Chat Application

This is a real-time chat application built with a Django backend, WebSocket communication, and Redis for message caching. The frontend is implemented using HTML templates. The project follows SOLID principles to ensure maintainability and scalability.

Project Versions

This project has two implementations:

1. Main branch (main) – Traditional Django templates for frontend rendering.
2. DRF branch (drf) – Django REST Framework (DRF) API backend for SPA/frontend or external clients.

Features

• User Authentication: Login and registration system for users.
• Room Management: Users can create or join chat rooms.
• Real-Time Messaging: WebSocket-based chat with message rate limiting (1 message per second, 10 messages per minute).
• Message Caching: Messages are stored in Redis for active rooms. When the first user joins a room, messages are fetched from the PostgreSQL database. Subsequent users retrieve messages from Redis. Messages are cleared from Redis when all users leave the room.

Tech Stack

• Backend: Django with WebSocket support (via Django Channels)
• Database: PostgreSQL
• Caching: Redis
• Frontend: HTML templates
• Containerization: Docker

Prerequisites

• Docker
• Docker Compose

Setup and Installation

1. Clone the repository:

   git clone <repository-url>
   cd <repository-directory>

2. IF .env DOESN'T EXIST сreate a .env file in the project root with the following configuration:

POSTGRES_DB_NAME=postgres
POSTGRES_DB_USER=postgres
POSTGRES_DB_PASSWORD=postgres
POSTGRES_DB_HOST=postgres
POSTGRES_DB_PORT=5432
DJANGO_SECRET_KEY=django-insecure-1!p(mrem9s2(bi9vu%24g+mr1!o7$v6*0^6l^421)0-6)&74r=
REDIS_URL=redis://redis:6379
HOST=http://127.0.0.1:8000/
DOMAIN=127.0.0.1:8000

3. Build and run the project using Docker Compose:

docker-compose build
docker-compose up

4. Access the application at:
   http://127.0.0.1:8000

Test

docker exec -it django_app bash
pytest

Usage

1. Login/Register: Create an account or log in to access the chat features.
2. Room Selection/Creation: Choose an existing room or create a new one.
3. Chatting: Send and receive messages in real-time within the selected room.

Architecture

• WebSocket Communication: Real-time messaging is handled using Django Channels with WebSocket protocol.
• Redis Caching: Messages are cached in Redis for performance. When a room is empty, messages are cleared from Redis to free up memory.
• Rate Limiting: Implemented to prevent spam, allowing only 1 message per second and 10 messages per minute per user.
• SOLID Principles: The codebase adheres to SOLID principles for clean, maintainable, and scalable code.