import {
	useCallback,
	useEffect,
	useState,
	useRef,
	useLayoutEffect,
} from '@wordpress/element';
import { useDispatch, useSelect } from '@wordpress/data';
import { __ } from '@wordpress/i18n';
import { useForm } from 'react-hook-form';
import apiFetch from '@wordpress/api-fetch';
import { motion } from 'framer-motion';
import { STORE_KEY } from '../store';
import { MagnifyingGlassIcon, XMarkIcon } from '@heroicons/react/24/outline';
import usePopper from '../hooks/use-popper';
import { classNames } from '../helpers';
import { useDebounce } from '../hooks/use-debounce';
import LoadingSpinner from './loading-spinner';

const container = {
	closed: { opacity: 0 },
	open: {
		opacity: 1,
		transition: {
			delayChildren: 0.05,
			staggerChildren: 0.05,
		},
	},
};
const item = {
	open: {
		y: 0,
		opacity: 1,
	},
	closed: {
		y: 20,
		opacity: 0,
	},
};
const validationRegex = /^[a-zA-Z0-9\-_'& ]{1,50}$/;

const BusinessTypes = () => {
	const { setWebsiteTypeAIStep, setBusinessTypeListAIStep } =
		useDispatch( STORE_KEY );
	const { businessType, businessTypeList } = useSelect( ( select ) => {
		const { getAIStepData } = select( STORE_KEY );
		return getAIStepData();
	} );

	const [ referenceRef, popperRef ] = usePopper( {
		placement: 'bottom',
		modifiers: [ { name: 'offset', options: { offset: [ 0, 0 ] } } ],
	} );

	const [ openSuggestions, setOpenSuggestions ] = useState( false );
	const [ isFetching, setIsFetching ] = useState( false );
	const reqAbort = useRef( null );
	const scrollableRef = useRef( null );

	const { register, setValue, reset, setFocus, watch } = useForm( {
		defaultValues: { keyword: businessType ?? '' },
	} );
	const watchedKeyword = watch( 'keyword' );
	const debouncedKeyword = useDebounce( watchedKeyword, 300 );

	const fetchCategories = async ( keyword = '' ) => {
		if ( reqAbort.current ) {
			reqAbort.current.abort();
			reqAbort.current = null;
		}
		setIsFetching( true );
		reqAbort.current = new AbortController();
		try {
			const response = await apiFetch( {
				path: `zipwp/v1/search-category`,
				method: 'POST',
				data: { keyword },
				headers: {
					'content-type': 'application/json',
					'X-WP-Nonce': aiBuilderVars.rest_api_nonce,
					_ajax_nonce: aiBuilderVars._ajax_nonce,
				},
				signal: reqAbort.current.signal,
			} );

			if ( response.success ) {
				setBusinessTypeListAIStep( response?.data?.data );
			}

			setIsFetching( false );
		} catch ( error ) {
			// Do Nothing.
		}
	};

	const handleClear = () => {
		if ( scrollableRef.current ) {
			scrollableRef.current.scrollTop = 0;
		}

		reset( { keyword: '' } );
		setWebsiteTypeAIStep( '' );
		setBusinessTypeListAIStep( [] );

		if ( ! openSuggestions ) {
			return;
		}
		setTimeout( () => {
			setFocus( 'keyword' );
		}, 10 );
	};

	const handleCloseSuggestions = ( inputField ) => {
		if ( ! watchedKeyword && '' !== businessType ) {
			setValue( 'keyword', businessType );
		}
		if (
			watchedKeyword &&
			'' !== businessType &&
			watchedKeyword !== businessType
		) {
			setValue( 'keyword', watchedKeyword );
		}
		setOpenSuggestions( false );

		if ( ! inputField ) {
			return;
		}
		inputField?.blur();
	};

	const handleSearch = useCallback( () => {
		fetchCategories( ! openSuggestions ? '' : debouncedKeyword );
	}, [ debouncedKeyword ] );

	useEffect( () => {
		handleSearch();
	}, [ handleSearch ] );

	useLayoutEffect( () => {
		if ( openSuggestions && ! watchedKeyword ) {
			setBusinessTypeListAIStep( [] );
		}
	}, [ watchedKeyword ] );

