"use client";

import { useState, type ReactNode } from "react";
import { motion, useMotionTemplate, useReducedMotion, useSpring } from "motion/react";

type HoverSpotlightProps = {
  /** Stays clickable: the dark layer lets the pointer through. */
  children: ReactNode;
  /** Size of the light in pixels. */
  radius?: number;
  /** Colour of the dark around the light. Match your background. */
  dim?: string;
  className?: string;
};

const FOLLOW = { stiffness: 300, damping: 32 };

/* HoverSpotlight: when the mouse comes in, the block goes dark and only a soft circle around the pointer stays lit. Touch and keyboard see it fully lit. */
export function HoverSpotlight({ children, radius = 140, dim = "rgb(8 7 16 / 0.9)", className = "" }: HoverSpotlightProps) {
  const reduce = useReducedMotion();
  const [on, setOn] = useState(false);
  const x = useSpring(0, FOLLOW);
  const y = useSpring(0, FOLLOW);
  const size = useSpring(radius * 3, { stiffness: 120, damping: 22 });
  const background = useMotionTemplate`radial-gradient(circle ${size}px at ${x}px ${y}px, transparent 50%, ${dim} 100%)`;

  const onMove = (e: React.PointerEvent<HTMLDivElement>) => {
    if (reduce || e.pointerType === "touch") return;
    const r = e.currentTarget.getBoundingClientRect();
    const px = e.clientX - r.left;
    const py = e.clientY - r.top;
    if (on) {
      x.set(px);
      y.set(py);
    } else {
      x.jump(px);
      y.jump(py);
      size.set(radius);
      setOn(true);
    }
  };

  const onLeave = () => {
    size.set(radius * 3);
    setOn(false);
  };

  return (
    <div onPointerMove={onMove} onPointerLeave={onLeave} className={`relative ${className}`}>
      {children}
      <motion.div
        aria-hidden
        className="pointer-events-none absolute inset-0"
        initial={false}
        animate={{ opacity: on ? 1 : 0 }}
        transition={{ duration: 0.35 }}
        style={{ background }}
      />
    </div>
  );
}