import { ENTRIES } from '../data/entries.js';

// Cesium 懒加载：脚本首次进入“地理”视图时才加载；用 Proxy 惰性访问 window.Cesium，
// 使下方 50 余处 Cesium.xxx 引用无需逐个改动。
const Cesium = new Proxy({}, {
  get(_t, prop) { return window.Cesium[prop]; },
});

const CESIUM_BASE = '/cesium';

function loadCesium() {
  return new Promise((resolve, reject) => {
    if (window.Cesium) return resolve();
    window.CESIUM_BASE_URL = CESIUM_BASE;
    const s = document.createElement('script');
    s.src = `${CESIUM_BASE}/Cesium.js`;
    s.onload = () => resolve();
    s.onerror = () => reject(new Error('Cesium 脚本加载失败'));
    document.head.appendChild(s);
  });
}

// 免费、无需 Ion 令牌的影像与地形源
const IMAGERY_URL =
  'https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}';
const TERRAIN_URL =
  'https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer';

// 右键环视角度限制与灵敏度
const MAX_LOOK_ROT = (40 * Math.PI) / 180; // 左右旋转 ±40°
const MAX_LOOK_TILT = (20 * Math.PI) / 180; // 上下倾角 ±20°
const LOOK_RATE = Math.PI / 720; // 每像素约 0.25°

// 计算多边形集合的球面面积（km²），用于按国土面积分级国家名字号
function sphericalAreaKm2(polys) {
  let area = 0;
  for (let p = 0; p < polys.length; p++) {
    const rings = polys[p];
    for (let r = 0; r < rings.length; r++) {
      const ring = rings[r];
      let s = 0;
      for (let i = 0; i < ring.length; i++) {
        const [lng1, lat1] = ring[i];
        const [lng2, lat2] = ring[(i + 1) % ring.length];
        let dlng = ((lng2 - lng1) * Math.PI) / 180;
        while (dlng > Math.PI) dlng -= 2 * Math.PI;
        while (dlng < -Math.PI) dlng += 2 * Math.PI;
        const f1 = (lat1 * Math.PI) / 180;
        const f2 = (lat2 * Math.PI) / 180;
        s += dlng * (2 + Math.sin(f1) + Math.sin(f2));
      }
      const ringArea = Math.abs(s) / 2;
      area += (r === 0 ? 1 : -1) * ringArea;
    }
  }
  const R = 6371; // km
  return area * R * R;
}

// 生成便签 canvas：黄底圆角 + 左侧箭头 + 黑色加粗文字（整张图，箭头尖端指向坐标）
// 选中态：先描粗边再填充，得到一条干净的 2px 外描边（四周预留 B 的 padding 防止裁切）
function makeStickyNote(text, fontSize, selected = false) {
  const padX = 8, padY = 5, radius = 7, arrowW = 10, arrowH = 14, S = 2, B = 2; // S: 2x 超采样，B: 边框预留
  const font = `bold ${fontSize}px "Noto Serif SC", "Songti SC", "STSong", "SimSun", Georgia, serif`;
  const m = document.createElement('canvas');
  const mctx = m.getContext('2d');
  mctx.font = font;
  const textW = mctx.measureText(text).width;
  const bodyW = Math.max(1, Math.ceil(textW + padX * 2));
  const w = arrowW + bodyW;
  const h = Math.ceil(fontSize + padY * 2);
  const cw = w + B * 2;
  const ch = h + B * 2;
  const c = document.createElement('canvas');
  c.width = cw * S;
  c.height = ch * S;
  const ctx = c.getContext('2d');
  ctx.scale(S, S);

