🎟️ Coupon Distribution System

📖 Overview

This is a Round-Robin Coupon Distribution System with an Admin Panel.
It ensures fair coupon distribution while preventing abuse using IP tracking and session cookies.

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🚀 Tech Stack

🖥 Backend

• Node.js & Express.js – REST API development
• PostgreSQL – Database for storing coupons, claims, and admin users
• JWT Authentication – Secure admin access
• Rate Limiting (express-rate-limit) – Prevent abuse
• bcrypt – Secure password hashing
• cookie-parser – Handle session cookies

🌍 Frontend

• React.js – User Interface
• Axios – API calls
• React Router – Client-side routing
• tailwindcss – UI styling

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🛠 Features

🔹 Admin Features

✅ Admin Login & Logout – Secure access via JWT authentication
✅ Add New Coupons – Dynamically create discount codes
✅ View All Coupons – See available & claimed coupons
✅ Update Coupons – Modify coupon details
✅ Security Measures – JWT, bcrypt password hashing

🔹 User Features

✅ Claim a Coupon – Users can claim 1 coupon per 24 hours
✅ IP Address Tracking – Ensures fair distribution
✅ Session Cookies – Prevent multiple claims per session

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🔑 Test Admin Credentials

• Username: admin
• Password: admin123

(Change these after first login for security.)

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📌 How to Use

➡️ Admin Panel

• Login as admin using the test credentials.
• Add new coupons from the dashboard.
• Monitor claimed coupons via the admin panel.

➡️ Claiming a Coupon

• Visit the /claim-coupon page.
• Click "Claim Coupon" (Allowed once per session & IP per day).
• Get your discount code! 🎉

📡 API Endpoints

🔐 Admin Routes

Method	Endpoint	Description	Authentication
POST	/api/admin/login	Admin login	❌ No (public)
POST	/api/admin/logout	Admin logout	✅ Yes (JWT)
GET	/api/admin/coupons	Fetch all coupons	✅ Yes (JWT)
POST	/api/admin/add-coupon	Add a new coupon	✅ Yes (JWT)
PUT	/api/admin/update-coupon/:id	Update coupon details	✅ Yes (JWT)

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🌍 Public Routes

Method	Endpoint	Description	Protection
GET	/api/all-coupons	Get all available & claimed coupons	❌ No
POST	/api/claim-coupon	Claim a coupon	✅ Yes (IP & Cookie Restriction)

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🛡 Security Features

🔹 IP Address Tracking

• Each coupon claim stores the user's IP address in the database.
• Users can claim only 1 coupon per 24 hours per IP.

🔹 Session Cookie Enforcement

• A session cookie (claimed) is set when a user claims a coupon.
• If the user refreshes and tries to claim again, the API denies the request.