import { questionApi } from "@api/question";
import { devlog } from "@frontend/kitui";
import { questionToEditQuestionRequest } from "@model/question/edit";
import { QuestionType, RawQuestion, rawQuestionToQuestion } from "@model/question/question";
import { AnyQuizQuestion, ImageQuestionVariant, QuestionVariant, createQuestionImageVariant, createQuestionVariant } from "@model/questionTypes/shared";
import { produce } from "immer";
import { enqueueSnackbar } from "notistack";
import { isAxiosCanceledError } from "../../utils/isAxiosCanceledError";
import { notReachable } from "../../utils/notReachable";
import { RequestQueue } from "../../utils/requestQueue";
import { QuestionsStore, useQuestionsStore } from "./store";
import { nanoid } from "nanoid";


export const setQuestions = (questions: RawQuestion[] | null) => setProducedState(state => {
    state.questions = questions?.map(rawQuestionToQuestion) ?? [];
}, {
    type: "setQuestions",
    questions,
});

const addQuestion = (question: AnyQuizQuestion) => setProducedState(state => {
    state.questions.push(question);
}, {
    type: "addQuestion",
    question,
});

const removeQuestion = (questionId: string) => setProducedState(state => {
    const index = state.questions.findIndex(q => q.id === questionId);
    if (index === -1) return;

    state.questions.splice(index, 1);
}, {
    type: "removeQuestion",
    questionId,
});

const setQuestionBackendId = (questionId: string, backendId: number) => setProducedState(state => {
    const question = state.questions.find(q => q.id === questionId);
    if (!question) return;

    question.backendId = backendId;
}, {
    type: "setQuestionBackendId",
    questionId: questionId,
    backendId,
});

export const reorderQuestions = (
    sourceIndex: number,
    destinationIndex: number,
) => {
    if (sourceIndex === destinationIndex) return;

    setProducedState(state => {
        const [removed] = state.questions.splice(sourceIndex, 1);
        state.questions.splice(destinationIndex, 0, removed);
    });
};

export const toggleExpandQuestion = (questionId: string) => setProducedState(state => {
    const question = state.questions.find(q => q.id === questionId);
    if (!question) return;

    question.expanded = !question.expanded;
});

export const collapseAllQuestions = () => setProducedState(state => {
    state.questions.forEach(question => question.expanded = false);
});

export const addQuestionVariant = (questionId: string) => {
    updateQuestion(questionId, question => {
        switch (question.type) {
            case "variant":
            case "emoji":
            case "select":
                question.content.variants.push(createQuestionVariant());
                break;
            case "images":
            case "varimg":
                question.content.variants.push(createQuestionImageVariant());
                break;
            case "text":
            case "date":
            case "number":
            case "file":
            case "page":
            case "rating":
                throw new Error(`Cannot add variant to question of type "${question.type}"`);
            default: notReachable(question);
        }
    });
};

export const deleteQuestionVariant = (questionId: string, variantId: string) => {
    updateQuestion(questionId, question => {
        if (!("variants" in question.content)) return;

        const variantIndex = question.content.variants.findIndex(variant => variant.id === variantId);
        if (variantIndex === -1) return;

        question.content.variants.splice(variantIndex, 1);
    });
};

export const setQuestionVariantField = (
    questionId: string,
    variantId: string,
    field: keyof QuestionVariant,
    value: QuestionVariant[keyof QuestionVariant],
) => {
    updateQuestion(questionId, question => {
        if (!("variants" in question.content)) return;

        const variantIndex = question.content.variants.findIndex(variant => variant.id === variantId);
        if (variantIndex === -1) return;

        const variant = question.content.variants[variantIndex];
        variant[field] = value;
    });
};

export const setQuestionImageVariantField = (
    questionId: string,
    variantId: string,
    field: keyof ImageQuestionVariant,
    value: ImageQuestionVariant[keyof ImageQuestionVariant],
) => {
    updateQuestion(questionId, question => {
        if (!("variants" in question.content)) return;

        const variantIndex = question.content.variants.findIndex(variant => variant.id === variantId);
        if (variantIndex === -1) return;

        const variant = question.content.variants[variantIndex];
        if (!("originalImageUrl" in variant)) return;

        variant[field] = value;
    });
};

export const reorderQuestionVariants = (
    questionId: string,
    sourceIndex: number,
    destinationIndex: number,
) => {
    if (sourceIndex === destinationIndex) return;

    updateQuestion(questionId, question => {
        if (!("variants" in question.content)) return;

        const [removed] = question.content.variants.splice(sourceIndex, 1);
        question.content.variants.splice(destinationIndex, 0, removed);

    });
};

export const setQuestionBackgroundImage = (
    questionId: string,
    url: string,
) => {
    updateQuestion(questionId, question => {
        if (question.content.back === url) return;

        if (
            question.content.back !== question.content.originalBack
        ) URL.revokeObjectURL(question.content.back);
        question.content.back = url;
    });
};

export const setQuestionOriginalBackgroundImage = (
    questionId: string,
    url: string,
) => {
    updateQuestion(questionId, question => {
        if (question.content.originalBack === url) return;

