/* Astrion 官网主页交互
 * 1) 多层视差星空（无连线、无光晕：实心星点 + 闪烁 + 极慢漂移 + 鼠标/滚动视差 + 偶发流星）
 * 2) 顶栏滚动态
 * 3) FAQ 手风琴平滑展开（details + 高度动画）
 * 4) 演示区 iframe 等比缩放（内部固定 1400×860 逻辑尺寸）
 * 5) 挂载品牌眼睛（眨眼 + 鼠标追踪）
 */

(function () {
  'use strict';

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

  /* ═══════════ 1) 星空 ═══════════ */

  var canvas = document.getElementById('starfield');
  var ctx = canvas.getContext('2d');
  var W = 0;
  var H = 0;
  var DPR = Math.min(window.devicePixelRatio || 1, 2);

  // 层：远 → 近。count 按屏幕面积缩放，drift 为每秒下落 px，parallax 为鼠标/滚动视差系数
  var LAYERS = [
    { density: 1 / 5200, sizeMin: 0.4, sizeMax: 0.9, drift: 1.2, parallax: 6, twinkle: 0.35, alpha: 0.55 },
    { density: 1 / 9800, sizeMin: 0.7, sizeMax: 1.3, drift: 2.6, parallax: 14, twinkle: 0.55, alpha: 0.75 },
    { density: 1 / 21000, sizeMin: 1.1, sizeMax: 1.9, drift: 4.5, parallax: 26, twinkle: 0.8, alpha: 1.0 }
  ];

  var stars = [];
  var meteors = [];
  var nextMeteorAt = 0;

  function resize() {
    W = window.innerWidth;
    H = window.innerHeight;
    canvas.width = Math.round(W * DPR);
    canvas.height = Math.round(H * DPR);
    canvas.style.width = W + 'px';
    canvas.style.height = H + 'px';
    ctx.setTransform(DPR, 0, 0, DPR, 0, 0);
    seed();
    if (reduceMotion) draw(0, 0, 0);
  }

  function seed() {
    stars = [];
    var area = W * H;
    for (var li = 0; li < LAYERS.length; li++) {
      var L = LAYERS[li];
      var n = Math.max(12, Math.round(area * L.density));
      for (var i = 0; i < n; i++) {
        stars.push({
          layer: li,
          x: Math.random() * W,
          y: Math.random() * H,
          r: L.sizeMin + Math.random() * (L.sizeMax - L.sizeMin),
          // 闪烁相位与速度（部分星几乎不闪，画面才稳）
          phase: Math.random() * Math.PI * 2,
          speed: 0.25 + Math.random() * 0.9,
          amp: 0.25 + Math.random() * 0.75
        });
      }
    }
  }

  // 鼠标视差目标值
  var mouseTx = 0;
  var mouseTy = 0;
  var mouseX = 0;
  var mouseY = 0;

  window.addEventListener('mousemove', function (e) {
    mouseTx = e.clientX / W - 0.5;
    mouseTy = e.clientY / H - 0.5;
  }, { passive: true });

  function scheduleMeteor(now) {
    // 22～48 秒一颗，保持稀有
    nextMeteorAt = now + 22000 + Math.random() * 26000;
  }

  function spawnMeteor() {
    var fromLeft = Math.random() < 0.5;
    var startX = fromLeft ? -40 : W * (0.35 + Math.random() * 0.65);
    var startY = Math.random() * H * 0.4;
    var angle = fromLeft ? 0.32 + Math.random() * 0.2 : Math.PI - (0.32 + Math.random() * 0.2);
    var speed = 380 + Math.random() * 240;
    meteors.push({
      x: startX,
      y: startY,
      vx: Math.cos(angle) * speed,
      vy: Math.abs(Math.sin(angle)) * speed,
      life: 0,
      ttl: 0.7 + Math.random() * 0.35
    });
  }

  var lastTs = 0;

  function tick(ts) {
    if (document.hidden) {
      lastTs = ts;
      requestAnimationFrame(tick);
      return;
    }
    var dt = Math.min((ts - lastTs) / 1000 || 0, 0.05);
    lastTs = ts;
    var now = ts;

    // 鼠标视差缓动
    mouseX += (mouseTx - mouseX) * 0.04;
    mouseY += (mouseTy - mouseY) * 0.04;

    if (now >= nextMeteorAt) {
      spawnMeteor();
      scheduleMeteor(now);
    }

    draw(dt, ts, window.scrollY || 0);

