// Windy webcams layer (Wave 6.1) — live webcams near wherever you're looking,
// worldwide. Viewport-driven like the radius layer: each time the camera stops
// moving we ask proxy/windy for the ~50 nearest cams (key injected server-side,
// 10 min cache, coarsened cache key so nearby pans reuse entries). Cams render
// as entities so the InfoBox shows the live preview image + a player link.

export default function create(ctx) {
  const { viewer, Cesium, lib, ui } = ctx;
  const ds = new Cesium.CustomDataSource('windycams');
  ds.show = false;
  viewer.dataSources.add(ds);

  let enabled = false;
  let inFlight = false;
  let debounce = null;
  let moveUnsub = null;

  ui.addLayer('windycams', 'Webcams (Windy)', false, (on) => {
    enabled = on;
    ds.show = on;
    if (on) {
      moveUnsub = viewer.camera.moveEnd.addEventListener(scheduleRefresh);
      refresh();
    } else {
      if (moveUnsub) { moveUnsub(); moveUnsub = null; }
      if (debounce) { clearTimeout(debounce); debounce = null; }
      ui.setStatus('windycams', '', 'ok');
    }
  }, 'Context');

  function scheduleRefresh() {
    if (!enabled) return;
    if (debounce) clearTimeout(debounce);
    debounce = setTimeout(refresh, 400);
  }

  function viewCenter() {
    const c = Cesium.Cartographic.fromCartesian(viewer.camera.positionWC);
    const km = Math.min(250, Math.max(15, Math.round(c.height / 2000)));
    return { lat: Cesium.Math.toDegrees(c.latitude), lon: Cesium.Math.toDegrees(c.longitude), km };
  }

  async function refresh() {
    if (!enabled || inFlight) return;
    inFlight = true;
    try {
      const { lat, lon, km } = viewCenter();
      let res;
      try {
        res = await fetch(`proxy/windy?nearby=${lat.toFixed(2)},${lon.toFixed(2)},${km}`);
      } catch {
        ui.setStatus('windycams', 'network error', 'warn'); return;
      }
      if (res.status === 401) { ui.setStatus('windycams', 'key rejected — needs a Webcams API key', 'err'); return; }
      if (res.status === 503) { ui.setStatus('windycams', 'no key — add windycredentials.json', 'err'); return; }
      if (!res.ok) { ui.setStatus('windycams', `HTTP ${res.status}`, 'warn'); return; }
      let j;
      try { j = await res.json(); } catch { ui.setStatus('windycams', 'bad response', 'err'); return; }
      const cams = j.webcams || [];
      ds.entities.removeAll();
      for (const w of cams) {
        const loc = w.location || {};
        if (!isFinite(loc.latitude) || !isFinite(loc.longitude)) continue;
        const img = lib.safeUrl(((w.images || {}).current || {}).preview);
        const detail = lib.safeUrl((w.urls || {}).detail || ((w.player || {}).day));
        ds.entities.add({
          position: Cesium.Cartesian3.fromDegrees(loc.longitude, loc.latitude),
          point: {
            pixelSize: 6, color: lib.cz('#ffd166'),
            outlineColor: Cesium.Color.BLACK, outlineWidth: 1,
            disableDepthTestDistance: 50000,
          },
          description:
            `<p><b>${lib.escapeHtml(w.title || 'Webcam')}</b></p>` +
            (img ? `<p><img src="${lib.escapeHtml(img)}" style="width:100%;border-radius:6px" alt="webcam preview"/></p>` : '') +
            `<p style="opacity:.7">${lib.escapeHtml([loc.city, loc.country].filter(Boolean).join(' · '))}</p>` +
            (detail ? `<p><a href="${lib.escapeHtml(detail)}" target="_blank" rel="noopener">Open live player ↗</a></p>` : ''),
        });
      }
      ui.setStatus('windycams', `${ds.entities.values.length} cams near view${j.total ? ` · ${j.total} in area` : ''}`, 'ok');
    } finally {
      inFlight = false;
    }
  }

  return { id: 'windycams' };
}