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

import AbandonPopup from "@/components/AbandonPopup";
import Layout from "@/components/High/Layout";
import Finish from "@/exams/Finish";
import Level from "@/exams/Level";
import Listening from "@/exams/Listening";
import Reading from "@/exams/Reading";
import Selection from "@/exams/Selection";
import Speaking from "@/exams/Speaking";
import Writing from "@/exams/Writing";
import useUser from "@/hooks/useUser";
import { Exam, UserSolution, Variant } from "@/interfaces/exam";
import { Stat } from "@/interfaces/user";
import useExamStore from "@/stores/examStore";
import {
  evaluateSpeakingAnswer,
  evaluateWritingAnswer,
} from "@/utils/evaluation";
import { getExam } from "@/utils/exams";
import axios from "axios";
import { useRouter } from "next/router";
import { toast, ToastContainer } from "react-toastify";
import { v4 as uuidv4 } from "uuid";

interface Props {
  page: "exams" | "exercises";
}

export default function ExamPage({ page }: Props) {
  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 [showAbandonPopup, setShowAbandonPopup] = useState(false);
  const [avoidRepeated, setAvoidRepeated] = useState(false);
  const [timeSpent, setTimeSpent] = useState(0);
  const [statsAwaitingEvaluation, setStatsAwaitingEvaluation] = useState<
    string[]
  >([]);
  const [variant, setVariant] = useState<Variant>("full");

  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 assignment = useExamStore((state) => state.assignment);

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

  useEffect(() => setSessionId(uuidv4()), []);
  useEffect(() => {
    if (user?.type === "developer") console.log(exam);
  }, [exam, user]);

  useEffect(() => {
    selectedModules.length > 0 && timeSpent === 0 && !showSolutions;
    if (selectedModules.length > 0 && timeSpent === 0 && !showSolutions) {
      const timerInterval = setInterval(() => {
        setTimeSpent((prev) => prev + 1);
      }, 1000);

      return () => {
        clearInterval(timerInterval);
      };
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [selectedModules.length]);

  useEffect(() => {
    if (showSolutions) setModuleIndex(-1);
  }, [showSolutions]);

  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((module) =>
          getExam(module, avoidRepeated, variant),
        );
        Promise.all(examPromises).then((values) => {
          if (values.every((x) => !!x)) {
            setExams(values.map((x) => x!));
          } else {
            toast.error("Something went wrong, please try again");
            setTimeout(router.reload, 500);
          }
        });
      }
    })();
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [selectedModules, setExams, exams]);

  useEffect(() => {
    if (
      selectedModules.length > 0 &&
      exams.length !== 0 &&
      moduleIndex >= selectedModules.length &&
      !hasBeenUploaded &&
      !showSolutions
    ) {
      const newStats: Stat[] = userSolutions.map((solution) => ({
        ...solution,
        id: solution.id || uuidv4(),
        timeSpent,
        session: sessionId,
        exam: solution.exam!,
        module: solution.module!,
        user: user?.id || "",
        date: new Date().getTime(),
        ...(assignment ? { assignment: assignment.id } : {}),
      }));

      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]);

  useEffect(() => {
    setIsEvaluationLoading(statsAwaitingEvaluation.length !== 0);
  }, [statsAwaitingEvaluation]);

  useEffect(() => {
    if (statsAwaitingEvaluation.length > 0) {
      checkIfStatsHaveBeenEvaluated(statsAwaitingEvaluation);
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [statsAwaitingEvaluation]);

  const checkIfStatsHaveBeenEvaluated = (ids: string[]) => {
    setTimeout(async () => {
      const awaitedStats = await Promise.all(
        ids.map(async (id) => (await axios.get<Stat>(`/api/stats/${id}`)).data),
      );
      const solutionsEvaluated = awaitedStats.every((stat) =>
        stat.solutions.every((x) => x.evaluation !== null),
      );
      if (solutionsEvaluated) {
        const statsUserSolutions: UserSolution[] = awaitedStats.map((stat) => ({
          id: stat.id,
          exercise: stat.exercise,
          score: stat.score,
          solutions: stat.solutions,
          type: stat.type,
          exam: stat.exam,
          module: stat.module,
        }));

        const updatedUserSolutions = userSolutions.map((x) => {
          const respectiveSolution = statsUserSolutions.find(
            (y) => y.exercise === x.exercise,
          );
          return respectiveSolution ? respectiveSolution : x;
        });

        setUserSolutions(updatedUserSolutions);
        return setStatsAwaitingEvaluation((prev) =>
          prev.filter((x) => !ids.includes(x)),
        );
      }

      return checkIfStatsHaveBeenEvaluated(ids);
    }, 5 * 1000);
  };

  const updateExamWithUserSolutions = (exam: Exam): Exam => {
    if (exam.module === "reading" || exam.module === "listening") {
      const parts = exam.parts.map((p) =>
        Object.assign(p, {
          exercises: p.exercises.map((x) =>
            Object.assign(x, {
              userSolutions: userSolutions.find((y) => x.id === y.exercise)
                ?.solutions,
            }),
          ),
        }),
      );
      return Object.assign(exam, { parts });
    }

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

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

    if (exam && !solutionExams.includes(exam.id)) return;

    if (
      exam &&
      (exam.module === "writing" || exam.module === "speaking") &&
      solutions.length > 0 &&
      !showSolutions
    ) {
      setHasBeenUploaded(true);
      setIsEvaluationLoading(true);

      Promise.all(
        exam.exercises.map(async (exercise) => {
          const evaluationID = uuidv4();
          if (exercise.type === "writing")
            return await evaluateWritingAnswer(
              exercise,
              solutions.find((x) => x.exercise === exercise.id)!,
              evaluationID,
            );

          if (
            exercise.type === "interactiveSpeaking" ||
            exercise.type === "speaking"
          )
            return await evaluateSpeakingAnswer(
              exercise,
              solutions.find((x) => x.exercise === exercise.id)!,
              evaluationID,
            );
        }),
      )
        .then((responses) => {
          setStatsAwaitingEvaluation((prev) => [
            ...prev,
            ...responses.filter((x) => !!x).map((r) => (r as any).id),
          ]);
          setUserSolutions([
            ...userSolutions,
            ...responses.filter((x) => !!x),
          ] as any);
        })
        .finally(() => {
          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,
      },
      level: {
        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
          page={page}
          user={user!}
          disableSelection={page === "exams"}
          onStart={(modules: Module[], avoid: boolean, variant: Variant) => {
            setModuleIndex(0);
            setAvoidRepeated(avoid);
            setSelectedModules(modules);
            setVariant(variant);
          }}
        />
      );
    }

    if (moduleIndex >= selectedModules.length || moduleIndex === -1) {
      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}
        />
      );
    }

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

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

  return (
    <>
      <ToastContainer />
      {user && (
        <Layout
          user={user}
          className="justify-between"
          focusMode={
            selectedModules.length !== 0 &&
            !showSolutions &&
            moduleIndex < selectedModules.length
          }
          onFocusLayerMouseEnter={() => setShowAbandonPopup(true)}
        >
          <>
            {renderScreen()}
            {!showSolutions && moduleIndex < selectedModules.length && (
              <AbandonPopup
                isOpen={showAbandonPopup}
                abandonPopupTitle="Leave Exercise"
                abandonPopupDescription="Are you sure you want to leave the exercise? You will lose all your progress."
                abandonConfirmButtonText="Confirm"
                onAbandon={() => router.reload()}
                onCancel={() => setShowAbandonPopup(false)}
              />
            )}
          </>
        </Layout>
      )}
    </>
  );
}