import type {
	Order,
	Quote,
	CheckoutValidateRequest,
	CheckoutAddress,
	CheckoutShipmentItem,
	CheckoutParcel,
	CheckoutParcelContent,
	PluginSettings,
} from '../../../types';
import { isQuoteDropoff, isQuoteDDP } from './quoteHelpers';
import {
	isEUCountry,
	mapDestination,
	parseNum,
	splitName,
	truncateText,
} from '../../../shared/utils';

export interface OrderToCheckoutValidatePayloadOptions {
	/** Discount code to apply when validating (e.g. from ConfirmBookingModal). */
	discountCode?: string | null;
	/** Override collection date (for collection services). When not provided, uses first quote date. */
	collectionDate?: string | null;
	/** Override DDP (Delivery Duty Paid). When not provided, uses quote tags. */
	ddp?: boolean;
	/** Override IOSS (Import One-Stop Shop). */
	ioss?: string | null;
}

/**
 * Build CheckoutValidateRequest from WooCommerce order, store, selected quote and extras.
 */
export function orderToCheckoutValidatePayload(
	order: Order,
	settings: PluginSettings,
	quote: Quote,
	extras: string[],
	options?: OrderToCheckoutValidatePayloadOptions
): CheckoutValidateRequest | null {
	const store = settings.shipping;

	if (!store?.country || !order?.shipping?.country) return null;

	const origin: CheckoutAddress = {
		useAddress: {
			...store,
			companyStatus: settings.tax.vatStatus ?? null,
			companyTaxNumber: settings.tax.vatNumber ?? null,
			eori: settings.tax.eori ?? null,
			taxId: null,
		},
	};

	const defaultDimension = settings.packages.find(
		(pkg) => pkg.id === settings.defaultPackageId
	);

	const orderRef = String(order.id);
	const ddp = options?.ddp ?? null;
	const ioss = options?.ioss ?? null;
	const collectionDate = options?.collectionDate ?? null;

	let totalWeight = 0;
	let totalValue = 0;
	let max_length = 0;
	let max_width = 0;
	let max_height = 0;
	const contents: CheckoutParcelContent[] = [];

	const defaultTariff = settings.overrides.defaultTariffCode;
	const defaultCountryOfManufacture =
		settings.overrides.defaultCountryOfManufacture;

	for (const orderItem of order.items ?? []) {
		const weightPerUnit = parseNum(orderItem.dimensions?.weight) ?? 0;
		const quantity = Math.max(0, orderItem.quantity);
		totalWeight += weightPerUnit * quantity;
		totalValue += (parseNum(orderItem.total) ?? 0);
		max_length = Math.max(max_length, parseNum(orderItem.dimensions?.length) ?? 0);
		max_width = Math.max(max_width, parseNum(orderItem.dimensions?.width) ?? 0);
		max_height = Math.max(max_height, parseNum(orderItem.dimensions?.height) ?? 0);

		const tariffCode = orderItem.tariff_code?.trim() || defaultTariff || '';
		const countryOfManufacture =
			orderItem.country_of_manufacture?.trim() ||
			defaultCountryOfManufacture ||
			'CN';

		contents.push({
			quantity,
			description: truncateText(orderItem.name, 256),
			value: Math.round((parseNum(orderItem.total) ?? 0) * 100),
			weight: weightPerUnit,
			countryOfManufacture: countryOfManufacture,
			tariffCode: tariffCode,
		});
	}

	const contentSummary =
		contents.length > 0
			? contents
					.map((c) => `${c.quantity}x ${c.description || 'Item'}`)
					.join(', ')
			: 'Order contents #' + orderRef;

			
	// IOSS only applies for shipments to EU with total value up to 150 EUR
	// (exchange was not considered in this calculation for simplicity, as it would require fetching historical rates)
	const isIOSS_Eligible = isEUCountry(order?.shipping?.country) && totalValue <= 150;

	const parcels: CheckoutParcel[] = [
		{
			ref: orderRef,
			weight: totalWeight,
			length: max_length || defaultDimension?.length || 10,
			width: max_width || defaultDimension?.width || 10,
			height: max_height || defaultDimension?.height || 10,
			value: Math.round(totalValue * 100),
			contentSummary,
			contents: contents.length > 0 ? contents : undefined,
		},
	];

	const shipmentItem: CheckoutShipmentItem = {
		$type: 'shipment',
		serviceSlug: quote.service.slug,
		origin,
		destination: mapDestination(order),
		parcels,
		extras: extras?.map((e) => ({ key: e })) ?? [],
		collectionDate,
		ref: orderRef,
		customs: {
			exportReason: 'Sale',
			dutyTerms: ddp ? "ddp" : null,
			ioss: isIOSS_Eligible ? ioss : null,
		},
	};

	const orderPayload = {
		ref: orderRef,
		items: [shipmentItem],
		billingAddress: origin,
		customer: {
			...splitName(store.contactName ?? 'Woo Shop'),
			email: store.email || null,
		},
		discountCode: options?.discountCode ?? null,
	};

	return orderPayload;
}