    // 流星生命推进
    for (var i = meteors.length - 1; i >= 0; i--) {
      var m = meteors[i];
      m.life += dt;
      m.x += m.vx * dt;
      m.y += m.vy * dt;
      if (m.life > m.ttl || m.y > H + 60) meteors.splice(i, 1);
    }

    requestAnimationFrame(tick);
  }

  function draw(dt, ts, scrollY) {
    ctx.clearRect(0, 0, W, H);
    var t = ts / 1000;

    for (var i = 0; i < stars.length; i++) {
      var s = stars[i];
      var L = LAYERS[s.layer];
      if (dt) {
        s.y += L.drift * dt;
        if (s.y > H + 4) { s.y = -4; s.x = Math.random() * W; }
      }
      // 视差：滚动让星野整体上移（近处更明显），鼠标让层间错动
      var px = s.x + mouseX * L.parallax * 2;
      var py = s.y - (scrollY * L.parallax * 0.012) + mouseY * L.parallax;
      // 纵向包裹，保证滚动后星点仍铺满
      var wrappedY = ((py % (H + 8)) + (H + 8)) % (H + 8) - 4;

      var tw = 1 - L.twinkle * 0.5 + L.twinkle * 0.5 * Math.sin(t * s.speed + s.phase) * s.amp;
      var a = L.alpha * Math.max(0.15, Math.min(1, tw));
      ctx.globalAlpha = a;
      ctx.fillStyle = '#dfe6f5';
      ctx.fillRect(px, wrappedY, s.r, s.r);
    }

    // 流星：短细线段，头部略亮（线性渐变线条，不是光晕）
    for (var j = 0; j < meteors.length; j++) {
      var m = meteors[j];
      var fade = 1 - m.life / m.ttl;
      var tailX = m.x - m.vx * 0.14;
      var tailY = m.y - m.vy * 0.14;
      var grad = ctx.createLinearGradient(tailX, tailY, m.x, m.y);
      grad.addColorStop(0, 'rgba(223,230,245,0)');
      grad.addColorStop(1, 'rgba(223,230,245,' + (0.6 * fade).toFixed(3) + ')');
      ctx.globalAlpha = 1;
      ctx.strokeStyle = grad;
      ctx.lineWidth = 1.1;
      ctx.beginPath();
      ctx.moveTo(tailX, tailY);
      ctx.lineTo(m.x, m.y);
      ctx.stroke();
    }

    ctx.globalAlpha = 1;
  }

  resize();
  window.addEventListener('resize', resize, { passive: true });

  if (reduceMotion) {
    draw(0, 0, 0); // 静态星图
  } else {
    scheduleMeteor(performance.now() + 6000); // 首颗稍提前，证明存在
    requestAnimationFrame(tick);
    // 滚动时重绘由 rAF 持续驱动，无需 scroll 监听
  }

  /* ═══════════ 2) 顶栏滚动态 ═══════════ */

  var topbar = document.getElementById('topbar');
  function onScroll() {
    topbar.classList.toggle('scrolled', (window.scrollY || 0) > 24);
  }
  window.addEventListener('scroll', onScroll, { passive: true });
  onScroll();

  /* ═══════════ 3) FAQ 平滑手风琴 ═══════════ */

  var faqItems = document.querySelectorAll('.faq-item');
  faqItems.forEach(function (item) {
    var summary = item.querySelector('.faq-q');
    var panel = item.querySelector('.faq-a');
    summary.addEventListener('click', function (e) {
      e.preventDefault();
      if (reduceMotion) {
        item.open = !item.open;
        return;
      }
      if (item.open) {
        // 收起：先固定高度再过渡到 0
        var h0 = panel.offsetHeight;
        panel.style.height = h0 + 'px';
        requestAnimationFrame(function () {
          panel.style.transition = 'height 0.22s ease';
          panel.style.height = '0px';
        });
        panel.addEventListener('transitionend', function done() {
          panel.removeEventListener('transitionend', done);
          panel.style.cssText = '';
          item.open = false;
        });
      } else {
        item.open = true;
        var h1 = panel.offsetHeight;
        panel.style.height = '0px';
        requestAnimationFrame(function () {
          panel.style.transition = 'height 0.24s ease';
          panel.style.height = h1 + 'px';
        });
        panel.addEventListener('transitionend', function done() {
          panel.removeEventListener('transitionend', done);
          panel.style.cssText = '';
        });
      }
    });
  });

  /* ═══════════ 4) 演示区等比缩放 ═══════════ */

  var frame = document.getElementById('demoFrame');
  var iframe = document.getElementById('demoIframe');
  var DEMO_W = 1400;
  var DEMO_H = 860;

  function fitDemo() {
    var available = frame.clientWidth;
    var scale = Math.min(1, available / DEMO_W);
    iframe.style.transform = 'scale(' + scale + ')';
    frame.style.height = Math.round(DEMO_H * scale) + 'px';
  }

  if ('ResizeObserver' in window) {
    new ResizeObserver(fitDemo).observe(frame);
  }
  window.addEventListener('resize', fitDemo, { passive: true });
  fitDemo();

  /* ═══════════ 5) 品牌眼睛 ═══════════ */

  if (window.AstrionAvatar) {
    AstrionAvatar.mount(document.getElementById('heroMascot'), { mode: 'idle', blink: true, track: true });
  }

  /* ═══════════ 6) 运行模式动画（功能 01 行） ═══════════ */

  if (window.AnimModes && document.getElementById('animModes')) {
    AnimModes.init(document.getElementById('animModes'));
  }

  /* ═══════════ 7) 沙箱与网络授权动画（功能 02 行） ═══════════ */

  if (window.AnimSandbox && document.getElementById('animSandbox')) {
    AnimSandbox.init(document.getElementById('animSandbox'));
  }
})();