feature\AlgorithmIdentifierType;
use SpomkyLabs\Pki\CryptoTypes\Asymmetric\RFC8410\RFC8410PublicKey;
use UnexpectedValueException;

/**
 * Implements an intermediary class to store Ed448 public key.
 *
 * @see https://tools.ietf.org/html/rfc8410
 */
final class Ed448PublicKey extends RFC8410PublicKey
{
    /**
     * @param string $publicKey Public key data
     */
    private function __construct(string $publicKey)
    {
        if (mb_strlen($publicKey, '8bit') !== 57) {
            throw new UnexpectedValueException('Ed448 public key must be exactly 57 bytes.');
        }
        parent::__construct($publicKey);
    }

    public static function create(string $publicKey): self
    {
        return new self($publicKey);
    }

    public function algorithmIdentifier(): AlgorithmIdentifierType
    {
        return Ed448AlgorithmIdentifier::create();
    }
}
