A real-time collaborative drawing application backend built with Go, Firebase, and WebSockets.

Phaint is a collaborative digital canvas platform that allows multiple users to create, edit, and share drawing projects in real-time. This backend handles user authentication, project management, real-time collaboration through WebSockets, and persistent storage using Firebase.

• Multi-user canvas editing with live cursor tracking
• Real-time synchronization of drawing operations
• User presence indicators with color-coded cursors
• WebSocket-based communication for low-latency updates

• User registration and authentication via Firebase Auth
• Email/password authentication
• User profile management

• Create and manage drawing projects
• Project collaboration with invite system
• Canvas-based project organization
• Persistent project data storage

• Multiple drawing tools (paths, rectangles, circles)
• Customizable stroke properties and fills
• Interactive elements with action support
• Canvas background customization

• WebSocket Handler: Manages real-time connections and broadcasts
• Canvas Service: Thread-safe canvas and vector element management
• Firebase Integration: Authentication and data persistence
• Project System: Multi-canvas project organization
• Invitation System: Secure project sharing

• Canvas: Individual drawing surfaces with vector data
• VectorElements: Paths, rectangles, and circles with properties
• Projects: Collections of canvases with metadata
• Users: Authentication and profile information

Create config/secrets/config.yaml:

firebase:
 database_url: "your-firebase-database-url"
 credential_path: "\\config\\secrets\\firebase-credentials.json"
 web_api_key: "your-firebase-web-api-key"

1. Create a Firebase project
2. Enable Firestore Database
3. Enable Authentication with Email/Password
4. Download service account credentials
5. Place credentials in config/secrets/firebase-credentials.json

{
 "UID": "string",
 "mail": "string", 
 "username": "string"
}

{
 "UID": "string",
 "PID": "string",
 "ProjectName": "string",
 "CreationDate": "string",
 "Collaborators": ["string"],
 "CanvasesData": [Canvas]
}

{
 "CreatorUID": "string",
 "Link": "string",
 "ProjectID": "string",
 "Used": boolean
}

• Go 1.19+
• Firebase project with Firestore enabled
• Firebase service account credentials

1. Clone the repository:

git clone <repository-url>
cd phaint_be

2. Install dependencies:

go mod tidy

3. Set up configuration files (see Configuration section)

4. Run the application:

go run main.go

The server will start on port 8080.

phaint_be/
├── config/ # Configuration management
├── internal/
│ ├── handlers/ # HTTP and WebSocket handlers
│ ├── services/ # Business logic services
│ └── utils/ # Utility functions
├── models/ # Data models
└── main.go # Application entry point

1. Fork the repository
2. Create a feature branch
3. Implement changes with tests
4. Submit a pull request

For issues and questions, please open an issue on the repository or contact the development team.