const _get = require('lodash.get');

import { EmptyResultError, ValidationError } from '../errors';
import {
	DIGITAL_AND_BUNDLE_PRODUCT_CODES,
	DIGITAL_PRODUCT_CODES,
	EPAPER_CODE,
	PREMIUM_DIGITAL_AND_BUNDLE_PRODUCT_CODES,
	PRINT_PRODUCT_CODES,
	STANDARD_DIGITAL_AND_BUNDLE_PRODUCT_CODES
} from '../static-data/product-codes';
import {
	OfferResponse,
	Charges,
	Pricing,
	FormattedPrice
} from '../types/offer';

const DIGITAL = 'DIGITAL';
const TRIAL = 'TRIAL';
const BUNDLE = 'BUNDLE';
const PRINT = 'PRINT';
const BASIS_RECURRING = 'RECURRING';

/** Class representing a offer. */
export class Offer {

	public rawResponse: OfferResponse;
	public id: string;
	public type: string;
	public productName: string;
	public productType: string;
	public productCode: string;
	public pricing: OfferResponse['pricing'];
	public productCodes: Array<string>;
	public printProductCode: string;
	public digitalProductCode: string;
	public displayName: string;

	/**
	 * Create a offer
	 * @param offer Membership graphql offerById data response.
	 */
	constructor(offer: OfferResponse) {
		try {
			this.rawResponse = offer;
			this.id = offer.id;
			this.type = offer.type.toUpperCase();
			this.productName = offer.product.name;
			//  when we don't have a displayName let's default
			// to an empty string so that we can fallback to offer mapping name
			this.displayName = offer.displayName || "";
			this.productType = offer.product.type.toUpperCase();
			this.productCode = offer.product.code.toUpperCase();
			this.productCodes = offer.product.products || [];
			this.printProductCode = this.productCodes.find(code => PRINT_PRODUCT_CODES.includes(code.toUpperCase())) || '';
			this.digitalProductCode = this.productCodes.find(code => DIGITAL_AND_BUNDLE_PRODUCT_CODES.includes(code.toUpperCase())) || '';
			this.pricing = offer.pricing;
		} catch (error) {
			throw new ValidationError('Invalid offer response', error);
		}
	}

	/**
	 * Is this offer a digital product.
	 * @returns true|false
	 */
	public isDigital(): boolean {
		return this.productType === DIGITAL;
	}

	/**
	 * Is this offer a trial product.
	 * @returns true|false
	 */
	public isTrial(): boolean {
		return this.type === TRIAL;
	}

	/**
	 *  Is this offer a print product.
	 * @returns true|false
	 */
	public isPrint(): boolean {
		return this.productType === PRINT && this.productCode !== EPAPER_CODE;
	}

	/**
	 *  Is this offer a bundle product.
	 * @returns true|false
	 */
	public isBundle(): boolean {
		return this.productType === BUNDLE;
	}

	/**
	 *  Is this offer a standard product.
	 * @returns true|false
	 */
	public isStandard(): boolean {
		return STANDARD_DIGITAL_AND_BUNDLE_PRODUCT_CODES.includes(this.productCode);
	}

	/**
	 *  Is this offer a premium product.
	 * @returns true|false
	 */
	public isPremium(): boolean {
		return PREMIUM_DIGITAL_AND_BUNDLE_PRODUCT_CODES.includes(this.productCode);
	}

	/**
	 *  Is this offer an ePaper product.
	 * @returns true|false
	 */
	public isEpaper(): boolean {
		return this.productType === PRINT && this.productCode === EPAPER_CODE;
	}

