Revert "LYNX-889: [AC-2.4.9] Merging guest and customer cart logic using Admin Configuration" (#369)

Due to PAT failure on delivery PR, need to revert -
magento-commerce/magento2ce#9920

Author: deepak-soni1

app/code/Magento/Checkout/Model/Config.php

@@ -57,11 +57,6 @@
                     <label>Enable Clear Shopping Cart</label>
                     <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
                 </field>
-                <field id="cart_merge_preference" translate="label" type="select" sortOrder="100" showInDefault="1" showInWebsite="0" showInStore="0">
-                    <label>Cart Merge Preference</label>
-                    <source_model>Magento\Checkout\Model\Config\Source\CartMergePreference</source_model>
-                    <comment>Select how cart item quantities should be merged</comment>
-                </field>
             </group>
             <group id="cart_link" translate="label" sortOrder="3" showInDefault="1" showInWebsite="1">
                 <label>My Cart Link</label>

app/code/Magento/Checkout/Model/Config/Source/CartMergePreference.php

@@ -21,7 +21,6 @@
                 <number_items_to_display_pager>20</number_items_to_display_pager>
                 <crosssell_enabled>1</crosssell_enabled>
                 <enable_clear_shopping_cart>0</enable_clear_shopping_cart>
-                <cart_merge_preference>merge</cart_merge_preference>
             </cart>
             <cart_link>
                 <use_qty>1</use_qty>

app/code/Magento/Checkout/etc/adminhtml/system.xml

@@ -1,47 +1,42 @@
 <?php
 /**
- * Copyright 2019 Adobe
- * All Rights Reserved.
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
  */
 declare(strict_types=1);
 
 namespace Magento\QuoteGraphQl\Model\Cart\MergeCarts;
 
-use Magento\Catalog\Api\Data\ProductInterface;
-use Magento\Catalog\Api\ProductRepositoryInterface;
+
 use Magento\CatalogInventory\Api\StockRegistryInterface;
-use Magento\Checkout\Model\Config;
 use Magento\Framework\Exception\CouldNotSaveException;
 use Magento\Framework\Exception\NoSuchEntityException;
 use Magento\Quote\Api\CartItemRepositoryInterface;
 use Magento\Quote\Api\Data\CartInterface;
 use Magento\Quote\Api\Data\CartItemInterface;
-use Magento\Quote\Model\Quote\Item;
-use Psr\Log\LoggerInterface;
 
 class CartQuantityValidator implements CartQuantityValidatorInterface
 {
     /**
-     * @var array
+     * @var CartItemRepositoryInterface
      */
-    private array $cumulativeQty = [];
+    private $cartItemRepository;
+
+    /**
+     * @var StockRegistryInterface
+     */
+    private $stockRegistry;
 
     /**
-     * CartQuantityValidator Constructor
-     *
      * @param CartItemRepositoryInterface $cartItemRepository
      * @param StockRegistryInterface $stockRegistry
-     * @param Config $config
-     * @param ProductRepositoryInterface $productRepository
-     * @param LoggerInterface $logger
      */
     public function __construct(
-        private readonly CartItemRepositoryInterface $cartItemRepository,
-        private readonly StockRegistryInterface      $stockRegistry,
-        private readonly Config                      $config,
-        private readonly ProductRepositoryInterface  $productRepository,
-        private readonly LoggerInterface             $logger
+        CartItemRepositoryInterface $cartItemRepository,
+        StockRegistryInterface $stockRegistry
     ) {
+        $this->cartItemRepository = $cartItemRepository;
+        $this->stockRegistry = $stockRegistry;
     }
 
