/* eslint-disable @next/next/no-img-element */
import Head from "next/head";
import {useEffect, useState} from "react";
import {Module} from "@/interfaces";

import Selection from "@/exams/Selection";
import Reading from "@/exams/Reading";
import {
	Exam,
	ListeningExam,
	ReadingExam,
	SpeakingExam,
	UserSolution,
	Evaluation,
	WritingExam,
	WritingExercise,
	SpeakingExercise,
} from "@/interfaces/exam";
import Listening from "@/exams/Listening";
import Writing from "@/exams/Writing";
import {ToastContainer, toast} from "react-toastify";
import Finish from "@/exams/Finish";
import axios from "axios";
import {withIronSessionSsr} from "iron-session/next";
import {sessionOptions} from "@/lib/session";
import {Stat} from "@/interfaces/user";
import Speaking from "@/exams/Speaking";
import {v4 as uuidv4} from "uuid";
import useUser from "@/hooks/useUser";
import useExamStore from "@/stores/examStore";
import Layout from "@/components/High/Layout";
import {speakingReverseMarking, writingReverseMarking} from "@/utils/score";

export const getServerSideProps = withIronSessionSsr(({req, res}) => {
	const user = req.session.user;

	if (!user) {
		res.setHeader("location", "/login");
		res.statusCode = 302;
		res.end();
		return {
			props: {
				user: null,
			},
		};
	}

	return {
		props: {user: req.session.user},
	};
}, sessionOptions);

export default function Page() {
	const [hasBeenUploaded, setHasBeenUploaded] = useState(false);
	const [moduleIndex, setModuleIndex] = useState(0);
	const [sessionId, setSessionId] = useState("");
	const [exam, setExam] = useState<Exam>();
	const [isEvaluationLoading, setIsEvaluationLoading] = useState(false);

	const [exams, setExams] = useExamStore((state) => [state.exams, state.setExams]);
	const [userSolutions, setUserSolutions] = useExamStore((state) => [state.userSolutions, state.setUserSolutions]);
	const [showSolutions, setShowSolutions] = useExamStore((state) => [state.showSolutions, state.setShowSolutions]);
	const [selectedModules, setSelectedModules] = useExamStore((state) => [state.selectedModules, state.setSelectedModules]);
	const setHasExamEnded = useExamStore((state) => state.setHasExamEnded);

	const {user} = useUser({redirectTo: "/login"});

	useEffect(() => setSessionId(uuidv4()), []);

	useEffect(() => {
		(async () => {
			if (selectedModules.length > 0 && exams.length > 0 && moduleIndex < selectedModules.length) {
				const nextExam = exams[moduleIndex];
				setExam(nextExam ? updateExamWithUserSolutions(nextExam) : undefined);
			}
		})();
		// eslint-disable-next-line react-hooks/exhaustive-deps
	}, [selectedModules, moduleIndex, exams]);

	useEffect(() => {
		(async () => {
			if (selectedModules.length > 0 && exams.length === 0) {
				const examPromises = selectedModules.map(getExam);
				Promise.all(examPromises).then((values) => {
					if (values.every((x) => !!x)) {
						setExams(values.map((x) => x!));
					}
				});
			}
		})();
	}, [selectedModules, setExams, exams]);

	useEffect(() => {
		if (selectedModules.length > 0 && exams.length !== 0 && moduleIndex >= selectedModules.length && !hasBeenUploaded) {
			const newStats: Stat[] = userSolutions.map((solution) => ({
				...solution,
				session: sessionId,
				exam: solution.exam!,
				module: solution.module!,
				user: user?.id || "",
				date: new Date().getTime(),
			}));

			axios
				.post<{ok: boolean}>("/api/stats", newStats)
				.then((response) => setHasBeenUploaded(response.data.ok))
				.catch(() => setHasBeenUploaded(false));
		}
		// eslint-disable-next-line react-hooks/exhaustive-deps
	}, [selectedModules, moduleIndex, hasBeenUploaded]);

	const getExam = async (module: Module): Promise<Exam | undefined> => {
		const examRequest = await axios<Exam[]>(`/api/exam/${module}`);
		if (examRequest.status !== 200) {
			toast.error("Something went wrong!");
			return undefined;
		}

		const newExam = examRequest.data;

		switch (module) {
			case "reading":
				return newExam.shift() as ReadingExam;
			case "listening":
				return newExam.shift() as ListeningExam;
			case "writing":
				return newExam.shift() as WritingExam;
			case "speaking":
				return newExam.shift() as SpeakingExam;
		}
	};

	const evaluateSpeakingAnswer = async (examId: string, exerciseId: string, solution: UserSolution) => {
		const speakingExam = exams.find((x) => x.id === examId)!;
		const exercise = speakingExam.exercises.find((x) => x.id === exerciseId)! as SpeakingExercise;

		const blobResponse = await axios.get(solution.solutions[0].solution.trim(), {responseType: "arraybuffer"});
		const audioBlob = Buffer.from(blobResponse.data, "binary");
		const audioFile = new File([audioBlob], "audio.wav", {type: "audio/wav"});

		const formData = new FormData();
		formData.append("audio", audioFile, "audio.wav");
		formData.append("question", `${exercise.text.replaceAll("\n", "")} You should talk about: ${exercise.prompts.join(", ")}`);

		const config = {
			headers: {
				"Content-Type": "audio/mp3",
			},
		};

