Add abstract class for promotions in a subset of items

src/Promotion/Action/AbstractFixedDiscountPromotionActionCommand.php

@@ -0,0 +1,143 @@
+<?php
+
+/*
+ * This file is part of Monsieur Biz' Advanced Promotion plugin for Sylius.
+ * (c) Monsieur Biz <[email protected]>
+ * For the full copyright and license information, please view the LICENSE.txt
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace MonsieurBiz\SyliusAdvancedPromotionPlugin\Promotion\Action;
+
+use Doctrine\Common\Collections\Collection;
+use InvalidArgumentException;
+use MonsieurBiz\SyliusAdvancedPromotionPlugin\Promotion\Applicator\UnitsPromotionAdjustmentsApplicatorInterface;
+use Sylius\Component\Core\Distributor\MinimumPriceDistributorInterface;
+use Sylius\Component\Core\Distributor\ProportionalIntegerDistributorInterface;
+use Sylius\Component\Core\Model\OrderInterface;
+use Sylius\Component\Core\Model\OrderItemInterface;
+use Sylius\Component\Core\Promotion\Action\DiscountPromotionActionCommand;
+use Sylius\Component\Promotion\Model\PromotionInterface;
+use Sylius\Component\Promotion\Model\PromotionSubjectInterface;
+use Webmozart\Assert\Assert;
+
+/**
+ * @SuppressWarnings(PHPMD.LongClassName)
+ */
+abstract class AbstractFixedDiscountPromotionActionCommand extends DiscountPromotionActionCommand
+{
+    public function __construct(
+        private ProportionalIntegerDistributorInterface $distributor,
+        /** We use our custom UnitsPromotionAdjustmentsApplicatorInterface to be able to filter on a subset of items */
+        private UnitsPromotionAdjustmentsApplicatorInterface $unitsPromotionAdjustmentsApplicator,
+        private ?MinimumPriceDistributorInterface $minimumPriceDistributor = null,
+    ) {
+    }
+
+    /**
+     * Abstract method to implement to call `executeOnItems` with your items.
+     *
+     * Example :
+     *
+     *     public function execute(PromotionSubjectInterface $subject, array $configuration, PromotionInterface $promotion): bool
+     *    {
+     *        return $this->executeOnItems($subject, $configuration, $promotion, $subject->getMyCustomItems());
+     *    }
+     */
+    abstract public function execute(PromotionSubjectInterface $subject, array $configuration, PromotionInterface $promotion): bool;
+
+    /**
+     * This method is the same as Sylius but we filter on given order items.
+     *
+     * @see \Sylius\Component\Core\Promotion\Action\FixedDiscountPromotionActionCommand::execute()
+     *
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.NPathComplexity)
+     * @SuppressWarnings(PHPMD.ElseExpression)
+     */
+    protected function executeOnItems(PromotionSubjectInterface $subject, array $configuration, PromotionInterface $promotion, ?Collection $orderItems = null): bool
+    {
+        /** @var OrderInterface $subject */
+        Assert::isInstanceOf($subject, OrderInterface::class);
+
+        if (!$this->isSubjectValid($subject)) {
+            return false;
+        }
+
+        // If no given items, promotion is on all items
+        // It will have the same behavior as the default UnitsPromotionAdjustmentsApplicator
+        // @see \Sylius\Component\Core\Promotion\Applicator\UnitsPromotionAdjustmentsApplicator
+        if (null == $orderItems) {
+            $orderItems = $subject->getItems();
+        }
+
+        $channel = $subject->getChannel();
+        $channelCode = $subject->getChannel()?->getCode();
+        if (!$channel || !$channelCode || !isset($configuration[$channelCode])) {
+            return false;
+        }
+
+        try {
+            $this->isConfigurationValid($configuration[$channelCode]);
+        } catch (InvalidArgumentException) {
+            return false;
+        }
+
+        $subjectTotal = $this->getSubjectTotal($subject, $promotion);
+        $promotionAmount = $this->calculateAdjustmentAmount($subjectTotal, $configuration[$channelCode]['amount']);
+
+        if (0 === $promotionAmount) {
+            return false;
+        }
+
+        if (null !== $this->minimumPriceDistributor) {
+            $splitPromotion = $this->minimumPriceDistributor->distribute($orderItems->toArray(), $promotionAmount, $channel, $promotion->getAppliesToDiscounted());
+        } else {
+            $itemsTotal = [];
+            foreach ($orderItems as $orderItem) {
+                /** @var OrderItemInterface $orderItem */
+                Assert::isInstanceOf($orderItem, OrderItemInterface::class);
+
+                if ($promotion->getAppliesToDiscounted()) {
+                    $itemsTotal[] = $orderItem->getTotal();
+
+                    continue;
+                }
+
+                $variant = $orderItem->getVariant();
+                if (!$variant || !$variant->getAppliedPromotionsForChannel($channel)->isEmpty()) {
+                    $itemsTotal[] = 0;
+
+                    continue;
+                }
+
+                $itemsTotal[] = $orderItem->getTotal();
+            }
+
+            $splitPromotion = $this->distributor->distribute($itemsTotal, $promotionAmount);
+        }
+
+        // We add `$orderItems` as last argument to apply promotion only on these items
+        $this->unitsPromotionAdjustmentsApplicator->apply($subject, $promotion, $splitPromotion, $orderItems);
+
+        return true;
+    }
+
+    protected function isConfigurationValid(array $configuration): void
+    {
+        Assert::keyExists($configuration, 'amount');
+        Assert::integer($configuration['amount']);
+    }
+
+    private function calculateAdjustmentAmount(int $promotionSubjectTotal, int $targetPromotionAmount): int
+    {
+        return -1 * min($promotionSubjectTotal, $targetPromotionAmount);
+    }
+
+    private function getSubjectTotal(OrderInterface $order, PromotionInterface $promotion): int
+    {
+        return $promotion->getAppliesToDiscounted() ? $order->getPromotionSubjectTotal() : $order->getNonDiscountedItemsTotal();
+    }
+}