DDDBoilerplate/src/Sales/Domain/Model/Order.php

<?php

declare(strict_types=1);

namespace MiniShop\Sales\Domain\Model;

use MiniShop\Sales\Domain\Event\OrderCancelled;
use MiniShop\Sales\Domain\Event\OrderConfirmed;
use MiniShop\Sales\Domain\Event\OrderPlaced;
use MiniShop\Sales\Domain\Exception\EmptyOrderException;
use MiniShop\Sales\Domain\Exception\InvalidOrderStateException;

final class Order
{
    private OrderStatus $status;
    /** @var list<OrderLine> */
    private array $lines;
    /** @var list<object> */
    private array $domainEvents = [];

    private function __construct(
        public readonly OrderId $id,
        public readonly CustomerId $customerId,
        private readonly \DateTimeImmutable $placedAt,
    ) {
        $this->status = OrderStatus::Draft;
        $this->lines = [];
    }

    /**
     * @param list<OrderLine> $lines
     */
    public static function place(
        OrderId $id,
        CustomerId $customerId,
        array $lines,
        \DateTimeImmutable $placedAt,
    ): self {
        if ($lines === []) {
            throw EmptyOrderException::noLines();
        }

        $order = new self($id, $customerId, $placedAt);
        $order->lines = $lines;
        $order->status = OrderStatus::Placed;

        $order->recordEvent(new OrderPlaced($id, $customerId, $order->total(), $placedAt));

        return $order;
    }

    public function confirm(): void
    {
        if ($this->status !== OrderStatus::Placed) {
            throw InvalidOrderStateException::cannotConfirm($this->status);
        }

        $this->status = OrderStatus::Confirmed;
        $this->recordEvent(new OrderConfirmed(
            $this->id,
            $this->customerId,
            $this->total(),
            $this->lines,
        ));
    }

    public function cancel(): void
    {
        if ($this->status !== OrderStatus::Placed) {
            throw InvalidOrderStateException::cannotCancel($this->status);
        }

        $this->status = OrderStatus::Cancelled;
        $this->recordEvent(new OrderCancelled($this->id));
    }

    public function total(): Money
    {
        return array_reduce(
            $this->lines,
            static fn (Money $carry, OrderLine $line): Money => $carry->add($line->lineTotal()),
            Money::zero($this->lines[0]->unitPrice->currency),
        );
    }

    public function status(): OrderStatus
    {
        return $this->status;
    }

    /** @return list<OrderLine> */
    public function lines(): array
    {
        return $this->lines;
    }

    public function placedAt(): \DateTimeImmutable
    {
        return $this->placedAt;
    }

    /** @return list<object> */
    public function releaseEvents(): array
    {
        $events = $this->domainEvents;
        $this->domainEvents = [];

        return $events;
    }

    private function recordEvent(object $event): void
    {
        $this->domainEvents[] = $event;
    }
}