import React, { HTMLAttributes, useState } from "react";
import snarkdown from "snarkdown";
import useBaseUrl from "@docusaurus/useBaseUrl";
// @ts-expect-error no types
import { useDoc } from "@docusaurus/theme-common/internal";
import { useHistory, useLocation } from "@docusaurus/router";
import clsx from "clsx";

import { useCurrentTutorial } from "../../hooks/use-current-tutorial";
import { UnitCircle } from "../unit-circle";
import { TutorialCircle } from "../tutorial-circle";
import { useTutorialUIPackage } from "../../hooks/use-tutorial-ui-package";
import { PreferredUIPackage } from "../../context/TutorialUIPackageContext";

const uiNames: Record<PreferredUIPackage, string> = {
    headless: "Headless",
    antd: "Ant Design",
    mui: "Material UI",
    mantine: "Mantine",
    "chakra-ui": "Chakra UI",
};
const baseIconUrl =
    "https://refine.ams3.cdn.digitaloceanspaces.com/website/static/icons/colored/ui-framework-";

type LinkWithIdProps = HTMLAttributes<HTMLAnchorElement> & {
    id: string;
    isCurrent?: boolean;
    dangerouslySetInnerHTML?: { __html: string };
};

const LinkWithId = ({
    id,
    isCurrent,
    className,
    dangerouslySetInnerHTML,
    ...rest
}: LinkWithIdProps) => {
    const toUrl = useBaseUrl(`/docs/${id}`, { forcePrependBaseUrl: true });

    return (
        <a
            {...rest}
            href={toUrl}
            className={clsx(
                className,
                isCurrent
                    ? "text-gray-800 dark:text-gray-0"
                    : " hover:!text-refine-link-light active:!text-refine-link-light dark:hover:!text-refine-link-dark dark:active:!text-refine-link-dark",
            )}
            dangerouslySetInnerHTML={dangerouslySetInnerHTML}
        />
    );
};

const markdownConverter = (text: string) => {
    const numericStartRegexp = /^\d+\.\s?/g;
    // use this to get the numeric start
    const _numericStart = text.match(numericStartRegexp)?.[0] || "";
    const numericStartIgnore = text.replace(numericStartRegexp, "");

    const marked = snarkdown(numericStartIgnore);

    return `${marked}`;
};

const TutorialUIStatus = () => {
    const { preferred: preferredUIPackage } = useTutorialUIPackage();

    return (
        <div className="mt-4">
            <div
                className={clsx(
                    "rounded",
                    " bg-gray-50 dark:bg-gray-800",
                    "p-4",
                )}
            >
                <div className={clsx("font-semibold text-sm leading-6")}>
                    Current Framework
                </div>
                <div
                    className={clsx(
                        "flex items-center justify-between",
                        "pt-3",
                    )}
                >
                    <div className="flex items-center gap-2">
                        <img
                            src={`${baseIconUrl}${preferredUIPackage}.svg`}
                            className="h-auto w-6"
                        />
                        <span className="text-sm leading-6">
                            {uiNames[preferredUIPackage]}
                        </span>
                    </div>
                    <div>
                        <LinkWithId
                            id="tutorial/introduction/select-framework"
                            className={clsx(
                                "underline",
                                "text-sm",
                                "text-refine-link-light",
                                "dark:text-refine-link-dark",
                            )}
                        >
                            Change
                        </LinkWithId>
                    </div>
                </div>
            </div>
        </div>
    );
};

type TocLinkProps = {
    item: any;
    activeId?: string;
    setActiveId?: React.Dispatch<React.SetStateAction<string>>;
};

const TocLink: React.FC<TocLinkProps> = ({ item, activeId, setActiveId }) => {
    const location = useLocation();
    const history = useHistory();
    const { hash: locationHash } = location;

    React.useEffect(() => {
        const targetElement = document.getElementById(item.id);

        if (targetElement) {
            const observer = new IntersectionObserver(
                (entries) => {
                    entries.forEach((entry) => {
                        if (entry.isIntersecting) {
                            const hash = `#${item.id}`;
                            if (hash !== locationHash) {
                                setActiveId(item.id);
                                window.history.replaceState({}, "", hash);
                            }
                        }
                    });
                },
                {
                    rootMargin: "0px 0px -80% 0px",
                },
            );

            observer.observe(targetElement);

            return () => {
                observer.unobserve(targetElement);
            };
        }
    }, [item.id]);

    return (
        <a
            href={`#${item.id}`}
            dangerouslySetInnerHTML={{ __html: item.value }}
            className={clsx(
                "text-gray-800 dark:text-gray-0 hover:!text-refine-link active:!text-refine-link dark:hover:!text-refine-link-dark dark:active:!text-refine-link-dark",
                activeId === item.id &&
                    "!text-refine-link-light dark:!text-refine-link-dark",
            )}
        ></a>
    );
};

export const TutorialTOC = () => {
    const {
        toc,
        metadata: { id: currentDocId },
    } = useDoc();
    const currentTutorial = useCurrentTutorial();
    const { hash } = useLocation();

    const baseActiveId = `${hash}`.replace("#", "");

    const [selectedUnit, setSelectedUnit] = useState(currentTutorial.unit);
    const [activeId, setActiveId] = React.useState<string | undefined>(
        baseActiveId,
    );

