import * as React from 'react';

import omit from 'lodash/omit';
import pick from 'lodash/pick';
import set from 'lodash/set';

import { useCalculateFeeLineTaxAndTotals } from './use-calculate-fee-line-tax-and-totals';
import { useFeeLineData } from './use-fee-line-data';
import { updatePosDataMeta } from './utils';
import { useLocalMutation } from '../../hooks/mutations/use-local-mutation';
import { useCurrentOrder } from '../contexts/current-order';

type OrderDocument = import('@wcpos/database').OrderDocument;
type FeeLine = NonNullable<OrderDocument['fee_lines']>[number];

/**
 * Account for string or number changes just in case
 */
interface Changes {
	name?: string;
	total?: string | number;
	amount?: string;
	percent?: boolean;
	prices_include_tax?: boolean;
}

/**
 *
 */
export const useUpdateFeeLine = () => {
	const { currentOrder } = useCurrentOrder();
	const { localPatch } = useLocalMutation();
	const { calculateFeeLineTaxesAndTotals } = useCalculateFeeLineTaxAndTotals();
	const { getFeeLineData } = useFeeLineData();

	/**
	 * Applies updates to a line item based on provided changes.
	 */
	const applyChangesToLineItem = React.useCallback(
		(lineItem: FeeLine, changes: Changes): FeeLine => {
			const { amount, percent, prices_include_tax, percent_of_cart_total_with_tax } =
				getFeeLineData(lineItem);

			const newData = {
				...{ amount, percent, prices_include_tax, percent_of_cart_total_with_tax },
				...pick(changes, [
					'amount',
					'percent',
					'prices_include_tax',
					'percent_of_cart_total_with_tax',
				]),
			};

			let updatedItem = { ...lineItem };
			updatedItem = updatePosDataMeta(updatedItem, newData);

			const remainingChanges = omit(changes, [
				'amount',
				'percent',
				'prices_include_tax',
				'percent_of_cart_total_with_tax',
			]);

			for (const key of Object.keys(remainingChanges)) {
				// Special case for nested changes, only meta_data at the moment
				const nestedKey = key.split('.');
				if (nestedKey.length === 1) {
					(updatedItem as any)[key] = remainingChanges[key];
				} else {
					set(updatedItem, nestedKey, remainingChanges[key]);
				}
			}

			return calculateFeeLineTaxesAndTotals(updatedItem);
		},
		[calculateFeeLineTaxesAndTotals, getFeeLineData]
	);

	/**
	 * Update fee line
	 *
	 * @TODO - what if more than one property is changed at once?
	 */
	const updateFeeLine = React.useCallback(
		async (uuid: string, changes: Changes) => {
			const order = currentOrder.getLatest();
			const json = order.toMutableJSON();
			let updated = false;

			const updatedLineItems = json.fee_lines?.map((feeLine) => {
				if (
					updated ||
					!feeLine.meta_data?.some((m) => m.key === '_woocommerce_pos_uuid' && m.value === uuid)
				) {
					return feeLine;
				}

				const updatedItem = applyChangesToLineItem(feeLine, changes);
				updated = true;
				return updatedItem;
			});

			if (updated && updatedLineItems) {
				return localPatch({ document: order, data: { fee_lines: updatedLineItems } });
			}
		},
		[applyChangesToLineItem, currentOrder, localPatch]
	);

	return { updateFeeLine };
};