     /**
@@ -50,171 +45,32 @@ public function __construct(
      * @param CartInterface $customerCart
      * @param CartInterface $guestCart
      * @return bool
-     * @throws NoSuchEntityException
      */
     public function validateFinalCartQuantities(CartInterface $customerCart, CartInterface $guestCart): bool
     {
         $modified = false;
-        $this->cumulativeQty = [];
-
+        /** @var CartItemInterface $guestCartItem */
         foreach ($guestCart->getAllVisibleItems() as $guestCartItem) {
-            foreach ($customerCart->getAllVisibleItems() as $customerCartItem) {
-                if (!$customerCartItem->compare($guestCartItem)) {
-                    continue;
-                }
-
-                if ($this->config->getCartMergePreference() === Config::CART_PREFERENCE_CUSTOMER) {
-                    $this->safeDeleteCartItem((int) $guestCart->getId(), (int) $guestCartItem->getItemId());
-                    $modified = true;
-                    continue;
-                }
-
-                $sku = $this->getSkuFromItem($customerCartItem);
-                $product = $this->getProduct((int) $customerCartItem->getProduct()->getId());
-                $isAvailable = $customerCartItem->getChildren()
-                    ? $this->isCompositeProductQtyValid($guestCartItem, $customerCartItem)
-                    : $this->isProductQtyValid($product, $sku, $guestCartItem->getQty(), $customerCartItem->getQty());
-
-                if ($this->config->getCartMergePreference() === Config::CART_PREFERENCE_GUEST) {
-                    $this->safeDeleteCartItem((int) $customerCart->getId(), (int) $customerCartItem->getItemId());
-                    $modified = true;
-                }
-
-                if (!$isAvailable) {
-                    $this->safeDeleteCartItem((int) $guestCart->getId(), (int) $guestCartItem->getItemId());
-                    $modified = true;
+            foreach ($customerCart->getAllItems() as $customerCartItem) {
+                if ($customerCartItem->compare($guestCartItem)) {
+                    $product = $customerCartItem->getProduct();
+                    $stockCurrentQty = $this->stockRegistry->getStockStatus(
+                        $product->getId(),
+                        $product->getStore()->getWebsiteId()
+                    )->getQty();
+                    if ($stockCurrentQty < $guestCartItem->getQty() + $customerCartItem->getQty()) {
+                        try {
+                            $this->cartItemRepository->deleteById($guestCart->getId(), $guestCartItem->getItemId());
+                            $modified = true;
+                        } catch (NoSuchEntityException $e) {
+                            continue;
+                        } catch (CouldNotSaveException $e) {
+                            continue;
+                        }
+                    }
                 }
             }
         }
-
         return $modified;
     }
-
-    /**
-     * Get SKU from Cart Item
-     *
-     * @param CartItemInterface $item
-     * @return string
-     * @throws NoSuchEntityException
-     */
-    private function getSkuFromItem(CartItemInterface $item): string
-    {
-        return $item->getProduct()->getOptions()
-            ? $this->getProduct((int) $item->getProduct()->getId())->getSku()
-            : $item->getProduct()->getSku();
-    }
-
-    /**
-     * Get current cart item quantity based on merge preference
-     *
-     * @param float $guestQty
-     * @param float $customerQty
-     * @return float
-     */
-    private function getCurrentCartItemQty(float $guestQty, float $customerQty): float
-    {
-        return match ($this->config->getCartMergePreference()) {
-            Config::CART_PREFERENCE_CUSTOMER => $customerQty,
-            Config::CART_PREFERENCE_GUEST => $guestQty,
-            default => $guestQty + $customerQty
-        };
-    }
-
-    /**
-     * Validate product stock availability
-     *
-     * @param ProductInterface $product
-     * @param string $sku
-     * @param float $guestQty
-     * @param float $customerQty
-     * @return bool
-     */
-    private function isProductQtyValid(
-        ProductInterface $product,
-        string $sku,
-        float $guestQty,
-        float $customerQty
-    ): bool {
-        $salableQty = $this->stockRegistry->getStockStatus(
-            $product->getId(),
-            $product->getStore()->getWebsiteId()
-        )->getQty();
-
-        $this->cumulativeQty[$sku] ??= 0;
-        $this->cumulativeQty[$sku] += $this->getCurrentCartItemQty($guestQty, $customerQty);
-
-        return $salableQty >= $this->cumulativeQty[$sku];
-    }
-
-    /**
-     * Validate composite product quantities
-     *
-     * @param Item $guestCartItem
-     * @param Item $customerCartItem
-     * @return bool
-     * @throws NoSuchEntityException
-     */
-    private function isCompositeProductQtyValid(
-        Item $guestCartItem,
-        Item $customerCartItem
-    ): bool {
-        $guestChildItems = $this->retrieveChildItems($guestCartItem);
-        foreach ($customerCartItem->getChildren() as $customerChildItem) {
-            $childProduct = $customerChildItem->getProduct()->getOptions()
-                ? $this->getProduct((int) $customerChildItem->getProduct()->getId())
-                : $customerChildItem->getProduct();
-            $sku = $childProduct->getSku();
-            $customerItemQty = $customerCartItem->getQty() * $customerChildItem->getQty();
-            $guestItemQty = $guestCartItem->getQty() * $guestChildItems[$sku]->getQty();
-
-            if (!$this->isProductQtyValid($childProduct, $sku, $guestItemQty, $customerItemQty)) {
-                return false;
-            }
-        }
-
-        return true;
-    }
-
-    /**
-     * Get product by ID
-     *
-     * @param int $productId
-     * @return ProductInterface
-     * @throws NoSuchEntityException
-     */
-    private function getProduct(int $productId): ProductInterface
-    {
-        return $this->productRepository->getById($productId);
-    }
-
-    /**
-     * Retrieve child items from a quote item
-     *
-     * @param Item $quoteItem
-     * @return Item[]
-     */
-    private function retrieveChildItems(Item $quoteItem): array
-    {
-        $childItems = [];
-        foreach ($quoteItem->getChildren() as $childItem) {
-            $childItems[$childItem->getProduct()->getSku()] = $childItem;
-        }
-        return $childItems;
-    }
-
-    /**
-     * Safely delete a cart item by ID
-     *
-     * @param int $cartId
-     * @param int $itemId
-     * @return void
-     */
-    private function safeDeleteCartItem(int $cartId, int $itemId): void
-    {
-        try {
-            $this->cartItemRepository->deleteById($cartId, $itemId);
-        } catch (NoSuchEntityException|CouldNotSaveException $e) {
-            $this->logger->error($e);
-        }
-    }
 }

