import { Discount } from "../../model/discount";


export function findDiscountFactor(discount: Discount | null | undefined): number {
    if (!discount) return 1;

    if (discount.Layer === 1) return discount.Target.Products[0].Factor;

    return discount.Target.Factor;
}

export function findNkoDiscount(discounts: Discount[]): Discount | null {
    const applicableDiscounts = discounts.filter(discount => discount.Condition.UserType === "nko");

    if (!applicableDiscounts.length) return null;

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

    return maxValueDiscount;
} 

export function findPrivilegeDiscount(
    privilegeId: string,
    privilegeAmount: number,
    discounts: Discount[],
    userId: string,
): Discount | null {
    const applicableDiscounts = discounts.filter(discount => {
        return (
            discount.Layer === 1
            && privilegeId === discount.Condition.Product
            && privilegeAmount >= Number(discount.Condition.Term)
            && (discount.Condition.User === "" || discount.Condition.User === userId)
        );
    });

    if (!applicableDiscounts.length) return null;

    let maxValueDiscount: Discount = applicableDiscounts[0];
    for (const discount of applicableDiscounts) {
        if (discount.Condition.User !== "" && discount.Condition.User === userId) {
            maxValueDiscount = discount;
            break;
        }

        if (Number(discount.Condition.Term) > Number(maxValueDiscount.Condition.Term)) {
            maxValueDiscount = discount;
        }
    }

    return maxValueDiscount;
}

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

    if (!applicableDiscounts.length) return null;

    let maxValueDiscount: Discount = applicableDiscounts[0];
    for (const discount of applicableDiscounts) {
        if (discount.Condition.User !== "" && discount.Condition.User === userId) {
            maxValueDiscount = discount;
            break;
        }

        if (Number(discount.Condition.PriceFrom) > Number(maxValueDiscount.Condition.PriceFrom)) {
            maxValueDiscount = discount;
        }
    }

    return maxValueDiscount;
}

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

    if (!applicableDiscounts.length) return null;

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

    return maxValueDiscount;
}

export function findLoyaltyDiscount(
    purchasesAmount: number,
    discounts: Discount[],
): Discount | null {
    const applicableDiscounts = discounts.filter(discount => {
        return (
            discount.Layer === 4
            && discount.Condition.UserType !== "nko"
            && purchasesAmount >= Number(discount.Condition.PurchasesAmount)
        );
    });

    if (!applicableDiscounts.length) return null;

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

    return maxValueDiscount;
}