"use client";

import { useEffect, useRef, useState, type ReactNode } from "react";

type RevealProps = {
  children: ReactNode;
  className?: string;
  /** Stagger delay in ms once visible */
  delay?: number;
  /** Optional custom y offset in px */
  offset?: number;
};

export default function Reveal({
  children,
  className = "",
  delay = 0,
  offset = 36,
}: RevealProps) {
  const ref = useRef<HTMLDivElement>(null);
  const [visible, setVisible] = useState(false);

  useEffect(() => {
    const el = ref.current;
    if (!el) return;

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    if (reduce) {
      setVisible(true);
      return;
    }

    const io = new IntersectionObserver(
      ([entry]) => {
        if (entry.isIntersecting) {
          setVisible(true);
          io.disconnect();
        }
      },
      { threshold: 0.12, rootMargin: "0px 0px -6% 0px" },
    );
    io.observe(el);
    return () => io.disconnect();
  }, []);

  return (
    <div
      ref={ref}
      className={className}
      style={{
        opacity: visible ? 1 : 0,
        transform: visible ? "translate3d(0,0,0)" : `translate3d(0,${offset}px,0)`,
        filter: visible ? "blur(0)" : "blur(8px)",
        transition: `opacity 0.9s cubic-bezier(0.16,1,0.3,1) ${delay}ms, transform 0.9s cubic-bezier(0.16,1,0.3,1) ${delay}ms, filter 0.9s cubic-bezier(0.16,1,0.3,1) ${delay}ms`,
        willChange: "opacity, transform, filter",
      }}
    >
      {children}
    </div>
  );
}