import { useEffect, useRef, useState } from "react";
import { Download, Link2, Lock, PlayCircle } from "lucide-react";

// Standalone, login-free video page for a shared /watch/<token> link. Rendered OUTSIDE the app
// tree (no auth, no providers) — like the /privacy and /terms pages. Uses plain fetch and a tiny
// self-contained i18n dict (the public viewer has no app language preference).

// Advertise the playing video to the OS via the Media Session API: lock-screen / control-center
// metadata + play/pause handlers. This is also what lets a browser's own "background playback"
// feature keep the audio going when the page is backgrounded — it's exactly how youtube.com stays
// playing in the background on Brave iOS. We deliberately do NOT route the audio through the Web
// Audio API: `createMediaElementSource` pulls the element out of the normal media pipeline that the
// background feature (and iOS) hooks into, and iOS then suspends the AudioContext on background —
// which STOPPED playback instead of keeping it alive (measured on iPad Brave). A plain <video> +
// MediaSession leaves the browser's native background handling in charge.
function useMediaSession(
  videoRef: React.RefObject<HTMLVideoElement | null>,
  meta: Meta | null,
  ready: boolean,
) {
  useEffect(() => {
    if (!ready || !meta || !("mediaSession" in navigator)) return;
    const video = videoRef.current;
    try {
      navigator.mediaSession.metadata = new MediaMetadata({
        title: meta.title || "Video",
        artist: meta.uploader || "Siftlode",
        artwork: meta.poster_url
          ? [{ src: meta.poster_url, sizes: "512x512", type: "image/jpeg" }]
          : [],
      });
      navigator.mediaSession.setActionHandler("play", () => void video?.play());
      navigator.mediaSession.setActionHandler("pause", () => video?.pause());
    } catch {
      /* MediaMetadata / handlers unsupported — ignore */
    }
  }, [ready, meta, videoRef]);
}

type Meta = {
  needs_password: boolean;
  title?: string | null;
  uploader?: string | null;
  uploader_url?: string | null;
  source_url?: string | null;
  extra_links?: string[];
  duration_s?: number | null;
  allow_download?: boolean;
  file_url?: string;
  poster_url?: string | null;
};

// Compact display of a URL: drop the protocol + trailing slash so it fits on one line.
function displayUrl(url: string): string {
  try {
    const u = new URL(url);
    return (u.host + u.pathname + u.search).replace(/\/$/, "");
  } catch {
    return url;
  }
}

const STR = {
  en: {
    loading: "Loading…",
    gone: "This link is no longer available.",
    goneHint: "It may have expired or been revoked by the owner.",
    passwordTitle: "This video is password-protected",
    passwordPlaceholder: "Enter password",
    watch: "Watch",
    wrong: "Wrong password.",
    download: "Download",
    links: "Links",
    brand: "Shared via Siftlode",
  },
  hu: {
    loading: "Betöltés…",
    gone: "Ez a link már nem elérhető.",
    goneHint: "Lehet, hogy lejárt, vagy a tulajdonos visszavonta.",
    passwordTitle: "Ez a videó jelszóval védett",
    passwordPlaceholder: "Add meg a jelszót",
    watch: "Megnézem",
    wrong: "Hibás jelszó.",
    download: "Letöltés",
    links: "Linkek",
    brand: "Megosztva a Siftlode-dal",
  },
  de: {
    loading: "Wird geladen…",
    gone: "Dieser Link ist nicht mehr verfügbar.",
    goneHint: "Er ist möglicherweise abgelaufen oder wurde widerrufen.",
    passwordTitle: "Dieses Video ist passwortgeschützt",
    passwordPlaceholder: "Passwort eingeben",
    watch: "Ansehen",
    wrong: "Falsches Passwort.",
    download: "Herunterladen",
    links: "Links",
    brand: "Geteilt über Siftlode",
  },
} as const;

const lang =
  ((navigator.language || "en").slice(0, 2) as keyof typeof STR) in STR
    ? ((navigator.language || "en").slice(0, 2) as keyof typeof STR)
    : "en";
const T = STR[lang];

export default function WatchPage() {
  const token = window.location.pathname.split("/watch/")[1]?.split(/[/?#]/)[0] ?? "";
  const [status, setStatus] = useState<"loading" | "ready" | "password" | "gone">("loading");
  const [meta, setMeta] = useState<Meta | null>(null);
  const [password, setPassword] = useState("");
  const [error, setError] = useState<string | null>(null);
  const [unlocking, setUnlocking] = useState(false);
  const videoRef = useRef<HTMLVideoElement>(null);
  useMediaSession(videoRef, meta, status === "ready");

