refactor: move Cesium Ion asset detection into Map layer of core

Detection logic was previously passed in from the visualizer as a prop
(`hasCesiumIonAsset`). Core already owns both `property` (ViewerProperty)
and `layers` (Layer[]) in `Map/index.tsx`, so computing the boolean there
keeps Ion-awareness entirely within core — consistent with how credits are
already surfaced via `getCredits`.

`CoreVisualizerProps` no longer exposes `hasCesiumIonAsset`; callers are
unaffected.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ZTongci

src/Map/cesiumIonDetection.ts

@@ -0,0 +1,57 @@
+import type { Layer, LayerSimple } from "../mantle";
+
+import type { TileProperty, ViewerProperty } from "./types/viewerProperty";
+
+const CESIUM_ION_URL_PATTERN = "ion.cesium.com";
+const CESIUM_ION_LEGACY_TILE_TYPES = new Set([
+  "default",
+  "default_road",
+  "default_label",
+  "black_marble",
+]);
+
+function isIonUrl(url?: string | null): boolean {
+  return !!url && url.includes(CESIUM_ION_URL_PATTERN);
+}
+
+function tileUsesIon(tile: TileProperty): boolean {
+  if (!tile.type) return false;
+  if (tile.type.startsWith("cesium_ion")) return true;
+  if (CESIUM_ION_LEGACY_TILE_TYPES.has(tile.type)) return true;
+  return false;
+}
+
+function terrainUsesIon(property?: ViewerProperty): boolean {
+  const terrain = property?.terrain;
+  if (!terrain?.enabled) return false;
+  if (terrain.type === "cesium" || terrain.type === "cesiumion") return true;
+  if (isIonUrl(property?.assets?.cesium?.terrain?.ionUrl)) return true;
+  return false;
+}
+
+function layerUsesIon(layer: LayerSimple): boolean {
+  const data = layer.data;
+  if (!data) return false;
+  if (data.type === "osm-buildings") return true;
+  if (data.type === "google-photorealistic") {
+    if (data.provider === "reearth") return false;
+    if (data.serviceTokens?.googleMapApiKey && data.provider !== "cesium-ion") return false;
+    return true;
+  }
+  if (data.type === "3dtiles" && isIonUrl(data.url)) return true;
+  return false;
+}
+
+function anyLayerUsesIon(layer: Layer): boolean {
+  if (layer.type === "group") {
+    return layer.children.some(anyLayerUsesIon);
+  }
+  return layerUsesIon(layer);
+}
+
+export function computeHasCesiumIonAsset(property?: ViewerProperty, layers?: Layer[]): boolean {
+  if (property?.tiles?.some(tileUsesIon)) return true;
+  if (terrainUsesIon(property)) return true;
+  if (layers?.some(anyLayerUsesIon)) return true;
+  return false;
+}

src/Map/index.tsx

@@ -2,6 +2,7 @@ import { forwardRef, useMemo, type Ref, type JSX } from "react";
 
 import { INTERACTION_MODES } from "../shared/interactionMode";
 
+import { computeHasCesiumIonAsset } from "./cesiumIonDetection";
 import Geoid from "./Geoid";
 import useHooks, { MapRef } from "./hooks";
 import Layers, { type Props as LayersProps } from "./Layers";
@@ -44,7 +45,10 @@ export type Props = {
   | "selectedLayerId"
   | "viewerProperty"
 > &
-  Omit<EngineProps, "onLayerSelect" | "layerSelectionReason" | "selectedLayerId"> &
+  Omit<
+    EngineProps,
+    "onLayerSelect" | "layerSelectionReason" | "selectedLayerId" | "hasCesiumIonAsset"
+  > &
   Omit<SketchProps, "layersRef" | "engineRef" | "SketchComponent">;
 
 function MapFn(
@@ -102,6 +106,11 @@ function MapFn(
     onAPIReady,
   });
 
+  const hasCesiumIonAsset = useMemo(
+    () => computeHasCesiumIonAsset(props.property, layers),
+    [props.property, layers],
+  );
+
   const selectedLayerIds = useMemo(
     () => ({
       layerId: selectedLayer.layerId,
@@ -125,7 +134,8 @@ function MapFn(
       onLayerSelect={handleEngineLayerSelect}
       featureFlags={featureFlags}
       onMount={handleEngineMount}
-      {...props}>
+      {...props}
+      hasCesiumIonAsset={hasCesiumIonAsset}>
       <Layers
         ref={layersRef}
         engineRef={engineRef}

src/Visualizer/index.tsx

@@ -50,7 +50,6 @@ export type CoreVisualizerProps = {
   hiddenLayers?: string[];
   zoomedLayerId?: string;
   displayCredits?: boolean;
-  hasCesiumIonAsset?: boolean;
   onCameraChange?: (camera: Camera) => void;
   onLayerDrop?: (layerId: string, propertyKey: string, position: LatLng | undefined) => void;
   onLayerSelect?: (
@@ -90,7 +89,6 @@ export const CoreVisualizer = memo(
         meta,
         customProvider,
         displayCredits = true,
-        hasCesiumIonAsset,
         style,
         zoomedLayerId,
         children,
@@ -172,7 +170,6 @@ export const CoreVisualizer = memo(
                 meta={meta}
                 customProvider={customProvider}
                 displayCredits={displayCredits}
-                hasCesiumIonAsset={hasCesiumIonAsset}
                 style={style}
                 featureFlags={featureFlags}
                 shouldRender={shouldRender}