/* ==========================================================================
   Olzinger – Hauptskript
   Navigation, mobiles Menü, dezente Einblendungen, Leistungs-Karussell (mobil)
   und Kartenstapel (Desktop). Bewusst ohne Bibliotheken.
   ========================================================================== */
(function (w, d) {
  'use strict';

  var html = d.documentElement;
  var $ = function (s, c) { return (c || d).querySelector(s); };
  var $$ = function (s, c) { return Array.prototype.slice.call((c || d).querySelectorAll(s)); };

  var reduce = w.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var hasIO = 'IntersectionObserver' in w;
  w.__olzReady = true;

  /* ---------- Dynamische Jahreszahlen ---------- */
  var nowYear = new Date().getFullYear();
  $$('[data-current-year]').forEach(function (el) { el.textContent = nowYear; });
  $$('[data-years]').forEach(function (el) { el.textContent = nowYear - 1985; });

  /* ---------- Wärmebild (ruhiger Hintergrund im Hero) ---------- */
  var canvas = $('[data-thermal]');
  if (canvas && w.OlzThermal) {
    var thermal = w.OlzThermal.init(canvas, {
      hero: $('[data-hero]'),
      calm: $('.hero__aside'),
      reduceMotion: reduce
    });
    if (thermal) thermal.heatUp();
  } else if (canvas) {
    html.classList.add('no-webgl');
  }

  /* ---------- Mobiles Menü ---------- */
  var menu = $('[data-menu]');
  var toggle = $('[data-menu-toggle]');
  var menuOpen = false;

  if (menu) { menu.hidden = false; menu.setAttribute('inert', ''); menu.setAttribute('aria-hidden', 'true'); }

  function setMenu(open) {
    if (!menu || !toggle || open === menuOpen) return;
    menuOpen = open;
    menu.classList.toggle('is-open', open);
    if (open) menu.removeAttribute('inert'); else menu.setAttribute('inert', '');
    menu.setAttribute('aria-hidden', open ? 'false' : 'true');
    toggle.setAttribute('aria-expanded', open ? 'true' : 'false');
    toggle.querySelector('.sr-only').textContent = open ? 'Menü schließen' : 'Menü öffnen';
    html.classList.toggle('menu-open', open);
    // Inhalt hinter dem Menü für Tastatur und Screenreader sperren
    [d.getElementById('main'), $('.footer')].forEach(function (el) { if (el) el.inert = open; });
  }
  if (toggle) toggle.addEventListener('click', function () { setMenu(!menuOpen); });
  d.addEventListener('keydown', function (e) {
    if (e.key === 'Escape' && menuOpen) { setMenu(false); toggle.focus(); }
  });
  // Wird das Fenster breit genug für die Desktop-Navigation (z. B. Tablet drehen), Menü schließen
  var deskMQ = w.matchMedia('(min-width: 1181px)');
  var onDesk = function (e) { if (e.matches) setMenu(false); };
  if (deskMQ.addEventListener) deskMQ.addEventListener('change', onDesk); else if (deskMQ.addListener) deskMQ.addListener(onDesk);

  /* ---------- Anker-Links: Menü schließen, Thema ans Formular geben ---------- */
  d.addEventListener('click', function (e) {
    var a = e.target.closest('a[href*="#"]');
    if (!a) return;
    if (a.dataset.topic) w.dispatchEvent(new CustomEvent('olz:topic', { detail: a.dataset.topic }));
    if (menuOpen) setMenu(false);
  });

  /* ---------- Navigation: Hintergrund ab Scroll, beim Runterscrollen ausblenden ---------- */
  var nav = $('[data-nav]');
  if (nav) {
    var lastY = w.scrollY, ticking = false;
    var onScroll = function () {
      ticking = false;
      var y = w.scrollY;
      nav.classList.toggle('is-scrolled', y > 40);
      if (!menuOpen) {
        if (y > 420 && y > lastY + 4) nav.classList.add('is-hidden');
        else if (y < lastY - 4 || y <= 420) nav.classList.remove('is-hidden');
      }
      lastY = y;
    };
    w.addEventListener('scroll', function () {
      if (!ticking) { ticking = true; w.requestAnimationFrame(onScroll); }
    }, { passive: true });
    nav.addEventListener('focusin', function () { nav.classList.remove('is-hidden'); });
    onScroll();
  }

  // Aktiven Menüpunkt markieren
  var navLinks = $$('[data-nav-link]');
  if (hasIO && navLinks.length) {
    var linkFor = {};
    navLinks.forEach(function (l) { linkFor[l.getAttribute('href').slice(1)] = l; });
    var activeIO = new IntersectionObserver(function (entries) {
      entries.forEach(function (en) {
        var link = linkFor[en.target.id];
        if (link) link.classList.toggle('is-active', en.isIntersecting);
      });
    }, { rootMargin: '-45% 0px -54% 0px' });
    Object.keys(linkFor).forEach(function (id) {
      var sec = d.getElementById(id);
      if (sec) activeIO.observe(sec);
    });
  }

