import { isAfter, isBefore, parseISO } from 'date-fns';
import { SubscriptionDetails } from '../types/subscription';
import { SubscriptionHistoryModel } from '../models/subscription';

const getPrice = ({ term = 'P1M', price }: SubscriptionDetails): number => {
	switch (term) {
		case 'P2Y':
			return price.value / 24;
		case 'P1Y':
		case 'P52W':
		case 'P364D':
			return price.value / 12;
		case 'P91D':
		case 'P13W':
			return price.value / 3;
		case 'P3M':
			return price.value / 3;
		case 'P1M':
		case 'P4W':
		case 'P28D':
		default:
			return price.value;
	}
};

const isSameProduct = (first: Array<string> = [], second: Array<string> = []): boolean => {
	if (first.length !== second.length) {
		return false;
	}
	const firstSet = new Set(first);
	return second.every(val => firstSet.has(val));
};

export const ensureDiscount = ({ subscriptionBefore, subscriptionAfter }: SubscriptionHistoryModel): boolean => {
	if (!subscriptionBefore || !subscriptionAfter) {
		return false;
	}
	const currentPrice = getPrice(subscriptionBefore);
	const nextPrice = getPrice(subscriptionAfter);
	return currentPrice > nextPrice && isSameProduct(subscriptionBefore.products, subscriptionAfter.products);
};

export const findFutureEvent = (history: Array<SubscriptionHistoryModel> = [], eventType: string): SubscriptionHistoryModel | undefined => {
	return history.find(item => {
		return item.eventType === eventType && isBefore(new Date(), parseISO(item.eventEffectiveDate));
	});
};

export const isEventDateAfter = (subscriptionBefore: SubscriptionHistoryModel, subscriptionAfter: SubscriptionHistoryModel): boolean => {
	if (!subscriptionBefore || !subscriptionAfter) {
		return false;
	}
	return isAfter(parseISO(subscriptionBefore.eventDate), parseISO(subscriptionAfter.eventDate));
};

export const findEvent = (history: Array<SubscriptionHistoryModel> = [], eventType: string): SubscriptionHistoryModel | undefined => {
	return history.find(item => item.eventType === eventType);
};