Design a complete Chat Room using multithreaded environment that should be capable to communicate with several threads at a time. The processes can send and receive messages with single and group chat. For each user a separate thread should be created. When a user uses the chat room for the first time, he/she must register/sign up a new account with a user name and password. The messages are saved for each user in a separate file. The message received or sent is saved along with the Date/Time and name of the sender or receiver. As it is done on the phones. When a user Login later he/she can view the earlier messages sent or received.

C/C++/JAVA preferred.