import clsx from 'clsx';
import { useSelect, useDispatch } from '@wordpress/data';
import { ToolbarButton, ToolbarGroup } from '@wordpress/components';
import { displayShortcut, isKeyboardEvent } from '@wordpress/keycodes';
import { __ } from '@wordpress/i18n';
import {
	BlockControls,
	InnerBlocks,
	InspectorControls,
	useInnerBlocksProps,
	RichText,
	useBlockProps,
	useBlockEditingMode,
	store as blockEditorStore,
	getColorClassName,
} from '@wordpress/block-editor';
import { isURL, prependHTTP } from '@wordpress/url';
import { useState, useEffect, useRef } from '@wordpress/element';
import { link as linkIcon, removeSubmenu } from '@wordpress/icons';
import { speak } from '@wordpress/a11y';
import { createBlock } from '@wordpress/blocks';
import { useMergeRefs, usePrevious } from '@wordpress/compose';
import { ItemSubmenuIcon } from './icons';
import {
	Controls,
	LinkUI,
	useEntityBinding,
	useHandleLinkChange,
	useIsInvalidLink,
	InvalidDraftDisplay,
	useEnableLinkStatusValidation,
	useIsDraggingWithin,
	selectLabelText,
} from '../navigation-link/shared';
import {
	getColors,
	getNavigationChildBlockProps,
} from '../navigation/edit/utils';
import { DEFAULT_BLOCK } from '../navigation/constants';

const ALLOWED_BLOCKS = [
	'core/navigation-link',
	'core/navigation-submenu',
	'core/page-list',
	'core/loginout',
];

/**
 * @typedef {'post-type'|'custom'|'taxonomy'|'post-type-archive'} WPNavigationLinkKind
 */

/**
 * Navigation Link Block Attributes
 *
 * @typedef {Object} WPNavigationLinkBlockAttributes
 *
 * @property {string}               [label]         Link text.
 * @property {WPNavigationLinkKind} [kind]          Kind is used to differentiate between term and post ids to check post draft status.
 * @property {string}               [type]          The type such as post, page, tag, category and other custom types.
 * @property {string}               [rel]           The relationship of the linked URL.
 * @property {number}               [id]            A post or term id.
 * @property {boolean}              [opensInNewTab] Sets link target to _blank when true.
 * @property {string}               [url]           Link href.
 */

export default function NavigationSubmenuEdit( {
	attributes,
	isSelected,
	setAttributes,
	mergeBlocks,
	onReplace,
	context,
	clientId,
} ) {
	const { label, url, description, kind, type, id } = attributes;

	const { showSubmenuIcon, maxNestingLevel, submenuVisibility } = context;
	const blockEditingMode = useBlockEditingMode();

	// Force click-only behavior in contentOnly mode to prevent hover dropdowns
	const openSubmenusOnClick =
		blockEditingMode !== 'default' ? true : submenuVisibility === 'click';

	// URL binding logic
	const { hasUrlBinding, isBoundEntityAvailable, entityRecord } =
		useEntityBinding( {
			clientId,
			attributes,
		} );

	const handleLinkChange = useHandleLinkChange( {
		clientId,
		attributes,
		setAttributes,
		allowTextUpdate: true,
	} );

	const { __unstableMarkNextChangeAsNotPersistent, replaceBlock } =
		useDispatch( blockEditorStore );
	const [ isLinkOpen, setIsLinkOpen ] = useState( false );
	// Use internal state instead of a ref to make sure that the component
	// re-renders when the popover's anchor updates.
	const [ popoverAnchor, setPopoverAnchor ] = useState( null );
	const listItemRef = useRef( null );
	const isDraggingWithin = useIsDraggingWithin( listItemRef );
	const itemLabelPlaceholder = __( 'Add text…' );
	const ref = useRef();

	const {
		parentCount,
		isParentOfSelectedBlock,
		isImmediateParentOfSelectedBlock,
		hasChildren,
		selectedBlockHasChildren,
		onlyDescendantIsEmptyLink,
	} = useSelect(
		( select ) => {
			const {
				hasSelectedInnerBlock,
				getSelectedBlockClientId,
				getBlockParentsByBlockName,
				getBlock,
				getBlockCount,
				getBlockOrder,
			} = select( blockEditorStore );

			let _onlyDescendantIsEmptyLink;

			const selectedBlockId = getSelectedBlockClientId();

			const selectedBlockChildren = getBlockOrder( selectedBlockId );

