import { useContext, useEffect, useRef, useState } from "react";
import { Link } from "react-router";
import { Trans } from "@lingui/react/macro";
import { t } from "@lingui/core/macro";
import {
  PlayerContext,
  type PlayerItem,
  playerItemKey,
} from "../contexts/PlayerContext.ts";
import { MediaPlayer } from "./MediaPlayer.tsx";
import { fmt } from "../utils/duration.ts";
import Thumbnail from "./Thumbnail.tsx";

type EmbedItem = Extract<PlayerItem, { kind: "embed" }>;

// The stored embedUrl is the canonical, non-playing form — it is also rendered
// outside the player, so the autoplay parameter is added here at playback time
// rather than baked into rich_content. Only a fresh play() sets autoplay: a
// session restored from localStorage has no user gesture behind it, so it stays
// paused, matching how MediaPlayer treats file items.
// Bandcamp's EmbeddedPlayer has no autoplay parameter — that is what the native
// playback path (GERBEUR_BANDCAMP_PLAYER=native) exists to solve.
function playbackUrl(item: EmbedItem, autoplay: boolean) {
  if (!autoplay) return item.embedUrl;
  try {
    const url = new URL(item.embedUrl);
    if (item.type === "youtube") url.searchParams.set("autoplay", "1");
    else if (item.type === "soundcloud") {
      url.searchParams.set("auto_play", "true");
    } else return item.embedUrl;
    return url.toString();
  } catch {
    return item.embedUrl; // malformed stored URL — hand it to the iframe as-is
  }
}

export function GlobalPlayer() {
  const {
    current,
    queue,
    queueIndex,
    hasNext,
    hasPrevious,
    resolving,
    startTime,
    autoplay,
    stop,
    next,
    previous,
    playAt,
    seekRef,
    toggleRef,
    onPlayStateChange,
    onTimeUpdate,
    onEnded,
    onError,
  } = useContext(PlayerContext);
  const ref = useRef<HTMLDivElement>(null);
  const currentRowRef = useRef<HTMLLIElement>(null);
  const [reduced, setReduced] = useState(false);
  const [prevKey, setPrevKey] = useState(current ? playerItemKey(current) : null);

  const currentKey = current ? playerItemKey(current) : null;
  if (prevKey !== currentKey) {
    setPrevKey(currentKey);
    if (current) setReduced(false);
  }

  useEffect(() => {
    if (!current) {
      document.body.classList.remove("has-player");
      document.body.style.removeProperty("--player-height");
      return;
    }

    const el = ref.current;
    if (!el) return;

    document.body.style.setProperty("--player-height", `${el.offsetHeight}px`);
    document.body.classList.add("has-player");

    const observer = new ResizeObserver(() => {
      document.body.style.setProperty(
        "--player-height",
        `${el.offsetHeight}px`,
      );
    });
    observer.observe(el);
    return () => {
      observer.disconnect();
      document.body.classList.remove("has-player");
      document.body.style.removeProperty("--player-height");
    };
  }, [current]);

  // Keep the playing row visible as the queue advances on its own.
  useEffect(() => {
    currentRowRef.current?.scrollIntoView({ block: "nearest" });
  }, [queueIndex]);

  if (!current) return null;

  // Files are classed by their media kind; everything else carries a brand key,
  // so a native Bandcamp stream keeps the same styling as the Bandcamp embed.
  const typeClass = current.kind === "file"
    ? (current.mimeType.startsWith("video/") ? "file-video" : "file-audio")
    : current.type;

  const title = current.title ??
    (current.kind === "embed"
      ? current.embedUrl
      : current.kind === "file"
      ? current.fileUrl
      : current.streamUrl);

  const showQueue = queue.length > 1;

