Daily Coding Challenge (Full Stack)

This project contains a frontend (vanilla HTML/JS) and a Node/Express backend with MongoDB for users, questions, quizzes, and attempts.

Project Structure

IWP_PROJECT/
├─ frontend/
│  ├─ index.html
│  ├─ admin.html
│  ├─ faculty.html
│  ├─ student.html
│  ├─ *.js, *.css, assets
│
├─ backend/
│  ├─ server.js
│  ├─ routes/
│  ├─ models/
│  ├─ middleware/
│  ├─ .env               # not committed (use .env.example)
│  ├─ package.json
│
├─ .gitignore
├─ README.md

Prerequisites

• Node.js 18+
• MongoDB (Atlas or local)

Backend: Environment Variables

Create backend/.env with these two keys (no quotes, single line for URI):

MONGO_URI=<your mongodb connection string>
JWT_SECRET=<your jwt secret>

Examples:

• Atlas SRV (requires DNS that supports SRV/TXT):

MONGO_URI=mongodb+srv://<user>:<URL_ENCODED_PWD>@cluster0.xxxxx.mongodb.net/Daily_coding_challenge?retryWrites=true&w=majority

• Atlas Standard (non‑SRV, avoids SRV DNS):

MONGO_URI=mongodb://<user>:<URL_ENCODED_PWD>@cluster0-shard-00-00.xxxxx.mongodb.net:27017,cluster0-shard-00-01.xxxxx.mongodb.net:27017,cluster0-shard-00-02.xxxxx.mongodb.net:27017/Daily_coding_challenge?ssl=true&replicaSet=<yourReplicaSet>&authSource=admin

• Local MongoDB:

MONGO_URI=mongodb://127.0.0.1:27017/Daily_coding_challenge

Install & Run (Backend)

From backend/:

npm install
node server.js

Expected output:

• ✅ MongoDB Connected: ...
• 🚀 Server running at http://localhost:5000

Run (Frontend)

Serve the frontend/ folder as static files (e.g., VS Code Live Server) and open frontend/index.html.

• Login via /auth/login. The frontend stores a JWT and sends it in the Authorization: Bearer <token> header.
• Admin can:
  • Add questions (POST /questions)
  • Add users with class (POST /admin/users)
  • Schedule quizzes by class (POST /quizzes)
• Students see today’s quiz (GET /student/quizzes) and submit (POST /student/attempt).
• Faculty can view students of their class (GET /faculty/students).

Deploying

• Backend:

  • Render/Railway/Fly.io → create a Web Service.
  • Set MONGO_URI and JWT_SECRET in the service’s environment variables.
  • Start command: node backend/server.js.

• Frontend:

  • Netlify/Vercel/Cloudflare Pages → deploy the frontend/ directory.
  • If backend is on a different origin, ensure CORS is enabled on the backend (already added) and the frontend uses the correct absolute URLs.

Troubleshooting

• SRV DNS issues with mongodb+srv://:
  • Use the Standard/non‑SRV connection string from Atlas (starts with mongodb://) OR change your DNS to public (8.8.8.8 / 1.1.1.1).
• 401 Unauthorized from frontend:
  • Re‑login so the JWT is stored; the frontend attaches it automatically.
• Collections missing:
  • MongoDB creates them on the first insert. Use Admin dashboard to add data.

Security

• Do not commit backend/.env. Use backend/.env.example for guidance.
• Keep JWT_SECRET private; rotate in production.