Move metadata to lazy loading

Moves the previous config reader middleware (which loads metadata) to be
dynamically lazyloaded when needed

src/app.ts

@@ -10,7 +10,6 @@ import newsletterRouter from "./services/newsletter/newsletter-router.js";
 import versionRouter from "./services/version/version-router.js";
 import admissionRouter from "./services/admission/admission-router.js";
 
-import { InitializeConfigReader } from "./middleware/config-reader.js";
 import Models from "./database/models.js";
 import { StatusCode } from "status-code-enum";
 import Config from "./config.js";
@@ -20,8 +19,6 @@ const app: Application = express();
 // Utility packages (detailed in the readme)
 // app.use(helmet({ crossOriginResourcePolicy: false }));
 
-app.use(InitializeConfigReader);
-
 // Enable request output when not a test
 if (!Config.TEST) {
     app.use(morgan("dev"));

src/metadata.ts

@@ -0,0 +1,30 @@
+import Config from "./config.js";
+import axios, { AxiosResponse } from "axios";
+
+interface MetadataFormat {
+    androidVersion: string;
+    iosVersion: string;
+}
+
+export default class Metadata {
+    private static metadata: MetadataFormat | undefined = undefined;
+
+    static async load<T extends keyof MetadataFormat>(key: T): Promise<MetadataFormat[T]> {
+        if (this.metadata) {
+            return this.metadata[key];
+        }
+
+        const response: AxiosResponse = await axios.get(Config.METADATA_URL);
+        const loaded: MetadataFormat = response.data as MetadataFormat;
+
+        if (!loaded) {
+            return Promise.reject("InvalidConfigFormat");
+        }
+
+        this.metadata = loaded;
+
+        console.log(this.metadata);
+
+        return this.metadata[key];
+    }
+}

src/services/version/version-router.ts

@@ -1,6 +1,6 @@
 import { Router } from "express";
 import { Request, Response } from "express-serve-static-core";
-import { ConfigReader } from "../../middleware/config-reader.js";
+import Metadata from "../../metadata.js";
 import { StatusCode } from "status-code-enum";
 
 const versionRouter: Router = Router();
@@ -18,8 +18,8 @@ const versionRouter: Router = Router();
  * }
  */
 
-versionRouter.get("/android/", (_: Request, res: Response) => {
-    const androidVersion: string = ConfigReader.androidVersion;
+versionRouter.get("/android/", async (_: Request, res: Response) => {
+    const androidVersion: string = await Metadata.load("androidVersion");
     res.status(StatusCode.SuccessOK).send({ version: androidVersion });
 });
 
@@ -35,8 +35,8 @@ versionRouter.get("/android/", (_: Request, res: Response) => {
  *   "version": "2024.1.1"
  * }
  */
-versionRouter.get("/ios/", (_: Request, res: Response) => {
-    const iosVersion: string = ConfigReader.iosVersion;
+versionRouter.get("/ios/", async (_: Request, res: Response) => {
+    const iosVersion: string = await Metadata.load("iosVersion");
     res.status(StatusCode.SuccessOK).send({ version: iosVersion });
 });