package vs;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.nio.charset.StandardCharsets;

public class SyslogServer {

    private static final int SYSLOG_PORT = 514;
    private static final int DISCOVERY_PORT = 8888;
    private static final int MAX_MESSAGE_LENGTH = 1024;

    public static void main(String[] args) {
        System.out.println("=== Syslog Server Management ===");
        
        // Startet den Syslog-Server
        new Thread(() -> runSyslogServer()).start();

        // Startet den Discovery-Server
        new Thread(() -> runDiscoveryServer()).start();
    }

    private static void runSyslogServer() {
        try (DatagramSocket socket = new DatagramSocket(SYSLOG_PORT)) {
            byte[] buffer = new byte[2048];
            System.out.println("[INFO] Syslog-Dienst aktiv auf Port " + SYSLOG_PORT);

            while (true) {
                DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
                socket.receive(packet);

                int length = packet.getLength();
                if (length > MAX_MESSAGE_LENGTH) {
                    System.err.println("[WARN] Nachricht von " + packet.getAddress() + " zu lang. Ignoriert.");
                    continue;
                }

                String raw = new String(packet.getData(), 0, length, StandardCharsets.UTF_8);
                String clean = raw.replace("\uFEFF", "").replace("", "");

                // Trennung von Metadaten und Inhalt
                int splitIndex = clean.lastIndexOf("]") + 1;
                String metadata = "Unbekannt";
                String messageContent = clean;

                if (splitIndex > 0 && splitIndex < clean.length()) {
                    metadata = clean.substring(0, splitIndex).trim();
                    messageContent = clean.substring(splitIndex).trim();
                }

                String separator = "==================================================";
                System.out.println("\n" + separator);
                System.out.println("NEUE SYSLOG-NACHRICHT");
                System.out.println("Quelle:    " + packet.getAddress().getHostAddress() + ":" + packet.getPort());
                System.out.println("Metadaten: " + metadata);
                System.out.println("Inhalt:    " + messageContent);
                System.out.println(separator);
            }
        } catch (IOException e) {
            System.err.println("[ERROR] Syslog-Server Fehler: " + e.getMessage());
        }
    }

    private static void runDiscoveryServer() {
        try (DatagramSocket socket = new DatagramSocket(DISCOVERY_PORT)) {
            byte[] buffer = new byte[256];
            System.out.println("[INFO] Discovery-Service aktiv auf Port " + DISCOVERY_PORT);

            while (true) {
                DatagramPacket request = new DatagramPacket(buffer, buffer.length);
                socket.receive(request);

                DatagramPacket response = new DatagramPacket(
                    new byte[0], 0, request.getAddress(), request.getPort()
                );
                socket.send(response);
                System.out.println("[DISCOVERY] Server-IP an Client mit der IP [" + request.getAddress().getHostAddress() + "] gemeldet.");
            }
        } catch (IOException e) {
            System.err.println("[ERROR] Discovery-Fehler: " + e.getMessage());
        }
    }
}