// hooks.jsx — shared hooks
const { useEffect, useRef, useState } = React;

function useReveal() {
  useEffect(() => {
    const els = document.querySelectorAll('[data-reveal]');
    const io = new IntersectionObserver((entries) => {
      entries.forEach(e => {
        if (e.isIntersecting) {
          e.target.classList.add('is-in');
          io.unobserve(e.target);
        }
      });
    }, { threshold: 0.12, rootMargin: '0px 0px -8% 0px' });
    els.forEach(el => io.observe(el));
    return () => io.disconnect();
  });
}

function useScrolled(threshold = 20) {
  const [scrolled, setScrolled] = useState(false);
  useEffect(() => {
    const onScroll = () => setScrolled(window.scrollY > threshold);
    onScroll();
    window.addEventListener('scroll', onScroll, { passive: true });
    return () => window.removeEventListener('scroll', onScroll);
  }, [threshold]);
  return scrolled;
}

// magnet hover for buttons
function useMagnet(strength = 0.25) {
  const ref = useRef(null);
  useEffect(() => {
    const el = ref.current;
    if (!el) return;
    const onMove = (e) => {
      const r = el.getBoundingClientRect();
      const x = e.clientX - (r.left + r.width / 2);
      const y = e.clientY - (r.top + r.height / 2);
      el.style.transform = `translate(${x*strength}px, ${y*strength}px)`;
    };
    const onLeave = () => { el.style.transform = ''; };
    el.addEventListener('mousemove', onMove);
    el.addEventListener('mouseleave', onLeave);
    return () => {
      el.removeEventListener('mousemove', onMove);
      el.removeEventListener('mouseleave', onLeave);
    };
  }, [strength]);
  return ref;
}

Object.assign(window, { useReveal, useScrolled, useMagnet });