import { useEffect, useRef, useState } from 'react';
import { useTranslation } from 'react-i18next';
import { VideoOff, WifiOff } from 'lucide-react';
import { getAuthToken, withStreamToken } from '../api/client';

export type CameraTileMode = 'live' | 'snapshot' | 'paused';

interface CameraTileProps {
  printerId: number;
  printerName: string;
  cameraRotation?: number;
  mode: CameraTileMode;
  snapshotIntervalMs: number;
  connected: boolean;
  onClick?: () => void;
}

// Tiles render lighter than EmbeddedCameraViewer's full window: lower fps,
// no drag/resize/zoom shell, and snapshot fallback when off-cap. The server
// still does the MJPEG fan-out, so per-tile cost is one TLS pull on the wire.
const LIVE_FPS = 8;

export function CameraTile({
  printerId,
  printerName,
  cameraRotation = 0,
  mode,
  snapshotIntervalMs,
  connected,
  onClick,
}: CameraTileProps) {
  const { t } = useTranslation();
  const [bust, setBust] = useState(0);
  const [errored, setErrored] = useState(false);
  const lastModeRef = useRef<CameraTileMode>(mode);

  // Tell the backend to release its MJPEG transcoder when this tile stops
  // being live — either by unmounting or by transitioning to snapshot/paused.
  // EmbeddedCameraViewer uses the same /camera/stop with keepalive on unmount.
  useEffect(() => {
    const wasLive = lastModeRef.current === 'live';
    const isLive = mode === 'live';
    lastModeRef.current = mode;
    if (wasLive && !isLive) {
      const headers: Record<string, string> = {};
      const token = getAuthToken();
      if (token) headers['Authorization'] = `Bearer ${token}`;
      fetch(`/api/v1/printers/${printerId}/camera/stop`, {
        method: 'POST',
        keepalive: true,
        headers,
      }).catch(() => {});
    }
    setErrored(false);
    setBust((b) => b + 1);
  }, [mode, printerId]);

  useEffect(() => {
    return () => {
      if (lastModeRef.current === 'live') {
        const headers: Record<string, string> = {};
        const token = getAuthToken();
        if (token) headers['Authorization'] = `Bearer ${token}`;
        fetch(`/api/v1/printers/${printerId}/camera/stop`, {
          method: 'POST',
          keepalive: true,
          headers,
        }).catch(() => {});
      }
    };
  }, [printerId]);

  useEffect(() => {
    if (mode !== 'snapshot') return;
    const interval = setInterval(() => setBust((b) => b + 1), snapshotIntervalMs);
    return () => clearInterval(interval);
  }, [mode, snapshotIntervalMs]);

  const liveUrl = withStreamToken(
    `/api/v1/printers/${printerId}/camera/stream?fps=${LIVE_FPS}&t=${bust}`,
  );
  const snapshotUrl = withStreamToken(
    `/api/v1/printers/${printerId}/camera/snapshot?t=${bust}`,
  );

  const handleClick = () => {
    if (onClick) onClick();
  };

  const transform = cameraRotation ? `rotate(${cameraRotation}deg)` : undefined;

  return (
    <button
      type="button"
      onClick={handleClick}
      className="group relative aspect-video w-full overflow-hidden rounded-lg border border-bambu-dark-tertiary bg-black text-left focus:outline-none focus:ring-2 focus:ring-bambu-green"
      title={printerName}
    >
      {!connected || mode === 'paused' ? (
        <div className="absolute inset-0 flex items-center justify-center bg-bambu-dark/60">
          {connected ? (
            <VideoOff className="h-8 w-8 text-bambu-gray/70" aria-hidden="true" />
          ) : (
            <WifiOff className="h-8 w-8 text-bambu-gray/70" aria-hidden="true" />
          )}
        </div>
      ) : errored ? (
        <div className="absolute inset-0 flex flex-col items-center justify-center gap-1 bg-black/80 text-bambu-gray">
          <VideoOff className="h-7 w-7" aria-hidden="true" />
          <span className="text-xs">{t('printers.camWall.noSignal')}</span>
        </div>
      ) : (
        <img
          key={`${mode}-${bust}`}
          src={mode === 'live' ? liveUrl : snapshotUrl}
          alt={printerName}
          draggable={false}
          loading="lazy"
          className="h-full w-full select-none object-contain"
          style={{ transform }}
          onError={() => setErrored(true)}
        />
      )}

      {/* Mode indicator */}
      <span
        className={`absolute right-2 top-2 rounded px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide ${
          mode === 'live'
            ? 'bg-red-500/80 text-white'
            : mode === 'snapshot'
              ? 'bg-amber-500/70 text-black'
              : 'bg-bambu-dark-tertiary/70 text-bambu-gray'
        }`}
      >
        {mode === 'live'
          ? t('printers.camWall.live')
          : mode === 'snapshot'
            ? t('printers.camWall.snap')
            : t('printers.camWall.off')}
      </span>

      {/* Name overlay */}
      <span className="absolute inset-x-0 bottom-0 truncate bg-gradient-to-t from-black/80 to-transparent px-2 pb-1.5 pt-3 text-xs font-medium text-white">
        {printerName}
      </span>
    </button>
  );
}