clavardator/server/src/main/java/fr/insa/clavardator/server/Proxy.java

package fr.insa.clavardator.server;

import fr.insa.clavardator.lib.errors.UsernameTakenException;
import fr.insa.clavardator.lib.message.Message;
import fr.insa.clavardator.lib.network.TcpConnection;
import fr.insa.clavardator.lib.network.TcpListener;
import fr.insa.clavardator.lib.users.UserInformation;
import fr.insa.clavardator.lib.util.Log;

import java.io.EOFException;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

public class Proxy {
	private static final int PROXY_PORT = 35750;
	private final HashMap<String, TcpConnection> users = new HashMap<>();
	private final TcpListener proxyListener;

	public Proxy() {
		proxyListener = new TcpListener(PROXY_PORT);
		proxyListener.acceptConnection(clientSocket -> {

					Log.v(getClass().getSimpleName(), "Accepting a new user");
					TcpConnection connection = new TcpConnection(clientSocket);
					connection.receive(msg -> {

						if (msg instanceof Message) {
							Log.v(getClass().getSimpleName(), "Transmitting message: " + msg);
							transmitMessage((Serializable) msg, ((Message) msg).getRecipient().id);

						} else if (msg instanceof UsernameTakenException) {
							UsernameTakenException unameTaken = ((UsernameTakenException) msg);
							transmitMessage(unameTaken, unameTaken.recipient);

						} else if (msg instanceof UserInformation) {
							Log.v(getClass().getSimpleName(), "Registering new user: " + msg);
							users.put(((UserInformation) msg).id, connection);
							for (String userId : users.keySet()) {
								UserInformation userInfo = ((UserInformation) msg);
								if (!userId.equals(userInfo.id)) {
									transmitMessage((Serializable) msg, userId);
								}
							}
						}

					}, e -> {
						if (e instanceof EOFException) {
							for (Map.Entry<String, TcpConnection> user : users.entrySet()) {
								if (user.getValue().equals(connection)) {
									Log.v(getClass().getSimpleName(), "Disconnecting user " + user.getKey());
									users.remove(user.getKey());
									break;
								}
							}
						} else {
							Log.e(getClass().getSimpleName(), "Error while receiving message to transmit", e);
						}
					});
				},
				e -> Log.e(getClass().getSimpleName(), "Error while accepting a user", e));
	}


	void transmitMessage(Serializable msg, String recipientId) {
		TcpConnection user = users.get(recipientId);
		if (user == null) {
			Log.e(getClass().getSimpleName(), "Cannot find the recipient in the connected users");
		} else {
			user.send(msg, null, e -> Log.e(getClass().getSimpleName(), "Error while sending message", e));
		}
	}

	public void stop() {
		proxyListener.stopAccepting();
		for (TcpConnection connection : users.values()) {
			connection.close();
		}
	}
}