/* eslint-disable @next/next/no-img-element */
import { MultipleChoiceExercise, MultipleChoiceQuestion, ShuffleMap } from "@/interfaces/exam";
import useExamStore from "@/stores/examStore";
import clsx from "clsx";
import { useEffect, useState } from "react";
import reactStringReplace from "react-string-replace";
import { CommonProps } from ".";
import Button from "../Low/Button";
import { v4 } from "uuid";

function Question({
	id,
	variant,
	prompt,
	options,
	userSolution,
	onSelectOption,
}: MultipleChoiceQuestion & {
	userSolution: string | undefined;
	onSelectOption?: (option: string) => void;
	showSolution?: boolean,
}) {

	const renderPrompt = (prompt: string) => {
		return reactStringReplace(prompt, /(<u>.*?<\/u>)/g, (match) => {
			const word = match.replaceAll("<u>", "").replaceAll("</u>", "");
			return word.length > 0 ? <u key={v4()}>{word}</u> : null;
		});
	};

	return (
		<div className="flex flex-col gap-8">
			{isNaN(Number(id)) ? (
				<span className="text-lg">{renderPrompt(prompt).filter((x) => x?.toString() !== "<u>")}</span>
			) : (
				<span className="text-lg">
					<>
						{id} - <span>{renderPrompt(prompt).filter((x) => x?.toString() !== "<u>")}</span>
					</>
				</span>
			)}
			<div className="flex flex-wrap gap-4 justify-between">
				{variant === "image" &&
					options.map((option) => (
						<div
							key={v4()}
							onClick={() => (onSelectOption ? onSelectOption(option.id.toString()) : null)}
							className={clsx(
								"flex flex-col items-center border border-mti-gray-platinum p-4 px-8 rounded-xl gap-4 cursor-pointer bg-white relative select-none",
								userSolution === option.id.toString() && "border-mti-purple-light",
							)}>
							<span key={v4()} className={clsx("text-sm", userSolution !== option.id.toString() && "opacity-50")}>{option.id.toString()}</span>
							<img src={option.src!} alt={`Option ${option.id.toString()}`} />
						</div>
					))}
				{variant === "text" &&
					options.map((option) => (
						<div
							key={v4()}
							onClick={() => (onSelectOption ? onSelectOption(option.id.toString()) : null)}
							className={clsx(
								"flex border p-4 rounded-xl gap-2 cursor-pointer bg-white text-base select-none",
								userSolution === option.id.toString() && "border-mti-purple-light",
							)}>
							<span className="font-semibold">{option.id.toString()}.</span>
							<span>{option.text}</span>
						</div>
					))}
			</div>
		</div>
	);
}

export default function MultipleChoice({ id, prompt, type, questions, userSolutions, onNext, onBack }: MultipleChoiceExercise & CommonProps) {
	const [answers, setAnswers] = useState<{ question: string; option: string }[]>(userSolutions);

	const {
		questionIndex,
		exam,
		shuffles,
		hasExamEnded,
		partIndex,
		userSolutions: storeUserSolutions,
		setQuestionIndex,
		setUserSolutions,
		setCurrentSolution
	} = useExamStore((state) => state);

	const shuffleMaps = shuffles.find((x) => x.exerciseID == id)?.shuffles;

	const scrollToTop = () => Array.from(document.getElementsByTagName("body")).forEach((body) => body.scrollTo(0, 0));

	useEffect(() => {
		setUserSolutions(
			[...storeUserSolutions.filter((x) => x.exercise !== id), {
				exercise: id, solutions: answers, score: calculateScore(), type
			}]);
		// eslint-disable-next-line react-hooks/exhaustive-deps
	}, [answers]);

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

	const onSelectOption = (option: string) => {
		const question = questions[questionIndex];
		setAnswers((prev) => [...prev.filter((x) => x.question !== question.id), { option, question: question.id }]);
	};

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

	const getShuffledSolution = (originalSolution: string, questionShuffleMap: ShuffleMap) => {
		for (const [newPosition, originalPosition] of Object.entries(questionShuffleMap.map)) {
			if (originalPosition === originalSolution) {
				return newPosition;
			}
		}
		return originalSolution;
	}


	const calculateScore = () => {
		const total = questions.length;
		const correct = answers.filter((x) => {
			const matchingQuestion = questions.find((y) => {
				return y.id.toString() === x.question.toString();
			});

			let isSolutionCorrect;
			if (!shuffleMaps) {
				isSolutionCorrect = matchingQuestion?.solution === x.option;
			} else {
				const shuffleMap = shuffleMaps.find((map) => map.questionID == x.question);
				if (shuffleMap) {
					isSolutionCorrect = getShuffledSolution(x.option, shuffleMap) == matchingQuestion?.solution;
				} else {
					isSolutionCorrect = matchingQuestion?.solution === x.option;
				}
			}
			return isSolutionCorrect || false;
		}).length;
		const missing = total - correct;
		return { total, correct, missing };
	};

	const next = () => {
		if (questionIndex === questions.length - 1) {
			onNext({ exercise: id, solutions: answers, score: calculateScore(), type, shuffleMaps: shuffleMaps });
		} else {
			setQuestionIndex(questionIndex + 1);
		}
		scrollToTop();
	};

	const back = () => {
		if (questionIndex === 0) {
			onBack({ exercise: id, solutions: answers, score: calculateScore(), type, shuffleMaps: shuffleMaps });
		} else {
			if (exam?.module === "level" && typeof exam.parts[0].intro !== "undefined" && questionIndex === 0) return; 
			setQuestionIndex(questionIndex - 1);
		}

		scrollToTop();
	};

	return (
		<>
			<div className="flex flex-col gap-2 mt-4 h-fit w-full mb-20 bg-mti-gray-smoke rounded-xl px-16 py-8">
				{/*<span className="text-xl font-semibold mb-2">{"Select the appropriate option."}</span>*/}
				{questionIndex < questions.length && (
					<Question
						{...questions[questionIndex]}
						userSolution={answers.find((x) => questions[questionIndex].id === x.question)?.option}
						onSelectOption={onSelectOption}
					/>
				)}
			</div>

			<div className="self-end flex justify-between w-full gap-8 absolute bottom-8 left-0 px-8">
				<Button color="purple" variant="outline" onClick={back} className="max-w-[200px] w-full"
					disabled={
						exam && exam.module === "level" && 
						typeof exam.parts[0].intro === "string" && 
						partIndex === 0 &&
						questionIndex === 0
					}
				>
					Back
				</Button>

				<Button color="purple" onClick={next} className="max-w-[200px] self-end w-full">
					Next
				</Button>
			</div>
		</>
	);
}
