[5.4] Add catalog pricing rule ID to purchasable/line item

CHANGELOG-WIP.md

@@ -11,13 +11,18 @@
 - Added Promotional Price column to product index.
 
 ### Development
+- Line item snapshots now contain the `catalogPricingRuleId` field. ([#3910](https://github.com/craftcms/commerce/issues/3910))
 - Added the `localized` GraphQL product query field. ([#3783](https://github.com/craftcms/commerce/discussions/3783))
 
 ### Extensibility
 - Added `craft\commerce\base\Gateway::getConfig()`.
 - Added `craft\commerce\base\Gateway::getOrderCondition()`.
 - Added `craft\commerce\base\Gateway::hasOrderCondition()`.
 - Added `craft\commerce\base\Gateway::setOrderCondition()`.
+- Added `craft\commerce\base\Purchasable::$catalogPricingRuleId`.
+- Added `craft\commerce\base\Purchasable::getCatalogPricingRule()`.
+- Added `craft\commerce\base\Gateway::setOrderCondition()`.
+- Added `craft\commerce\base\Gateway::getOrderCondition()`.
 - Added `craft\commerce\elements\Product::$defaultBasePromotionalPrice`
 - Added `craft\commerce\elements\conditions\customers\ShippingMethodCustomerCondition`.
 - Added `craft\commerce\elements\conditions\customers\ShippingRuleCustomerCondition`.

src/base/Purchasable.php

@@ -17,6 +17,7 @@
 use craft\commerce\helpers\Currency;
 use craft\commerce\helpers\Localization;
 use craft\commerce\helpers\Purchasable as PurchasableHelper;
+use craft\commerce\models\CatalogPricingRule;
 use craft\commerce\models\InventoryItem;
 use craft\commerce\models\InventoryLevel;
 use craft\commerce\models\LineItem;
@@ -184,6 +185,20 @@ abstract class Purchasable extends Element implements PurchasableInterface, HasS
      */
     private ?float $_basePromotionalPrice = null;
 
+    /**
+     * The ID of the catalog pricing rule that is affecting the sale price of this purchasable.
+     *
+     * @var int|null
+     * @since 5.4.0
+     */
+    public ?int $catalogPricingRuleId = null;
+
+    /**
+     * @var CatalogPricingRule|null
+     * @since 5.4.0
+     * @see getCatalogPricingRule()
+     */
+    private ?CatalogPricingRule $_catalogPricingRule = null;
 
     /**
      * @var bool
@@ -614,6 +629,21 @@ public function setPromotionalPrice(?float $price): void
         $this->_promotionalPrice = $price;
     }
 
+    /**
+     * @return CatalogPricingRule|null
+     * @throws InvalidConfigException
+     * @throws SiteNotFoundException
+     * @since 5.4.0
+     */
+    public function getCatalogPricingRule(): ?CatalogPricingRule
+    {
+        if ($this->_catalogPricingRule === null && $this->catalogPricingRuleId !== null) {
+            $this->_catalogPricingRule = Plugin::getInstance()->getCatalogPricingRules()->getCatalogPricingRuleById($this->catalogPricingRuleId, $this->storeId);
+        }
+
+        return $this->_catalogPricingRule;
+    }
+
     /**
      * @inheritdoc
      */
@@ -705,7 +735,9 @@ public function getTaxCategory(): TaxCategory
      */
     public function getSnapshot(): array
     {
-        return [];
+        return [
+            'catalogPricingRuleId' => $this->catalogPricingRuleId,
+        ];
     }
 
     /**

src/elements/db/PurchasableQuery.php

@@ -705,13 +705,33 @@ protected function beforePrepare(): bool
             'subquery.price',
             'subquery.promotionalPrice as promotionalPrice',
             'subquery.salePrice as salePrice',
+            'catprice.catalogPricingRuleId as catalogPricingRuleId',
             'inventoryitems.id as inventoryItemId',
         ]);
 
         $this->query->leftJoin(Table::SITESTORES . ' sitestores', '[[elements_sites.siteId]] = [[sitestores.siteId]]');
         $this->query->leftJoin(Table::PURCHASABLES_STORES . ' purchasables_stores', '[[purchasables_stores.storeId]] = [[sitestores.storeId]] AND [[purchasables_stores.purchasableId]] = [[commerce_purchasables.id]]');
         $this->query->leftJoin(['inventoryitems' => Table::INVENTORYITEMS], '[[inventoryitems.purchasableId]] = [[commerce_purchasables.id]]');
 
+        // Retrieve the catalog pricing rule ID used to determine the price
+        $customerId = $this->forCustomer;
+        if ($customerId === null) {
+            $customerId = Craft::$app->getUser()->getIdentity()?->id;
+        } elseif ($customerId === false) {
+            $customerId = null;
+        }
+        $cprIdQuery = Plugin::getInstance()
+            ->getCatalogPricing()
+            ->createCatalogPricesQuery(userId: $customerId)
+            ->select([
+                'purchasableId',
+                'storeId',
+                'price',
+                new Expression('MIN([[catalogPricingRuleId]]) as [[catalogPricingRuleId]]'),
+            ])
+            ->groupBy(['cp.purchasableId', 'cp.storeId', 'cp.price']);
+        $this->query->leftJoin(['catprice' => $cprIdQuery], '[[catprice.purchasableId]] = [[commerce_purchasables.id]] AND [[catprice.storeId]] = [[sitestores.storeId]] AND [[catprice.price]] = [[subquery.salePrice]]');
+
         $this->subQuery->addSelect([
             'catalogprices.price',
             'catalogprices.promotionalPrice',

src/models/LineItem.php

@@ -930,6 +930,7 @@ private function _populateFromPurchasable(PurchasableInterface $purchasable): vo
         }
 
         $snapshot = [
+            // @TODO move these to base purchasable on next breaking change
             'price' => $purchasable->getPrice(),
             'sku' => $purchasable->getSku(),
             'description' => $purchasable->getDescription(),