"use client";

import { useEffect, useRef } from "react";

export default function FilmGrain() {
  const canvasRef = useRef<HTMLCanvasElement>(null);

  useEffect(() => {
    const canvas = canvasRef.current;
    if (!canvas) return;

    const ctx = canvas.getContext("2d");
    if (!ctx) return;

    let animId: number;
    let lastFrame = 0;
    const fps = 24; // Cinematic film fps
    const frameInterval = 1000 / fps;

    const resize = () => {
      canvas.width = window.innerWidth / 2;
      canvas.height = window.innerHeight / 2;
    };
    resize();
    window.addEventListener("resize", resize);

    const render = (timestamp: number) => {
      animId = requestAnimationFrame(render);

      const delta = timestamp - lastFrame;
      if (delta < frameInterval) return;
      lastFrame = timestamp - (delta % frameInterval);

      const { width, height } = canvas;
      const imageData = ctx.createImageData(width, height);
      const data = imageData.data;

      for (let i = 0; i < data.length; i += 4) {
        const noise = Math.random() * 20;
        data[i] = noise;
        data[i + 1] = noise;
        data[i + 2] = noise;
        data[i + 3] = 12; // Very subtle
      }

      ctx.putImageData(imageData, 0, 0);
    };

    animId = requestAnimationFrame(render);

    return () => {
      cancelAnimationFrame(animId);
      window.removeEventListener("resize", resize);
    };
  }, []);

  return (
    <canvas
      ref={canvasRef}
      className="pointer-events-none fixed inset-0 z-[9990] h-full w-full opacity-[0.35] mix-blend-overlay"
      style={{ imageRendering: "pixelated" }}
      aria-hidden="true"
    />
  );
}