import { useCallback, useDebugValue, useMemo, useState } from "react";
import { enqueueSnackbar } from "notistack";
import moment from "moment";

import { isResultQuestionEmpty } from "@/components/ViewPublicationPage/tools/checkEmptyData";
import { useQuizSettings } from "@contexts/QuizDataContext";

import { useQuizViewStore } from "@stores/quizView";

import { useVkMetricsGoals } from "@/utils/hooks/metrics/useVkMetricsGoals";
import { useYandexMetricsGoals } from "@/utils/hooks/metrics/useYandexMetricsGoals";

export function useQuestionFlowControl() {
  const { settings, questions } = useQuizSettings();
  const sortedQuestions = useMemo(() => {
    return [...questions].sort((a, b) => a.page - b.page);
  }, [questions]);
  const [currentQuestionId, setCurrentQuestionId] = useState<string | null>(getFirstQuestionId);
  const answers = useQuizViewStore((state) => state.answers);
  const pointsSum = useQuizViewStore((state) => state.pointsSum);
  const setCurrentQuizStep = useQuizViewStore((state) => state.setCurrentQuizStep);
  const vkMetrics = useVkMetricsGoals(settings.cfg.vkMetricsNumber);
  const yandexMetrics = useYandexMetricsGoals(settings.cfg.yandexMetricsNumber);

  const currentQuestion = sortedQuestions.find((question) => question.id === currentQuestionId) ?? sortedQuestions[0];

  const linearQuestionIndex =
    currentQuestion && sortedQuestions.every(({ content }) => content.rule.parentId !== "root") // null when branching enabled
      ? sortedQuestions.indexOf(currentQuestion)
      : null;

  function getFirstQuestionId() {
    if (sortedQuestions.length === 0) return null;

    if (settings.cfg.haveRoot) {
      const nextQuestion = sortedQuestions.find(
        (question) => question.id === settings.cfg.haveRoot || question.content.id === settings.cfg.haveRoot
      );
      if (!nextQuestion) return null;

      return nextQuestion.id;
    }

    return sortedQuestions[0].id;
  }

  const nextQuestionIdPointsLogic = useCallback(() => {
    return sortedQuestions.find((question) => question.type === "result" && question.content.rule.parentId === "line");
  }, [sortedQuestions]);

  const nextQuestionIdMainLogic = useCallback(() => {
    const questionAnswer = answers.find(({ questionId }) => questionId === currentQuestion.id);

    if (questionAnswer && !moment.isMoment(questionAnswer.answer)) {
      const userAnswers = Array.isArray(questionAnswer.answer) ? questionAnswer.answer : [questionAnswer.answer];

      for (const branchingRule of currentQuestion.content.rule.main) {
        if (userAnswers.some((answer) => branchingRule.rules[0].answers.includes(answer))) {
          return branchingRule.next;
        }
      }
    }

    if (!currentQuestion.required) {
      const defaultNextQuestionId = currentQuestion.content.rule.default;
      if (defaultNextQuestionId.length > 1 && defaultNextQuestionId !== " ") return defaultNextQuestionId;
      //Вопросы типа страница, ползунок, своё поле для ввода и дата не могут иметь больше 1 ребёнка. Пользователь не может настроить там дефолт
      //Кинуть на ребёнка надо даже если там нет дефолта
      if (
        ["date", "page", "text", "number"].includes(currentQuestion.type) &&
        currentQuestion.content.rule.children.length === 1
      )
        return currentQuestion.content.rule.children[0];
    }

    //ничё не нашли, ищем резулт
    return sortedQuestions.find((q) => {
      return q.type === "result" && q.content.rule.parentId === currentQuestion.content.id;
    })?.id;
  }, [answers, currentQuestion, sortedQuestions]);

  const nextQuestionId = useMemo(() => {
    if (settings.cfg.score) {
      return nextQuestionIdPointsLogic();
    }
    return nextQuestionIdMainLogic();
  }, [nextQuestionIdMainLogic, nextQuestionIdPointsLogic, settings.cfg.score]);

  const prevQuestion =
    linearQuestionIndex !== null
      ? sortedQuestions[linearQuestionIndex - 1]
      : sortedQuestions.find(
          (q) =>
            q.id === currentQuestion?.content.rule.parentId || q.content.id === currentQuestion?.content.rule.parentId
        );

