UIKit/src/utils/cart/privilegeDiscount.ts

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


export function applyPrivilegeDiscount(
    cartData: CartData,
    discounts: Discount[],
) {
    cartData.services.forEach(service => {
        service.privileges.forEach(privilege => {
            const privilegeDiscount = findPrivilegeDiscount(privilege.privilegeId, privilege.price, discounts);
            if (privilegeDiscount) privilege.price *= privilegeDiscount.factor;
        });
    });
}

export function findPrivilegeDiscount(
    privilegeId: string,
    privilegePrice: number,
    discounts: Discount[],
): {
    discount: Discount | null,
    factor: number,
} {
    const applicableDiscounts = discounts.filter(discount => {
        const conditionMinPrice = parseFloat(discount.Condition.Term);
        if (!isFinite(conditionMinPrice)) throw new Error(`Couldn't parse Discount.Condition.Term: ${discount.Condition.Term}`);

        return (
            discount.Layer === 1 &&
            privilegeId === discount.Condition.Product &&
            privilegePrice >= conditionMinPrice
        );
    });

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

    const maxValueDiscount = applicableDiscounts.reduce((prev, current) =>
        parseFloat(current.Condition.Term) > parseFloat(prev.Condition.Term) ? current : prev
    );

    return { discount: maxValueDiscount, factor: maxValueDiscount.Target.Products[0].Factor };
}