feat(quiz): add dynamic options and question management with validation

backend/.env

@@ -0,0 +1,4 @@
+PORT=8000
+MONGO_URI=mongodb://127.0.0.1:27017/notesDB
+NODE_ENV=development
+UPLOAD_DIR=uploads/

backend/connector/database.connector.js

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+const mongoose = require("mongoose");
+
+const database = async () => {
+  const MONGO_URI = process.env.MONGO_URI;
+
+  if (!MONGO_URI) {
+    console.error("Missing MONGO_URI in .env");
+    process.exit(1);
+  }
+
+  try {
+    await mongoose.connect(MONGO_URI, {
+      useNewUrlParser: true,
+      useUnifiedTopology: true,
+    });
+    console.log("Connected to MongoDB");
+  } catch (error) {
+    console.error("MongoDB connection failed:", error.message);
+    process.exit(1);
+  }
+};
+
+module.exports = database;

backend/controllers/notes.controller.js

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+const { successResponse, errorResponse } = require("../utils/response");
+const {
+  handleMultipleFileUpload,
+  createNoteWithAttachment,
+} = require("../services/notes.service");
+const { asyncHandler } = require("../utils/asyncHandler");
+
+exports.createNote = asyncHandler(async (req, res) => {
+  // File + body handled together
+  const fileMetadataArray = handleMultipleFileUpload(req);
+  const noteData = {
+    title: req.body.title,
+    content: req.body.content,
+    createdBy: req.body.createdBy,
+  };
+
+  // const savedNote = await createNoteWithAttachment(noteData, fileMetadataArray);
+  const savedNote = {
+    ...noteData,
+    attachments: fileMetadataArray,
+    _id: "mock-id-123",
+    uploadedAt: new Date(),
+  }; //remove this(23-28) line when implementing actual DB save
+  console.log("Saved Note:", savedNote);
+  return successResponse(
+    res,
+    savedNote,
+    "Note created successfully with attachment"
+  );
+});

backend/index.js

@@ -1,7 +1,34 @@
-const express = require('express')
-const app = express()
-const port = 8000
+require("dotenv").config();
+const path = require("path");
+const express = require("express");
+const notesRouter = require("./routes/notes.route");
+const database = require("./connector/database.connector");
+const { errorHandler } = require("./middleware/errorHandler.middleware");
+const app = express();
+const cors = require("cors");
+const port = process.env.PORT ?? 8000;
+//CORS setup
+app.use(
+  cors({
+    origin: "http://localhost:3000", // React app
+    methods: ["GET", "POST", "PUT", "DELETE"],
+    credentials: true,
+  })
+);
+// Parse JSON bodies
+app.use(express.json());
 
+// Serve uploaded files statically (for viewing/downloading)
+app.use("/uploads", express.static(path.join(__dirname, "uploads")));
+
+// Notes + file-upload routes
+app.use("/api/notes", notesRouter);
+
+// Global error handler
+app.use(errorHandler);
+//database connection is established in database.connector.js
+// database();
+// Start server
 app.listen(port, () => {
-  console.log(`Example app listening on port ${port}`)
-})
+  console.log(`Example app listening on port ${port}`);
+});

backend/middleware/errorHandler.middleware.js

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+const { errorResponse } = require("../utils/response");
+
+exports.errorHandler = (err, req, res, next) => {
+  console.error("Global Error:", err);
+
+  const statusCode = err.statusCode || 500;
+  const message = err.message || "Internal Server Error";
+
+  return errorResponse(res, message, statusCode, err);
+};

backend/middleware/notes.validate.js

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+const { errorResponse } = require("../utils/response");
+
+exports.validateBody = (schema) => (req, res, next) => {
+  try {
+    console.log("Incoming body before validation:", req.body);
+
+    if (!req.body) {
+      return res.status(400).json({ message: "Request body is missing" });
+    }
+
+    const data = {
+      title: req.body.title || "",
+      content: req.body.content || "",
+      createdBy: req.body.createdBy || "",
+    };
+
+    const parsed = schema.parse(data);
+    console.log("Zod Validation Success", parsed);
+    next();
+  } catch (error) {
+    console.error("Zod Validation Error Details:", error);
+    return res.status(400).json({
+      message: "Invalid input",
+      errors: error.errors || [],
+    });
+  }
+};

backend/middleware/upload.middleware.js

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+const multer = require("multer");
+const path = require("path");
+
+// Storage config – save files in /uploads folder
+const storage = multer.diskStorage({
+  destination: function (req, file, cb) {
+    cb(null, path.join(__dirname, "..", "uploads"));
+  },
+  filename: function (req, file, cb) {
+    const uniqueSuffix = Date.now() + "-" + Math.round(Math.random() * 1e9);
+    cb(null, uniqueSuffix + "-" + file.originalname);
+  },
+});
+
+// Allowed file types
+const allowedTypes = [
+  "application/pdf",
+  "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+  "application/vnd.openxmlformats-officedocument.presentationml.presentation",
+  "image/jpeg",
+  "image/png",
+];
+
+// Filter invalid file types
+function fileFilter(req, file, cb) {
+  if (allowedTypes.includes(file.mimetype)) {
+    cb(null, true);
+  } else {
+    cb(new Error("Unsupported file type"), false);
+  }
+}
+
+// 10 MB limit
+const upload = multer({
+  storage,
+  fileFilter,
+  limits: { fileSize: 10 * 1024 * 1024 },
+});
+
+module.exports = upload;

backend/models/notes.model.js

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+const mongoose = require("mongoose");
+
+const AttachmentSchema = new mongoose.Schema(
+  {
+    originalName: { type: String, required: true },
+    mimeType: { type: String, required: true },
+    size: { type: Number, required: true },
+    url: { type: String, required: true },
+  },
+  { _id: false } // prevent extra _id in array
+);
+
+const NoteSchema = new mongoose.Schema(
+  {
+    title: { type: String, required: true },
+    content: { type: String, required: true },
+    createdBy: { type: String, required: true }, // can hold professor’s ID/name
+    uploadedAt: { type: Date, default: Date.now },
+    attachments: [AttachmentSchema],
+  },
+  { timestamps: true }
+);
+
+module.exports = mongoose.model("Note", NoteSchema);