	const handleKeyDown = ( event ) => {
		const businessTypesWrapper = document.getElementById(
			'business-types-suggestions'
		);
		if ( ! businessTypesWrapper ) {
			return;
		}
		const focusableElements = Array.from(
			businessTypesWrapper.querySelectorAll(
				'button, input, [tabindex]:not([tabindex="-1"])'
			)
		);
		// eslint-disable-next-line @wordpress/no-global-active-element
		let index = focusableElements.indexOf( document.activeElement );

		switch ( event.key ) {
			case 'Escape':
				// Close the suggestion when Esc is pressed
				handleCloseSuggestions( event?.target );
				break;
			case 'ArrowUp':
				// Focus the previous element when Up Arrow is pressed
				index--;
				if ( index < 0 ) {
					index = focusableElements.length - 1;
				} // Loop back to the end if at the beginning
				focusableElements[ index ].focus();
				event.preventDefault(); // Prevent the default scroll behavior
				break;
			case 'ArrowDown':
				// Focus the next element when Down Arrow is pressed
				index++;
				if ( index >= focusableElements.length ) {
					index = 0;
				} // Loop back to the beginning if at the end
				focusableElements[ index ].focus();
				event.preventDefault(); // Prevent the default scroll behavior
				break;
			default:
				break;
		}
	};

	const handleClickOutside = ( event ) => {
		const businessTypesWrapper = document.getElementById(
			'business-types-suggestions'
		);
		if (
			businessTypesWrapper &&
			! businessTypesWrapper.contains( event.target )
		) {
			handleCloseSuggestions();
		}
	};

	// handle outside click to close the suggestions.
	useEffect( () => {
		document.addEventListener( 'mousedown', handleClickOutside );
		return () =>
			document.removeEventListener( 'mousedown', handleClickOutside );
	}, [ handleClickOutside ] );

	// Reset the keyword when business type is changed.
	useEffect( () => {
		if ( businessType ) {
			return;
		}
		setValue( 'keyword', '' );
	}, [ businessType ] );

	const getIcon = () => {
		if ( isFetching && openSuggestions ) {
			return <LoadingSpinner className="text-accent-st w-4 h-4" />;
		}
		return watchedKeyword ? (
			<button
				className="inline-flex !p-0 !m-0 border-0 !bg-transparent focus:outline-none cursor-pointer"
				onClick={ handleClear }
			>
				<XMarkIcon className="w-4 h-4 !text-zip-app-inactive-icon peer-focus:text-nav-inactive !shrink-0" />
			</button>
		) : (
			<MagnifyingGlassIcon className="w-4 h-4 text-zip-app-inactive-icon peer-focus:text-nav-inactive !shrink-0" />
		);
	};

	const renderHighlightedText = ( text, highlight ) => {
		if ( ! highlight ) {
			return text;
		}

		const highlightTexts = highlight?.name?.matched_tokens || [];
		const parts = text.split(
			new RegExp(
				`(${ highlightTexts
					.join( '|' )
					.replace( /[.*+?^${}()|[\]\\]/g, '\\$&' ) })`,
				'gi'
			)
		);
		return (
			<span>
				{ parts.map( ( part, index ) =>
					highlightTexts.includes( part ) ? (
						<span key={ index } className="font-semibold">
							{ part }
						</span>
					) : (
						part
					)
				) }
			</span>
		);
	};

	// Include current input at the top of the list if the input is not empty and not in the list.
	const renderBusinessTypeList = () => {
		try {
			const businessTypes =
				!! businessTypeList && Array.isArray( businessTypeList )
					? businessTypeList
					: [];
			if ( ! watchedKeyword ) {
				return businessTypes;
			}
			const currentInput = businessTypes?.find(
				( { document: docItem } ) =>
					docItem.name?.toLowerCase()?.trim() ===
					watchedKeyword?.toLowerCase()?.trim()
			);
			if ( ! currentInput ) {
				return [
					{
						document: {
							name: watchedKeyword,
						},
						highlight: {
							name: {
								matched_tokens: [ watchedKeyword.trim() ],
							},
						},
					},
					...businessTypes,
				];
			}
			return businessTypes;
		} catch ( error ) {
			return [];
		}
	};