app/code/Magento/Checkout/etc/config.xml

@@ -24,6 +24,11 @@
 
 class MergeCarts implements ResolverInterface
 {
+    /**
+     * @var array
+     */
+    private array $fields;
+
     /**
      * MergeCarts Constructor
      *
@@ -40,8 +45,9 @@ public function __construct(
         private readonly CustomerCartResolver $customerCartResolver,
         private readonly QuoteIdToMaskedQuoteIdInterface $quoteIdToMaskedQuoteId,
         private readonly CartQuantityValidatorInterface $cartQuantityValidator,
-        private readonly array $fields
+        array $fields
     ) {
+        $this->fields = $fields;
     }
 
     /**
@@ -90,10 +96,9 @@ public function resolve(
         $customerCart = $this->getCartForUser->execute($customerMaskedCartId, $currentUserId, $storeId);
         $guestCart = $this->getCartForUser->execute($guestMaskedCartId, null, $storeId);
 
-        // Validate cart quantities before merging and reload cart before cart merge
+        // Validate cart quantities before merging
         if ($this->cartQuantityValidator->validateFinalCartQuantities($customerCart, $guestCart)) {
             $guestCart = $this->getCartForUser->execute($guestMaskedCartId, null, $storeId);
-            $customerCart = $this->getCartForUser->execute($customerMaskedCartId, $currentUserId, $storeId);
         }
 
         // Merge carts and save

app/code/Magento/QuoteGraphQl/Model/Cart/MergeCarts/CartQuantityValidator.php

@@ -73,7 +73,6 @@
                 <item name="grouped_product_image" xsi:type="string">checkout/cart/grouped_product_image</item>
                 <item name="configurable_product_image" xsi:type="string">checkout/cart/configurable_product_image</item>
                 <item name="is_checkout_agreements_enabled" xsi:type="string">checkout/options/enable_agreements</item>
-                <item name="cart_merge_preference" xsi:type="string">checkout/cart/cart_merge_preference</item>
             </argument>
         </arguments>
     </type>

app/code/Magento/QuoteGraphQl/Model/Resolver/MergeCarts.php

@@ -523,7 +523,6 @@ type StoreConfig {
     grouped_product_image: ProductImageThumbnail! @doc(description: "checkout/cart/grouped_product_image: which image to use for grouped products.") @resolver(class: "Magento\\QuoteGraphQl\\Model\\Resolver\\StoreConfig")
     configurable_product_image: ProductImageThumbnail! @doc(description: "checkout/cart/configurable_product_image: which image to use for configurable products.") @resolver(class: "Magento\\QuoteGraphQl\\Model\\Resolver\\StoreConfig")
     is_checkout_agreements_enabled: Boolean! @doc(description: "Configuration data from checkout/options/enable_agreements")
-    cart_merge_preference: String! @doc(description: "Configuration data from checkout/cart/cart_merge_preference")
 }
 
 enum ProductImageThumbnail {