/* ============================================================
   维特尔液冷 — 页面交互
   滚动显现 · 指标滚动计数 · 导航状态 · 移动端菜单
   ============================================================ */
(function () {
  "use strict";

  var REDUCED = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
  var FINE_POINTER = window.matchMedia("(hover: hover) and (pointer: fine)").matches;
  var MOBILE_HERO = window.matchMedia("(max-width: 768px)").matches;

  /* ---------- 首屏视频:移动端/减少动画模式仅显示静态海报 ---------- */
  var heroMediaVideo = document.getElementById("heroMediaVideo");
  if (heroMediaVideo) {
    if (REDUCED || MOBILE_HERO) {
      heroMediaVideo.pause();
      heroMediaVideo.removeAttribute("autoplay");
    } else {
      var heroVideoSource = heroMediaVideo.querySelector("source[data-src]");
      if (heroVideoSource) {
        heroVideoSource.src = heroVideoSource.dataset.src;
        heroMediaVideo.load();
      }
      var playPromise = heroMediaVideo.play();
      if (playPromise && typeof playPromise.catch === "function") playPromise.catch(function () {});
    }
  }

  /* 截图辅助:?shot=1 时取消首屏满高(仅用于整页验证) */
  if (location.search.indexOf("shot") !== -1) {
    document.documentElement.classList.add("shot");
  }

  /* ---------- 导航滚动状态 ---------- */
  var nav = document.getElementById("nav");
  var backToTop = document.getElementById("backToTop");
  function onScroll() {
    nav.classList.toggle("scrolled", window.scrollY > 24);
    if (backToTop) backToTop.classList.toggle("is-visible", window.scrollY > window.innerHeight * 0.75);
  }
  window.addEventListener("scroll", onScroll, { passive: true });
  onScroll();

  if (backToTop) {
    backToTop.addEventListener("click", function () {
      window.scrollTo({ top: 0, behavior: REDUCED ? "auto" : "smooth" });
      document.querySelector(".brand").focus({ preventScroll: true });
    });
  }

  /* ---------- 当前章节高亮 / URL 锚点 ---------- */
  var sectionIds = ["technology", "solutions", "proof", "partners", "contact"];
  var trackedSections = sectionIds.map(function (id) { return document.getElementById(id); }).filter(Boolean);
  var navAnchors = [].slice.call(document.querySelectorAll('.nav-links a[href^="#"], .nav-mobile a[href^="#"]'));
  function setActiveSection(id) {
    navAnchors.forEach(function (link) {
      var active = link.getAttribute("href") === "#" + id;
      link.classList.toggle("is-active", active);
      if (active) link.setAttribute("aria-current", "location");
      else link.removeAttribute("aria-current");
    });
  }
  if (trackedSections.length) {
    var sectionFrame = 0;
    function updateActiveSection() {
      if (sectionFrame) return;
      sectionFrame = requestAnimationFrame(function () {
        sectionFrame = 0;
        var probe = window.scrollY + Math.max(120, window.innerHeight * 0.25);
        var current = trackedSections[0];
        trackedSections.forEach(function (section) {
          if (section.offsetTop <= probe) current = section;
        });
        setActiveSection(current.id);
      });
    }
    window.addEventListener("scroll", updateActiveSection, { passive: true });
    updateActiveSection();
  }

  /* ---------- 移动端菜单 ---------- */
  var toggle = document.getElementById("navToggle");
  var mobile = document.getElementById("navMobile");
  if (toggle) {
    toggle.addEventListener("click", function () {
      var open = nav.classList.toggle("open");
      toggle.setAttribute("aria-expanded", open ? "true" : "false");
      toggle.setAttribute("aria-label", open ? "关闭菜单" : "打开菜单");
    });
    mobile.querySelectorAll("a").forEach(function (a) {
      a.addEventListener("click", function () {
        nav.classList.remove("open");
        toggle.setAttribute("aria-expanded", "false");
      });
    });
    document.addEventListener("keydown", function (event) {
      if (event.key === "Escape" && nav.classList.contains("open")) {
        nav.classList.remove("open");
        toggle.setAttribute("aria-expanded", "false");
        toggle.setAttribute("aria-label", "打开菜单");
        toggle.focus();
      }
    });
  }

  /* ---------- 产品路径与当前产品 ---------- */
  var capList = document.querySelector(".cap-list");
  var capRows = [].slice.call(document.querySelectorAll(".cap-row"));
  if (capList && capRows.length) {
    if (REDUCED) {
      capList.classList.add("is-traced");
    } else {
      var capListIO = new IntersectionObserver(function (entries) {
        entries.forEach(function (entry) {
          if (entry.isIntersecting) {
            capList.classList.add("is-traced");
            capListIO.disconnect();
          }
        });
      }, { threshold: 0.1 });
      capListIO.observe(capList);

    }
  }

  /* ---------- 滚动显现 ---------- */
  var revealEls = [].slice.call(document.querySelectorAll("[data-reveal]"));
  if (REDUCED) {
    revealEls.forEach(function (el) { el.classList.add("is-visible"); });
  } else {
    var revealIO = new IntersectionObserver(function (entries) {
      entries.forEach(function (en) {
        if (en.isIntersecting) {
          en.target.classList.add("is-visible");
          revealIO.unobserve(en.target);
        }
      });
    }, { threshold: 0.12, rootMargin: "0px 0px -6% 0px" });
    revealEls.forEach(function (el) { revealIO.observe(el); });
  }

  /* ---------- 指标滚动计数 ---------- */
  var counters = [].slice.call(document.querySelectorAll(".count"));
  function animateCount(el) {
    var target = parseFloat(el.dataset.count);
    var decimals = parseInt(el.dataset.decimals || "0", 10);
    if (REDUCED) { el.textContent = target.toFixed(decimals); return; }
    var start = null, dur = 1600;
    function step(ts) {
      if (!start) start = ts;
      var p = Math.min((ts - start) / dur, 1);
      var eased = 1 - Math.pow(1 - p, 4);
      el.textContent = (target * eased).toFixed(decimals);
      if (p < 1) requestAnimationFrame(step);
      else el.textContent = target.toFixed(decimals);
    }
    requestAnimationFrame(step);
  }
  if (REDUCED) {
    /* 降级:不依赖 IO,直接呈现终值 */
    counters.forEach(function (el) {
      animateCount(el);
      var cell = el.closest(".kpi-cell");
      if (cell) cell.classList.add("powered");
    });
  } else {
    var countIO = new IntersectionObserver(function (entries) {
      entries.forEach(function (en) {
        if (en.isIntersecting) {
          var cell = en.target.closest(".kpi-cell");
          /* 仪表上电:先扫描线,数字随后点亮,单位与标签再延迟出现 */
          if (cell) cell.classList.add("powered");
          setTimeout(function () { animateCount(en.target); }, 240);
          countIO.unobserve(en.target);
        }
      });
    }, { threshold: 0.5 });
    counters.forEach(function (el) { countIO.observe(el); });
  }

  /* ---------- 工况面板:项目阶段切换(视觉) ---------- */
  document.querySelectorAll(".cond-chips").forEach(function (group) {
    group.querySelectorAll(".cond-chip").forEach(function (chip) {
      chip.addEventListener("click", function () {
        group.querySelectorAll(".cond-chip").forEach(function (c) {
          c.classList.toggle("on", c === chip);
        });
      });
    });
  });
})();