UIKit/lib/utils/cart/serviceDiscount.ts

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


export function applyServiceDiscounts(
    cartData: CartData,
    discounts: Discount[],
) {
    cartData.services.forEach(service => {
        service.tariffs.map(tariff => {
            tariff.privileges.forEach(privilege => {
                const privilegeDiscount = findServiceDiscount(privilege.serviceKey, privilege.price, discounts);
                if (!privilegeDiscount) return;

                const discountAmount = privilege.price * (1 - findDiscountFactor(privilegeDiscount));
                privilege.price -= discountAmount;
                cartData.allAppliedDiscounts.push(privilegeDiscount);
                service.appliedServiceDiscount = privilegeDiscount;

                tariff.price -= discountAmount;
                service.price -= discountAmount;
                cartData.priceAfterDiscounts -= discountAmount;
            });
        });
    });
}

export function findServiceDiscount(
    serviceKey: string,
    currentPrice: number,
    discounts: Discount[],
): Discount | null {
    const applicableDiscounts = discounts.filter(discount => {
        return (
            discount.Layer === 2 &&
            discount.Condition.Group === serviceKey &&
            currentPrice >= discount.Condition.PriceFrom
        );
    });

    if (!applicableDiscounts.length) return null;

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

    return maxValueDiscount;
}