// Key-gated features (Wave 4.1) — the upstream God's Eye View extras, built in
// but dormant until a working key activates them. Keys live in assets/keys.json
// (gitignored — copy assets/keys.json.example) and are CLIENT-EXPOSED by
// design: restrict each key at its provider (see README §Key-gated extras).
// No file / empty key = the feature stays hidden or explains itself.
//
//   google    → "3D" basemap mode: Google Photorealistic 3D Tiles  (metered 🔴)
//   cesiumIon → "Bing" basemap mode: Bing aerial via Cesium ion    (free 🟡)
//   tomtom    → Traffic flow overlay layer                         (free 🟡)
//
// OpenAI voice is NOT here — its key must never ship to a server; see voice.js.

export async function loadKeys() {
  try {
    const r = await fetch('assets/keys.json', { cache: 'no-store' });
    if (r.ok) return await r.json();
  } catch { /* absent file = no keys, by design */ }
  return {};
}

// hooks: { onBasemapReady(kind, resource), mode3dActive(), solarActive() }
export async function initKeyed(ctx, hooks) {
  const { viewer, Cesium } = ctx;
  const keys = await loadKeys();

  // ---- Bing aerial (Cesium ion asset 2) → "Bing" basemap mode ----
  if (keys.cesiumIon) {
    try {
      Cesium.Ion.defaultAccessToken = keys.cesiumIon;
      const prov = await Cesium.IonImageryProvider.fromAssetId(2);
      const layer = viewer.imageryLayers.addImageryProvider(prov);
      layer.show = false;
      hooks.onBasemapReady('bing', layer);
    } catch (err) {
      console.warn('[godsigh] Cesium ion key configured but Bing failed:', err);
    }
  }

  // ---- Google Photorealistic 3D Tiles → "3D" basemap mode ----
  if (keys.google) {
    try {
      const tiles = await Cesium.Cesium3DTileset.fromUrl(
        `https://tile.googleapis.com/v1/3dtiles/root.json?key=${encodeURIComponent(keys.google)}`,
        { showCreditsOnScreen: true }, // Google attribution is a licence condition
      );
      tiles.show = false;
      viewer.scene.primitives.add(tiles);
      // keyed.js owns tiles.show: on only in 3D mode and never inside Solar
      // System mode (which hides the globe but not this primitive — without
      // this, tiles would render under the orrery and stream paid quota).
      viewer.scene.preUpdate.addEventListener(() => {
        const want = hooks.mode3dActive() && !hooks.solarActive();
        if (tiles.show !== want) tiles.show = want;
      });
      hooks.onBasemapReady('3d', tiles);
    } catch (err) {
      console.warn('[godsigh] Google key configured but 3D tiles failed:', err);
    }
  }

  // ---- TomTom live traffic flow — row always present so the capability is
  // discoverable; keyless it just says how to get the (free) key. ----
  initTraffic(ctx, keys.tomtom);

  return keys;
}

function initTraffic({ viewer, ui, Cesium }, key) {
  let layer = null;
  if (key) {
    const prov = new Cesium.UrlTemplateImageryProvider({
      url: `https://api.tomtom.com/traffic/map/4/tile/flow/relative0/{z}/{x}/{y}.png?key=${encodeURIComponent(key)}`,
      maximumLevel: 20,
      credit: 'Traffic © TomTom',
    });
    layer = viewer.imageryLayers.addImageryProvider(prov);
    layer.alpha = 0.75;
    layer.show = false;
  }
  ui.addLayer('tomtom', 'Traffic flow (TomTom)', false, (on) => {
    if (!layer) {
      // ponytail: key is not validated up front; a bad key just renders no tiles
      ui.setStatus('tomtom', on ? 'needs key — assets/keys.json (free: developer.tomtom.com)' : '', on ? 'warn' : 'off');
      return;
    }
    layer.show = on;
    ui.setStatus('tomtom', on ? 'live congestion tiles · © TomTom' : '', on ? 'ok' : 'off');
  }, 'Context');
  ui.setStatus('tomtom', key ? 'key loaded — toggle on' : 'off — free key unlocks', 'off');
}