Integrate backend question service with frontend

.gitignore

@@ -26,3 +26,4 @@ dist-ssr
 
 # Environment files
 .env
+firebase.json

backend/question-service/app.ts

@@ -3,6 +3,7 @@ import dotenv from "dotenv";
 import swaggerUi from "swagger-ui-express";
 import yaml from "yaml";
 import fs from "fs";
+import cors from "cors";
 
 import connectDB from "./config/db.ts";
 import questionRoutes from "./src/routes/questionRoutes.ts";
@@ -16,6 +17,9 @@ const app = express();
 
 connectDB();
 
+app.use(cors());
+app.options("*", cors());
+
 app.use(express.json());
 app.use("/api", questionRoutes);
 app.use("/docs", swaggerUi.serve, swaggerUi.setup(swaggerDocument));

backend/question-service/config/firebase.ts

@@ -0,0 +1,42 @@
+import admin from "firebase-admin";
+import { v4 as uuidv4 } from "uuid";
+import serviceAccount from "../firebase.json";
+
+admin.initializeApp({
+  credential: admin.credential.cert(serviceAccount as admin.ServiceAccount),
+  storageBucket: "gs://peerprep-c3bd1.appspot.com",
+});
+
+const bucket = admin.storage().bucket();
+
+const uploadFileToFirebase = async (
+  file: Express.Multer.File,
+): Promise<string> => {
+  return new Promise((resolve, reject) => {
+    const fileName = uuidv4();
+    const ref = bucket.file(fileName);
+
+    const blobStream = ref.createWriteStream({
+      metadata: {
+        contentType: file.mimetype,
+      },
+    });
+
+    blobStream.on("error", (error) => {
+      reject(error);
+    });
+
+    blobStream.on("finish", async () => {
+      try {
+        await ref.makePublic();
+        resolve(`https://storage.googleapis.com/${bucket.name}/${fileName}`);
+      } catch (error) {
+        reject(error);
+      }
+    });
+
+    blobStream.end(file.buffer);
+  });
+};
+
+export { bucket, uploadFileToFirebase };

backend/question-service/config/multer.ts

@@ -0,0 +1,6 @@
+import multer from "multer";
+
+const storage = multer.memoryStorage();
+const upload = multer({ storage }).array("images[]");
+
+export { upload };