"use client";

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

interface FadeInProps {
  children: ReactNode;
  delay?: number;
  className?: string;
}

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

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

    const obs = new IntersectionObserver(
      ([entry]) => {
        if (entry.isIntersecting) {
          setVisible(true);
          obs.unobserve(el);
        }
      },
      { threshold: 0.15 }
    );

    obs.observe(el);
    return () => obs.disconnect();
  }, []);

  return (
    <div
      ref={ref}
      className={className}
      style={{
        opacity: visible ? 1 : 0,
        transform: visible ? "translateY(0)" : "translateY(28px)",
        transition: `opacity 0.7s ease ${delay}s, transform 0.7s ease ${delay}s`,
      }}
    >
      {children}
    </div>
  );
}