  return (
    <div
      className={`global-player global-player--${typeClass}${
        reduced ? " global-player--reduced" : ""
      }`}
      ref={ref}
    >
      <div className="global-player-header">
        {current.artworkUrl && (
          <Thumbnail
            src={current.artworkUrl}
            className="global-player-artwork"
            placeholder={{ siteName: current.subtitle }}
            placeholderClassName="global-player-artwork"
            loading="eager"
          />
        )}
        <div className="global-player-heading">
          {current.dumpHref
            ? (
              <Link to={current.dumpHref} className="global-player-title">
                {title}
              </Link>
            )
            : <span className="global-player-title">{title}</span>}
          {current.subtitle && (
            <span className="global-player-subtitle">{current.subtitle}</span>
          )}
        </div>
        {showQueue && (
          <div className="global-player-transport">
            <button
              type="button"
              className="btn btn--ghost"
              onClick={previous}
              disabled={!hasPrevious}
              aria-label={t`Previous track`}
            >
              ⏮
            </button>
            <span className="global-player-position">
              {queueIndex + 1} / {queue.length}
            </span>
            <button
              type="button"
              className="btn btn--ghost"
              onClick={next}
              disabled={!hasNext}
              aria-label={t`Next track`}
            >
              ⏭
            </button>
          </div>
        )}
        <button
          type="button"
          className="btn btn--ghost"
          onClick={() => setReduced((r) => !r)}
          aria-label={reduced ? t`Expand player` : t`Collapse player`}
        >
          {reduced ? "▲" : "▼"}
        </button>
        <button
          type="button"
          className="btn btn--ghost"
          onClick={stop}
          aria-label={t`Close player`}
        >
          ✕
        </button>
      </div>
      <div className="global-player-body">
        {current.kind === "embed"
          ? (
            <div className="global-player-iframe-wrap">
              <iframe
                src={playbackUrl(current, autoplay)}
                className={`global-player-iframe--${current.type}`}
                allow="autoplay; encrypted-media"
                allowFullScreen
              />
            </div>
          )
          : current.kind === "file"
          ? (
            <div className="global-player-media-wrap">
              <MediaPlayer
                key={current.fileUrl}
                src={current.fileUrl}
                kind={current.mimeType.startsWith("video/") ? "video" : "audio"}
                mime={current.mimeType}
                autoplay={autoplay}
                startTime={startTime}
                onPlayStateChange={onPlayStateChange}
                onTimeUpdate={onTimeUpdate}
                onEnded={onEnded}
                seekRef={seekRef}
                toggleRef={toggleRef}
              />
            </div>
          )
          : (
            <div className="global-player-media-wrap">
              <MediaPlayer
                // Keyed on the signed URL so a re-resolve remounts the element
                // and MediaPlayer's mount-only startTime effect resumes it.
                key={current.streamUrl}
                src={current.streamUrl}
                kind="audio"
                mime="audio/mpeg"
                trackStyle="progress"
                autoplay={autoplay}
                startTime={startTime}
                onPlayStateChange={onPlayStateChange}
                onTimeUpdate={onTimeUpdate}
                onEnded={onEnded}
                onError={onError}
                seekRef={seekRef}
                toggleRef={toggleRef}
              />
              {resolving && (
                <p className="global-player-status">
                  <Trans>Refreshing stream…</Trans>
                </p>
              )}
            </div>
          )}

        {showQueue && !reduced && (
          <ol className="global-player-tracks">
            {queue.map((item, i) => {
              const isCurrent = i === queueIndex;
              const num = item.kind === "stream" ? item.trackNum : undefined;
              const dur = item.kind === "stream" ? item.duration : undefined;
              return (
                <li
                  key={playerItemKey(item)}
                  ref={isCurrent ? currentRowRef : undefined}
                  className={`global-player-track${
                    isCurrent ? " is-current" : ""
                  }`}
                >
                  <button type="button" onClick={() => playAt(i)}>
                    <span className="global-player-track-num">
                      {num ?? i + 1}
                    </span>
                    <span className="global-player-track-title">
                      {item.title}
                    </span>
                    {dur !== undefined && (
                      <span className="global-player-track-dur">
                        {fmt(dur)}
                      </span>
                    )}
                  </button>
                </li>
              );
            })}
          </ol>
        )}
      </div>
    </div>
  );
}