// IDL for exercise 6

const short messlen = 60;
const short namelen = 10;

typedef string<messlen>	mess;
typedef string<namelen>	name;
typedef long		messid;

interface chat
{

	// the id of the next message, can be used to know what to poll
	// we could do without this, but it is a good example
	readonly attribute messid nextmessage;

	// operation for joining a chat
	// returns success, and the number of next (not yet posted) message
	boolean join(in name username, out messid firstmessage);

	// operation to poll new messages
	// return success, message(mesageid)
	// strings are empty ("") in case of failed poll
	boolean pollmessage(in messid messageid, out name username,
			    out mess message);

	// operation to post a new message
	// returns the id of the message
	messid postmessage(in name username, in mess message);

	// diconnection
	// we could have done without this as the server does not
	// keep any information about clients
	void disconnect(in name username);
};