provider_imap/lib/Client/Command/CapabilityCommand.php

<?php

declare(strict_types=1);

namespace KTXM\ProviderImap\Client\Command;

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

/**
 * @implements CommandInterface<CapabilityResult>
 */
final class CapabilityCommand implements CommandInterface
{
    public function name(): string
    {
        return 'CAPABILITY';
    }

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

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

        return new RequestFrame('CAPABILITY');
    }

    public function handle(ResponseStream $responses, SessionContext $context): CapabilityResult
    {
        $capabilities = [];

        foreach ($responses as $response) {
            if ($response instanceof UntaggedResponse && $response->label() === 'CAPABILITY') {
                $capabilities = array_map('strtoupper', $response->payloadTokens());
            }

            if ($response instanceof TaggedResponse) {
                if (!$response->isOk()) {
                    throw new ImapException('CAPABILITY failed: ' . $response->text());
                }
            }
        }

        $context->replaceCapabilities(...$capabilities);

        return new CapabilityResult($context->capabilities());
    }
}