  useEffect(() => {
    if (!token) {
      setStatus("gone");
      return;
    }
    fetch(`/api/public/watch/${encodeURIComponent(token)}`)
      .then((r) => (r.ok ? r.json() : Promise.reject(r.status)))
      .then((m: Meta) => {
        if (m.needs_password) setStatus("password");
        else {
          setMeta(m);
          setStatus("ready");
        }
      })
      .catch(() => setStatus("gone"));
  }, [token]);

  const unlock = async () => {
    setUnlocking(true);
    setError(null);
    try {
      const r = await fetch(`/api/public/watch/${encodeURIComponent(token)}/unlock`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ password }),
      });
      if (r.status === 403) {
        setError(T.wrong);
        return;
      }
      if (!r.ok) {
        setStatus("gone");
        return;
      }
      setMeta(await r.json());
      setStatus("ready");
    } finally {
      setUnlocking(false);
    }
  };

  return (
    <div className="min-h-screen bg-bg text-fg flex flex-col items-center">
      <div className="w-full max-w-4xl px-4 py-6 flex-1 flex flex-col">
        <div className="flex items-center gap-2 mb-5 text-sm text-muted">
          <PlayCircle className="w-5 h-5 text-accent" />
          <span className="font-semibold text-fg">Siftlode</span>
        </div>

        {status === "loading" && (
          <div className="flex-1 grid place-items-center text-muted">{T.loading}</div>
        )}

        {status === "gone" && (
          <div className="flex-1 grid place-items-center text-center">
            <div>
              <div className="text-lg font-semibold">{T.gone}</div>
              <div className="text-sm text-muted mt-1">{T.goneHint}</div>
            </div>
          </div>
        )}

        {status === "password" && (
          <div className="flex-1 grid place-items-center">
            <div className="w-full max-w-sm rounded-2xl glass p-6">
              <div className="flex items-center gap-2 font-medium mb-4">
                <Lock className="w-4 h-4 text-accent" /> {T.passwordTitle}
              </div>
              <input
                type="password"
                value={password}
                autoFocus
                onChange={(e) => setPassword(e.target.value)}
                onKeyDown={(e) => e.key === "Enter" && password && unlock()}
                placeholder={T.passwordPlaceholder}
                className="w-full rounded-lg bg-surface border border-border px-3 py-2 text-sm outline-hidden focus:ring-2 focus:ring-accent/40"
              />
              {error && <div className="text-sm text-red-400 mt-2">{error}</div>}
              <button
                onClick={unlock}
                disabled={!password || unlocking}
                className="mt-4 w-full rounded-lg bg-accent text-accent-fg hover:opacity-90 disabled:opacity-50 py-2 text-sm font-medium transition"
              >
                {T.watch}
              </button>
            </div>
          </div>
        )}

        {status === "ready" && meta && (
          <div>
            {/* Shrink-wrap the player to the video so a vertical/short clip renders as a narrow
                player instead of a wide box with black bars; a landscape clip fills the width. */}
            <div className="rounded-xl overflow-hidden bg-black border border-border w-fit max-w-full mx-auto">
              <video
                ref={videoRef}
                controls
                playsInline
                src={meta.file_url}
                poster={meta.poster_url || undefined}
                className="max-h-[80vh] max-w-full mx-auto block"
              />
            </div>
            <div className="mt-3 flex items-start gap-3">
              <div className="min-w-0 flex-1">
                <h1 className="text-lg font-semibold leading-snug">{meta.title || "Video"}</h1>
                {meta.uploader &&
                  (meta.uploader_url ? (
                    <a
                      href={meta.uploader_url}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="text-sm text-muted hover:text-accent hover:underline"
                    >
                      {meta.uploader}
                    </a>
                  ) : (
                    <div className="text-sm text-muted">{meta.uploader}</div>
                  ))}
              </div>
              {meta.allow_download && (
                <a
                  href={meta.file_url}
                  className="shrink-0 inline-flex items-center gap-1.5 rounded-lg bg-surface hover:bg-card px-3 py-2 text-sm font-medium transition"
                >
                  <Download className="w-4 h-4" /> {T.download}
                </a>
              )}
            </div>
            {(meta.source_url || (meta.extra_links && meta.extra_links.length > 0)) && (
              <div className="mt-3 flex flex-col gap-1.5">
                {[meta.source_url, ...(meta.extra_links ?? [])]
                  .filter((u): u is string => !!u)
                  .map((url) => (
                    <a
                      key={url}
                      href={url}
                      target="_blank"
                      rel="noopener noreferrer"
                      title={url}
                      className="inline-flex items-center gap-1.5 text-sm text-muted hover:text-accent hover:underline min-w-0"
                    >
                      <Link2 className="w-3.5 h-3.5 shrink-0" />
                      <span className="truncate">{displayUrl(url)}</span>
                    </a>
                  ))}
              </div>
            )}
          </div>
        )}
      </div>
      <div className="text-xs text-muted py-4">{T.brand}</div>
    </div>
  );
}