nshop/packages/Longyi/FreeGift/src/Services/GiftRegistry.php

<?php

namespace Longyi\FreeGift\Services;

use Longyi\FreeGift\Config\Gift;
use Longyi\FreeGift\Repositories\FreeGiftItemRepository;
use Webkul\Checkout\Contracts\Cart as CartContract;

/**
 * 单次请求内的赠品注册表（按购物车维度）。
 *
 * 对应 Amasty 的 Model\Registry，但这里额外负责：
 *  - 首次访问时从 free_gift_items 回填状态（reservedQty / is_item_deleted）
 *  - 规则重算结束后把结果写回 free_gift_items
 */
class GiftRegistry
{
    /**
     * @var array<int, GiftItemsGroup>
     */
    protected array $groups = [];

    /**
     * @var array<int, bool>
     */
    protected array $hydrated = [];

    public function __construct(
        protected FreeGiftItemRepository $giftItemRepository
    ) {}

    /**
     * 取（或初始化）某个购物车的赠品分组。
     */
    public function group(int $cartId): GiftItemsGroup
    {
        if (! isset($this->groups[$cartId])) {
            $this->groups[$cartId] = new GiftItemsGroup();
        }

        if (! isset($this->hydrated[$cartId])) {
            $this->hydrate($cartId);

            $this->hydrated[$cartId] = true;
        }

        return $this->groups[$cartId];
    }

    /**
     * 用购物车里的真实赠品行刷新 reservedQty。
     *
     * free_gift_items 只是缓存，cart_items 才是真相；每次重算都以购物车为准，
     * 避免用户在另一个标签页删了东西导致数量对不上。
     */
    public function syncReservedQty(CartContract $cart, GiftItemsGroup $group): void
    {
        $reserved = [];

        foreach ($cart->all_items as $cartItem) {
            $ruleId = $cartItem->additional[Gift::CART_ITEM_FLAG] ?? null;

            if (! $ruleId) {
                continue;
            }

            $key = ((int) $ruleId).':'.$cartItem->sku;

            $reserved[$key] = ($reserved[$key] ?? 0) + (float) $cartItem->quantity;
        }

        foreach ($group->getItems() as $item) {
            $item->setReservedQty($reserved[$item->getKey()] ?? 0);

            unset($reserved[$item->getKey()]);
        }

        // 购物车里存在但注册表里没有的赠品行（规则被删掉等）交给 syncGiftItems 清理
    }

    /**
     * 把注册表写回 free_gift_items。
     */
    public function persist(int $cartId): void
    {
        if (! isset($this->groups[$cartId])) {
            return;
        }

        foreach ($this->groups[$cartId]->getItems() as $item) {
            // 规则已经不再命中，且购物车里也没有残留 → 直接删掉状态行
            if ($item->getAllowedQty() < 1) {
                if ($item->getId()) {
                    $this->giftItemRepository->delete($item->getId());

                    $item->setId(null);
                }

                continue;
            }

            $data = [
                'cart_id'         => $cartId,
                'cart_item_id'    => $item->getCartItemId(),
                'product_id'      => $item->getProductId(),
                'sku'             => $item->getSku(),
                'rule_id'         => $item->getRuleId(),
                'rule_type'       => $item->getRuleType(),
                'allowed_qty'     => $item->getAllowedQty(),
                'reserved_qty'    => $item->getReservedQty(),
                'discount_amount' => $item->getDiscount(),
                'auto_add'        => $item->isAutoAdd(),
                'is_item_deleted' => $item->isDeleted(),
            ];

            if ($item->getId()) {
                $this->giftItemRepository->update($data, $item->getId());
            } else {
                $row = $this->giftItemRepository->create($data);

                $item->setId((int) $row->id);
            }
        }
    }

    /**
     * 丢弃某个购物车的注册表缓存（购物车被清空 / 合并时使用）。
     */
    public function forget(int $cartId): void
    {
        unset($this->groups[$cartId], $this->hydrated[$cartId]);
    }

    /**
     * 从 free_gift_items 回填。
     */
    protected function hydrate(int $cartId): void
    {
        foreach ($this->giftItemRepository->getByCart($cartId) as $row) {
            $item = new GiftItem(
                (string) $row->sku,
                (int) $row->rule_id,
                $row->discount_amount,
                (int) $row->rule_type,
                (bool) $row->auto_add
            );

            $item->setId((int) $row->id)
                ->setProductId($row->product_id ? (int) $row->product_id : null)
                ->setCartItemId($row->cart_item_id ? (int) $row->cart_item_id : null)
                ->setReservedQty((float) $row->reserved_qty)
                ->setStoredQty((float) $row->allowed_qty)
                ->setDeleted((bool) $row->is_item_deleted);

            $this->groups[$cartId]->put($item);
        }
    }
}