https://www.facebook.com/groups/223889134481096/permalink/898716313665038/

SellOnlineTicket.php

<?php

declare(strict_types=1);

class SellOnlineTicket implements Command
{
   public function clientDetails(): ClientDetails
   {}

   public function clientEmail(): Email
   {}

   public function eventId(): EventId
   {}
}

SellOnlineTicketHandler.php

<?php

declare(strict_types=1);

class SellOnlineTicketHandler implements CommandHandler
{
    private $transactionManager;
    private $ticketGenerator;
    private $ticketSender;
    private $tickets;

    public function __construct(
        TransactionManager $manager,
        TicketGenerator $generator,
        Tickets $tickets,
        TicketSender $sender
    ) {
        $this->transactionManager = $manager;
        $this->ticketGenerator = $generator;
        $this->ticketSender = $sender;
        $this->tickets = $tickets;
    }

    public function execute(SellOnlineTicket $command): void
    {
        $this->transactionManager->begin();
        try {
            $ticket = $this->ticketGenerator->generate(
                $command->clientDetails(),
                $command->eventId()
            );
            $this->tickets->add($ticket);
            $this->transactionManager->commit();
        } catch (Throwable $e) {
            $this->transactionManager->rollback();
            throw $e;
        }

        $this->ticketSender->send($ticket, $command->clientEmail());
    }
}

TicketGenerator.php

<?php

declare(strict_types=1);

interface TicketGenerator
{
    public function generate(ClientDetails $details, EventId $id): Ticket;
}

Tickets.php

<?php

declare(strict_types=1);

interface Tickets
{
    /**
     * @throws TicketNotFound
     */
    public function get(TicketNumber $number): Ticket;
    public function add(Ticket): void;
}

TicketSender.php

<?php

declare(strict_types=1);

interface TicketSender
{
    /**
     * @throws EmailSenderFailure
     */
    public function send(Ticket $ticket, Email $email): void;
}

TransactionManager.php

<?php

declare(strict_types=1);

interface TransactionManager
{
    public function begin(): void;
    public function commit(): void;
    public function rollback(): void;
}