/* =============================================
   Skiply.ai — Connected Systems section
   Scan-the-shoe → distribute-to-tree motion sequence
   ============================================= */

'use strict';

document.addEventListener('DOMContentLoaded', () => {
  const section = document.getElementById('connected-systems');
  const shoeStage = document.getElementById('shoeStage');
  const horizon = document.getElementById('scanHorizon');
  const flowLine = document.querySelector('.connected__flow-line');
  const flowDot = document.querySelector('.connected__flow-dot');
  const mesh = document.getElementById('shoeMesh');
  const meshClip = document.getElementById('meshClip');
  const particlesHost = document.getElementById('scanParticles');
  const labels = Array.from(document.querySelectorAll('.scan-label'));
  const treeSvg = document.getElementById('treeSvg');
  const branchGroups = Array.from(document.querySelectorAll('.connected__branch-group'));
  const nodes = Array.from(document.querySelectorAll('.connected__node'));
  const routes = Array.from(document.querySelectorAll('.route'));

  if (!section || !shoeStage || typeof gsap === 'undefined') return;

  const reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  /* ── Build scan particles ───────────────────── */
  const PARTICLE_COUNT = 14;
  const particles = [];
  for (let i = 0; i < PARTICLE_COUNT; i++) {
    const p = document.createElement('span');
    p.className = 'scan-particle';
    const left = 8 + Math.random() * 84;
    const top = 6 + Math.random() * 88;
    const size = 2 + Math.random() * 3;
    p.style.left = left + '%';
    p.style.top = top + '%';
    p.style.width = size + 'px';
    p.style.height = size + 'px';
    particlesHost.appendChild(p);
    particles.push({ el: p, left });
  }

  /* ── Ambient dust: persistent, independent of the scroll timeline ── */
  const ambientHost = document.getElementById('ambientParticles');
  const AMBIENT_COUNT = 22;
  for (let i = 0; i < AMBIENT_COUNT; i++) {
    const p = document.createElement('span');
    p.className = 'ambient-particle';
    const size = 1.5 + Math.random() * 2;
    p.style.left = Math.random() * 100 + '%';
    p.style.top = Math.random() * 100 + '%';
    p.style.width = size + 'px';
    p.style.height = size + 'px';
    p.style.setProperty('--dur', (2.5 + Math.random() * 3).toFixed(2) + 's');
    p.style.setProperty('--delay', (Math.random() * 4).toFixed(2) + 's');
    p.style.setProperty('--dx', (Math.random() * 20 - 10).toFixed(1) + 'px');
    p.style.setProperty('--dy', (-6 - Math.random() * 16).toFixed(1) + 'px');
    ambientHost.appendChild(p);
  }

  if (reduceMotion) {
    gsap.set(shoeStage, { opacity: 1 });
    gsap.set(mesh, { opacity: 0.75 });
    gsap.set(meshClip, { '--reveal': '115%' });
    gsap.set(labels, { opacity: 1, y: 0, scale: 1 });
    gsap.set(particles.map((p) => p.el), { opacity: 0.6 });
    gsap.set(horizon, { opacity: 0.85, scaleX: 1 });
    gsap.set(flowLine, { opacity: 0.7, scaleY: 1 });
    gsap.set(treeSvg, { opacity: 1 });
    gsap.set(branchGroups, { clipPath: 'inset(0% 0% 0% 0%)' });
    gsap.set(nodes, { opacity: 1, scale: 1 });
    routes.forEach((el) => el.classList.add('is-lit'));
    return;
  }

  gsap.set(shoeStage, { opacity: 0 });
  gsap.set(labels, { opacity: 0, y: 10, scale: 0.9, transformOrigin: '50% 50%' });

  function playIntro() {
    const tl = gsap.timeline({ defaults: { ease: 'power2.out' } });

    // 1. Stage fades up, ambient glow already pulsing via CSS
    tl.to(shoeStage, { opacity: 1, duration: 0.5 }, 0);

    // 2. The horizon line is the whole scan effect: it lights up and
    //    grows outward from center, passing through the shoe and
    //    extending past its silhouette on both sides. The wireframe
    //    mesh reveals in step with it.
    tl.to(horizon, { opacity: 0.85, duration: 0.2 }, 0.3)
      .to(horizon, { scaleX: 1, duration: 0.6, ease: 'power2.out' }, 0.3)
      .to(mesh, { opacity: 0.75, duration: 0.2 }, 0.3)
      .to(meshClip, { '--reveal': '115%', duration: 0.6, ease: 'power2.out' }, 0.3);

    // 3. Particles twinkle in across the same window the horizon grows
    particles.forEach(({ el, left }) => {
      const t = 0.3 + (left / 100) * 0.6;
      tl.to(el, { opacity: 1, duration: 0.25 }, t)
        .to(el, { opacity: 0.45, y: -4, duration: 0.5 }, t + 0.25);
    });

    // 4. Annotation labels appear one at a time, each a distinct beat
    labels.forEach((label, i) => {
      tl.to(label, { opacity: 1, y: 0, scale: 1, duration: 0.4, ease: 'back.out(1.7)' }, 0.45 + i * 0.32);
    });

    // 5. The horizon line hands off into a connector that carries the
    //    light down from the shoe stage into the tree's attachment point.
    tl.to(flowLine, { opacity: 0.7, scaleY: 1, duration: 0.4, ease: 'power1.out' }, 1.1)
      .fromTo(flowDot, { opacity: 0, top: '0%' }, { opacity: 1, top: '100%', duration: 0.4, ease: 'power1.in' }, 1.1)
      .to(flowDot, { opacity: 0, duration: 0.15 }, 1.5);

    // 6. The tree becomes visible, then each branch draws itself in
    //    center-out: the middle line first, then the two adjacent, then
    //    the two outer ones — each followed by its node flashing and
    //    its pill lighting up as the light "arrives".
    const centerIndex = Math.floor(branchGroups.length / 2);
    const STEP = 0.22;
    const BRANCH_DUR = 0.9;

    tl.addLabel('branches', 1.5)
      .to(treeSvg, { opacity: 1, duration: 0.3 }, 'branches');

    branchGroups.forEach((group, i) => {
      const pos = `branches+=${(Math.abs(i - centerIndex) * STEP).toFixed(2)}`;
      tl.fromTo(group,
        { clipPath: 'inset(0% 0% 100% 0%)' },
        { clipPath: 'inset(0% 0% 0% 0%)', duration: BRANCH_DUR, ease: 'power2.out' },
        pos
      );
      // Opacity reveal is permanent; the scale punch alone yoyos back down.
      tl.to(nodes[i], { opacity: 1, duration: 0.15 }, `${pos}+=${BRANCH_DUR - 0.15}`);
      tl.fromTo(nodes[i],
        { scale: 1 },
        { scale: 1.5, duration: 0.18, yoyo: true, repeat: 1, ease: 'power2.out' },
        `${pos}+=${BRANCH_DUR - 0.15}`
      );
      tl.call(() => routes[i].classList.add('is-lit'), null, `${pos}+=${(BRANCH_DUR - 0.05).toFixed(2)}`);
    });

    return tl;
  }

  if (typeof ScrollTrigger !== 'undefined') {
    gsap.registerPlugin(ScrollTrigger);
    ScrollTrigger.create({
      trigger: section,
      start: 'top 70%',
      once: true,
      onEnter: playIntro,
    });
  } else {
    playIntro();
  }
});