		const response = await axios.post("/api/evaluate/speaking", formData, config);

		if (response.status === 200) {
			setUserSolutions([
				...userSolutions.filter((x) => x.exercise !== exerciseId),
				{
					...solution,
					score: {
						correct: speakingReverseMarking[response.data.overall] || 0,
						missing: 0,
						total: 100,
					},
					solutions: [{id: exerciseId, solution: response.data.fullPath, evaluation: response.data}],
				},
			]);
		}
	};

	const evaluateWritingAnswer = async (examId: string, exerciseId: string, solution: UserSolution) => {
		const writingExam = exams.find((x) => x.id === examId)!;
		const exercise = writingExam.exercises.find((x) => x.id === exerciseId)! as WritingExercise;

		const response = await axios.post<Evaluation>("/api/evaluate/writing", {
			question: `${exercise.prompt} ${exercise.attachment ? exercise.attachment.description : ""}`.replaceAll("\n", ""),
			answer: solution.solutions[0].solution.trim().replaceAll("\n", " "),
		});

		if (response.status === 200) {
			setUserSolutions([
				...userSolutions.filter((x) => x.exercise !== exerciseId),
				{
					...solution,
					score: {
						correct: writingReverseMarking[response.data.overall] || 0,
						missing: 0,
						total: 100,
					},
					solutions: [{id: exerciseId, solution: solution.solutions[0].solution, evaluation: response.data}],
				},
			]);
		}
	};

	const updateExamWithUserSolutions = (exam: Exam): Exam => {
		const exercises = exam.exercises.map((x) =>
			Object.assign(x, !x.userSolutions ? {userSolutions: userSolutions.find((y) => x.id === y.exercise)?.solutions} : x.userSolutions),
		);

		return Object.assign(exam, exercises);
	};

	const onFinish = (solutions: UserSolution[]) => {
		const solutionIds = solutions.map((x) => x.exercise);

		if (exam && (exam.module === "writing" || exam.module === "speaking") && solutions.length > 0 && !showSolutions) {
			setHasBeenUploaded(true);
			setIsEvaluationLoading(true);
			Promise.all(
				exam.exercises.map((exercise) =>
					(exam.module === "writing" ? evaluateWritingAnswer : evaluateSpeakingAnswer)(
						exam.id,
						exercise.id,
						solutions.find((x) => x.exercise === exercise.id)!,
					),
				),
			).finally(() => {
				setIsEvaluationLoading(false);
				setHasBeenUploaded(false);
			});
		}

		axios.get("/api/stats/update");

		setUserSolutions([...userSolutions.filter((x) => !solutionIds.includes(x.exercise)), ...solutions]);
		setModuleIndex((prev) => prev + 1);
	};

	const aggregateScoresByModule = (answers: UserSolution[]): {module: Module; total: number; missing: number; correct: number}[] => {
		const scores: {[key in Module]: {total: number; missing: number; correct: number}} = {
			reading: {
				total: 0,
				correct: 0,
				missing: 0,
			},
			listening: {
				total: 0,
				correct: 0,
				missing: 0,
			},
			writing: {
				total: 0,
				correct: 0,
				missing: 0,
			},
			speaking: {
				total: 0,
				correct: 0,
				missing: 0,
			},
		};

		answers.forEach((x) => {
			scores[x.module!] = {
				total: scores[x.module!].total + x.score.total,
				correct: scores[x.module!].correct + x.score.correct,
				missing: scores[x.module!].missing + x.score.missing,
			};
		});

		return Object.keys(scores)
			.filter((x) => scores[x as Module].total > 0)
			.map((x) => ({module: x as Module, ...scores[x as Module]}));
	};

	const renderScreen = () => {
		if (selectedModules.length === 0) {
			return <Selection user={user!} onStart={setSelectedModules} disableSelection />;
		}

		if (moduleIndex >= selectedModules.length) {
			return (
				<Finish
					isLoading={isEvaluationLoading}
					user={user!}
					modules={selectedModules}
					onViewResults={() => {
						setShowSolutions(true);
						setModuleIndex(0);
						setExam(exams[0]);
					}}
					scores={aggregateScoresByModule(userSolutions)}
				/>
			);
		}

		if (exam && exam.module === "reading") {
			return <Reading exam={exam} onFinish={onFinish} showSolutions={showSolutions} />;
		}

		if (exam && exam.module === "listening") {
			return <Listening exam={exam} onFinish={onFinish} showSolutions={showSolutions} />;
		}

		if (exam && exam.module === "writing") {
			return <Writing exam={exam} onFinish={onFinish} showSolutions={showSolutions} />;
		}

		if (exam && exam.module === "speaking") {
			return <Speaking exam={exam} onFinish={onFinish} showSolutions={showSolutions} />;
		}

		return <>Loading...</>;
	};

	return (
		<>
			<Head>
				<title>Exam | IELTS GPT</title>
				<meta
					name="description"
					content="A training platform for the IELTS exam provided by the Muscat Training Institute and developed by eCrop."
				/>
				<meta name="viewport" content="width=device-width, initial-scale=1" />
				<link rel="icon" href="/favicon.ico" />
			</Head>
			<ToastContainer />
			{user && (
				<Layout user={user} className="justify-between" focusMode={selectedModules.length !== 0}>
					{renderScreen()}
				</Layout>
			)}
		</>
	);
}