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


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

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

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

export function findPrivilegeDiscount(
    privilegeId: string,
    privilegePrice: number,
    discounts: Discount[],
): Discount | null {
    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 null;

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

    return maxValueDiscount;
}