"use client";

import { useEffect, useRef } from "react";

/**
 * Lightweight scroll reveal via IntersectionObserver (no GSAP dependency
 * so it works even before the smooth-scroll module mounts). Adds .is-in.
 * CSS already shows content under reduced motion.
 */
export default function Reveal({
  children,
  as: Tag = "div",
  className = "",
  delay = 0,
}: {
  children: React.ReactNode;
  as?: keyof React.JSX.IntrinsicElements;
  className?: string;
  delay?: number;
}) {
  const ref = useRef<HTMLElement>(null);

  useEffect(() => {
    const el = ref.current;
    if (!el) return;
    const io = new IntersectionObserver(
      ([e]) => {
        if (e.isIntersecting) {
          el.classList.add("is-in");
          io.disconnect();
        }
      },
      { threshold: 0.15, rootMargin: "0px 0px -8% 0px" }
    );
    io.observe(el);
    return () => io.disconnect();
  }, []);

  const Comp = Tag as React.ElementType;
  return (
    <Comp
      ref={ref}
      className={`reveal ${className}`}
      style={{ transitionDelay: `${delay}ms` }}
    >
      {children}
    </Comp>
  );
}