import { FillBlanksExercise, FillBlanksMCOption } from "@/interfaces/exam";
import clsx from "clsx";
import { Fragment, useCallback, useEffect, useMemo, useRef, useState } from "react";
import reactStringReplace from "react-string-replace";
import { CommonProps } from "../types";
import { v4 } from "uuid";
import MCDropdown from "./MCDropdown";
import useExamStore, { usePersistentExamStore } from "@/stores/exam";
import PracticeBadge from "@/components/Low/PracticeBadge";

const FillBlanks: React.FC<FillBlanksExercise & CommonProps> = ({
	id,
	type,
	isPractice = false,
	prompt,
	solutions,
	text,
	words,
	userSolutions,
	variant,
	registerSolution,
	headerButtons,
	footerButtons,
	preview,
}) => {
	const examState = useExamStore((state) => state);
	const persistentExamState = usePersistentExamStore((state) => state);

	const {
		exerciseIndex,
		partIndex,
		shuffles,
		exam,
	} = examState; !preview ? examState : persistentExamState;

	const [answers, setAnswers] = useState<{ id: string; solution: string }[]>(userSolutions);
	const shuffleMaps = shuffles.find((x) => x.exerciseID == id)?.shuffles;
	const dropdownRef = useRef<HTMLDivElement>(null);

	const excludeWordMCType = (x: any) => {
		return typeof x === "string" ? x : (x as { letter: string; word: string });
	};

	let correctWords: any;
	if (exam && (exam.module === "level" || exam.module === "reading") && exam.parts[partIndex].exercises[exerciseIndex].type === "fillBlanks") {
		correctWords = (exam.parts[partIndex].exercises[exerciseIndex] as FillBlanksExercise).words;
	}

	useEffect(() => {
		const handleClickOutside = (event: MouseEvent) => {
			if (dropdownRef.current && !dropdownRef.current.contains(event.target as Node)) {
				setOpenDropdownId(null);
			}
		};

		document.addEventListener('mousedown', handleClickOutside);
		return () => {
			document.removeEventListener('mousedown', handleClickOutside);
		};
	}, []);

	const calculateScore = useCallback(() => {
		const total = text.match(/({{\d+}})/g)?.length || 0;
		const correct = answers!.filter((x) => {
			const solution = solutions.find((y) => x.id.toString() === y.id.toString())?.solution;
			if (!solution) return false;
			const option = correctWords!.find((w: any) => {
				if (typeof w === "string") {
					return w.toLowerCase() === x.solution.toLowerCase();
				} else if ("letter" in w) {
					return w.letter.toLowerCase() === x.solution.toLowerCase();
				} else {
					return w.id.toString() === x.id.toString();
				}
			});
			if (!option) return false;

			if (typeof option === "string") {
				return solution.toLowerCase() === option.toLowerCase();
			} else if ("letter" in option) {
				return solution.toLowerCase() === option.word.toLowerCase();
			} else if ("options" in option) {
				return option.options[solution as keyof typeof option.options] == x.solution;
			}
			return false;
		}).length;
		const missing = total - answers!.filter((x) => solutions.find((y) => x.id.toString() === y.id.toString())).length;
		return { total, correct, missing };
	}, [answers, correctWords, solutions, text]);

	useEffect(() => {
		registerSolution(() => ({
			exercise: id,
			solutions: answers,
			score: calculateScore(),
			type,
			shuffleMaps,
			isPractice
		}));
		// eslint-disable-next-line react-hooks/exhaustive-deps
	}, [id, answers, type, isPractice, shuffleMaps, calculateScore]);

	const [openDropdownId, setOpenDropdownId] = useState<string | null>(null);

	const renderLines = useCallback(
		(line: string) => {
			return (
				<div className="text-xl leading-relaxed" key={v4()} ref={dropdownRef}>
					{reactStringReplace(line, /({{\d+}})/g, (match, i, original) => {
						const id = match.replaceAll(/[\{\}]/g, "");
						const userSolution = answers.find((x) => x.id === id);
						const styles = clsx(
							"rounded-full hover:text-white transition duration-300 ease-in-out my-1 px-5 py-2 text-center w-fit inline-block",
							!userSolution && "text-center text-mti-purple-light bg-mti-purple-ultralight",
							userSolution && "text-center text-mti-purple-dark bg-mti-purple-ultralight",
						);

						const currentSelection = words.find((x) => {
							if (typeof x !== "string" && "id" in x) {
								return (x as FillBlanksMCOption).id.toString() == id.toString();
							}
							return false;
						}) as FillBlanksMCOption;

						return variant === "mc" ? (
							<MCDropdown
								id={id}
								options={currentSelection.options}
								onSelect={(value) => onSelection(id, value)}
								selectedValue={userSolution?.solution}
								className="inline-block py-2 px-1 align-middle"
								width={220}
								isOpen={openDropdownId === id}
								onToggle={() => setOpenDropdownId(prevId => prevId === id ? null : id)}
							/>
						) : (
							<input
								key={`input-${id}`}
								className={styles}
								onChange={(e) => setAnswers((prev) => [...prev.filter((x) => x.id !== id), { id, solution: e.target.value }])}
								value={userSolution?.solution}
							/>
						);
					})}
				</div>
			);
		},
		[variant, words, answers, openDropdownId],
	);

	const memoizedLines = useMemo(() => {
		return text.split("\\n").map((line, index) => (
			<div key={index} className={clsx(variant === "mc" && "whitespace-pre-wrap")}>
				{renderLines(line)}
				<br />
			</div>
		));
		// eslint-disable-next-line react-hooks/exhaustive-deps
	}, [text, variant, renderLines]);

	const onSelection = (questionID: string, value: string) => {
		setAnswers((prev) => [...prev.filter((x) => x.id !== questionID), { id: questionID, solution: value }]);
	};

	return (
		<div className="flex flex-col gap-4">
			{headerButtons}
			<div className={clsx("flex flex-col gap-4 mt-4 h-full w-full relative", (headerButtons && footerButtons) && "mb-20")}>
				{variant !== "mc" && (
					<span className="text-sm w-full leading-6">
						{prompt.split("\\n").map((line, index) => (
							<Fragment key={index}>
								{line}
								<br />
							</Fragment>
						))}
					</span>
				)}
				{isPractice && <PracticeBadge className="w-fit self-end" />}
				<span className="bg-mti-gray-smoke rounded-xl px-5 py-6">{memoizedLines}</span>
				{variant !== "mc" && (
					<div className="bg-mti-gray-smoke rounded-xl px-5 py-6 flex flex-col gap-4">
						<span className="font-medium text-mti-purple-dark">Options</span>
						<div className="flex gap-4 flex-wrap">
							{words.map((v) => {
								v = excludeWordMCType(v);
								const text = typeof v === "string" ? v : `${v.letter} - ${v.word}`;

								return (
									<span
										className={clsx(
											"border border-mti-purple-light rounded-full px-3 py-0.5 transition ease-in-out duration-300",
											!!answers.find(
												(x) =>
													x.solution.toLowerCase() ===
													(typeof v === "string" ? v : "letter" in v ? v.letter : "").toLowerCase(),
											) && "bg-mti-purple-dark text-white",
										)}
										key={v4()}>
										{text}
									</span>
								);
							})}
						</div>
					</div>
				)}
				{footerButtons}
			</div>
		</div>
	);
};

//FillBlanks.whyDidYouRender = true

export default FillBlanks;