GoChat - Complete Real-time Chat Application

A full-stack real-time chat application built with Go backend and Next.js frontend.

🚀 Features

Backend (Go)

• Real-time WebSocket messaging
• MongoDB for message persistence
• Redis for job queuing
• Email notifications via MailHog
• Room-based chat system
• User presence management
• CORS-enabled API
• Docker containerization

Frontend (Next.js)

• Modern React with TypeScript
• Real-time messaging interface
• Connection testing & diagnostics
• Responsive design with Tailwind CSS
• shadcn/ui components
• User presence indicators

📁 Project Structure

``` gochat-server/ ├── cmd/ │ └── main.go # Application entry point ├── internal/ │ ├── config/ # Configuration management │ ├── database/ # MongoDB connection │ ├── handlers/ # HTTP & WebSocket handlers │ ├── hub/ # WebSocket hub & client management │ ├── models/ # Data models │ ├── queue/ # Job queue management │ └── services/ # Business logic services ├── frontend/ # Next.js frontend application │ ├── app/ # Next.js app directory │ ├── components/ # React components │ └── lib/ # Utility functions ├── docker-compose.yaml # Docker services configuration ├── dockerfile # Go application container ├── go.mod # Go dependencies └── README.md # This file ```

🛠️ Setup & Installation

Prerequisites

• Go 1.23+
• Node.js 18+
• Docker & Docker Compose

1. Clone the Repository

```bash git clone cd gochat-server ```

2. Start Backend Services

```bash

Start all services (MongoDB, Redis, MailHog, Go server)

docker-compose up -d

Check services are running

docker-compose ps ```

3. Setup Frontend

```bash cd frontend npm install npm run dev ```

4. Access the Application

• Frontend: http://localhost:3000
• Backend API: http://localhost:8080
• Connection Test: http://localhost:3000/test

🔧 Configuration

Environment Variables

Create a .env file in the root directory:

```env

Server Configuration

PORT=8080

Database Configuration

MONGO_URI=mongodb://admin:password123@localhost:27017/chatdb?authSource=admin DATABASE_NAME=chatdb

Redis Configuration

REDIS_ADDR=localhost:6379

SMTP Configuration (MailHog)

SMTP_HOST=localhost SMTP_PORT=1025 SMTP_USER= SMTP_PASS=

CORS Configuration

CORS_ORIGINS=http://localhost:3000,http://127.0.0.1:3000 ```

🚀 Usage

1. Test Connection

1. Visit http://localhost:3000/test
2. Click "Run All Tests" to verify backend connectivity
3. Ensure all tests pass before proceeding

2. Start Chatting

1. Go to http://localhost:3000
2. Enter your username, user ID, and room ID
3. Click "Join Room" to start chatting
4. Open multiple browser tabs to test real-time messaging

3. Monitor Services

• MailHog UI: http://localhost:8025 (Email testing)
• Mongo Express: http://localhost:8082 (Database admin)
• Redis Commander: http://localhost:8081 (Redis admin)
• Asynq Monitor: http://localhost:8083 (Job queue monitoring)

🏗️ Architecture

Backend Architecture

``` ┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐ │ WebSocket │ │ REST API │ │ Job Queue │ │ Handlers │ │ Handlers │ │ Workers │ └─────────────────┘ └─────────────────┘ └─────────────────┘ │ │ │ └───────────────────────┼───────────────────────┘ │ ┌─────────────────────────────────────────────────┐ │ Hub (Message Broker) │ └─────────────────────────────────────────────────┘ │ ┌───────────────────────┼───────────────────────┐ │ │ │ ┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐ │ MongoDB │ │ Redis │ │ SMTP │ │ (Messages) │ │ (Queues) │ │ (MailHog) │ └─────────────────┘ └─────────────────┘ └─────────────────┘ ```

Frontend Architecture

``` ┌─────────────────────────────────────────────────────────────┐ │ Next.js Frontend │ ├─────────────────────────────────────────────────────────────┤ │ HomePage │ ChatRoom │ ConnectionTest │ UI Components │ ├─────────────────────────────────────────────────────────────┤ │ WebSocket Client & REST API Client │ └─────────────────────────────────────────────────────────────┘ │ ┌─────────────────────┐ │ Go Backend API │ │ (localhost:8080) │ └─────────────────────┘ ```

🔍 API Endpoints

WebSocket

• ws://localhost:8080/ws/{roomID}/{userID}?username={username}

REST API

• GET /health - Health check
• GET /test - Frontend connectivity test
• GET /rooms/{roomID}/messages?limit={limit} - Get message history
• GET /rooms/{roomID}/users - Get room users
• POST /queue-email - Queue email notification

🐛 Troubleshooting

Common Issues

1. CORS Errors

   • Ensure CORS middleware is properly configured in cmd/main.go
   • Check that frontend URL is in allowed origins

2. WebSocket Connection Failed

   • Verify Go server is running on port 8080
   • Check WebSocket upgrader configuration
   • Ensure no firewall blocking connections

3. Database Connection Issues

   • Verify MongoDB is running: docker-compose ps
   • Check MongoDB credentials in environment variables
   • Ensure database is accessible on port 27017

4. Frontend Build Errors

   • Run npm install in frontend directory
   • Check Node.js version (18+ required)
   • Verify all dependencies are installed

Debug Commands

```bash

Check Docker services

docker-compose ps

View Go server logs

docker-compose logs gochat-server

Check MongoDB connection

docker-compose exec mongodb mongosh

Check Redis connection

docker-compose exec redis redis-cli ping

Test backend health

curl http://localhost:8080/health ```

🚀 Deployment

Production Deployment

1. Update environment variables for production
2. Build frontend: cd frontend && npm run build
3. Build Go binary: go build -o main cmd/main.go
4. Deploy using Docker or your preferred platform

Docker Production Build

```bash

Build production images

docker-compose -f docker-compose.prod.yml build

Deploy to production

docker-compose -f docker-compose.prod.yml up -d ```

🤝 Contributing

1. Fork the repository
2. Create a feature branch: git checkout -b feature-name
3. Make your changes
4. Test thoroughly using the connection test
5. Submit a pull request

📝 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Echo Framework for the Go web framework
• Gorilla WebSocket for WebSocket implementation
• Next.js for the React framework
• shadcn/ui for the UI components
• MongoDB for data persistence
• Redis for job queuing
• MailHog for email testing