ENGCOM-1204: [Backport 2.1] Configurable product price options by store #14479

 - Merge Pull Request #14479 from simpleadm/magento2:backport/2.1-configurable-lowest-price-provider-by-store
 - Merged commits:
   1. fb03cfb

Author: magento-engcom-team

app/code/Magento/ConfigurableProduct/Pricing/Price/LowestPriceOptionsProvider.php

@@ -9,6 +9,8 @@
 use Magento\Catalog\Model\ResourceModel\Product\LinkedProductSelectBuilderInterface;
 use Magento\Framework\App\ResourceConnection;
 use Magento\Catalog\Model\ResourceModel\Product\CollectionFactory;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Framework\App\ObjectManager;
 
 /**
  * Retrieve list of products where each product contains lower price than others at least for one possible price type
@@ -31,7 +33,12 @@ class LowestPriceOptionsProvider implements LowestPriceOptionsProviderInterface
     private $collectionFactory;
 
     /**
-     * Key is product id. Value is prepared product collection
+     * @var StoreManagerInterface
+     */
+    private $storeManager;
+
+    /**
+     * Key is product id and store id. Value is array of prepared linked products
      *
      * @var array
      */
@@ -41,34 +48,39 @@ class LowestPriceOptionsProvider implements LowestPriceOptionsProviderInterface
      * @param ResourceConnection $resourceConnection
      * @param LinkedProductSelectBuilderInterface $linkedProductSelectBuilder
      * @param CollectionFactory $collectionFactory
+     * @param StoreManagerInterface $storeManager
      */
     public function __construct(
         ResourceConnection $resourceConnection,
         LinkedProductSelectBuilderInterface $linkedProductSelectBuilder,
-        CollectionFactory $collectionFactory
+        CollectionFactory $collectionFactory,
+        StoreManagerInterface $storeManager = null
     ) {
         $this->resource = $resourceConnection;
         $this->linkedProductSelectBuilder = $linkedProductSelectBuilder;
         $this->collectionFactory = $collectionFactory;
+        $this->storeManager = $storeManager
+            ?: ObjectManager::getInstance()->get(StoreManagerInterface::class);
     }
 
     /**
      * {@inheritdoc}
      */
     public function getProducts(ProductInterface $product)
     {
-        if (!isset($this->productsMap[$product->getId()])) {
+        $key = $this->storeManager->getStore()->getId() . '-' . $product->getId();
+        if (!isset($this->productsMap[$key])) {
             $productIds = $this->resource->getConnection()->fetchCol(
                 '(' . implode(') UNION (', $this->linkedProductSelectBuilder->build($product->getId())) . ')'
             );
 
-            $this->productsMap[$product->getId()] = $this->collectionFactory->create()
+            $this->productsMap[$key] = $this->collectionFactory->create()
                 ->addAttributeToSelect(
                     ['price', 'special_price', 'special_from_date', 'special_to_date', 'tax_class_id']
                 )
                 ->addIdFilter($productIds)
                 ->getItems();
         }
-        return $this->productsMap[$product->getId()];
+        return $this->productsMap[$key];
     }
 }