	const debouncedType = useDebounce( watchedKeyword, 500 );

	useEffect( () => {
		setWebsiteTypeAIStep( watchedKeyword );
	}, [ debouncedType ] );

	return (
		<div
			id="business-types-suggestions"
			ref={ referenceRef }
			className={ classNames(
				'relative pr-3 pl-4 py-3 bg-white rounded-md border border-solid border-border-tertiary',
				{
					'pb-0 rounded-b-none border-b-0 shadow-md': openSuggestions,
				}
			) }
			onKeyDown={ handleKeyDown }
		>
			<div className="flex items-center justify-start w-full gap-2">
				{ getIcon() }
				<input
					className="!text-sm !p-0 !mx-0 !border-0 !rounded-none !min-h-0 !shadow-none leading-[1.375rem] focus:!outline-none focus:!shadow-none w-full placeholder:!text-zip-app-inactive-icon placeholder:!text-base focus:ring-0"
					type="text"
					placeholder={ __( 'Type to search', 'ai-builder' ) }
					onFocus={ () => setOpenSuggestions( true ) }
					autoComplete="off"
					onKeyDown={ ( event ) => {
						if ( ! validationRegex.test( event.key ) ) {
							event.preventDefault();
						}
					} }
					onPaste={ ( event ) => {
						event.preventDefault();
						let text = event.clipboardData.getData( 'text' );
						if (
							! validationRegex.test(
								event.clipboardData.getData( 'text' )
							)
						) {
							text = text
								.substring( 0, 50 )
								.replace( /[^a-zA-Z0-9\-_'& ]/g, '' );
						}
						window.document.execCommand(
							'insertText',
							false,
							text
						);
					} }
					maxLength={ 50 }
					{ ...register( 'keyword' ) }
				/>
			</div>
			<div
				ref={ popperRef }
				className={ classNames(
					'w-[calc(100%_+_2px)] px-3 pb-3 z-10 bg-white shadow-md border-x border-b border-t-0 border-solid border-border-tertiary rounded-b-md',
					{
						invisible: ! openSuggestions,
					}
				) }
			>
				{ openSuggestions && (
					<hr
						className="!mx-0 !my-3 border-t border-solid border-b-0 border-border-tertiary"
						tabIndex={ -1 }
					/>
				) }
				<div
					ref={ scrollableRef }
					className="max-h-[300px] w-full overflow-y-auto overflow-x-hidden [&::-webkit-scrollbar]:w-1.5 [&::-webkit-scrollbar]:h-1/2 [&::-webkit-scrollbar-thumb]:h-16 [&::-webkit-scrollbar-thumb]:rounded-md [&::-webkit-scrollbar-thumb]:bg-dark-app-background/20 [&::-webkit-scrollbar-thumb:hover]:bg-dark-app-background/30 [&::-webkit-scrollbar-track]:bg-white [&::-webkit-scrollbar-track]:rounded-md scroll-p-0"
				>
					<motion.ul
						className="w-full flex flex-col gap-1"
						initial={ false }
						animate={ openSuggestions ? 'open' : 'closed' }
						variants={ container }
					>
						{ renderBusinessTypeList()?.length > 0 &&
							renderBusinessTypeList().map(
								( { document: typeItem, highlight } ) => (
									<motion.li
										key={ typeItem.name }
										className={ classNames(
											'flex items-center justify-start w-full gap-2 py-2 px-3 bg-background-tertiary rounded border-0 bg-transparent hover:!bg-zip-app-light-bg focus:bg-zip-app-light-bg text-zip-body-text hover:text-zip-app-heading focus:outline-none focus:shadow-none cursor-pointer',
											{
												'!bg-zip-app-light-bg !text-zip-app-heading':
													typeItem.name ===
													businessType,
											}
										) }
										onClick={ () => {
											setValue(
												'keyword',
												typeItem.name
											);
											setWebsiteTypeAIStep(
												typeItem.name
											);
											setOpenSuggestions( false );
										} }
										variants={ item }
									>
										{ renderHighlightedText(
											typeItem.name,
											highlight
										) }
									</motion.li>
								)
							) }
					</motion.ul>
				</div>
			</div>
		</div>
	);
};

export default BusinessTypes;
