// Submarine cables — TeleGeography routes + landing points, bundled in
// assets/cables/ (CC BY-NC-SA 3.0, © TeleGeography; see assets/README.md).
// Static context like infra.js: no time dynamics, loaded once at boot.

export default function create(ctx) {
  const { viewer, lib, ui, Cesium } = ctx;

  const ds = new Cesium.CustomDataSource('cables');
  viewer.dataSources.add(ds);

  let enabled = true;
  ui.addLayer('cables', 'Submarine cables', true, (on) => { enabled = on; ds.show = on; }, 'Context');
  ui.setStatus('cables', 'loading…', 'warn');

  const CREDIT = '<p style="opacity:.7">© TeleGeography — submarinecablemap.com (CC BY-NC-SA 3.0). Routes are schematic.</p>';

  // Landing-point labels only appear zoomed well in; the dots a bit earlier.
  const labelFade = new Cesium.NearFarScalar(2.0e5, 1.0, 1.2e6, 0.0);
  const dotFade = new Cesium.NearFarScalar(1.0e6, 1.0, 8.0e6, 0.0);

  async function load() {
    let cables, landings;
    try {
      [cables, landings] = await Promise.all([
        fetch('assets/cables/cable-geo.json').then((r) => r.json()),
        fetch('assets/cables/landing-point-geo.json').then((r) => r.json()),
      ]);
    } catch (err) {
      ui.setStatus('cables', 'failed to load bundled data', 'err');
      return;
    }

    let nCables = 0;
    for (const f of cables.features || []) {
      const g = f.geometry;
      if (!g || g.type !== 'MultiLineString') continue;
      const p = f.properties || {};
      const color = lib.cz(p.color || '#5aa7d0', 0.85);
      const name = p.name || 'Submarine cable';
      for (const line of g.coordinates) {
        if (!Array.isArray(line) || line.length < 2) continue;
        ds.entities.add({
          name: `Cable — ${name}`,
          polyline: {
            positions: Cesium.Cartesian3.fromDegreesArray(line.flat()),
            width: 1.4,
            material: color,
          },
          description: `<p><b>${lib.escapeHtml(name)}</b> — international submarine cable system.</p>` + CREDIT,
        });
      }
      nCables++;
    }

    let nLandings = 0;
    for (const f of landings.features || []) {
      const g = f.geometry;
      if (!g || g.type !== 'Point') continue;
      const [lon, lat] = g.coordinates;
      if (!isFinite(lon) || !isFinite(lat)) continue;
      const name = (f.properties || {}).name || 'Landing point';
      ds.entities.add({
        name: `Landing — ${name}`,
        position: Cesium.Cartesian3.fromDegrees(lon, lat),
        point: {
          pixelSize: 4, color: lib.cz('#8fd8ff'),
          outlineColor: Cesium.Color.BLACK, outlineWidth: 1,
          translucencyByDistance: dotFade,
          disableDepthTestDistance: Number.POSITIVE_INFINITY,
        },
        label: {
          text: name,
          font: '10px "Segoe UI", system-ui, sans-serif',
          fillColor: lib.cz('#8fd8ff'),
          outlineColor: Cesium.Color.fromCssColorString('#0a0f14'),
          outlineWidth: 3,
          style: Cesium.LabelStyle.FILL_AND_OUTLINE,
          verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
          pixelOffset: new Cesium.Cartesian2(0, -6),
          translucencyByDistance: labelFade,
          disableDepthTestDistance: Number.POSITIVE_INFINITY,
        },
        description: `<p><b>${lib.escapeHtml(name)}</b> — cable landing point.</p>` + CREDIT,
      });
      nLandings++;
    }

    ds.show = enabled;
    ui.setStatus('cables', `${nCables} cables · ${nLandings} landings`, 'ok');
  }

  load();
  return { id: 'cables' };
}