prooph event bus process manager plugin

ProcessManagerPlugin.php

<?php

declare(strict_types=1);

namespace Prooph\ServiceBus\Plugin;

use Prooph\Common\Event\ActionEvent;
use Prooph\ServiceBus\CommandBus;
use Prooph\ServiceBus\EventBus;
use Prooph\ServiceBus\MessageBus;

final class ProcessManagerPlugin extends AbstractPlugin
{
    private $commandBus;

    public function __construct(CommandBus $commandBus)
    {
        $this->commandBus = $commandBus;
    }

    public function attachToMessageBus(MessageBus $messageBus): void
    {
        $this->listenerHandlers[] = $messageBus->attach(
            MessageBus::EVENT_DISPATCH,
            function (ActionEvent $actionEvent): void {
                if ($actionEvent->getParam(MessageBus::EVENT_PARAM_MESSAGE_HANDLED, false)) {
                    return;
                }

                $message = $actionEvent->getParam(MessageBus::EVENT_PARAM_MESSAGE);
                $handlers = $actionEvent->getParam(EventBus::EVENT_PARAM_EVENT_LISTENERS, []);

                foreach ($handlers as $handler) {
                    $commands = $handler->handle($message);

                    foreach ($commands as $command) {
                        $this->commandBus->dispatch($command);
                    }
                }

                $actionEvent->setParam(MessageBus::EVENT_PARAM_MESSAGE_HANDLED, true);
            },
            MessageBus::PRIORITY_INVOKE_HANDLER
        );
    }
}