	/**
	 *  Returns print product code.
	 * @returns N5D, N6D, NWE
	 */
	public getPrintProductCode(): string {
		const printProductCode = this.productCodes.find(code => PRINT_PRODUCT_CODES.includes(code.toUpperCase()));

		if (!printProductCode) {
			throw new EmptyResultError('No print product code for this offer could be found', { offerId: this.id });
		}

		return printProductCode;
	}

	/**
	 *  Returns digital product code.
	 * @returns P1, P2, P3
	 */
	public getDigitalProductCode(): string {
		const digitalProductCode = this.productCodes.find(code => DIGITAL_PRODUCT_CODES.includes(code.toUpperCase()));

		if (!digitalProductCode) {
			throw new EmptyResultError('No digital product code for this offer could be found', { offerId: this.id });
		}

		return digitalProductCode;
	}

	/**
	 * Gets all the available billing countries for the offer.
	 * @returns all the available billing countries (three letter ISO 3166-1 country code).
	 */
	public getBillingCountries(): Array<string> {
		const billingCountries = this.pricing.map((price: Pricing) => price.country);

		if (!billingCountries.length) {
			throw new EmptyResultError('No billing countries for this offer could be found', { offerId: this.id });
		}

		return billingCountries;
	}

	/**
	 * Return billing countries that offer this currency code
	 * @param currencyCode ISO 4217 3 character currency code
	 * @returns all the available billing countries (three letter ISO 3166-1 country code).
	 */
	public getBillingCountriesForCurrency(currencyCode: string): Array<string> {
		const billingCountries = this.pricing
			.filter((price: Pricing) => price.currency === currencyCode)
			.map((price: Pricing) => price.country);

		if (!billingCountries.length) {
			throw new EmptyResultError('No billing countries for this offer could be found', { offerId: this.id });
		}

		return billingCountries;
	}

	/**
	 * Gets all the prices for the specified country in the offer.
	 * @param countryCode three letter ISO 3166-1 country code.
	 * @param pricing all pricing for the offer.
	 * @returns only the pricing for the country code given.
	 */
	public getCountryPricing(countryCode: string = '', pricing: OfferResponse['pricing'] = []): OfferResponse['pricing'] {
		const code = countryCode.toUpperCase();

		const countryPricing = pricing.filter((price: Pricing) => _get(price, 'country', '').toUpperCase() === code);

		if (!countryPricing.length) {
			throw new EmptyResultError(`Pricing could not be found for country code: ${countryCode}`);
		}

		return countryPricing;

	}

	/**
	 * Gets all the prices for the specified fulfilment option in the offer.
	 * @param fulfilmentOption newspaper delivery type.
	 * @param pricing all pricing for the offer.
	 * @returns only the pricing for the fulfilment option given.
	 */
	public getFulfilmentPricing(fulfilmentOption: string = '', pricing: OfferResponse['pricing'] = []): OfferResponse['pricing'] {
		const option = fulfilmentOption.toUpperCase();
		const fulfilmentPricing = pricing.filter((price: Pricing) => _get(price, 'option.code', '').toUpperCase() === option);

		if (!fulfilmentPricing.length) {
			throw new EmptyResultError(`Pricing could not be found for this fulfilmentOption: ${fulfilmentOption}`);
		}

		return fulfilmentPricing;

	}

	/**
	 * Gets all the prices for the specified term in the offer.
	 * @param term payment/billing term - how often the user will make a payment.
	 * @param pricing all pricing for the offer.
	 * @returns only the pricing for the term given.
	 */
	public getTermPricing(term: string = '',  pricing: OfferResponse['pricing'] = []): Pricing {
		const price = pricing.find(price => this.pricingHasTerm(term, price));

		if (!price) {
			throw new EmptyResultError(`Pricing could not be found for paymentTerm: ${term}`);
		}

		return price;
	}

	/**
	 * Gets all formatted charges for an offer based on country code and fulfilment option.
	 * @param countryCode three letter ISO 3166-1 country code.
	 * @param fulfilmentOption newspaper delivery type.
	 * @returns all formatted charges for given country code and fulfilment option.
	 */
	public getAvailableCharges(countryCode: string, fulfilmentOption?: string): Array<FormattedPrice> {
		if (countryCode && fulfilmentOption) {
			return this.getAvailableChargesForCountryAndFulfilmentOption(countryCode, fulfilmentOption);
		} else if (countryCode) {
			return this.getAvailableChargesForCountry(countryCode);
		} else {
			return this.getAllAvailableCharges();
		}
	}

	/**
	 * Gets all available charges for the offer.
	 * @returns all available formatted charges.
	 */
	public getAllAvailableCharges(): Array<FormattedPrice> {
		return this.pricing.map(price => this.formatPricing(price));
	}

