Communication Networks Final Project - Vessages

Created by: Tuan Vu

Description of App: An instant messaging platform that is defined by a client-server architecture that has user authentication and real-time online status.

Required Features

The following required functionality is completed:

• Client-Server Architecture
  • Client can connect to the server using correct IP and port
  • Client can send and receive msgs to/from the server following TCP connection
  • Client reconnects to the server if a connection is lost (Bonus)
  • Client gracefully exits without affecting other connected clients (Bonus)
  • Server can bind to a specific IP and port for incoming client connections
  • Server can handle multiple simultaneous client connections using threads or async I/O
  • Server can gracefully handle client disconnections without crashing (Bonus)
  • Server maintains a list of active client connections in memory
  • Server interprets and responds to client commands
• User Authentication
  • Clients can register new accounts with REGISTER command
  • Server should validate unique username on registration and stores new user into file
  • Server sends error if the username already exists on registration
  • Client can log into account with LOGIN command
  • Server validates the username and password
  • Server sends success or error message upon login attempt
  • Server keeps track of logged-in users and prevents duplicate logins with the same username
• Online Clients
  • Server maintains an updated list of online clients in-memory
  • Clients receive a list of online users upon login
  • Server broadcasts updates to all connected clients when a user logs in or out
  • Clients can send a WHO command to request a current list of online users
• Messaging
  • Client can send a direct message to another online user using SEND command
  • Server validates recipient username is online and forwards message, else server sends error to sender client
  • Client receives the message in real-time
  • Messages are displayed with a sender's username and timestamp
• Database/File Storage
  • File schema includes a users object that contains fields for a username, password, and status
  • File is updated in real-time for user registration and login attempts
  • File can be backed up and restored without data loss