feat: add Ref city hover details to public maps

app/game-engine/src/scenario/mapLoader.ts

@@ -1,18 +1,23 @@
 import fs from 'node:fs/promises';
 import path from 'node:path';
 
-import { MapDefinitionSchema, type MapDefinition } from '@sammo-ts/logic';
+import { MapDefinitionSchema, RegionMapSchema, type MapDefinition } from '@sammo-ts/logic';
 
 import { resolveWorkspaceRoot } from '../paths.js';
 
 const REPO_ROOT = resolveWorkspaceRoot();
 const DEFAULT_MAP_ROOT = path.resolve(REPO_ROOT, 'resources', 'map');
+const DEFAULT_REGION_MAP_PATH = path.resolve(DEFAULT_MAP_ROOT, 'region_map.json');
 
 export interface MapLoaderOptions {
     mapRoot?: string;
     filePrefix?: string;
 }
 
+export interface RegionMapLoaderOptions {
+    regionMapPath?: string;
+}
+
 const readJsonFile = async (filePath: string): Promise<unknown> => {
     const raw = await fs.readFile(filePath, 'utf8');
     return JSON.parse(raw) as unknown;
@@ -34,3 +39,17 @@ export const loadMapDefinitionByName = async (mapName: string, options?: MapLoad
     const mapPath = resolveMapDefinitionPath(mapName, options);
     return loadMapDefinition(mapPath);
 };
+
+export const loadRegionDisplayMapByName = async (
+    mapName: string,
+    options?: RegionMapLoaderOptions
+): Promise<Record<number, string>> => {
+    const raw = await readJsonFile(options?.regionMapPath ?? DEFAULT_REGION_MAP_PATH);
+    const regionMaps = RegionMapSchema.parse(raw);
+    const selected = regionMaps[mapName] ?? {};
+    return Object.fromEntries(
+        Object.entries(selected)
+            .map(([key, value]) => [Number(key), value] as const)
+            .filter(([key]) => Number.isSafeInteger(key))
+    );
+};