core/src/Checkout/Services/CheckoutService.php

<?php

namespace Modules\Core\Checkout\Services;

use Lunar\Exceptions\FingerprintMismatchException;
use Lunar\Exceptions\Carts\CartException;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Event;
use Lunar\Base\Addressable;
use Lunar\DataTypes\ShippingOption;
use Lunar\Facades\ShippingManifest;
use Lunar\Models\Cart;
use Lunar\Models\Order;
use Modules\Core\Cart\Services\CartService;
use Modules\Core\Checkout\Events\BillingAddressSet;
use Modules\Core\Checkout\Events\OrderPlaced;
use Modules\Core\Checkout\Events\ShippingAddressSet;
use Modules\Core\Checkout\Events\ShippingOptionSelected;
use Modules\Core\Checkout\Exceptions\InvalidShippingOptionException;

/**
 * Storefront-facing checkout operations, mirroring
 * Modules\Core\Cart\Services\CartService's shape — one boboko-owned API a
 * storefront calls, keeping Lunar's own Cart/ShippingManifest primitives an
 * implementation detail. See docs/checkout.md for the full design —
 * Checkout is the middle of a three-stage lifecycle (Cart → Checkout →
 * Order): it owns the placement moment itself (address, shipping selection,
 * placeOrder()) and ends the instant an Order exists. What happens to that
 * Order afterward (status transitions, fulfillment) is deliberately out of
 * scope here — see OrderPlaced's docblock.
 *
 * Depends on CartService for cart access rather than reaching into
 * Lunar\Facades\CartSession directly a second time, so Checkout stays
 * layered on top of Cart's own service boundary instead of duplicating it.
 */
class CheckoutService
{
    public function __construct(
        private readonly CartService $cart,
    ) {}

    public function setShippingAddress(array|Addressable $address): Cart
    {
        $cart = $this->cart->currentOrCreate()->setShippingAddress($address);

        Event::dispatch(new ShippingAddressSet($cart, $address));

        return $cart;
    }

    public function setBillingAddress(array|Addressable $address): Cart
    {
        $cart = $this->cart->currentOrCreate()->setBillingAddress($address);

        Event::dispatch(new BillingAddressSet($cart, $address));

        return $cart;
    }

    /**
     * Every shipping option currently available for the cart — already
     * fully backed by the merged Shipping-Carriers work: this runs every
     * registered Lunar\Shipping\Interfaces\ShippingRateInterface driver
     * (ACS/Box Now live-rate quoting alongside table-rate-shipping's own
     * flat-rate/free-shipping/collection drivers) through
     * ShippingManifest's pipeline. No rate-resolution logic lives here —
     * this is a thin pass-through.
     *
     * @return Collection<int, ShippingOption>
     */
    public function getShippingOptions(): Collection
    {
        return ShippingManifest::getOptions($this->cart->currentOrCreate());
    }

    /**
     * @throws InvalidShippingOptionException if $identifier doesn't resolve
     *   to a real, currently-available option for the cart
     */
    public function selectShippingOption(string $identifier): Cart
    {
        $cartBefore = $this->cart->currentOrCreate();
        $option = ShippingManifest::getOption($cartBefore, $identifier);

        if ($option === null) {
            throw new InvalidShippingOptionException($identifier);
        }

        $cart = $cartBefore->setShippingOption($option);

        Event::dispatch(new ShippingOptionSelected($cart, $option));

        return $cart;
    }

    /**
     * $fingerprint is mandatory, not optional — the caller must prove the
     * cart total the shopper last saw (Cart::fingerprint()) still matches
     * before an order is placed. Cart::checkFingerprint() throws Lunar's own
     * FingerprintMismatchException on a mismatch (a line's price changed,
     * stock adjusted the total, another tab modified the cart) rather than
     * silently placing an order at a different total than what was shown.
     *
     * No exception wrapping: Lunar\Validation\Cart\ValidateCartForOrderCreation
     * (run inside Cart::createOrder()) already throws
     * Lunar\Exceptions\Carts\CartException with a field-keyed MessageBag
     * ($exception->errors()) for address/shipping-option validation and the
     * duplicate-order guard — already the right shape for a storefront to
     * render as form errors directly. FingerprintMismatchException
     * propagates the same way, for the same reason.
     *
     * @throws FingerprintMismatchException
     * @throws CartException
     */
    public function placeOrder(string $fingerprint): Order
    {
        $cart = $this->cart->currentOrCreate();
        $cart->checkFingerprint($fingerprint);

        $order = $cart->createOrder();

        Event::dispatch(new OrderPlaced($order));

        return $order;
    }
}