/**
 * External dependencies
 */
import classNames from 'classnames';
import { __, _n, sprintf } from '@wordpress/i18n';
import { useState, useEffect, useRef } from '@wordpress/element';
import { dispatch } from '@wordpress/data';
import {
	translateJQueryEventToNative,
	renderFrontend,
} from '@woocommerce/base-utils';
import { useStoreCart } from '@woocommerce/base-context/hooks';
import Drawer from '@woocommerce/base-components/drawer';
import { CART_STORE_KEY as storeKey } from '@woocommerce/block-data';

/**
 * Internal dependencies
 */
import CartLineItemsTable from '../cart/full-cart/cart-line-items-table';
import withMiniCartConditionalHydration from './with-mini-cart-conditional-hydration';
import './style.scss';

interface MiniCartBlockProps {
	isPlaceholderOpen?: boolean;
}

const MiniCartBlock = ( {
	isPlaceholderOpen = false,
}: MiniCartBlockProps ): JSX.Element => {
	const { cartItems, cartItemsCount, cartIsLoading } = useStoreCart();
	const [ isOpen, setIsOpen ] = useState< boolean >( isPlaceholderOpen );
	const emptyCartRef = useRef< HTMLDivElement | null >( null );
	// We already rendered the HTML drawer placeholder, so we want to skip the
	// slide in animation.
	const [ skipSlideIn, setSkipSlideIn ] = useState< boolean >(
		isPlaceholderOpen
	);

	useEffect( () => {
		const openMiniCartAndRefreshData = () => {
			dispatch( storeKey ).invalidateResolutionForStore();
			setSkipSlideIn( false );
			setIsOpen( true );
		};

		// Make it so we can read jQuery events triggered by WC Core elements.
		const removeJQueryAddedToCartEvent = translateJQueryEventToNative(
			'added_to_cart',
			'wc-blocks_added_to_cart'
		);

		document.body.addEventListener(
			'wc-blocks_added_to_cart',
			openMiniCartAndRefreshData
		);

		return () => {
			removeJQueryAddedToCartEvent();

			document.body.removeEventListener(
				'wc-blocks_added_to_cart',
				openMiniCartAndRefreshData
			);
		};
	}, [] );

	useEffect( () => {
		// If the cart has been completely emptied, move focus to empty cart
		// element.
		if ( isOpen && ! cartIsLoading && cartItems.length === 0 ) {
			if ( emptyCartRef.current instanceof HTMLElement ) {
				emptyCartRef.current.focus();
			}
		}
	}, [ isOpen, cartIsLoading, cartItems.length, emptyCartRef ] );

	const contents =
		! cartIsLoading && cartItems.length === 0 ? (
			<div
				className="wc-block-mini-cart__empty-cart"
				tabIndex={ -1 }
				ref={ emptyCartRef }
			>
				{ __( 'Cart is empty', 'woo-gutenberg-products-block' ) }
			</div>
		) : (
			<CartLineItemsTable
				lineItems={ cartItems }
				isLoading={ cartIsLoading }
			/>
		);

	return (
		<>
			<button
				className="wc-block-mini-cart__button"
				onClick={ () => {
					if ( ! isOpen ) {
						setIsOpen( true );
						setSkipSlideIn( false );
					}
				} }
			>
				{ sprintf(
					/* translators: %d is the count of items in the cart. */
					_n(
						'%d item',
						'%d items',
						cartItemsCount,
						'woo-gutenberg-products-block'
					),
					cartItemsCount
				) }
			</button>
			<Drawer
				className={ classNames(
					'wc-block-mini-cart__drawer',
					'is-mobile',
					{
						'is-loading': cartIsLoading,
					}
				) }
				title={
					cartIsLoading
						? __( 'Your cart', 'woo-gutenberg-products-block' )
						: sprintf(
								/* translators: %d is the count of items in the cart. */
								_n(
									'Your cart (%d item)',
									'Your cart (%d items)',
									cartItemsCount,
									'woo-gutenberg-products-block'
								),
								cartItemsCount
						  )
				}
				isOpen={ isOpen }
				onClose={ () => {
					setIsOpen( false );
				} }
				slideIn={ ! skipSlideIn }
			>
				{ contents }
			</Drawer>
		</>
	);
};

const renderMiniCartFrontend = () => {
	// Check if button is focused. In that case, we want to refocus it after we
	// replace it with the React equivalent.
	let focusedMiniCartBlock: HTMLElement | null = null;
	/* eslint-disable @wordpress/no-global-active-element */
	if (
		document.activeElement &&
		document.activeElement.classList.contains(
			'wc-block-mini-cart__button'
		) &&
		document.activeElement.parentNode instanceof HTMLElement
	) {
		focusedMiniCartBlock = document.activeElement.parentNode;
	}
	/* eslint-enable @wordpress/no-global-active-element */

	renderFrontend( {
		selector: '.wc-block-mini-cart',
		Block: withMiniCartConditionalHydration( MiniCartBlock ),
		getProps: ( el: HTMLElement ) => ( {
			isDataOutdated: el.dataset.isDataOutdated,
			isPlaceholderOpen: el.dataset.isPlaceholderOpen === 'true',
		} ),
	} );

	// Refocus previously focused button if drawer is not open.
	if (
		focusedMiniCartBlock instanceof HTMLElement &&
		! focusedMiniCartBlock.dataset.isPlaceholderOpen
	) {
		const innerButton = focusedMiniCartBlock.querySelector(
			'.wc-block-mini-cart__button'
		);
		if ( innerButton instanceof HTMLElement ) {
			innerButton.focus();
		}
	}
};

renderMiniCartFrontend();