Multi-user chat client. Needs server

Protocol structure:
<DataType>+' '+<Size of Message>+' '+<Message>

DataType:
MESSAGE
PING
PONG
NICK
CHAT
LIST

Structure of CHAT message:
“CHAT"+' '<Chat ID>+' '+<ChatCommand>+' '+<Message>

ChatCommand:
INIT
INVITE
LIST
ACCEPT
REJECT
LEAVE

The DataType and ChatCommand LIST both share the same message structure (also called MetaLinkList):
<Number of items in list>+' '+<Length of first item>+' '+<First item>+' '+<Length of second item>+' '+<Second item>+etc. etc.

Structure of INIT: //Only clients initiate this command
“INIT"+' '+<MetaLinkList of participants in new chat>
//Note that INIT is always prepended by chat ID of 0

Structure of INVITE: //Both server and client can do this
“INVITE"+' '+<MetaLinkList of participants to invite>

Structure of LIST //Server command
“LIST"+' '+<MetaLinkList of participants in current chat>

Structure of ACCEPT //Client command
"ACCEPT"+' '+""
//May change in the future

Structure of REJECT //Client command
"REJECT"+' '+""
//May change in the future

Structure of LEAVE //Both client and server (“kick") can do this
“LEAVE"+' '+<Optional leave message>

Structure of MESSAGE (server->client): //Chat ID 0==broadcast
“MESSAGE"+' '+<MetaLinkList with only sender Nick>+' '+<Message>
Structure of MESSAGE (client->server): //Chat ID 0==broadcast
“MESSAGE"+' '+<Message>