import java.rmi.Naming;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

public class ChatServerImpl extends UnicastRemoteObject implements ChatServer
{
	private List users = new LinkedList ();
	
	public synchronized void send (String name, String text) throws RemoteException
	{
		sendToAll (name + ": " + text);
	}

	public synchronized void disconnect (String name) throws RemoteException
	{
		users.remove(name);
		sendToAll ("<<" + name + " leaves the chat>>");
	}
	
	public synchronized void connect (String name, ChatClient client) throws RemoteException
	{
		users.add (new User (name, client));
		sendToAll ("<<" + name + " enters the chat>>");
	}

	public ChatServerImpl () throws RemoteException
	{
		super ();
	}

	private void sendToAll (String msg)
	{
		Iterator iter = users.iterator ();
		
		while (iter.hasNext ())
		{
			User user = (User) iter.next ();
			
			try
			{
				user.getClient ().send(msg);
			} 
			catch (RemoteException e)
			{
				users.remove (user.getName());
			}
		}
	}
	
	public static void main (String[] args)
	{
		try
		{
			ChatServerImpl server = new ChatServerImpl ();
			Naming.rebind ("//localhost:1099/ChatServer", server);
			System.out.println ("Ready for connections...");
		} 
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}
	
	private static class User
	{
		private String name;
		private ChatClient client;
		
		public User (String n, ChatClient c)
		{
			name = n;
			client = c;
		}
		
		public String getName ()
		{
			return name;
		}
		
		public ChatClient getClient ()
		{
			return client;
		}
		
		public boolean equals (Object obj)
		{
			if (this == obj)
				return true;
			
			if (obj == null)
				return false;
			
			if (obj instanceof String)
				return name.equals (obj);
			
			if (! (obj instanceof User))
				return false;
			
			return name.equals (((User) obj).name);
		}
	}
}