import { useContext, useEffect, useRef, useState } from "react";
import { PlayerContext } from "../contexts/PlayerContext.ts";
import { MediaPlayer } from "./MediaPlayer.tsx";

function itemKey(
  item: { kind: string; embedUrl?: string; fileUrl?: string } | null,
) {
  if (!item) return null;
  return item.kind === "embed" ? item.embedUrl : item.fileUrl;
}

export function GlobalPlayer() {
  const {
    current,
    startTime,
    autoplay,
    stop,
    seekRef,
    toggleRef,
    onPlayStateChange,
    onTimeUpdate,
  } = useContext(PlayerContext);
  const ref = useRef<HTMLDivElement>(null);
  const [reduced, setReduced] = useState(false);
  const [prevKey, setPrevKey] = useState(itemKey(current));

  if (prevKey !== itemKey(current)) {
    setPrevKey(itemKey(current));
    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]);

  if (!current) return null;

  const typeClass = current.kind === "embed"
    ? current.type
    : current.mimeType.startsWith("video/")
    ? "file-video"
    : "file-audio";

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

  return (
    <div
      className={`global-player global-player--${typeClass}${
        reduced ? " global-player--reduced" : ""
      }`}
      ref={ref}
    >
      <div className="global-player-header">
        <span className="global-player-title">{title}</span>
        <button
          type="button"
          className="btn btn--ghost"
          onClick={() => setReduced((r) => !r)}
        >
          {reduced ? "▲" : "▼"}
        </button>
        <button type="button" className="btn btn--ghost" onClick={stop}>
          ✕
        </button>
      </div>
      <div className="global-player-body">
        {current.kind === "embed"
          ? (
            <div className="global-player-iframe-wrap">
              <iframe
                src={current.embedUrl}
                className={`global-player-iframe--${current.type}`}
                allow="autoplay; encrypted-media"
                allowFullScreen
              />
            </div>
          )
          : (
            <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}
                seekRef={seekRef}
                toggleRef={toggleRef}
              />
            </div>
          )}
      </div>
    </div>
  );
}