import { useEffect, useRef, useState } from "react";
import { mediaSrc } from "../lib/api";

type Props = {
  videoId: string;
  title: string;
  watchUrl: string;
  poster?: string;
};

declare global {
  interface Window {
    Vimeo?: {
      Player: new (
        el: HTMLIFrameElement | HTMLElement,
        opts?: { id?: string | number; url?: string }
      ) => {
        on: (event: string, cb: (data?: unknown) => void) => void;
        destroy: () => void;
      };
    };
  }
}

let playerSdkPromise: Promise<void> | null = null;

function loadVimeoSdk(): Promise<void> {
  if (window.Vimeo?.Player) return Promise.resolve();
  if (playerSdkPromise) return playerSdkPromise;
  playerSdkPromise = new Promise((resolve, reject) => {
    const existing = document.querySelector<HTMLScriptElement>(
      'script[src="https://player.vimeo.com/api/player.js"]'
    );
    if (existing) {
      existing.addEventListener("load", () => resolve());
      existing.addEventListener("error", () => reject(new Error("Vimeo SDK failed")));
      if (window.Vimeo?.Player) resolve();
      return;
    }
    const s = document.createElement("script");
    s.src = "https://player.vimeo.com/api/player.js";
    s.async = true;
    s.onload = () => resolve();
    s.onerror = () => reject(new Error("Vimeo SDK failed"));
    document.body.appendChild(s);
  });
  return playerSdkPromise;
}

/**
 * Always embeds first. Only if Vimeo reports a privacy/error does the UI
 * fall back to opening the video on vimeo.com (last resort).
 */
export function VimeoEmbed({ videoId, title, watchUrl, poster }: Props) {
  const iframeRef = useRef<HTMLIFrameElement>(null);
  const [blocked, setBlocked] = useState(false);
  const embedSrc = `https://player.vimeo.com/video/${videoId}?title=0&byline=0&portrait=0`;

  useEffect(() => {
    let player: { destroy: () => void } | null = null;
    let cancelled = false;

    setBlocked(false);

    loadVimeoSdk()
      .then(() => {
        if (cancelled || !iframeRef.current || !window.Vimeo?.Player) return;
        player = new window.Vimeo.Player(iframeRef.current);
        player.on("error", (data: unknown) => {
          // Privacy / password / unavailable — leave site only as last resort
          console.warn("Vimeo player error", data);
          if (!cancelled) setBlocked(true);
        });
      })
      .catch(() => {
        // SDK load failure still keep iframe; browser may still play
      });

    return () => {
      cancelled = true;
      try {
        player?.destroy();
      } catch {
        /* ignore */
      }
    };
  }, [videoId]);

  if (blocked) {
    return (
      <a href={watchUrl} target="_blank" rel="noreferrer" className="project-page__video-link">
        {poster ? (
          <img src={mediaSrc(poster)} alt="" className="project-page__video-poster" />
        ) : (
          <div className="project-page__video-poster project-page__video-poster--empty" />
        )}
        <span className="project-page__video-cta">
          <span className="project-page__play" aria-hidden>
            ▶
          </span>
          Watch on Vimeo ↗
          <span className="project-page__video-note">
            This video can’t be embedded here (Vimeo privacy). Opens on Vimeo as a last resort.
          </span>
        </span>
      </a>
    );
  }

  return (
    <iframe
      ref={iframeRef}
      src={embedSrc}
      title={title}
      allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; fullscreen"
      allowFullScreen
      referrerPolicy="strict-origin-when-cross-origin"
    />
  );
}