  const ox = B, oy = B; // 形状整体内缩 B，给黑边留空间

  // 箭头 + 圆角矩形一体化路径（箭头尖端在 (ox, oy + h/2)，指向坐标）
  ctx.beginPath();
  ctx.moveTo(ox, oy + h / 2);
  ctx.lineTo(ox + arrowW, oy + h / 2 - arrowH / 2);
  ctx.lineTo(ox + arrowW, oy + radius);
  ctx.arcTo(ox + arrowW, oy, ox + arrowW + radius, oy, radius);
  ctx.lineTo(ox + w - radius, oy);
  ctx.arcTo(ox + w, oy, ox + w, oy + radius, radius);
  ctx.lineTo(ox + w, oy + h - radius);
  ctx.arcTo(ox + w, oy + h, ox + w - radius, oy + h, radius);
  ctx.lineTo(ox + arrowW + radius, oy + h);
  ctx.arcTo(ox + arrowW, oy + h, ox + arrowW, oy + h - radius, radius);
  ctx.lineTo(ox + arrowW, oy + h / 2 + arrowH / 2);
  ctx.closePath();

  if (selected) {
    // 先描粗边，再填充盖住内侧一半 → 外露 2px 干净黑边
    ctx.strokeStyle = '#14100d';
    ctx.lineWidth = B * 2; // 4px，外露 2px
    ctx.lineJoin = 'round';
    ctx.stroke();
  } else {
    // 非选中：柔和的投影
    ctx.shadowColor = 'rgba(0, 0, 0, 0.20)';
    ctx.shadowBlur = 5;
    ctx.shadowOffsetY = 2;
  }
  ctx.fillStyle = '#e0c46a';
  ctx.fill();

  // 黑色加粗文字
  ctx.fillStyle = '#14100d';
  ctx.font = font;
  ctx.textBaseline = 'middle';
  ctx.textAlign = 'center';
  ctx.fillText(text, ox + arrowW + bodyW / 2, oy + h / 2 + 1);

  return { canvas: c, scale: 1 / S, width: cw, height: ch, tipX: B, tipY: B + h / 2 };
}

export class CesiumGlobe {
  constructor({ onPick } = {}) {
    this.onPick = onPick;
    this.viewer = null;
    this.markers = [];
    this.selected = -1;
    this._created = false;
    this._visible = false;
    this._pendingData = 2; // 国家边界 + 城市数据
    this.ready = new Promise((resolve) => { this._resolveReady = resolve; });
    this.viewerReady = new Promise((resolve) => { this._resolveViewerReady = resolve; });
  }

  async ensureCreated() {
    if (this._created) return;
    this._created = true;

    try {
      await loadCesium();
    } catch (err) {
      this._created = false; // 失败可重试
      console.warn('[CesiumGlobe] Cesium 脚本加载失败：', err);
      return;
    }

    // 调整实体渲染顺序：先渲染标签（城市/国家名），再渲染 Billboard（标记便签），
    // 让词条标记始终显示在城市/国家名的上层。
    Cesium.DataSourceDisplay.defaultVisualizersCallback = function (
      scene,
      entityCluster,
      dataSource,
    ) {
      const entities = dataSource.entities;
      return [
        new Cesium.LabelVisualizer(entityCluster, entities),
        new Cesium.BillboardVisualizer(entityCluster, entities),
        new Cesium.GeometryVisualizer(
          scene,
          entities,
          dataSource._primitives,
          dataSource._groundPrimitives,
        ),
        new Cesium.ModelVisualizer(scene, entities),
        new Cesium.Cesium3DTilesetVisualizer(scene, entities),
        new Cesium.PointVisualizer(entityCluster, entities),
        new Cesium.PathVisualizer(scene, entities),
        new Cesium.PolylineVisualizer(
          scene,
          entities,
          dataSource._primitives,
          dataSource._groundPrimitives,
        ),
      ];
    };

    const container = document.getElementById('cesium-container');

    this.viewer = new Cesium.Viewer(container, {
      animation: false,
      timeline: false,
      geocoder: false,
      homeButton: false,
      sceneModePicker: false,
      baseLayerPicker: false,
      navigationHelpButton: false,
      fullscreenButton: false,
      infoBox: false,
      selectionIndicator: false,
      baseLayer: false,
      requestRenderMode: true,
    });

    const viewer = this.viewer;
    const scene = viewer.scene;