	/**
	 * Gets available chargers for specified country.
	 * @param countryCode three letter ISO 3166-1 country code.
	 * @returns formatted charges for specified country.
	 */
	public getAvailableChargesForCountry(countryCode: string): Array<FormattedPrice> {
		const pricing = this.getCountryPricing(countryCode, this.pricing);
		return pricing.map(price => this.formatPricing(price));
	}

	/**
	 * Gets available chargers for specified country and fulfilment option.
	 * @param countryCode three letter ISO 3166-1 country code.
	 * @param fulfilmentOption newspaper delivery type.
	 * @returns formatted charges for specified country and fulfilment option.
	 */
	public getAvailableChargesForCountryAndFulfilmentOption(countryCode: string, fulfilmentOption: string): Array<FormattedPrice> {
		const pricing = this.pricing.filter(price =>
			price.country.toUpperCase() === countryCode.toUpperCase() &&
			_get(price, 'option.code', '').toUpperCase() === fulfilmentOption.toUpperCase()
		);

		if (!pricing.length) {
			throw new EmptyResultError(`Pricing could not be found for the countryCode: ${countryCode} and fulfilmentOption: ${fulfilmentOption}`);
		}

		return pricing.map(price => this.formatPricing(price));
	}

	/**
	 * Gets currency for given specified country code
	 * @param countryCode three letter ISO 3166-1 country code.
	 * @returns currency ISO 4217 code.
	 */
	public getCurrency(countryCode: string): string {
		const countryPricing = this.getCountryPricing(countryCode, this.pricing);
		return _get(countryPricing, '[0].currency'); // Each price in the countryPricing array will have the same currency.
	}

	/**
	 * Gets subscription term.
	 * @param price selected price.
	 * @returns displayName and iso8601Duration.
	 */
	public getSubscriptionTerm(price: Pricing): Charges['subscriptionTerm'] {
		const charge = price.charges.find(charge => charge.basis.toUpperCase() === BASIS_RECURRING);

		if (!charge) {
			throw new EmptyResultError(`No charges were found for with the property of basis: ${BASIS_RECURRING}`);
		}

		// For trials set the information about when the main payment will start
		if (this.isTrial()) {
			charge.subscriptionTerm.paymentDueAfter = _get(charge, 'paymentDue.after');
		}

		return charge.subscriptionTerm;
	}

	/**
	 * Formats price by creating a new price object.
	 * @param price selected price.
	 * @returns formatted price.
	 */
	private formatPricing(price: Pricing): FormattedPrice {
		const subscriptionTerm = this.getSubscriptionTerm(price);
		const value = _get(price, 'total.value'); // For bundle charges, digital and print are split into two separate charges and therefore we need the total amount to get the correct price.
		const currencySymbol = _get(price, 'total.symbol');
		const trialValue = _get(price, 'trialTotal.value', null);

		const formattedPrice = Object.assign({}, {
			subscriptionName: subscriptionTerm.displayName,
			subscriptionCode: subscriptionTerm.iso8601Duration,
			subscriptionPaymentDue: subscriptionTerm.paymentDueAfter,
			subscriptionAutoRenewTerm: subscriptionTerm.autoRenewTerm,
			subscriptionTermType: subscriptionTerm.termType,
			currency: price.currency,
			symbol: currencySymbol,
			option: price.option,
			value,
			trialValue,
		});

		return formattedPrice;
	}

	/**
	 * Determines if charge exists for a specified term.
	 * @param term payment/billing term - how often the user will make a payment.
	 * @param charge selected charge.
	 * @returns true|false
	 */
	private chargeHasTerm(term: string, charge: Pricing['charges']): boolean {
		const displayName = _get(charge, 'subscriptionTerm.displayName', ''); // trial basis ONE_TIME offer charges do not have a subscriptionTerm
		return displayName.toLowerCase() === term.toLowerCase();
	}

	/**
	 * Determines if pricing has a specified term.
	 * @param term payment/billing term - how often the user will make a payment.
	 * @param price selected price.
	 * @returns true|false
	 */
	private pricingHasTerm(term: string, price: Pricing): boolean {
		return !!_get(price, 'charges').find((charge: Pricing['charges']) => this.chargeHasTerm(term, charge));
	}

}