			// Check for a single descendant in the submenu. If that block
			// is a link block in a "placeholder" state with no label then
			// we can consider as an "empty" link.
			if ( selectedBlockChildren?.length === 1 ) {
				const singleBlock = getBlock( selectedBlockChildren[ 0 ] );

				_onlyDescendantIsEmptyLink =
					singleBlock?.name === 'core/navigation-link' &&
					! singleBlock?.attributes?.label;
			}

			return {
				parentCount: getBlockParentsByBlockName(
					clientId,
					'core/navigation-submenu'
				).length,
				isParentOfSelectedBlock: hasSelectedInnerBlock(
					clientId,
					true
				),
				isImmediateParentOfSelectedBlock: hasSelectedInnerBlock(
					clientId,
					false
				),
				hasChildren: !! getBlockCount( clientId ),
				selectedBlockHasChildren: !! selectedBlockChildren?.length,
				onlyDescendantIsEmptyLink: _onlyDescendantIsEmptyLink,
			};
		},
		[ clientId ]
	);

	const validateLinkStatus = useEnableLinkStatusValidation( clientId );

	const prevHasChildren = usePrevious( hasChildren );

	// Check if the submenu's parent link is invalid or draft
	const [ isInvalid, isDraft ] = useIsInvalidLink(
		kind,
		type,
		id,
		validateLinkStatus
	);

	// Show the LinkControl on mount if the URL is empty
	// ( When adding a new menu item)
	// This can't be done in the useState call because it conflicts
	// with the autofocus behavior of the BlockListBlock component.
	useEffect( () => {
		if ( ! openSubmenusOnClick && ! url ) {
			setIsLinkOpen( true );
		}
	}, [] );

	/**
	 * The hook shouldn't be necessary but due to a focus loss happening
	 * when selecting a suggestion in the link popover, we force close on block unselection.
	 */
	useEffect( () => {
		if ( ! isSelected ) {
			setIsLinkOpen( false );
		}
	}, [ isSelected ] );

	// If the LinkControl popover is open and the URL has changed, close the LinkControl and focus the label text.
	useEffect( () => {
		if ( isLinkOpen && url ) {
			// Does this look like a URL and have something TLD-ish?
			if (
				isURL( prependHTTP( label ) ) &&
				/^.+\.[a-z]+/.test( label )
			) {
				// Focus and select the label text.
				selectLabelText( ref );
			}
		}
	}, [ url ] );

	const {
		textColor,
		customTextColor,
		backgroundColor,
		customBackgroundColor,
	} = getColors( context, parentCount > 0 );

	function onKeyDown( event ) {
		if ( isKeyboardEvent.primary( event, 'k' ) ) {
			// Required to prevent the command center from opening,
			// as it shares the CMD+K shortcut.
			// See https://github.com/WordPress/gutenberg/pull/59845.
			event.preventDefault();
			// If we don't stop propagation, this event bubbles up to the parent submenu item
			event.stopPropagation();
			setIsLinkOpen( true );
		}
	}

	const blockProps = useBlockProps( {
		ref: useMergeRefs( [ setPopoverAnchor, listItemRef ] ),
		className: clsx( 'wp-block-navigation-item', {
			'is-editing': isSelected || isParentOfSelectedBlock,
			'is-dragging-within': isDraggingWithin,
			'has-link': !! url,
			'has-child': hasChildren,
			'has-text-color': !! textColor || !! customTextColor,
			[ getColorClassName( 'color', textColor ) ]: !! textColor,
			'has-background': !! backgroundColor || customBackgroundColor,
			[ getColorClassName( 'background-color', backgroundColor ) ]:
				!! backgroundColor,
			'open-on-click': openSubmenusOnClick,
			'open-always': submenuVisibility === 'always',
		} ),
		style: {
			color: ! textColor && customTextColor,
			backgroundColor: ! backgroundColor && customBackgroundColor,
		},
		onKeyDown,
	} );

	// Always use overlay colors for submenus.
	const innerBlocksColors = getColors( context, true );

	const allowedBlocks =
		parentCount >= maxNestingLevel
			? ALLOWED_BLOCKS.filter(
					( blockName ) => blockName !== 'core/navigation-submenu'
			  )
			: ALLOWED_BLOCKS;

	const navigationChildBlockProps =
		getNavigationChildBlockProps( innerBlocksColors );
	const innerBlocksProps = useInnerBlocksProps( navigationChildBlockProps, {
		allowedBlocks,
		defaultBlock: DEFAULT_BLOCK,
		directInsert: true,