    // 贴合暗色主题
    scene.backgroundColor = Cesium.Color.fromCssColorString('#14100d');
    scene.skyAtmosphere.show = false;
    scene.skyBox.show = false;
    scene.sun.show = false;
    scene.moon.show = false;
    scene.globe.enableLighting = false;
    scene.globe.showGroundAtmosphere = false;
    scene.globe.baseColor = Cesium.Color.fromCssColorString('#d9e6f0'); // 冰盖浅色：影像/地形未覆盖的南北极区域显示为冰盖，而非黑洞

    // 相机交互：限制滚轮缩放范围，避免过近/过远
    const controller = scene.screenSpaceCameraController;
    controller.enableCollisionDetection = true; // 必须开启：缩放距离限制在关闭时会被忽略
    controller.minimumZoomDistance = 10000; // 最近约 10 km（区域尺度）
    controller.maximumZoomDistance = 8e6; // 最远约 8000 km

    // 限制鼠标按钮：只保留左键旋转 + 滚轮缩放；禁用中键倾斜、右键缩放
    controller.rotateEventTypes = Cesium.CameraEventType.LEFT_DRAG;
    controller.zoomEventTypes = [
      Cesium.CameraEventType.WHEEL,
      Cesium.CameraEventType.PINCH,
    ];
    controller.tiltEventTypes = [
      Cesium.CameraEventType.PINCH,
      {
        eventType: Cesium.CameraEventType.LEFT_DRAG,
        modifier: Cesium.KeyboardEventModifier.CTRL,
      },
    ];

    // 阻止右键弹出浏览器菜单
    scene.canvas.addEventListener('contextmenu', (e) => e.preventDefault());

    // 精细化渲染：质量与性能的平衡
    scene.globe.maximumScreenSpaceError = 2.0; // 默认细分，最省性能
    scene.globe.tileCacheSize = 600; // 更大的瓦片缓存，减少细节刷新
    scene.fxaa = true; // 开启抗锯齿
    viewer.resolutionScale = 1.0; // 关闭超采样（DPR 已提供足够分辨率），省填充率
    scene.maximumRenderTimeChange = Infinity; // 配合 requestRenderMode：静止时停止重绘，大幅省电省帧

    // 卫星影像
    const imagery = new Cesium.UrlTemplateImageryProvider({
      url: IMAGERY_URL,
      credit: 'Imagery © Esri, Maxar, Earthstar Geographics',
      maximumLevel: 19,
    });
    const imageryLayer = new Cesium.ImageryLayer(imagery, {
      // 卫星影像不覆盖极区（约 ±85° 外返回黑块），限制范围让极区用冰盖底色
      rectangle: Cesium.Rectangle.fromDegrees(-180, -85, 180, 85),
    });
    viewer.imageryLayers.add(imageryLayer);

    // 真实地形（Esri World Elevation 3D，免费无 token；失败则保持默认椭球）
    const terrain = new Cesium.Terrain(
      Cesium.ArcGISTiledElevationTerrainProvider.fromUrl(TERRAIN_URL),
    );
    terrain.errorEvent.addEventListener((err) => {
      console.warn('[CesiumGlobe] 地形加载失败，使用椭球：', err);
    });
    scene.setTerrain(terrain);

    viewer.clock.shouldAnimate = false;

    this._buildMarkers();
    this._setupPick();
    this._setupLookAround();
    this._loadBoundaries();
    this._buildCityLabels();

    viewer.camera.setView({
      destination: Cesium.Cartesian3.fromDegrees(35, 12, 7.2e6),
    });

    // 创建完成：同步当前选中/可见/相机状态（首次进入时这些调用可能因 viewer 未建而跳过）
    this.setSelected(this.selected);
    this.setVisible(this._visible);
    this.resize();
    this.flyToEntry(this.selected);

    // 地球已就绪（影像/地形/城市数据继续后台加载），通知 App 隐藏加载遮罩
    if (this._resolveViewerReady) {
      this._resolveViewerReady();
      this._resolveViewerReady = null;
    }
  }

