"use client";

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

// Blendet Inhalte sanft ein, sobald sie ins Bild scrollen. Feuert nur einmal
// pro Element (kein wiederholtes Ein-/Ausblenden beim Hoch-/Runterscrollen).
export function ScrollReveal({
  children,
  className = "",
  delayMs = 0,
}: {
  children: React.ReactNode;
  className?: string;
  delayMs?: number;
}) {
  const ref = useRef<HTMLDivElement>(null);
  const [visible, setVisible] = useState(false);

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

    const observer = new IntersectionObserver(
      ([entry]) => {
        if (entry.isIntersecting) {
          window.setTimeout(() => setVisible(true), delayMs);
          observer.disconnect();
        }
      },
      { threshold: 0.15 }
    );

    observer.observe(node);
    return () => observer.disconnect();
  }, [delayMs]);

  return (
    <div ref={ref} className={`rk-reveal ${className}`} data-visible={visible}>
      {children}
    </div>
  );
}