front-hub/src/utils/calcTariffPrices.ts

import { Discount, Tariff, findDiscountFactor } from "@frontend/kitui"
import { calcCart } from "./calcCart/calcCart"

export function calcIndividualTariffPrices(
	tariff: Tariff,
	discounts: Discount[],
	purchasesAmount: number,
	currentTariffs: Tariff[],
	isUserNko?: boolean,
): {
  priceBeforeDiscounts: number;
  priceAfterDiscounts: number;
} {
	const priceBeforeDiscounts =
    tariff.price || tariff.privileges.reduce((sum, privilege) => sum + privilege.amount * privilege.price, 0)
	let priceAfterDiscounts = priceBeforeDiscounts

	const cart = calcCart([...currentTariffs, tariff], discounts, purchasesAmount, isUserNko)

	cart.allAppliedDiscounts.forEach((discount) => {
		priceAfterDiscounts *= findDiscountFactor(discount)
	})

	return { priceBeforeDiscounts, priceAfterDiscounts }
}