  _buildMarkers() {
    ENTRIES.forEach((entry, i) => {
      const position = Cesium.Cartesian3.fromDegrees(entry.lng, entry.lat);
      const noteNormal = makeStickyNote(entry.name, 16, false);
      const noteSelected = makeStickyNote(entry.name, 16, true);
      this.markers.push({
        position,
        r2: Cesium.Cartesian3.magnitudeSquared(position),
        noteNormal,
        noteSelected,
        index: i,
      });
    });
    this._initMarkerLayer();
  }

  // 便签用 DOM 覆盖层渲染：始终在城市/国家名上层，且缩放到最近也不会漂移
  _initMarkerLayer() {
    const container = document.getElementById('cesium-container');
    this._markerLayer = document.createElement('div');
    this._markerLayer.id = 'marker-layer';
    container.appendChild(this._markerLayer);

    for (const m of this.markers) {
      const el = document.createElement('div');
      el.className = 'marker-note';
      el.style.width = `${m.noteNormal.width}px`;
      el.style.height = `${m.noteNormal.height}px`;
      el.dataset.index = m.index;
      m.el = el;
      m.tipX = m.noteNormal.tipX; // 箭头尖相对元素左上角的偏移
      m.tipY = m.noteNormal.tipY;
      m.normalUrl = m.noteNormal.canvas.toDataURL();
      m.selectedUrl = m.noteSelected.canvas.toDataURL();
      el.style.backgroundImage = `url("${m.normalUrl}")`;
      el.addEventListener('click', (e) => {
        e.stopPropagation();
        this.onPick?.(m.index);
      });
      this._markerLayer.appendChild(el);
    }

    // 用 postUpdate（每帧都触发，即使 requestRenderMode 下不真正渲染）更新便签位置，
    // 避免拖拽时 postRender 不触发导致的闪烁/消失。
    this.viewer.scene.postUpdate.addEventListener(() => this._updateMarkerLayer());
  }

  // 每帧更新便签屏幕位置（相机移动/缩放/飞行时跟随）
  _updateMarkerLayer() {
    const scene = this.viewer.scene;
    const camera = scene.camera;
    const camPos = camera.positionWC; // 每帧只取一次相机位置

    for (const m of this.markers) {
      const el = m.el;
      if (!el) continue;

      const win = Cesium.SceneTransforms.worldToWindowCoordinates(scene, m.position);
      if (!win) { el.style.display = 'none'; continue; }

      // 前/后半球：dot(P, C) > |P|²；地平线附近用 frontness 渐变淡出（避免 acos）
      const frontness = Cesium.Cartesian3.dot(m.position, camPos) - m.r2;
      if (frontness <= 0) { el.style.display = 'none'; continue; }
      const opacity = Math.min(1, frontness / (m.r2 * 0.02));

      el.style.display = 'block';
      el.style.opacity = String(opacity);
      el.style.left = `${win.x - m.tipX}px`;
      el.style.top = `${win.y - m.tipY}px`;
    }
  }

  _setupPick() {
    const viewer = this.viewer;
    // 移除 Viewer 默认的单击选中与双击“追踪实体”：否则双击后会锁定相机（定住）
    // 标记便签已改为 DOM 覆盖层，点击由 DOM 元素自行处理
    viewer.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_CLICK);
    viewer.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
  }

  // 右键环视：以点击处为球心，左右旋转 ±40°、上下倾角 ±20°，松开自动归位。
  // 不用原生 tilt（RIGHT_DRAG）：原生 tilt 会绕点击点做轨道移动，heading/pitch
  // 是相对“不断移动的相机位置”计算的，无法干净地限制成 40°/20°。
  _setupLookAround() {
    const scene = this.viewer.scene;
    const camera = this.viewer.camera;
    const handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
    this._lookState = null;
    this._orbitScratch = {
      offset: new Cesium.Cartesian3(),
      upAxis: new Cesium.Cartesian3(),
      eastAxis: new Cesium.Cartesian3(),
      northAxis: new Cesium.Cartesian3(),
      qAz: new Cesium.Quaternion(),
      qEl: new Cesium.Quaternion(),
      q: new Cesium.Quaternion(),
      rotMat: new Cesium.Matrix3(),
      newOffset: new Cesium.Cartesian3(),
      newPos: new Cesium.Cartesian3(),
      dir: new Cesium.Cartesian3(),
      upProj: new Cesium.Cartesian3(),
    };

