Live Chat Server

A real-time TCP-based chat application built with C# and .NET 8.0, featuring a multi-client server and console-based client interface.

Features

• Multi-client Support: Multiple users can connect and chat simultaneously
• Real-time Messaging: Instant message delivery to all connected clients
• User Join/Leave Notifications: Visual indicators with emojis when users connect or disconnect
• Async/Await Architecture: Modern C# patterns for optimal performance
• Cross-platform: Runs on Windows, Linux, and macOS

Project Structure

Live-Chat-Server/
├── ChatServer/
│   ├── Program.cs          # TCP server implementation
│   └── ChatServer.csproj   # Server project file
├── ChatClient/
│   ├── Program.cs          # TCP client implementation
│   └── ChatClient.csproj   # Client project file
└── README.md               # This file

Prerequisites

• .NET 8.0 SDK or later
• Windows, Linux, or macOS
• Terminal/Command Prompt access

Installation & Setup

1. Clone or download the project

   git clone <repository-url>
   cd Live-Chat-Server

2. Build the projects

   # Build server
   cd ChatServer
   dotnet build
   cd ..
   
   # Build client
   cd ChatClient
   dotnet build
   cd ..

Usage

Starting the Server

1. Open a terminal and navigate to the server directory:

   cd ChatServer

2. Run the server:

   dotnet run

3. You should see:

   Server started on port 5000...
   

Connecting Clients

1. Open a new terminal window/tab and navigate to the client directory:

   cd ChatClient

2. Run the client:

   dotnet run

3. Enter your username when prompted:

   Enter your name: YourName
   

4. Start chatting! Type messages and press Enter to send.

5. To disconnect: Press Enter on an empty line.

Running Multiple Clients

Open additional terminal windows and repeat the client connection steps to simulate multiple users chatting simultaneously.

Architecture

Server (ChatServer/Program.cs)

• TCP Listener: Listens on port 5000 for incoming connections
• Client Management: Maintains a thread-safe list of connected clients
• Message Broadcasting: Sends messages to all connected clients except the sender
• Async Operations: Uses async/await for non-blocking I/O operations

Client (ChatClient/Program.cs)

• TCP Connection: Connects to server at 127.0.0.1:5000
• Dual Threading: Separate threads for sending and receiving messages
• Cancellation Support: Graceful shutdown with CancellationToken
• Real-time Display: Continuous listening for incoming messages

Technical Details

Communication Protocol

1. Client connects to server via TCP
2. First message sent is the username
3. Server broadcasts join notification: 📢 Username joined the chat
4. All subsequent messages are broadcast as: Username: message
5. Leave notifications: ❌ Username left the chat

Key Features

• Thread Safety: Uses locks for client list management
• Error Handling: Graceful handling of client disconnections
• Resource Management: Proper disposal of network resources
• Async I/O: Non-blocking network operations

Example Chat Session

Server Console:
Server started on port 5000...
Client connected.
📢 Alice joined the chat
Alice: Hello everyone!
📢 Bob joined the chat
Bob: Hi Alice!
Alice: How are you doing?
❌ Alice left the chat

Client Console (Alice):
Enter your name: Alice
📢 Alice joined the chat
> Hello everyone!
📢 Bob joined the chat
Bob: Hi Alice!
> How are you doing?

Client Console (Bob):
Enter your name: Bob
Alice: Hello everyone!
📢 Bob joined the chat
> Hi Alice!
Alice: How are you doing?
>

Development

Building from Source

# Restore dependencies
dotnet restore

# Build all projects
dotnet build

# Run tests (if any)
dotnet test

Running Multiple Instances for Testing

# Terminal 1 - Start server
cd ChatServer && dotnet run

# Terminal 2 - First client
cd ChatClient && dotnet run

# Terminal 3 - Second client  
cd ChatClient && dotnet run

# Terminal 4 - Third client
cd ChatClient && dotnet run

Configuration Options

• Server Port: Default is 5000, modify in ChatServer/Program.cs
• Buffer Size: Default is 1024 bytes for message buffers
• Server Address: Currently set to 127.0.0.1 (localhost) for local testing

Code Structure

Server Architecture

// Main components:
- TcpListener: Accepts incoming connections
- HandleClientAsync(): Manages individual client connections
- Broadcast(): Sends messages to all connected clients
- Thread-safe client list management

Client Architecture

// Main components:
- TcpClient: Connects to server
- ReceiveMessagesAsync(): Listens for incoming messages
- Main thread: Handles user input
- CancellationToken: Graceful shutdown

Getting Started

1. Download and install .NET 8.0 SDK from Microsoft's official website
2. Clone this repository or download the source code
3. Follow the Installation & Setup instructions above
4. Start the server first, then connect multiple clients to test the chat functionality