provider_imap/lib/Client/Command/StartTlsCommand.php

<?php

declare(strict_types=1);

namespace KTXM\ProviderImap\Client\Command;

use KTXM\ProviderImap\Client\Command\Result\CommandStatusResult;
use KTXM\ProviderImap\Client\ImapException;
use KTXM\ProviderImap\Client\Protocol\RequestFrame;
use KTXM\ProviderImap\Client\Protocol\Response\TaggedResponse;
use KTXM\ProviderImap\Client\Protocol\ResponseStream;
use KTXM\ProviderImap\Client\SessionContext;
use KTXM\ProviderImap\Client\SessionState;

/**
 * @implements CommandInterface<CommandStatusResult>
 */
final class StartTlsCommand implements CommandInterface
{
    public function name(): string
    {
        return 'STARTTLS';
    }

    public function allowedStates(): array
    {
        return [SessionState::NotAuthenticated];
    }

    public function encode(string $tag, SessionContext $context): RequestFrame
    {
        unset($tag, $context);

        return new RequestFrame('STARTTLS');
    }

    public function handle(ResponseStream $responses, SessionContext $context): CommandStatusResult
    {
        foreach ($responses as $response) {
            if ($response instanceof TaggedResponse) {
                if (!$response->isOk()) {
                    throw new ImapException('STARTTLS failed: ' . $response->text());
                }

                $context->connection()->upgradeToTls();
                $context->replaceCapabilities();

                return new CommandStatusResult($response->status(), $response->text());
            }
        }

        throw new ImapException('STARTTLS did not receive a tagged completion response.');
    }
}