UIKit/src/utils/cart/cartDiscount.ts

import { CartData, Discount } from "../../model";


export function applyCartDiscount(
    cartData: CartData,
    discounts: Discount[],
) {
    const cartDiscount = findCartDiscount(cartData.priceAfterDiscounts, discounts);
    if (cartDiscount.discount) {
        cartData.priceAfterDiscounts *= cartDiscount.factor;
        cartData.allAppliedDiscounts.push(cartDiscount.discount);
        cartData.appliedCartPurchasesDiscount = cartDiscount.discount;
    }
}

export function findCartDiscount(
    cartPurchasesAmount: number,
    discounts: Discount[],
): {
    discount: Discount | null,
    factor: number,
} {
    const applicableDiscounts = discounts.filter(discount => {
        return (
            discount.Layer === 3 &&
            cartPurchasesAmount >= discount.Condition.CartPurchasesAmount
        );
    });

    if (!applicableDiscounts.length) return { discount: null, factor: 1 };

    const maxValueDiscount = applicableDiscounts.reduce((prev, current) => {
        return current.Condition.CartPurchasesAmount > prev.Condition.CartPurchasesAmount ? current : prev;
    });

    return { discount: maxValueDiscount, factor: maxValueDiscount.Target.Factor };
}