    React.useEffect(() => {
        setActiveId(baseActiveId);
    }, [baseActiveId]);

    const renderTocItem = (item: (typeof toc)[number]) => {
        return (
            <li
                key={item.id}
                style={{
                    marginLeft: (item.level - 2) * 12,
                }}
                className="mb-1"
            >
                <TocLink
                    item={item}
                    activeId={activeId}
                    setActiveId={setActiveId}
                />
            </li>
        );
    };

    const renderTOC = () => {
        if (toc.length === 0) return null;
        return (
            <ul className="mt-1 list-none pl-0">{toc.map(renderTocItem)}</ul>
        );
    };

    const renderUnitItem = (
        doc: NonNullable<
            typeof currentTutorial
        >["units"][number]["docs"][number],
    ) => {
        const formattedTitle = markdownConverter(doc.title);
        const unitNo = doc.title.split(".")[0];

        return (
            <li
                key={doc.id}
                className={clsx("flex flex-row items-start gap-2", "pb-4")}
            >
                <div className={clsx("mt-0.5", "h-8 w-8", "flex-shrink-0")}>
                    <TutorialCircle
                        id={doc.id}
                        width="100%"
                        height="100%"
                        unitNo={isNaN(Number(unitNo)) ? undefined : unitNo}
                        isCurrent={doc.current}
                    />
                </div>
                <div className="flex flex-col gap-2 pt-[6px]">
                    <LinkWithId
                        id={doc.id}
                        isCurrent={doc.current}
                        className={clsx("leading-[22px]", "no-underline", {
                            "text-gray-900 dark:text-white":
                                currentDocId === doc.id,
                            "hover:cursor-default hover:no-underline hover:text-gray-900":
                                doc.current,
                        })}
                        dangerouslySetInnerHTML={{ __html: formattedTitle }}
                    />

                    {doc.current && renderTOC()}
                </div>
            </li>
        );
    };

    const renderUnitDocs = (
        unit?: NonNullable<typeof currentTutorial>["units"][number],
    ) => {
        return (
            <div>
                <ul className={clsx("list-none", "pl-0")}>
                    {unit?.docs
                        .sort((a, b) =>
                            `${a.title}`?.localeCompare(`${b.title}`),
                        )
                        .map(renderUnitItem)}
                </ul>
            </div>
        );
    };

    const renderUnitTab = (unit: (typeof currentTutorial)["units"][number]) => {
        return (
            <button
                key={unit.no}
                type="button"
                data-unit-title={unit.title}
                data-unit-no={unit.no}
                data-unit-current={
                    unit.unit === selectedUnit ? "true" : undefined
                }
                onClick={() => setSelectedUnit(unit.unit)}
                className={clsx(
                    "tutorial-unit",
                    unit.unit === selectedUnit &&
                        "bg-gradient-to-t from-gray-50 dark:from-gray-700 from-40% to-gray-200 dark:to-gray-600",
                    "-mb-1",
                    "flex items-center justify-center",
                    "w-[40px] h-[44px]",
                    "cursor-pointer",
                    "rounded-tl-[24px] rounded-tr-[24px]",
                    "border-none",
                    "font-semibold",
                )}
            >
                <UnitCircle
                    unit={unit.unit}
                    width="32px"
                    height="32px"
                    isSelected={unit.unit === selectedUnit}
                />
            </button>
        );
    };

    const currentUnit:
        | NonNullable<typeof currentTutorial>["units"][number]
        | undefined = currentTutorial?.units.find(
        (unit) => unit.unit === selectedUnit,
    );

    const isFirstUnit =
        currentTutorial?.units?.find((el) => el?.unit === currentTutorial?.unit)
            ?.no === 1;

    return (
        <div className={clsx("tutorial-tracker", "max-h-[calc(100vh-6rem]")}>
            <div
                className={clsx(
                    "tutorial-units",
                    "mb-1 px-2",
                    "flex items-center gap-0.5",
                )}
            >
                {currentTutorial?.units.map(renderUnitTab)}
            </div>
            <div
                className={clsx(
                    "rounded",
                    "pt-6 px-3 pb-2",
                    "bg-gray-50 dark:bg-gray-700",
                )}
            >
                {/* <div className={clsx("mb-2", "text-sm font-bold")}>
                    {currentUnit?.title ?? currentUnit?.unit ?? "-"}
                </div> */}
                <div className={clsx("text-sm")}>
                    {renderUnitDocs(currentUnit)}
                </div>
            </div>
            {!isFirstUnit &&
                currentDocId !== "tutorial/introduction/select-framework" && (
                    <TutorialUIStatus />
                )}
        </div>
    );
};

export const useDocTOCwithTutorial = () => {
    const tutorial = useCurrentTutorial();
    const { frontMatter, toc } = useDoc();
    const hidden = frontMatter.hide_table_of_contents;
    const canRender = (!hidden && toc.length > 0) || tutorial?.isTutorial;
    const tutorialTOC = canRender ? <TutorialTOC /> : undefined;

    return {
        hidden,
        tutorialTOC,
    };
};