From 82189a6a21c9c69a925cfc5ee650d0da76c2472b Mon Sep 17 00:00:00 2001
From: Maxim Breitman <89523915+maximbreitman@users.noreply.github.com>
Date: Sat, 2 Mar 2024 06:42:02 +0300
Subject: [PATCH] Tiny rework of Protocol Version API (#1260)

---
 .../api/network/ProtocolVersion.java          | 55 ++++++++++++++-----
 .../client/HandshakeSessionHandler.java       |  2 +-
 .../util/ServerListPingHandler.java           |  2 +-
 3 files changed, 43 insertions(+), 16 deletions(-)

diff --git a/api/src/main/java/com/velocitypowered/api/network/ProtocolVersion.java b/api/src/main/java/com/velocitypowered/api/network/ProtocolVersion.java
index a1d3d1b542..e124245d56 100644
--- a/api/src/main/java/com/velocitypowered/api/network/ProtocolVersion.java
+++ b/api/src/main/java/com/velocitypowered/api/network/ProtocolVersion.java
@@ -21,8 +21,28 @@
  * Represents each Minecraft protocol version.
  */
 public enum ProtocolVersion implements Ordered<ProtocolVersion> {
-  UNKNOWN(-1, "Unknown"),
-  LEGACY(-2, "Legacy"),
+  UNKNOWN(-1, "Unknown") {
+    @Override
+    public boolean isUnknown() {
+      return true;
+    }
+
+    @Override
+    public boolean isSupported() {
+      return false;
+    }
+  },
+  LEGACY(-2, "Legacy") {
+    @Override
+    public boolean isLegacy() {
+      return true;
+    }
+
+    @Override
+    public boolean isSupported() {
+      return false;
+    }
+  },
   MINECRAFT_1_7_2(4,
       "1.7.2", "1.7.3", "1.7.4", "1.7.5"),
   MINECRAFT_1_7_6(5,
@@ -118,7 +138,7 @@ public enum ProtocolVersion implements Ordered<ProtocolVersion> {
   static {
     Set<ProtocolVersion> versions = EnumSet.noneOf(ProtocolVersion.class);
     for (ProtocolVersion value : values()) {
-      if (!value.isUnknown() && !value.isLegacy()) {
+      if (value.isSupported()) {
         versions.add(value);
       }
     }
@@ -192,13 +212,12 @@ public List<String> getVersionsSupportedBy() {
   }
 
   /**
-   * Gets the {@link ProtocolVersion} for the given protocol.
+   * Returns whether this {@link ProtocolVersion} is supported.
    *
-   * @param protocol the protocol as an int
-   * @return the protocol version
+   * @return if the protocol supported
    */
-  public static ProtocolVersion getProtocolVersion(int protocol) {
-    return ID_TO_PROTOCOL_CONSTANT.getOrDefault(protocol, UNKNOWN);
+  public boolean isSupported() {
+    return true;
   }
 
   /**
@@ -208,9 +227,7 @@ public static ProtocolVersion getProtocolVersion(int protocol) {
    * @return if the protocol supported
    */
   public static boolean isSupported(int protocol) {
-    ProtocolVersion version = ID_TO_PROTOCOL_CONSTANT.get(protocol);
-
-    return version != null && !version.isUnknown();
+    return getProtocolVersion(protocol).isSupported();
   }
 
   /**
@@ -220,7 +237,17 @@ public static boolean isSupported(int protocol) {
    * @return if the protocol supported
    */
   public static boolean isSupported(ProtocolVersion version) {
-    return version != null && !version.isUnknown();
+    return version != null && version.isSupported();
+  }
+
+  /**
+   * Gets the {@link ProtocolVersion} for the given protocol.
+   *
+   * @param protocol the protocol as an int
+   * @return the protocol version
+   */
+  public static ProtocolVersion getProtocolVersion(int protocol) {
+    return ID_TO_PROTOCOL_CONSTANT.getOrDefault(protocol, UNKNOWN);
   }
 
   /**
@@ -229,7 +256,7 @@ public static boolean isSupported(ProtocolVersion version) {
    * @return if the protocol is unknown
    */
   public boolean isUnknown() {
-    return this == UNKNOWN;
+    return false;
   }
 
   /**
@@ -238,7 +265,7 @@ public boolean isUnknown() {
    * @return if the protocol is legacy
    */
   public boolean isLegacy() {
-    return this == LEGACY;
+    return false;
   }
 
   @Override
diff --git a/proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java b/proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java
index 3948d08759..f1fc2d49f1 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java
@@ -117,7 +117,7 @@ public boolean handle(final HandshakePacket handshake) {
   }
 
   private void handleLogin(HandshakePacket handshake, InitialInboundConnection ic) {
-    if (!ProtocolVersion.isSupported(handshake.getProtocolVersion())) {
+    if (!handshake.getProtocolVersion().isSupported()) {
       // Bump connection into correct protocol state so that we can send the disconnect packet.
       connection.setState(StateRegistry.LOGIN);
       ic.disconnectQuietly(Component.translatable()
diff --git a/proxy/src/main/java/com/velocitypowered/proxy/connection/util/ServerListPingHandler.java b/proxy/src/main/java/com/velocitypowered/proxy/connection/util/ServerListPingHandler.java
index d253d35945..951d609861 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/connection/util/ServerListPingHandler.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/connection/util/ServerListPingHandler.java
@@ -143,7 +143,7 @@ private CompletableFuture<ServerPing> attemptPingPassthrough(VelocityInboundConn
    */
   public CompletableFuture<ServerPing> getInitialPing(VelocityInboundConnection connection) {
     VelocityConfiguration configuration = server.getConfiguration();
-    ProtocolVersion shownVersion = ProtocolVersion.isSupported(connection.getProtocolVersion())
+    ProtocolVersion shownVersion = connection.getProtocolVersion().isSupported()
         ? connection.getProtocolVersion() : ProtocolVersion.MAXIMUM_VERSION;
     PingPassthroughMode passthroughMode = configuration.getPingPassthrough();