Chatroom Project

This project is a feature-rich, secure chat application built with Python. It features a modern graphical user interface (GUI) built with customtkinter, end-to-end message encryption, and support for large file transfers. The application uses a multi-threaded server to handle concurrent client connections robustly.

Features

• Graphical User Interface: A modern, theme-aware GUI built with customtkinter.
• Private & Public Messaging: Send messages to all users in the public chat or privately to specific users.
• Secure Communication: All messages are end-to-end encrypted using AES to ensure privacy.
• Large File Sharing: Reliably send and receive files of any size (e.g., PDFs, images) with a custom networking protocol.
• Interactive File Downloads: Clickable links in the chat window open a "Save As" dialog for easy downloading.
• Emoji Support: An interactive, graphical emoji picker allows users to easily add emojis to their messages.
• Real-time User List: See a list of all currently active users in the chatroom.
• Concurrent Connections: The server uses multi-threading to handle multiple clients smoothly and simultaneously.

Tech Stack & Dependencies

This project is built entirely with Python and leverages a mix of standard and third-party libraries for GUI, networking, encryption, and file handling.

• customtkinter (external) – Provides a modern and theme-aware graphical user interface.
• tkinter (standard) – The underlying GUI framework included with Python.
• Pillow (external) – Used to handle and display images (e.g., emojis, media previews).
• socket (standard) – Powers low-level TCP communication between clients and server.
• threading (standard) – Enables the server to handle multiple clients concurrently.
• pycryptodome (external) – Provides AES encryption and decryption for secure messaging and file sharing.
• json (standard) – Used for serializing and parsing structured messages.
• os (standard) – Handles file system operations like reading, saving, and organizing uploaded files.
• No framework – The server and client are built entirely from scratch using core Python libraries.
• No database – The application stores data in-memory or directly on disk (e.g., via server_storage/).

Getting Started

Follow these steps to set up and run the project on your local machine.

1. Prerequisites

• Python 3.8 or newer
• pip for installing packages
• An environment manager like conda or venv

2. Setup

First, clone the repository and navigate into the project's root directory.

git clone <your-repository-url>
cd chatroom-project

Next, create and activate a virtual environment.

# Using venv
python -m venv venv
source venv/bin/activate  # On Mac/Linux
venv\Scripts\activate    # On Windows

# Or using Conda
conda create --name chatroom-env python=3.10
conda activate chatroom-env

Now, install the required packages.

pip install -r requirements.txt

Finally, ensure the project is recognized as a Python package by creating __init__.py files.

# On Mac/Linux
touch shared/__init__.py server/__init__.py client/__init__.py

# On Windows
type nul > shared\__init__.py
type nul > server\__init__.py
type nul > client\__init__.py

3. Running the Application

Important: Always run the following commands from the project's root directory (chatroom-project/).

Step 1: Start the Server Open a terminal and run:

python -m server.server

You should see the confirmation message: [STARTED] Chat server on 127.0.0.1:8888

Step 2: Start the Client(s) Open one or more new terminal windows and run:

# To run the Graphical User Interface (GUI)
python -m client.gui

# To run the Command-Line Interface (CLI)
python -m client.client

You can run multiple clients, and they will all connect to the same server.

Troubleshooting

Error: ModuleNotFoundError: No module named 'shared' (or similar)

• Cause: You are likely running the command from the wrong directory or not using the -m flag.
• Solution:
  1. Make sure your terminal's current directory is the project root (chatroom-project).
  2. Always use the python -m folder.file syntax to run scripts. This allows Python to correctly resolve the project's internal imports.

Project Structure

chatroom-project/
│
├── client/
│   ├── gui.py          # The main file for the graphical user interface.
│   └── client.py       # A secondary command-line client for testing.
│
├── server/
│   └── server.py       # The multi-threaded server application.
│
├── shared/
│   ├── common.py       # Helper functions for message building/parsing.
│   ├── config.py       # Configuration variables (IP, port).
│   └── encrypt.py      # Functions for AES encryption and decryption.
|   └── protocol.md     # Protocol used for message and file formats.
│
├── server_storage/     # Temporary storage of uploaded files.
|
├── requirements.txt    # A list of required Python packages.
├── server.log          # A log file to write events.
└── README.md           # This file.