availablequantitycalculator.php

<?php
 
namespace Bitrix\Sale\Reservation;
 
class AvailableQuantityCalculator
{
    private $storeProductQuantity = [];
    private $reservationHistory = [];
 
    public function setStoreQuantity(int $storeId, int $productId, float $quantity): void
    {
        $this->storeProductQuantity[$storeId][$productId] = $quantity;
    }
 
    public function addReservationHistory(int $storeId, int $productId, int $basketId, float $quantity): void
    {
        $this->reservationHistory[] = compact(
            'storeId',
            'productId',
            'basketId',
            'quantity',
        );
    }
 
    private function getPreparedReservationHistory(): array
    {
        $reverseHistory = array_reverse($this->reservationHistory);
        $negativeReservations = [];
 
        $tmp = [];
        foreach ($reverseHistory as $item)
        {
            $storeId = $item['storeId'];
            $productId = $item['productId'];
            $basketId = $item['basketId'];
            $quantity = $item['quantity'];
 
            $key = join("_", [
                $storeId,
                $productId,
                $basketId,
            ]);
 
            if ($quantity < 0.0)
            {
                $negativeReservations[$key] = $negativeReservations[$key] ?? 0.0;
                $negativeReservations[$key] += abs($quantity);
                continue;
            }
            elseif (isset($negativeReservations[$key]))
            {
                $negativeQuantity = $negativeReservations[$key];
                if ($negativeQuantity >= $quantity)
                {
                    $negativeQuantity -= $quantity;
                    if ($negativeQuantity > 0)
                    {
                        $negativeReservations[$key] = $negativeQuantity;
                    }
                    else
                    {
                        unset($negativeReservations[$key]);
                    }
                    continue;
                }
                else
                {
                    $item['quantity'] -= $negativeQuantity;
                    unset($negativeReservations[$key]);
                }
            }
 
            $tmp[] = $item;
        }
 
        return array_reverse($tmp);
    }
 
    public function getQuantityForItem(int $productId, int $basketId, int $storeId): float
    {
        $basketItemsStoreQuantity = $this->getQuantityForBatch([
            $basketId => $productId,
        ]);
        return $basketItemsStoreQuantity[$basketId][$storeId] ?? 0.0;
    }
 
    public function getQuantityForBatch(array $basket2productId): array
    {
        $basketItemsStoreQuantity = [];
        $currentStoreProductQuantity = $this->storeProductQuantity;
        $preparedReservationHistory = $this->getPreparedReservationHistory();
 
        foreach ($preparedReservationHistory as $item)
        {
            $storeId = $item['storeId'];
            $productId = $item['productId'];
            $basketId = $item['basketId'];
 
            $reservationQuantity = $item['quantity'];
            $storeQuantity = $currentStoreProductQuantity[$storeId][$productId] ?? 0.0;
 
            $isNeedBasketReservation = isset($basket2productId[$basketId]);
            if ($isNeedBasketReservation)
            {
                if ($storeQuantity > 0)
                {
                    $basketItemsStoreQuantity[$basketId][$storeId] ??= 0.0;
                    $basketItemsStoreQuantity[$basketId][$storeId] += min($storeQuantity, $reservationQuantity);
                }
            }
 
            if (isset($currentStoreProductQuantity[$storeId][$productId]))
            {
                $currentStoreProductQuantity[$storeId][$productId] -= $reservationQuantity;
            }
        }
 
        foreach ($basket2productId as $basketId => $productId)
        {
            foreach ($currentStoreProductQuantity as $storeId => $quantities)
            {
                if (
                    isset($basketItemsStoreQuantity[$basketId])
                    && !isset($basketItemsStoreQuantity[$basketId][$storeId])
                )
                {
                    continue;
                }
                $storeQuantity = $quantities[$productId] ?? 0.0;
                if ($storeQuantity > 0.0)
                {
                    $basketItemsStoreQuantity[$basketId][$storeId] ??= 0.0;
                    $basketItemsStoreQuantity[$basketId][$storeId] += $storeQuantity;
                }
            }
        }
 
        return $basketItemsStoreQuantity;
    }
}