import { useEffect, useMemo, useState } from "react";
import useTranslation from "next-translate/useTranslation";
import { useRouter } from "next/router";
import { getBilingualText } from "./summary/utils/helpers";

/**
 * MediaDetails
 * - Renders a YouTube player + a list of videos from mediaObj.value
 * - Loads first item by default (no autoplay)
 * - Plays only when user selects an item
 * - Stops playback when leaving the "case-media" parent tab (pass whichTab)
 * - Shows thumbnail with play overlay
 * - Optional duration badge (if you supply v.duration)
 * - "Watched" badge once a video has been played (session only)
 */

const extractYouTubeId = (input) => {
    if (!input) return null;

    // Already looks like a YouTube ID?
    if (/^[a-zA-Z0-9_-]{11}$/.test(input)) return input;

    try {
        const url = new URL(input);

        // youtu.be/<id>
        if (url.hostname.includes("youtu.be")) {
            return url.pathname.replace("/", "") || null;
        }

        // youtube.com/watch?v=<id>
        const v = url.searchParams.get("v");
        if (v) return v;

        // youtube.com/embed/<id>
        const embedMatch = url.pathname.match(/\/embed\/([^/]+)/);
        if (embedMatch?.[1]) return embedMatch[1];

        // youtube.com/shorts/<id>
        const shortsMatch = url.pathname.match(/\/shorts\/([^/]+)/);
        if (shortsMatch?.[1]) return shortsMatch[1];

        return null;
    } catch {
        return null;
    }
};

const MediaDetails = ({ mediaObj, whichTab, title, useNoCookie = true }) => {
    const { t } = useTranslation();
    const router = useRouter();

    const sourceMedia = mediaObj?.value;
    const isActive = whichTab ? whichTab === "case-media" : true;

    // Build list of playable items (publishable only)
    const videoItems = useMemo(() => {
        const isWelsh = router.locale === "cy";

        return (sourceMedia || [])
            .filter((x) => x?.pinswg_publishtoweb)
            .map((item) => {
                const link = isWelsh
                    ? item.pinswg_videoplatformurlwelsh
                    : item.pinswg_videoplatformurl;

                const videoId = extractYouTubeId(link);
                if (!videoId) return null;

                return {
                    key:
                        item.pinswg_documentid ||
                        item.pinswg_mediaid ||
                        `${item.pinswg_eventrecordingid}-${videoId}`,
                    videoId,
                    name: item.pinswg_eventrecordingname || "Video",
                    description: item.pinswg_description || "",
                    // If you later store duration in CRM, map it here (e.g. "03:42")
                    duration: item.pinswg_duration || null,
                    thumbnailHQ: `https://img.youtube.com/vi/${videoId}/hqdefault.jpg`,
                    thumbnailMax: `https://img.youtube.com/vi/${videoId}/maxresdefault.jpg`,
                    raw: item
                };
            })
            .filter(Boolean);
    }, [sourceMedia, router.locale]);

    const [selectedIndex, setSelectedIndex] = useState(0);

    // Default false so first item loads but does not play.
    const [autoplay, setAutoplay] = useState(false);

    // Bump this to force iframe remount (hard stop playback).
    const [playerInstance, setPlayerInstance] = useState(0);

    // Track which videos have been played (session only).
    const [watchedIds, setWatchedIds] = useState(() => new Set());

    // When list or locale changes: reset selection and do not autoplay
    useEffect(() => {
        setSelectedIndex(0);
        setAutoplay(false);
        setPlayerInstance((n) => n + 1);
    }, [videoItems.length, router.locale]);

    // When leaving the media tab: hard stop playback
    useEffect(() => {
        if (!isActive) {
            setAutoplay(false);
            setPlayerInstance((n) => n + 1);
        }
    }, [isActive]);

    const selected = videoItems[selectedIndex] || null;

    const domain = useNoCookie
        ? "https://www.youtube-nocookie.com"
        : "https://www.youtube.com";

    const embedSrc = selected
        ? `${domain}/embed/${selected.videoId}?rel=0&modestbranding=1&playsinline=1&autoplay=${
              autoplay ? "1" : "0"
          }`
        : "";

    if (!videoItems.length) return null;

    return (
        <div className="govuk-grid-row">
            <div className="card">
                <div className="card-body">
                    <h2 className="govuk-heading-m">{t("case:media-title")}</h2>

                    {/* Player: unmount when not active (guarantees playback stops) */}
                    {isActive && (
                        <div className="videoWrapper govuk-!-margin-bottom-4">
                            <iframe
                                key={`${selected?.videoId}-${playerInstance}`}
                                src={embedSrc}
                                title={selected?.name || "YouTube video"}
                                frameBorder="0"
                                allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
                                allowFullScreen
                            />
                        </div>
                    )}

                    {/* Selected info */}
                    {selected && (
                        <div className="govuk-!-margin-bottom-4">
                            <div className="govuk-body">
                                <b>{t("case:event-recording-name-label")}</b>:{" "}
                                {selected.name}
                            </div>

                            {!!selected.description && (
                                <div className="govuk-body">
                                    <b>
                                        {t(
                                            "case:event-recording-description-label"
                                        )}
                                    </b>
                                    :{" "}
                                    {getBilingualText(
                                        selected.description,
                                        router.locale
                                    )}
                                </div>
                            )}
                        </div>
                    )}

                    {/* Video list */}
                    <h3 className="govuk-heading-s">
                        {t("case:video-heading")}
                    </h3>

                    <ul className="govuk-list govuk-list--spaced">
                        {videoItems.map((v, idx) => {
                            const isSelected = idx === selectedIndex;

                            return (
                                <li key={v.key}>
                                    <button
                                        type="button"
                                        className={`videoTabButton ${
                                            isSelected ? "active" : ""
                                        }`}
                                        aria-current={
                                            isSelected ? "true" : undefined
                                        }
                                        onClick={() => {
                                            setSelectedIndex(idx);

                                            // Start playback only when user selects
                                            setAutoplay(true);

                                            // Force remount to stop previous + start clean
                                            setPlayerInstance((n) => n + 1);

                                            // Mark watched
                                            setWatchedIds((prev) => {
                                                const next = new Set(prev);
                                                next.add(v.videoId);
                                                return next;
                                            });
                                        }}
                                    >
                                        <div className="videoTabContent">
                                            <div className="thumbnailWrapper">
                                                <img
                                                    src={v.thumbnailMax}
                                                    onError={(e) => {
                                                        // fallback for videos without maxres
                                                        e.currentTarget.src =
                                                            v.thumbnailHQ;
                                                    }}
                                                    alt=""
                                                    className="videoThumbnail"
                                                    loading="lazy"
                                                />
                                                <span
                                                    className="playIcon"
                                                    aria-hidden="true"
                                                >
                                                    ▶
                                                </span>

                                                {!!v.duration && (
                                                    <span className="durationBadge">
                                                        {v.duration}
                                                    </span>
                                                )}

                                                {watchedIds.has(v.videoId) && (
                                                    <span className="watchedBadge">
                                                        Watched
                                                    </span>
                                                )}
                                            </div>

                                            <span className="videoTitle">
                                                {v.name}
                                            </span>
                                        </div>
                                    </button>
                                </li>
                            );
                        })}
                    </ul>
                </div>
            </div>
        </div>
    );
};

export default MediaDetails;