add implementation for getShuttleById

src/repositories/ApiBasedRepository.ts

@@ -109,7 +109,27 @@ export class ApiBasedRepository implements GetterRepository {
   }
 
   public async getShuttleById(shuttleId: string): Promise<IShuttle | null> {
-    return Promise.resolve(null);
+    if (!this.cache.shuttleByShuttleId) return null;
+    let shuttle = this.cache.shuttleByShuttleId[shuttleId];
+    if (!shuttle) return null;
+
+    // If the shuttle exists and not TTL, then return it
+
+    const now = Date.now();
+    if (
+      shuttle.millisecondsSinceEpoch !== undefined
+      && this.ttls.shuttleByShuttleId !== undefined
+      && now - shuttle.millisecondsSinceEpoch > this.ttls.shuttleByShuttleId
+    ) {
+      return shuttle;
+    }
+
+    // Otherwise, call getShuttlesBySystemId to update the data
+    await this.getShuttlesBySystemId(shuttle.systemId);
+
+    shuttle = this.cache.shuttleByShuttleId[shuttleId];
+    if (!shuttle) return null;
+    return shuttle;
   }
 
   public async getShuttlesByRouteId(routeId: string): Promise<[]> {