    handler.setInputAction((movement) => {
      // 旋转中心 = 相机当前注视的屏幕中心点（与原生 tilt 一致），
      // 而不是点击点：用点击点会导致一拖动就“瞬移”到点击处。
      const canvas = scene.canvas;
      const center = Cesium.Cartesian2.fromElements(
        canvas.clientWidth / 2,
        canvas.clientHeight / 2,
      );
      const pivot = camera.pickEllipsoid(center, scene.globe.ellipsoid);
      if (!Cesium.defined(pivot)) return;
      const sc = this._orbitScratch;
      const offset = Cesium.Cartesian3.subtract(camera.position, pivot, sc.offset);
      const upAxis = Cesium.Cartesian3.normalize(pivot, sc.upAxis);
      const eastAxis = Cesium.Cartesian3.cross(Cesium.Cartesian3.UNIT_Z, pivot, sc.eastAxis); // 绕它转 = 左右拖动（纬度方向倾倒）
      if (Cesium.Cartesian3.magnitudeSquared(eastAxis) < 1e-12) {
        eastAxis.x = 1;
        eastAxis.y = 0;
        eastAxis.z = 0; // 极点退化兜底
      } else {
        Cesium.Cartesian3.normalize(eastAxis, eastAxis);
      }
      const northAxis = Cesium.Cartesian3.normalize(
        Cesium.Cartesian3.cross(upAxis, eastAxis, sc.northAxis), // 绕它转 = 上下拖动（经度方向倾倒）
        sc.northAxis,
      );
      this._lookState = {
        pivot: Cesium.Cartesian3.clone(pivot),
        startOffset: Cesium.Cartesian3.clone(offset),
        eastAxis: Cesium.Cartesian3.clone(eastAxis),
        northAxis: Cesium.Cartesian3.clone(northAxis),
        position: Cesium.Cartesian3.clone(camera.position),
        direction: Cesium.Cartesian3.clone(camera.direction),
        up: Cesium.Cartesian3.clone(camera.up),
        azimuth: 0,
        elevation: 0,
        lastX: movement.position.x,
        lastY: movement.position.y,
      };
    }, Cesium.ScreenSpaceEventType.RIGHT_DOWN);

    handler.setInputAction((movement) => {
      if (!this._lookState) return;
      const s = this._lookState;
      const dx = movement.endPosition.x - s.lastX;
      const dy = movement.endPosition.y - s.lastY;
      s.lastX = movement.endPosition.x;
      s.lastY = movement.endPosition.y;
      s.azimuth = Cesium.Math.clamp(s.azimuth + dx * LOOK_RATE, -MAX_LOOK_ROT, MAX_LOOK_ROT);
      s.elevation = Cesium.Math.clamp(s.elevation + dy * LOOK_RATE, -MAX_LOOK_TILT, MAX_LOOK_TILT);
      this._orbitCamera(s);
    }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);

    handler.setInputAction(() => {
      if (!this._lookState) return;
      const s = this._lookState;
      this._lookState = null;
      camera.setView({
        destination: s.position,
        orientation: { direction: s.direction, up: s.up },
      });
    }, Cesium.ScreenSpaceEventType.RIGHT_UP);