  /* ---------- Dezente Einblendungen ---------- */
  var reveals = $$('[data-reveal]');
  if (hasIO && !reduce) {
    var revealIO = new IntersectionObserver(function (entries) {
      entries.forEach(function (en) {
        if (!en.isIntersecting) return;
        en.target.classList.add('is-in');
        revealIO.unobserve(en.target);
      });
    }, { rootMargin: '0px 0px -8% 0px' });
    reveals.forEach(function (el) { revealIO.observe(el); });
  } else {
    reveals.forEach(function (el) { el.classList.add('is-in'); });
  }

  /* ---------- Leistungen: Karussell (mobil) bzw. Kartenstapel (Desktop) ---------- */
  var stack = $('[data-stack]');
  var cards = $$('.svc');
  var stackNav = $('[data-stack-nav]');
  var stackMQ = w.matchMedia('(min-width: 900px) and (min-height: 660px)');

  if (stack && stackNav) {
    var prevBtn = $('[data-stack-prev]', stackNav);
    var nextBtn = $('[data-stack-next]', stackNav);
    var currentEl = $('[data-stack-current]', stackNav);
    var current = 0;

    var isCarousel = function () { return stack.scrollWidth > stack.clientWidth + 2; };
    var cardLeft = function (c) { return c.offsetLeft - cards[0].offsetLeft; };
    var cardIndex = function () {
      var x = stack.scrollLeft, best = 0, bestDist = Infinity;
      if (x >= stack.scrollWidth - stack.clientWidth - 2) return cards.length - 1;
      cards.forEach(function (c, i) {
        var dist = Math.abs(cardLeft(c) - x);
        if (dist < bestDist) { bestDist = dist; best = i; }
      });
      return best;
    };
    var updateNav = function () {
      stackNav.hidden = !isCarousel();
      current = cardIndex();
      currentEl.textContent = current + 1;
      prevBtn.disabled = current === 0;
      nextBtn.disabled = current === cards.length - 1;
    };
    // Schritt relativ zur echten Scrollposition (bei zwei Karten nebeneinander
    // liegen die letzten Karten jenseits der maximalen Scrollweite)
    var step = function (dir) {
      var x = stack.scrollLeft, i;
      if (dir > 0) { for (i = 0; i < cards.length - 1; i++) if (cardLeft(cards[i]) > x + 2) break; }
      else { for (i = cards.length - 1; i > 0; i--) if (cardLeft(cards[i]) < x - 2) break; }
      stack.scrollTo({ left: Math.min(cardLeft(cards[i]), stack.scrollWidth - stack.clientWidth), behavior: reduce ? 'auto' : 'smooth' });
    };

    var navTick = false;
    stack.addEventListener('scroll', function () {
      if (!navTick) { navTick = true; w.requestAnimationFrame(function () { navTick = false; updateNav(); }); }
    }, { passive: true });
    prevBtn.addEventListener('click', function () { step(-1); });
    nextBtn.addEventListener('click', function () { step(1); });
    w.addEventListener('resize', updateNav);
    updateNav();
  }

  // Desktop: hintere Karten treten beim Überdecken leicht zurück
  if (stack && !reduce) {
    var inners = cards.map(function (c) { return $('.svc__inner', c); });
    var stackTick = false;
    var paintStack = function () {
      stackTick = false;
      if (!stackMQ.matches) {
        inners.forEach(function (el) { el.style.transform = ''; el.style.removeProperty('--shade'); });
        return;
      }
      var vh = w.innerHeight;
      cards.forEach(function (card, i) {
        var next = cards[i + 1];
        if (!next) return;
        var stickyTop = parseFloat(getComputedStyle(next).top) || 100;
        var start = vh * 0.85;
        var p = (start - next.getBoundingClientRect().top) / (start - stickyTop);
        p = Math.max(0, Math.min(1, p));
        inners[i].style.transform = p ? 'scale(' + (1 - p * (0.1 - i * 0.012)) + ')' : '';
        inners[i].style.setProperty('--shade', (p * 0.5).toFixed(3));
      });
    };
    var requestPaint = function () {
      if (!stackTick) { stackTick = true; w.requestAnimationFrame(paintStack); }
    };
    w.addEventListener('scroll', requestPaint, { passive: true });
    w.addEventListener('resize', requestPaint);
    paintStack();
  }
})(window, document);