  const findResultPointsLogic = useCallback(() => {
    const results = sortedQuestions.filter(
      (e) => e.type === "result" && e.content.rule.minScore !== undefined && e.content.rule.minScore <= pointsSum
    );
    const numbers = results.map((e) =>
      e.type === "result" && e.content.rule.minScore !== undefined ? e.content.rule.minScore : 0
    );
    const indexOfNext = Math.max(...numbers);

    return results[numbers.indexOf(indexOfNext)];
  }, [pointsSum, sortedQuestions]);

  const nextQuestion = useMemo(() => {
    let next;
    if (settings.cfg.score) {
      if (linearQuestionIndex !== null) {
        next = sortedQuestions[linearQuestionIndex + 1];
        if (next?.type === "result" || next == undefined) next = findResultPointsLogic();
      }
    } else {
      if (linearQuestionIndex !== null) {
        next =
          sortedQuestions[linearQuestionIndex + 1] ??
          sortedQuestions.find((question) => question.type === "result" && question.content.rule.parentId === "line");
      } else {
        next = sortedQuestions.find((q) => q.id === nextQuestionId || q.content.id === nextQuestionId);
      }
    }

    return next;
  }, [nextQuestionId, findResultPointsLogic, linearQuestionIndex, sortedQuestions, settings.cfg.score]);

  const showResult = useCallback(() => {
    if (nextQuestion?.type !== "result") throw new Error("Current question is not result");

    setCurrentQuestionId(nextQuestion.id);
    if (
      settings.cfg.showfc !== false &&
      (settings.cfg.resultInfo.showResultForm === "after" || isResultQuestionEmpty(nextQuestion))
    )
      setCurrentQuizStep("contactform");
  }, [nextQuestion, setCurrentQuizStep, settings.cfg.resultInfo.showResultForm, settings.cfg.showfc]);

  const showResultAfterContactForm = useCallback(() => {
    if (currentQuestion?.type !== "result") throw new Error("Current question is not result");
    if (isResultQuestionEmpty(currentQuestion)) {
      enqueueSnackbar("Данные отправлены");
      return;
    }

    setCurrentQuizStep("question");
  }, [currentQuestion, setCurrentQuizStep]);

  const moveToPrevQuestion = useCallback(() => {
    if (!prevQuestion) throw new Error("Previous question not found");

    setCurrentQuestionId(prevQuestion.id);
  }, [prevQuestion]);

  const moveToNextQuestion = useCallback(() => {
    if (!nextQuestion) throw new Error("Next question not found");

    // Засчитываем  переход с вопроса дальше
    vkMetrics.questionPassed(currentQuestion.id);
    yandexMetrics.questionPassed(currentQuestion.id);

    if (nextQuestion.type === "result") return showResult();

    setCurrentQuestionId(nextQuestion.id);
  }, [currentQuestion.id, nextQuestion, showResult, vkMetrics, yandexMetrics]);

  const setQuestion = useCallback(
    (questionId: string) => {
      const question = sortedQuestions.find((q) => q.id === questionId);
      if (!question) return;

      setCurrentQuestionId(question.id);
    },
    [sortedQuestions]
  );

  const isPreviousButtonEnabled = Boolean(prevQuestion);

  const isNextButtonEnabled = useMemo(() => {
    const hasAnswer = answers.some(({ questionId }) => questionId === currentQuestion.id);

    if ("required" in currentQuestion.content && currentQuestion.content.required) {
      return hasAnswer;
    }

    return Boolean(nextQuestion);
  }, [answers, currentQuestion, nextQuestion]);

  useDebugValue({
    linearQuestionIndex,
    currentQuestion: currentQuestion,
    prevQuestion: prevQuestion,
    nextQuestion: nextQuestion,
  });

  return {
    currentQuestion,
    currentQuestionStepNumber: linearQuestionIndex === null ? null : linearQuestionIndex + 1,
    nextQuestion,
    isNextButtonEnabled,
    isPreviousButtonEnabled,
    moveToPrevQuestion,
    moveToNextQuestion,
    showResultAfterContactForm,
    setQuestion,
  };
}