"use client";

import { useEffect, useRef, useState } from "react";
import type HlsType from "hls.js";
import type { Ny511Camera } from "@/lib/types";

// 511NY stills are served with max-age=60, so refreshing faster buys nothing.
const SNAPSHOT_REFRESH_MS = 60_000;
// A failed stream is not given up on for good: 511NY feeds drop out briefly,
// and a permanent fallback left pinned tiles showing a stale still image.
const VIDEO_RETRY_MS = 30_000;
// In-place recoveries hls.js gets per session before we fall back to the snapshot.
const MAX_HLS_RECOVERIES = 3;

/**
 * One 511NY camera: the live HLS stream when the camera has one (NYSDOT's
 * skyvdn hosts send Access-Control-Allow-Origin: *), otherwise its snapshot on
 * a timer. A stream that fails falls back to the snapshot rather than a black box,
 * and video is retried every VIDEO_RETRY_MS while it stays down.
 */
export function CameraFeed({ camera, className }: { camera: Ny511Camera; className?: string }) {
  const videoRef = useRef<HTMLVideoElement>(null);
  const [videoFailed, setVideoFailed] = useState(false);
  const [tick, setTick] = useState(() => Date.now());
  const useVideo = !!camera.video_url && !videoFailed;

  useEffect(() => {
    if (useVideo) return;
    const id = setInterval(() => setTick(Date.now()), SNAPSHOT_REFRESH_MS);
    return () => clearInterval(id);
  }, [useVideo]);

  useEffect(() => {
    if (!videoFailed || !camera.video_url) return;
    const id = setTimeout(() => setVideoFailed(false), VIDEO_RETRY_MS);
    return () => clearTimeout(id);
  }, [videoFailed, camera.video_url]);

  useEffect(() => {
    const video = videoRef.current;
    const src = camera.video_url;
    if (!useVideo || !video || !src) return;
    let hls: HlsType | null = null;
    let cancelled = false;

    if (video.canPlayType("application/vnd.apple.mpegurl")) {
      video.src = src;   // Safari/iOS play HLS natively
    } else {
      import("hls.js")
        .then(({ default: Hls }) => {
          if (cancelled) return;
          if (!Hls.isSupported()) { setVideoFailed(true); return; }
          hls = new Hls({ maxBufferLength: 10, backBufferLength: 0 });
          let recoveries = 0;
          hls.on(Hls.Events.ERROR, (_evt, data) => {
            if (!data.fatal || !hls) return;
            if (recoveries++ < MAX_HLS_RECOVERIES) {
              if (data.type === Hls.ErrorTypes.MEDIA_ERROR) { hls.recoverMediaError(); return; }
              if (data.type === Hls.ErrorTypes.NETWORK_ERROR) { hls.startLoad(); return; }
            }
            setVideoFailed(true);
          });
          hls.loadSource(src);
          hls.attachMedia(video);
        })
        .catch(() => setVideoFailed(true));
    }
    return () => {
      cancelled = true;
      hls?.destroy();
      video.removeAttribute("src");
      video.load();   // stop the download, not just the playback
    };
  }, [useVideo, camera.video_url]);

  if (useVideo) {
    return <video ref={videoRef} muted autoPlay playsInline className={className} onError={() => setVideoFailed(true)} />;
  }
  if (!camera.image_url) {
    return <div className={`${className ?? ""} flex items-center justify-center text-[10px] text-ink-muted`}>No image</div>;
  }
  // eslint-disable-next-line @next/next/no-img-element
  return <img src={`${camera.image_url}?t=${tick}`} alt={`Camera: ${camera.name}`} className={className} />;
}