move parking structures to a sub-field of system

src/resolvers/ParkingSystemResolvers.ts

@@ -0,0 +1,29 @@
+import { Resolvers } from "../generated/graphql";
+import { ServerContext } from "../ServerContext";
+
+export const ParkingSystemResolvers: Resolvers<ServerContext> = {
+  ParkingSystem: {
+    parkingStructures: async (parent, _args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) {
+        return [];
+      }
+      const parkingRepository = system.parkingRepository;
+      if (!parkingRepository) return [];
+
+      return await parkingRepository.getParkingStructures();
+    },
+    parkingStructure: async (parent, args, contextValue, info) => {
+      if (!args.id) return null;
+
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) {
+        return null;
+      }
+      const parkingRepository = system.parkingRepository;
+      if (!parkingRepository) return null;
+
+      return await parkingRepository.getParkingStructureById(args.id);
+    },
+  }
+}