implement SIP

src/main/java/net/pixtaded/crab/client/CrabClient.java

@@ -84,16 +84,26 @@ public class CrabClient implements Crab {
     private void communicate() throws IOException {
         Scanner scanner = new Scanner(System.in);
         String message;
+        boolean preserveScreen = false;
+
         while (true) {
-            getLogs();
+            if (!preserveScreen) {
+                getLogs();
+            } else {
+                preserveScreen = false;
+            }
+
             System.out.print("Enter a message (or type '/exit' to exit): ");
             message = scanner.nextLine();
 
             if (message.equalsIgnoreCase("/exit")) {
                 break;
+            } else if (message.equalsIgnoreCase("/info")) {
+                sendPacket(SERVER_INFO, "", true);
+                preserveScreen = true;
+            } else {
+                if (!message.isEmpty()) sendMessage(message);
             }
-
-            if (!message.isEmpty()) sendMessage(message);
         }
     }
 
@@ -128,7 +138,28 @@ public class CrabClient implements Crab {
             } case LOGS -> {
                 byte[] bytes = socket.getInputStream().readNBytes(lastBufferLength);
                 cache = new Logs(lastBufferLength, new String(bytes, StandardCharsets.UTF_8));
-            } default -> {
+            } case SERVER_INFO -> {
+                InputStream input = socket.getInputStream();
+                int versionByte = input.read();
+                if (versionByte == -1) {
+                    System.out.println("The server did not provide any information...");
+                    return;
+                }
+
+                String protocolVersion;
+                switch (versionByte) {
+                    case 0x01 -> protocolVersion = "RACv1";
+                    case 0x02 -> protocolVersion = "RACv1.99";
+                    case 0x03 -> protocolVersion = "RACv2";
+                    default -> protocolVersion = "Unknown RAC version";
+                }
+
+                byte[] nameBytes = input.readAllBytes();
+                String serverName = new String(nameBytes, StandardCharsets.UTF_8);
+
+                System.out.println("\n\033[36mServer Information:\033[0m");
+                System.out.println("\033[33mProtocol:\033[0m " + protocolVersion);
+                System.out.println("\033[33mName:\033[0m " + serverName + "\n");
             }
         }
     }

src/main/java/net/pixtaded/crab/common/PID.java

@@ -7,4 +7,5 @@ public class PID {
     public static final byte CACHED_LOGS = 0x02;
     public static final byte AUTHENTICATED_MESSAGE = 0x02;
     public static final byte REGISTER = 0x03;
+    public static final byte SERVER_INFO = 0x69;
 }

src/main/java/net/pixtaded/crab/server/CrabServer.java

@@ -20,7 +20,7 @@ public class CrabServer implements Crab {
     private final Database db;
     private Logs cache = new Logs(0, "");
     public static final byte RAC_VERSION = 0x02;
-    public final ExecutorService threadPool = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
+    public final ExecutorService threadPool = Executors.newCachedThreadPool();
 
     public CrabServer() {
         this.db = new Database("data.db");