🎟️ Concurrent Ticket Booking System with Seat Locking and Confirmation

📌 Objective

Learn how to implement a ticket booking system in Node.js that safely handles concurrent seat reservation requests using a seat locking mechanism.

🚀 Features

• View available seats
• Lock a seat temporarily (1 minute timeout)
• Confirm a locked seat
• Prevents double booking (race condition safe)
• Automatic lock expiry after 1 minute

🛠️ Tech Stack

• Node.js
• Express.js

📂 Project Structure

.
├── index.js        # Main server file
├── package.json    # Dependencies
└── README.md       # Documentation

▶️ Setup Instructions

1. Clone the repo:

   git clone https://github.com/your-username/ticket-booking-system.git
   cd ticket-booking-system

2. Install dependencies:

   npm install

3. Start the server:

   node index.js

4. Server runs at:

   http://localhost:3000
   

---

📡 API Endpoints

1️⃣ Get All Seats

GET http://localhost:3000/seats

Response:

[
  { "id": 1, "status": "available" },
  { "id": 2, "status": "available" },
  { "id": 3, "status": "available" },
  { "id": 4, "status": "available" }
]

---

2️⃣ Lock a Seat

POST http://localhost:3000/lock/6

Response:

{ "message": "Seat 6 is locked successfully. Confirm within 1 minute" }

---

3️⃣ Confirm Booking

POST http://localhost:3000/confirm/6

Response:

{ "message": "Seat 6 booked successfully" }

---

4️⃣ Error: Confirm Without Lock

POST http://localhost:3000/confirm/2

Response:

{ "message": "Seat is not locked and cannot be booked" }

---

📸 Output

Here are the sample outputs when running the project: