public class SocketServer {

    public ServerSocket server;
    public static HashMap<Integer, PrintWriter> listOfClients;
    public int id=0;


    /**
     * Wait for Sockets from clients
     */
    public void listenToClients() {

        // Never stop waiting!
        while (true) {

            try {

                // Accept socket from this client
                Socket clientSocket = server.accept();

                // Add PrintWriter (from client) to array
                PrintWriter writer = new PrintWriter(clientSocket.getOutputStream());
                listOfClients.put(id, writer);

                // Create and start new thread for this client
                Thread clientThread = new Thread(new ClientHandler(clientSocket, id));
                clientThread.start();

                Logger.out("[Client#" + id + "] connected.");

                // Increase ID
                id++;
            } catch (IOException e) {
                Logger.out("Can't listen to client(s)! Error code: 002");
                e.printStackTrace();
            }
        }
    }

    /**
     * Runs the SocketServer
     * @return
     */
    public boolean runServer() {

        try {

            // Start serversocket
            server = new ServerSocket(5555);
            Logger.out("Server started.");
            Logger.out("Waiting for clients to connect...");

            // Initialize PrintWriter (from clients) list
            listOfClients = new HashMap<Integer, PrintWriter>();
            return true;
        } catch (IOException e) {
            Logger.out("Server can not be started! Error code: 001");
            e.printStackTrace();
            return false;
        }
    }

    /**
     * Sends a message to all connected clients
     * @param message
     */
    public static void sendToAllClients(String message) {

        // Go through list and send message to all clients
        for(PrintWriter writer : listOfClients.values()) {

            writer.println(message);
            writer.flush();
        }
    }

    /**
     * Sends a message to a specific client
     * @param recieverID
     * @param message
     */
    public static void sendToClient(int recieverID, String message) {

        //Get client from list and send message
        PrintWriter writer = listOfClients.get(recieverID);
        writer.println(message);
        writer.flush();
    }
}