package dslab.nameserver;

import java.io.InputStream;
import java.io.PrintStream;
import java.rmi.*;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;

import dslab.ComponentFactory;
import dslab.util.Config;

public class Nameserver implements INameserver {

    static Registry REGISTRY;

    /**
     * Creates a new server instance.
     *
     * @param componentId the id of the component that corresponds to the Config resource
     * @param config the component config
     * @param in the input stream to read console input from
     * @param out the output stream to write console output to
     */
    public Nameserver(String componentId, Config config, InputStream in, PrintStream out) {
        // only root nameserver creates RMI registry
        String registryName = config.getString("root_id");
        String registryHost = config.getString("registry.host");
        int registryPort = config.getInt("registry.port");
        if (componentId.equals("ns-root")) {
            // Root Nameserver
            INameserverRemote nameserverRemote = new NameServerRemote("Root Nameserver");
            try {
                INameserverRemote stub = (INameserverRemote) UnicastRemoteObject.exportObject(nameserverRemote, registryPort);
                REGISTRY = LocateRegistry.createRegistry(registryPort);
                REGISTRY.rebind(registryName, stub);
                System.out.println("Nameserver bound.");
            } catch (RemoteException e) {
                System.err.println("Nameserver exception:");
                e.printStackTrace();
            }
        } else {
            // Zone Nameserver
            String domain = config.getString("domain");
            try {
                 REGISTRY = LocateRegistry.getRegistry(registryHost, registryPort);
                 INameserverRemote nameserverRemote = (INameserverRemote) REGISTRY.lookup(registryName);
                 nameserverRemote.registerNameserver(domain, new NameServerRemote(domain));
            } catch (RemoteException | NotBoundException e) {
                e.printStackTrace();
            } catch (InvalidDomainException e) {
                e.printStackTrace();
            } catch (AlreadyRegisteredException e) {
                e.printStackTrace();
            }
            System.out.printf("Zone Nameserver %s started!%n", domain);
        }
    }

    @Override
    public void run() {
        // TODO
    }

    @Override
    public void nameservers() {
        // TODO
    }

    @Override
    public void addresses() {
        // TODO
    }

    @Override
    public void shutdown() {
        // TODO
    }

    public static void main(String[] args) throws Exception {
        INameserver component = ComponentFactory.createNameserver(args[0], System.in, System.out);
        component.run();
    }

}