'use client';

import { useEffect, useRef, useState } from 'react';

type Props = {
  color?: string;
  size?: number;
  className?: string;
};

export function CursorSpotlight({ color = 'rgba(94, 94, 94, 0.18)', size = 520, className = '' }: Props) {
  const ref = useRef<HTMLDivElement | null>(null);
  const [pos, setPos] = useState<{ x: number; y: number } | null>(null);
  const [enabled, setEnabled] = useState(false);

  useEffect(() => {
    const finePointer = window.matchMedia('(pointer: fine)').matches;
    const reduced = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
    if (!finePointer || reduced) return;
    setEnabled(true);

    const el = ref.current?.parentElement;
    if (!el) return;
    let raf = 0;
    const onMove = (e: MouseEvent) => {
      const rect = el.getBoundingClientRect();
      const x = e.clientX - rect.left;
      const y = e.clientY - rect.top;
      cancelAnimationFrame(raf);
      raf = requestAnimationFrame(() => setPos({ x, y }));
    };
    const onLeave = () => setPos(null);
    el.addEventListener('mousemove', onMove);
    el.addEventListener('mouseleave', onLeave);
    return () => {
      el.removeEventListener('mousemove', onMove);
      el.removeEventListener('mouseleave', onLeave);
      cancelAnimationFrame(raf);
    };
  }, []);

  if (!enabled) return null;

  return (
    <div
      ref={ref}
      aria-hidden
      className={className}
      style={{
        position: 'absolute',
        inset: 0,
        pointerEvents: 'none',
        opacity: pos ? 1 : 0,
        transition: 'opacity 0.4s ease',
        background: pos
          ? `radial-gradient(${size}px ${size}px at ${pos.x}px ${pos.y}px, ${color}, transparent 70%)`
          : 'transparent',
        zIndex: 1,
      }}
    />
  );
}