		// Ensure block toolbar is not too far removed from item
		// being edited.
		// see: https://github.com/WordPress/gutenberg/pull/34615.
		__experimentalCaptureToolbars: true,

		renderAppender:
			isSelected ||
			( isImmediateParentOfSelectedBlock &&
				! selectedBlockHasChildren ) ||
			// Show the appender while dragging to allow inserting element between item and the appender.
			hasChildren
				? InnerBlocks.ButtonBlockAppender
				: false,
	} );

	const ParentElement = openSubmenusOnClick ? 'button' : 'a';

	function transformToLink() {
		const newLinkBlock = createBlock( 'core/navigation-link', attributes );
		replaceBlock( clientId, newLinkBlock );
	}

	useEffect( () => {
		// If block becomes empty, transform to Navigation Link.
		if ( ! hasChildren && prevHasChildren ) {
			// This side-effect should not create an undo level as those should
			// only be created via user interactions.
			__unstableMarkNextChangeAsNotPersistent();
			transformToLink();
		}
	}, [ hasChildren, prevHasChildren ] );

	const canConvertToLink =
		! selectedBlockHasChildren || onlyDescendantIsEmptyLink;

	return (
		<>
			<BlockControls>
				<ToolbarGroup>
					{ ! openSubmenusOnClick && (
						<ToolbarButton
							name="link"
							icon={ linkIcon }
							title={ __( 'Link' ) }
							shortcut={ displayShortcut.primary( 'k' ) }
							onClick={ () => {
								setIsLinkOpen( true );
							} }
						/>
					) }

					<ToolbarButton
						name="revert"
						icon={ removeSubmenu }
						title={ __( 'Convert to Link' ) }
						onClick={ transformToLink }
						className="wp-block-navigation__submenu__revert"
						disabled={ ! canConvertToLink }
					/>
				</ToolbarGroup>
			</BlockControls>
			<InspectorControls group="content">
				<Controls
					attributes={ attributes }
					setAttributes={ setAttributes }
					clientId={ clientId }
					isLinkEditable={ ! openSubmenusOnClick }
				/>
			</InspectorControls>
			<div { ...blockProps }>
				<ParentElement className="wp-block-navigation-item__content">
					{ ! isInvalid && ! isDraft && (
						<>
							<RichText
								ref={ ref }
								identifier="label"
								className="wp-block-navigation-item__label"
								value={ label }
								onChange={ ( labelValue ) =>
									setAttributes( { label: labelValue } )
								}
								onMerge={ mergeBlocks }
								onReplace={ onReplace }
								aria-label={ __( 'Navigation link text' ) }
								placeholder={ itemLabelPlaceholder }
								withoutInteractiveFormatting
								onClick={ () => {
									if ( ! openSubmenusOnClick && ! url ) {
										setIsLinkOpen( true );
									}
								} }
							/>
							{ description && (
								<span className="wp-block-navigation-item__description">
									{ description }
								</span>
							) }
						</>
					) }
					{ ( isInvalid || isDraft ) && (
						<InvalidDraftDisplay
							label={ label }
							isInvalid={ isInvalid }
							isDraft={ isDraft }
							className="wp-block-navigation-item__label"
						/>
					) }
					{ ! openSubmenusOnClick && isLinkOpen && (
						<LinkUI
							clientId={ clientId }
							link={ attributes }
							entity={ {
								entityRecord,
								hasBinding: hasUrlBinding,
								isEntityAvailable: isBoundEntityAvailable,
							} }
							onClose={ () => {
								setIsLinkOpen( false );
							} }
							anchor={ popoverAnchor }
							onRemove={ () => {
								setAttributes( { url: '' } );
								speak( __( 'Link removed.' ), 'assertive' );
							} }
							onChange={ handleLinkChange }
						/>
					) }
				</ParentElement>
				{ ( showSubmenuIcon || openSubmenusOnClick ) && (
					<span className="wp-block-navigation__submenu-icon">
						<ItemSubmenuIcon />
					</span>
				) }
				<div { ...innerBlocksProps } />
			</div>
		</>
	);
}