    this._lookHandler = handler;
  }

  // 按累计角度（已限制）把相机绕点击点倾倒：左右 = 纬度方向（绕东西轴），
  // 上下 = 经度方向（绕南北轴）；up 始终强制北朝上。
  _orbitCamera(s) {
    const camera = this.viewer.camera;
    const sc = this._orbitScratch;
    Cesium.Quaternion.fromAxisAngle(s.eastAxis, s.azimuth, sc.qAz);
    Cesium.Quaternion.fromAxisAngle(s.northAxis, s.elevation, sc.qEl);
    Cesium.Quaternion.multiply(sc.qEl, sc.qAz, sc.q);
    Cesium.Matrix3.fromQuaternion(sc.q, sc.rotMat);
    Cesium.Matrix3.multiplyByVector(sc.rotMat, s.startOffset, sc.newOffset);
    Cesium.Cartesian3.add(s.pivot, sc.newOffset, sc.newPos);
    const dir = Cesium.Cartesian3.normalize(
      Cesium.Cartesian3.subtract(s.pivot, sc.newPos, sc.dir),
      sc.dir,
    );
    // 强制北朝上：up = 世界 Z 投影到垂直于视线的方向
    const z = dir.z;
    sc.upProj.x = -dir.x * z;
    sc.upProj.y = -dir.y * z;
    sc.upProj.z = 1 - z * z;
    if (Cesium.Cartesian3.magnitudeSquared(sc.upProj) < 1e-12) {
      Cesium.Cartesian3.clone(s.up, sc.upProj); // 垂直俯视时北朝上无定义，回退起始 up
    } else {
      Cesium.Cartesian3.normalize(sc.upProj, sc.upProj);
    }
    camera.setView({
      destination: Cesium.Cartesian3.clone(sc.newPos),
      orientation: {
        direction: Cesium.Cartesian3.clone(dir),
        up: Cesium.Cartesian3.clone(sc.upProj),
      },
    });
  }

  // 相机平滑飞至某个标记上空并居中：回到与初始一致的高度与北朝上方向，左键拖拽手感不变
  flyToEntry(index) {
    const entry = ENTRIES[index];
    if (!entry || !this.viewer) return;
    const now = Date.now();
    if (this._lastFly && now - this._lastFly < 400) return; // 双击/连点去抖，避免重复飞
    this._lastFly = now;
    const camera = this.viewer.camera;
    const height = camera.positionCartographic.height; // 保持当前缩放，平移过去
    camera.flyTo({
      destination: Cesium.Cartesian3.fromDegrees(entry.lng, entry.lat, height),
      orientation: {
        heading: 0,
        pitch: Cesium.Math.toRadians(-90),
        roll: 0,
      },
      duration: 1.2,
    });
  }

  // 加载行政区划（国家边界，自然地球 110m）：把多边形轮廓转成贴合地形的金色细线 + 国家名标签
  async _loadBoundaries() {
    try {
      const res = await fetch('/world-countries.geojson');
      const geojson = await res.json();
      const textGold = Cesium.Color.fromCssColorString('#e0c46a');
      const black = Cesium.Color.fromCssColorString('#14100d');

      const lines = [];
      for (const feature of geojson.features || []) {
        const props = feature.properties || {};
        const geom = feature.geometry;
        const isPoly = geom && (geom.type === 'Polygon' || geom.type === 'MultiPolygon');
        const polys = isPoly ? (geom.type === 'MultiPolygon' ? geom.coordinates : [geom.coordinates]) : [];
        const areaKm2 = isPoly ? sphericalAreaKm2(polys) : 0;

        // 国家名（优先中文），落在 NATURAL EARTH 提供的标注点上，字号按国土面积分级
        let cname = props.NAME_ZH || props.NAME;
        if (cname === '中华民国') cname = '中国台湾';
        if (cname && props.LABEL_X != null && props.LABEL_Y != null) {
          const fontSize = areaKm2 > 5e6 ? 30 : areaKm2 > 1.5e6 ? 19 : areaKm2 > 3e5 ? 15 : 12;
          this.viewer.entities.add({
            position: Cesium.Cartesian3.fromDegrees(props.LABEL_X, props.LABEL_Y),
            label: {
              text: cname,
              font: `bold ${fontSize}px "Noto Serif SC", "Songti SC", "STSong", "SimSun", Georgia, serif`,
              fillColor: black,
              style: Cesium.LabelStyle.FILL,
              heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
              distanceDisplayCondition: new Cesium.DistanceDisplayCondition(1e6, 1e7),
              scaleByDistance: new Cesium.NearFarScalar(1e4, 20 / 15, 6e6, 1.0),
              translucencyByDistance: new Cesium.NearFarScalar(9e6, 1.0, 1e7, 0.0),
            },
          });
        }

