import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Random;

public class LoadBalancer extends Thread {
    static String hosts[] = { "localhost", "localhost" };
    static int ports[] = { 8081, 8082 };
    static int nbHosts = 2;
    static Random rand = new Random();
    static ServerSocket ss;

    Socket client_socket;

    public LoadBalancer(Socket socket) {
        this.client_socket = socket;
    }

    @Override
    public void run() {
        try {
            InputStream client_is = this.client_socket.getInputStream();
            OutputStream client_os = this.client_socket.getOutputStream();

            // on selectionne un serveur au pif
            int id = rand.nextInt(nbHosts);
            Socket server_socket = new Socket(hosts[id], ports[id]);
            System.out.println("Established connection with server " + id + " : " + server_socket);

            InputStream server_is = server_socket.getInputStream();
            OutputStream server_os = server_socket.getOutputStream();

            // création du buffer de transfert
            byte[] buffer = new byte[1024];
            int buffer_length;

            // transfère de la requête du client vers le server
            buffer_length = client_is.read(buffer);
            System.out.println("Received " + buffer + " from client");
            server_os.write(buffer, 0, buffer_length);
            System.out.println("Sent the buffer to server " + id);

            // transfère de la requête du server vers le client
            buffer_length = server_is.read(buffer);
            System.out.println("Received " + buffer + " from server");
            client_os.write(buffer, 0, buffer_length);
            System.out.println("Sent the buffer to client");

            // fermeture des streams server
            server_os.close();
            server_is.close();

            // fermeture des streams client
            client_os.close();
            client_is.close();

            // fermeture des sockets client et serer
            this.client_socket.close();
            server_socket.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws IOException {
        System.out.println("Début du load balancer");
        try {
            ss = new ServerSocket(8080);
            System.out.println("ServerSocket créé");
            while (true) {
                Socket new_client = ss.accept();
                System.out.println("Nouvelle connection: " + new_client);
                LoadBalancer ld = new LoadBalancer(new_client);
                ld.start();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            ss.close();
        }
    }

}