        URL.revokeObjectURL(question.content.originalBack);
        question.content.originalBack = url;
    });
};

export const setVariantImageUrl = (
    questionId: string,
    variantId: string,
    url: string,
) => {
    updateQuestion(questionId, question => {
        if (!("variants" in question.content)) return;

        const variant = question.content.variants.find(variant => variant.id === variantId);
        if (!variant || !("originalImageUrl" in variant)) return;

        if (variant.extendedText === url) return;

        if (variant.extendedText !== variant.originalImageUrl) URL.revokeObjectURL(variant.extendedText);
        variant.extendedText = url;
    });
};

export const setVariantOriginalImageUrl = (
    questionId: string,
    variantId: string,
    url: string,
) => {
    updateQuestion(questionId, question => {
        if (!("variants" in question.content)) return;

        const variant = question.content.variants.find(
            variant => variant.id === variantId
        ) as ImageQuestionVariant | undefined;
        if (!variant || !("originalImageUrl" in variant)) return;

        if (variant.originalImageUrl === url) return;

        URL.revokeObjectURL(variant.originalImageUrl);
        variant.originalImageUrl = url;
    });
};

export const setPageQuestionPicture = (
    questionId: string,
    url: string,
) => {
    updateQuestion(questionId, question => {
        if (question.type !== "page") return;

        if (question.content.picture === url) return;

        if (
            question.content.picture !== question.content.originalPicture
        ) URL.revokeObjectURL(question.content.picture);
        question.content.picture = url;
    });
};

export const setPageQuestionOriginalPicture = (
    questionId: string,
    url: string,
) => {
    updateQuestion(questionId, question => {
        if (question.type !== "page") return;

        if (question.content.originalPicture === url) return;

        URL.revokeObjectURL(question.content.originalPicture);
        question.content.originalPicture = url;
    });
};

export const setQuestionInnerName = (
    questionId: string,
    name: string,
) => {
    updateQuestion(questionId, question => {
        question.content.innerName = name;
    });
};

const REQUEST_DEBOUNCE = 200;
const requestQueue = new RequestQueue();
let requestTimeoutId: ReturnType<typeof setTimeout>;

export const updateQuestion = (
    questionId: string,
    updateFn: (question: AnyQuizQuestion) => void,
) => {
    setProducedState(state => {
        const question = state.questions.find(q => q.id === questionId);
        if (!question) return;

        updateFn(question);
    }, {
        type: "updateQuestion",
        questionId,
        updateFn: updateFn.toString(),
    });

    clearTimeout(requestTimeoutId);
    requestTimeoutId = setTimeout(() => {
        requestQueue.enqueue(async () => {
            const question = useQuestionsStore.getState().questions.find(q => q.id === questionId);
            if (!question) return;

            const response = await questionApi.edit(questionToEditQuestionRequest(question));

            setQuestionBackendId(questionId, response.updated);
        }).catch(error => {
            if (isAxiosCanceledError(error)) return;

            devlog("Error editing question", { error, questionId });
            enqueueSnackbar("Не удалось сохранить вопрос");
        });
    }, REQUEST_DEBOUNCE);
};

export const createQuestion = async (quizId: number, type: QuestionType = "variant") => requestQueue.enqueue(async () => {
    try {
        const question = await questionApi.create({
            quiz_id: quizId,
            type,
        });

        addQuestion(rawQuestionToQuestion(question));
    } catch (error) {
        devlog("Error creating question", error);
        enqueueSnackbar("Не удалось создать вопрос");
    }
});

export const deleteQuestion = async (questionId: string) => requestQueue.enqueue(async () => {
    const question = useQuestionsStore.getState().questions.find(q => q.id === questionId);
    if (!question) return;

    try {
        await questionApi.delete(question.backendId);

        removeQuestion(questionId);
    } catch (error) {
        devlog("Error deleting question", error);
        enqueueSnackbar("Не удалось удалить вопрос");
    }
});

export const copyQuestion = async (questionId: string, quizId: number) => requestQueue.enqueue(async () => {
    const question = useQuestionsStore.getState().questions.find(q => q.id === questionId);
    if (!question) return;

    try {
        const { updated: newQuestionId } = await questionApi.copy(question.backendId, quizId);

        const copiedQuestion = structuredClone(question);
        copiedQuestion.backendId = newQuestionId;
        copiedQuestion.id = nanoid();

        setProducedState(state => {
            state.questions.push(copiedQuestion);
        }, {
            type: "copyQuestion",
            questionId: questionId,
            quizId,
        });
    } catch (error) {
        devlog("Error copying question", error);
        enqueueSnackbar("Не удалось скопировать вопрос");
    }
});

function setProducedState<A extends string | { type: unknown; }>(
    recipe: (state: QuestionsStore) => void,
    action?: A,
) {
    useQuestionsStore.setState(state => produce(state, recipe), false, action);
}