add case BuyXGetYAction

Author: engcom-Echo

app/code/Magento/SalesRule/Model/Validator.php

@@ -7,6 +7,7 @@
 namespace Magento\SalesRule\Model;
 
 use Magento\Framework\App\ObjectManager;
+use Magento\Quote\Model\Quote;
 use Magento\Quote\Model\Quote\Address;
 use Magento\Quote\Model\Quote\Item\AbstractItem;
 use Magento\SalesRule\Helper\CartFixedDiscount;
@@ -319,7 +320,7 @@ public function processShippingAmount(Address $address)
         $quote = $address->getQuote();
         $appliedRuleIds = [];
         foreach ($this->_getRules($address) as $rule) {
-            /* @var \Magento\SalesRule\Model\Rule $rule */
+            /* @var Rule $rule */
             if (!$rule->getApplyToShipping() || !$this->validatorUtility->canProcessRule($rule, $address)) {
                 continue;
             }
@@ -328,28 +329,28 @@ public function processShippingAmount(Address $address)
             $baseDiscountAmount = 0;
             $rulePercent = min(100, $rule->getDiscountAmount());
             switch ($rule->getSimpleAction()) {
-                case \Magento\SalesRule\Model\Rule::TO_PERCENT_ACTION:
+                case Rule::TO_PERCENT_ACTION:
                     $rulePercent = max(0, 100 - $rule->getDiscountAmount());
                 // break is intentionally omitted
                 // no break
-                case \Magento\SalesRule\Model\Rule::BY_PERCENT_ACTION:
+                case Rule::BY_PERCENT_ACTION:
                     $discountAmount = ($shippingAmount - $address->getShippingDiscountAmount()) * $rulePercent / 100;
                     $baseDiscountAmount = ($baseShippingAmount -
                             $address->getBaseShippingDiscountAmount()) * $rulePercent / 100;
                     $discountPercent = min(100, $address->getShippingDiscountPercent() + $rulePercent);
                     $address->setShippingDiscountPercent($discountPercent);
                     break;
-                case \Magento\SalesRule\Model\Rule::TO_FIXED_ACTION:
+                case Rule::TO_FIXED_ACTION:
                     $quoteAmount = $this->priceCurrency->convert($rule->getDiscountAmount(), $quote->getStore());
                     $discountAmount = $shippingAmount - $quoteAmount;
                     $baseDiscountAmount = $baseShippingAmount - $rule->getDiscountAmount();
                     break;
-                case \Magento\SalesRule\Model\Rule::BY_FIXED_ACTION:
+                case Rule::BY_FIXED_ACTION:
                     $quoteAmount = $this->priceCurrency->convert($rule->getDiscountAmount(), $quote->getStore());
                     $discountAmount = $quoteAmount;
                     $baseDiscountAmount = $rule->getDiscountAmount();
                     break;
-                case \Magento\SalesRule\Model\Rule::CART_FIXED_ACTION:
+                case Rule::CART_FIXED_ACTION:
                     $cartRules = $address->getCartFixedRules();
                     $quoteAmount = $this->priceCurrency->convert($rule->getDiscountAmount(), $quote->getStore());
                     $isAppliedToShipping = (int) $rule->getApplyToShipping();
@@ -385,6 +386,12 @@ public function processShippingAmount(Address $address)
                     }
                     $address->setCartFixedRules($cartRules);
                     break;
+                case Rule::BUY_X_GET_Y_ACTION:
+                    $qty = $this->getDiscountQtyAllItemsBuyXGetYAction($quote, $rule);
+                    $quoteAmount = $address->getBaseShippingAmount() / $quote->getItemsQty() * $qty;
+                    $discountAmount = $this->priceCurrency->convert($quoteAmount, $quote->getStore());
+                    $baseDiscountAmount = $quoteAmount;
+                    break;
             }
 
             $discountAmount = min($address->getShippingDiscountAmount() + $discountAmount, $shippingAmount);
@@ -426,9 +433,9 @@ public function initTotals($items, Address $address)
             return $this;
         }
 
-        /** @var \Magento\SalesRule\Model\Rule $rule */
+        /** @var Rule $rule */
         foreach ($this->_getRules($address) as $rule) {
-            if (\Magento\SalesRule\Model\Rule::CART_FIXED_ACTION == $rule->getSimpleAction()
+            if (Rule::CART_FIXED_ACTION == $rule->getSimpleAction()
                 && $this->validatorUtility->canProcessRule($rule, $address)
             ) {
                 $ruleTotalItemsPrice = 0;
@@ -481,6 +488,40 @@ private function isValidItemForRule(AbstractItem $item, Rule $rule)
         return true;
     }
 
+    /**
+     * Return discount Qty for all items at Buy_X_Get_Y_Action
+     *
+     * @param Quote $quote
+     * @param Rule $rule
+     * @return float
+     */
+    private function getDiscountQtyAllItemsBuyXGetYAction($quote, $rule)
+    {
+        $discountAllQty = 0;
+        foreach ($quote->getItems() as $item) {
+            $qty = $item->getQty();
+
+            $x = $rule->getDiscountStep();
+            $y = $rule->getDiscountAmount();
+            if (!$x || $y > $x) {
+                continue;
+            }
+            $buyAndDiscountQty = $x + $y;
+
+            $fullRuleQtyPeriod = floor($qty / $buyAndDiscountQty);
+            $freeQty = $qty - $fullRuleQtyPeriod * $buyAndDiscountQty;
+
+            $discountQty = $fullRuleQtyPeriod * $y;
+            if ($freeQty > $x) {
+                $discountQty += $freeQty - $x;
+            }
+
+            $discountAllQty += $discountQty;
+        }
+
+        return $discountAllQty;
+    }
+
     /**
      * Return item price
      *
@@ -564,7 +605,7 @@ public function prepareDescription($address, $separator = ', ')
     public function sortItemsByPriority($items, Address $address = null)
     {
         $itemsSorted = [];
-        /** @var $rule \Magento\SalesRule\Model\Rule */
+        /** @var $rule Rule */
         foreach ($this->_getRules($address) as $rule) {
             foreach ($items as $itemKey => $itemValue) {
                 if ($rule->getActions()->validate($itemValue)) {