🌐 Nexio-EventSphere — Backend

A modular Node.js backend for the EventSphere platform, combining MySQL (relational data), MongoDB (log storage), and Kafka (event streaming) for scalable, decoupled processing. Designed to power EventSphere’s web and mobile clients with robust APIs, event logging, and efficient data pipelines.

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⚡ Overview

This backend manages:

• Express API server with route-based services
• MySQL-backed schemas for users, events, and organizations
• Kafka producers/consumers for asynchronous logging
• MongoDB consumers for long-term log persistence

It supports JWT authentication, file uploads, admin and leader modules, and real-time data ingestion through Kafka.

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🚀 Quickstart (Local Setup)

1. Create .env in the project root (see variables below).

2. Install dependencies:

   npm install

3. (Optional) Start Kafka locally:

   docker-compose -f kafka/docker-compose.yml up -d

4. Run the server:

   npm start

The server verifies MySQL connectivity before startup. Ensure MySQL (and MongoDB for consumers) is running.

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🔑 Environment Variables

Create a .env file with:

MAINPORT=2025
JWT_SECRET=supersecret
MYSQL_HOST=127.0.0.1
MYSQL_USER=root
MYSQL_PASSWORD=example
MYSQL_DB=eventsphere
MONGO_URI=mongodb://localhost:27017/eventsphere
KAFKA_BROKER=localhost:9092
DISCORD_WEBHOOK_URL=
CLIENT_URL=http://localhost:3000
SERVER_URL=http://localhost

Variable	Purpose
MAINPORT	Server port (default 2025)
JWT_SECRET	JWT signing secret
MYSQL_*	MySQL connection credentials
MONGO_URI	MongoDB connection for log storage
KAFKA_BROKER	Kafka broker address
DISCORD_WEBHOOK_URL	Optional Discord webhook (tickets)
CLIENT_URL / SERVER_URL	Used for CORS and image URLs

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🏗 Architecture & Data Flow

• Server: server.js (Express, CORS, helmet, compression)
• Routes: Organized under routes/ (auth, admin, leader, user, image, fetch)
• Controllers: Handle business logic; Services: perform DB operations
• MySQL: Primary data storage (config/mysqlConfig.js)
• Kafka: Producers log activity → Consumers store batches in MongoDB
• MongoDB: Long-term storage for logs (database/mongodb/)

Example Flows

• Registration: /api/auth/register → authService.registerUser() → MySQL procedure CreateUser
• Image Upload: /api/image/upload → multer → imageService.saveImageDetails() → file moved to /uploads/
• Logging: Kafka producer publishes JSON → Consumer batch inserts into MongoDB every 15 minutes

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🔗 API Summary

Base path: /api

Module	Key Endpoints	Auth
Auth	POST /auth/register, POST /auth/login, GET /auth/auto-login	JWT
Image	POST /image/upload (multipart, fields: eventId, uploadedBy, caption)	API Key
Admin	CRUD for users, events, announcements, roles (/admin/*)	API Key
Leader	Manage members, roles, requests (/leader/*)	API Key
Fetch	Get events, organizations, announcements (/fetch/*)	API Key
User	POST /user/raiseTicket (triggers Discord webhook)	JWT

Responses are JSON and include success: true|false with proper HTTP codes.

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🧩 Kafka & Consumers

• Topics: FunctionCallLogs, LeaderActivityLogs

• Producers: producers/functionCallProducer.js, producers/leaderActivityProducer.js

• Consumers: consumers/functionCallLogConsumer.js, consumers/leaderActivityLogConsumer.js

  • Buffer messages, then bulk insert into MongoDB every 15 minutes

• Local Kafka: kafka/docker-compose.yml

  • Create topics via kafka-topics CLI if needed

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🖼 Image Upload Flow

1. middleware/uploadMiddleware.js handles file storage via multer

2. imageService.saveImageDetails():

   • Inserts record into MySQL
   • Renames file → <imageId>.png
   • Updates DB with public image URL (SERVER_URL + port)

3. Files served under /uploads path

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⚙️ Operations & Scaling

• Scale consumers horizontally (more Kafka partitions + consumer instances)
• Monitor consumer lag and MongoDB batch times
• Periodically backup MySQL and rotate MongoDB logs
• Use PM2 or containers for production runtime

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🤝 Contributing

1. Branch from main
2. Implement and test changes locally
3. Submit a PR with description and validation steps

Automated tests not yet included — test against seeded DB manually.

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🗂 File Map (Short)

server.js                 → Entry point
config/                   → MySQL, Kafka configs
routes/, controllers/     → API & logic
services/                 → DB business logic
producers/, consumers/    → Kafka modules
database/mongodb/         → Mongoose models
middleware/               → Auth, upload, API key
utils/, webhooks/         → Helpers, Discord integration

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🧾 License

Licensed under GNU GPL v3 — see LICENSE.