import { useCallback, useMemo, useState } from "react";
import { useTranslation } from "react-i18next";
import { useQueryClient } from "@tanstack/react-query";
import Modal from "./ui/Modal";
import { api, type DownloadJob } from "../lib/api";
import { qk } from "../lib/queryKeys";
import { jobTitle } from "./downloadTitle";
import { exposeVideoToBackgroundPlay } from "../lib/browserBackgroundPlay";
import { useMediaLogRef } from "../lib/mediaLog";
import { useMediaSession } from "../lib/mediaSession";
import { useMediaKeys } from "../lib/mediaKeys";
import { keptPosition, useResume } from "../lib/resume";
import RemoteImage from "./ui/RemoteImage";

// In-app player for a completed library item. We do NOT reuse PlayerModal (a cross-origin
// YouTube IFrame shell) or PlexPlayer (a Plex HLS/session shell): both are bound to their own domain
// APIs and can't point at a local file. Instead we reuse the shared a11y shell (`Modal`: focus-trap,
// ESC/back-to-close, scroll-lock, layer-stack, portal) and stream the local file into a NATIVE
// <video>/<audio controls> — the same element VideoEditor already plays this URL in. Downloads are a
// browser-native container (mp4/H.264/AAC + m4a/mp3), so native playback (seek via the range-aware
// /file endpoint, volume, fullscreen, speed) works with zero transcode; an uploaded media item may be
// any codec (best-effort playback).
//
// It opens where the viewer stopped (`job.position_seconds`, from the library listing) unless
// `fromStart`, and keeps the point on the server as it plays (`lib/resume.ts`); the OS's media
// controls and the basic keys drive it like the other players.
export default function LibraryPlayer({
  job,
  fromStart = false,
  onClose,
}: {
  job: DownloadJob;
  fromStart?: boolean;
  onClose: () => void;
}) {
  const { t } = useTranslation();
  const qc = useQueryClient();
  const fileUrl = useMemo(() => api.fileUrl(job.id), [job.id]);
  // Video vs audio-only comes from the stored media_kind (the single source every sibling reads —
  // WatchPage/downloadRow/the tray) — NOT a re-derived container list, which would misclassify
  // an uploaded audio file whose container is outside a hardcoded set (uploads accept any container).
  // Only fall back to the old dimension+container heuristic for a legacy asset with a null media_kind.
  const asset = job.asset;
  const isAudio =
    asset?.media_kind === "audio" ||
    (asset?.media_kind == null &&
      !(asset?.width && asset?.height) &&
      !!asset?.container &&
      ["m4a", "mp3", "opus", "ogg", "wav", "flac", "aac"].includes(asset.container.toLowerCase()));
  // Our self-hosted poster (always same-origin, never expires) is the primary; the source thumbnail is
  // the fallback. Same precedence as the library-row thumbnail.
  const poster = job.poster_url ? api.posterImageUrl(job.id) : (asset?.thumbnail_url ?? undefined);
  const logMedia = useMediaLogRef("library");
  // The element as STATE, so the session, the keys and the resume bind to it once it exists.
  const [media, setMedia] = useState<HTMLMediaElement | null>(null);
  const mediaRef = useCallback(
    (el: HTMLMediaElement | null) => {
      if (el instanceof HTMLVideoElement) exposeVideoToBackgroundPlay(el);
      logMedia(el);
      setMedia(el);
    },
    [logMedia],
  );

  const title = jobTitle(job);
  useMediaSession(media, {
    title,
    artist: job.display_uploader ?? asset?.uploader ?? null,
    artwork: poster ?? null,
  });
  useMediaKeys(media);
  // The library row's bar follows the point at once — every library listing this file may sit in
  // (each folder, search and the shared view is its own key under `files`) — rather than after the
  // next refetch. On the way out a listing read may already be out, having read the server before
  // the closing point lands: it is cancelled, or its answer replaced the row's point with the older
  // one, Continue opened there, and its first checkpoint wrote it back over the right one. Once the
  // point is on the server, the listings are read again.
  const lists = { queryKey: qk.files() };
  const keepPoint = (position: number, duration: number, leaving: boolean) => {
    const at = keptPosition(position, duration);
    if (leaving) void qc.cancelQueries(lists);
    qc.setQueriesData<DownloadJob[]>(lists, (jobs) =>
      jobs?.map((j) => (j.id === job.id ? { ...j, position_seconds: at } : j)),
    );
    if (leaving) {
      api.saveDownloadProgressBeacon(job.id, position, duration, () => {
        void qc.invalidateQueries(lists);
      });
    } else void api.saveDownloadProgress(job.id, position, duration).catch(() => {});
  };
  useResume(media, String(job.id), fromStart ? 0 : (job.position_seconds ?? 0), keepPoint);

  return (
    <Modal initialFocus="player" title={title} onClose={onClose} maxWidth="max-w-4xl">
      {isAudio ? (
        <div className="flex flex-col items-center gap-4 py-2">
          {poster ? (
            <RemoteImage
              src={poster}
              alt=""
              className="w-40 h-40 rounded-xl object-cover border border-border"
            />
          ) : null}
          <audio ref={mediaRef} src={fileUrl} controls autoPlay className="w-full">
            {t("downloads.player.unsupported")}
          </audio>
        </div>
      ) : (
        <video
          ref={mediaRef}
          src={fileUrl}
          poster={poster}
          controls
          autoPlay
          playsInline
          className="w-full max-h-[70dvh] rounded-lg bg-black object-contain"
        >
          {t("downloads.player.unsupported")}
        </video>
      )}
    </Modal>
  );
}