        if (!isPoly) continue;
        for (const poly of polys) {
          for (const ring of poly) {
            if (ring.length < 2) continue;
            const flat = [];
            for (const [lng, lat] of ring) flat.push(lng, lat);
            const positions = Cesium.Cartesian3.fromDegreesArray(flat);
            // 行政区划：一根黑线
            lines.push(new Cesium.GeometryInstance({ geometry: new Cesium.GroundPolylineGeometry({ positions, width: 2.6 }) }));
          }
        }
      }

      if (lines.length) {
        this.viewer.scene.groundPrimitives.add(
          new Cesium.GroundPolylinePrimitive({
            geometryInstances: lines,
            appearance: new Cesium.PolylineMaterialAppearance({
              material: Cesium.Material.fromType('Color', { color: black }),
            }),
          }),
        );
      }
    } catch (err) {
      console.warn('[CesiumGlobe] 行政区划加载失败：', err);
    } finally {
      this._dataReady();
    }
  }

  // 全部城市：Natural Earth 10m 人口稠密点（7342 个），中文名直接用数据自带的 name_zh
  async _buildCityLabels() {
    const scene = this.viewer.scene;
    const textGold = Cesium.Color.fromCssColorString('#e0c46a');
    const black = Cesium.Color.fromCssColorString('#14100d');
    const ddc = new Cesium.DistanceDisplayCondition(0, 4e6);
    const tdc = new Cesium.NearFarScalar(2e6, 1.0, 4e6, 0.0);

    let cities = [];
    try {
      const res = await fetch('/world-cities-zh.json');
      cities = await res.json();
    } catch (err) {
      console.warn('[CesiumGlobe] 城市数据加载失败：', err);
      cities = [];
    }

    // 用 primitive 集合替代 7342 个 entity，大幅降低 Cesium 实体系统开销
    const points = new Cesium.PointPrimitiveCollection();
    const labels = new Cesium.LabelCollection({ scene });
    scene.primitives.add(points);
    scene.primitives.add(labels);

    for (const c of cities) {
      const position = Cesium.Cartesian3.fromDegrees(c.lng, c.lat);
      points.add({
        position,
        pixelSize: 3,
        color: textGold,
        outlineColor: black,
        outlineWidth: 1,
        heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
        distanceDisplayCondition: ddc,
        translucencyByDistance: tdc,
      });
      labels.add({
        position,
        text: c.name,
        font: 'bold 14px "Noto Serif SC", "Songti SC", "STSong", "SimSun", Georgia, serif',
        fillColor: black,
        style: Cesium.LabelStyle.FILL,
        horizontalOrigin: Cesium.HorizontalOrigin.CENTER,
        verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
        pixelOffset: new Cesium.Cartesian2(0, -6),
        heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
        distanceDisplayCondition: ddc,
        translucencyByDistance: tdc,
      });
    }
    this._dataReady();
  }

  _dataReady() {
    this._pendingData--;
    if (this._pendingData <= 0 && this._resolveReady) {
      this._resolveReady();
      this._resolveReady = null;
    }
  }

  setSelected(index) {
    this.selected = index;
    if (!this.viewer) return;
    this.markers.forEach((m) => {
      const on = m.index === index;
      if (m.el) m.el.style.backgroundImage = `url("${on ? m.selectedUrl : m.normalUrl}")`;
    });
  }

  setVisible(visible) {
    this._visible = visible;
    if (visible && this.viewer) this.viewer.scene.requestRender();
  }

  // 等待当前视图的影像/地形瓦片加载完成（超时兜底），用于切换时“一起出现”
  waitUntilViewReady(timeout = 4000) {
    return new Promise((resolve) => {
      const globe = this.viewer.scene.globe;
      let done = false;
      const finish = () => {
        if (done) return;
        done = true;
        globe.tileLoadProgressEvent.removeEventListener(onProgress);
        resolve();
      };
      const onProgress = (remaining) => { if (remaining <= 0) finish(); };
      globe.tileLoadProgressEvent.addEventListener(onProgress);
      if (globe.tilesLoaded) finish();
      setTimeout(finish, timeout);
    });
  }

  resize() {
    if (this.viewer) this.viewer.resize();
  }
}