This is a [Next.js](https://nextjs.org) project bootstrapped with [`create-next-app`](https://nextjs.org/docs/app/api-reference/cli/create-next-app).

## Getting Started

First, run the development server:

```bash
npm run dev
# or
yarn dev
# or
pnpm dev
# or
bun dev
```

Open [http://localhost:3000](http://localhost:3000) with your browser to see the result.

You can start editing the page by modifying `app/page.tsx`. The page auto-updates as you edit the file.

This project uses [`next/font`](https://nextjs.org/docs/app/building-your-application/optimizing/fonts) to automatically optimize and load [Geist](https://vercel.com/font), a new font family for Vercel.

## Learn More

To learn more about Next.js, take a look at the following resources:

- [Next.js Documentation](https://nextjs.org/docs) - learn about Next.js features and API.
- [Learn Next.js](https://nextjs.org/learn) - an interactive Next.js tutorial.

You can check out [the Next.js GitHub repository](https://github.com/vercel/next.js) - your feedback and contributions are welcome!

## Deploy on Vercel

The easiest way to deploy your Next.js app is to use the [Vercel Platform](https://vercel.com/new?utm_medium=default-template&filter=next.js&utm_source=create-next-app&utm_campaign=create-next-app-readme) from the creators of Next.js.

Check out our [Next.js deployment documentation](https://nextjs.org/docs/app/building-your-application/deploying) for more details.

## Queue / Ticketing demo (WebSocket + JWT)

This repository contains a minimal demo of a queue system for high-concurrency ticket sales. Key ideas:

- When an event reaches a concurrency threshold (e.g. 100 users), the server enables a queue for that event.
- Users connect via WebSocket (Socket.IO). When queueing is active they are placed in a FIFO queue.
- The server grants access (issues a signed JWT) to up to CONCURRENT_ACTIVE users (default 50) at a time.
- The JWT is valid for a short period (default 15 minutes). When it expires the server revokes access and grants the next users in queue.
- The client uses the JWT to authenticate purchase API calls.

Files added in this demo:

- `app/api/socketio/route.js` — Next.js App Router API route that initializes the Socket.IO server, queue logic and JWT issuance with MySQL persistence.
- `app/api/events/route.js` — API for fetching event and ticket information from MySQL.
- `app/api/purchase/route.js` — API for processing ticket purchases with JWT verification.
- `database/schema.sql` — MySQL database schema with tables for events, tickets, queue, orders, and active sessions.
- `.env.example` — example environment variables for the queue system and MySQL connection.
- `app/page.tsx` — modern, responsive client UI that connects via Socket.IO and provides a full ticket purchasing experience.

Important notes and limitations:

- The server implementation in `server/index.js` is an in-memory demo. For production use a shared, persistent store (Redis) for queue/locks and a robust MySQL schema if you need persistence.
- Add authentication, rate-limiting, and persistent sessions before using in production.

Running locally

1. **Setup MySQL Database:**
   ```sql
   -- Execute the schema in database/schema.sql
   mysql -u root -p < database/schema.sql
   ```

2. **Environment Configuration:**
   Copy `.env.example` to `.env` and configure your settings:
   ```bash
   cp .env.example .env
   ```
   Update the MySQL connection details and JWT secret.

3. **Install Dependencies:**
   ```powershell
   pnpm install
   ```

4. **Start the Application:**
   ```powershell
   pnpm dev
   ```

5. **Access the Application:**
   Open `http://localhost:3000` - the page will automatically:
   - Initialize the Socket.IO server via `/api/socketio`
   - Connect to the queue system on port 4000
   - Load event and ticket data from MySQL
   - Provide a modern, responsive ticket purchasing interface

Next steps / improvements

- Move queue state to Redis (ZSET) to support multiple server instances.
- Persist issued tokens and sessions in DB to support revocation and auditing.
- Add server-side validation of the JWT on purchase endpoints.
- Add tests around queue promotion logic and token expiration.