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          | 81 ++++++++++++-------
 .../client/HandshakeSessionHandler.java       |  2 +-
 .../util/ServerListPingHandler.java           |  2 +-
 3 files changed, 56 insertions(+), 29 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 a1d3d1b54..e124245d5 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 @@ import java.util.Set;
  * 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);
       }
     }
@@ -191,6 +211,35 @@ public enum ProtocolVersion implements Ordered<ProtocolVersion> {
     return ImmutableList.copyOf(names);
   }
 
+  /**
+   * Returns whether this {@link ProtocolVersion} is supported.
+   *
+   * @return if the protocol supported
+   */
+  public boolean isSupported() {
+    return true;
+  }
+
+  /**
+   * Returns whether the protocol is supported.
+   *
+   * @param protocol the protocol as an int
+   * @return if the protocol supported
+   */
+  public static boolean isSupported(int protocol) {
+    return getProtocolVersion(protocol).isSupported();
+  }
+
+  /**
+   * Returns whether the {@link ProtocolVersion} is supported.
+   *
+   * @param version the protocol version
+   * @return if the protocol supported
+   */
+  public static boolean isSupported(ProtocolVersion version) {
+    return version != null && version.isSupported();
+  }
+
   /**
    * Gets the {@link ProtocolVersion} for the given protocol.
    *
@@ -201,35 +250,13 @@ public enum ProtocolVersion implements Ordered<ProtocolVersion> {
     return ID_TO_PROTOCOL_CONSTANT.getOrDefault(protocol, UNKNOWN);
   }
 
-  /**
-   * Returns whether the protocol is supported.
-   *
-   * @param protocol the protocol as an int
-   * @return if the protocol supported
-   */
-  public static boolean isSupported(int protocol) {
-    ProtocolVersion version = ID_TO_PROTOCOL_CONSTANT.get(protocol);
-
-    return version != null && !version.isUnknown();
-  }
-
-  /**
-   * Returns whether the {@link ProtocolVersion} is supported.
-   *
-   * @param version the protocol version
-   * @return if the protocol supported
-   */
-  public static boolean isSupported(ProtocolVersion version) {
-    return version != null && !version.isUnknown();
-  }
-
   /**
    * Returns whether this {@link ProtocolVersion} is unknown to the proxy.
    *
    * @return if the protocol is unknown
    */
   public boolean isUnknown() {
-    return this == UNKNOWN;
+    return false;
   }
 
   /**
@@ -238,7 +265,7 @@ public enum ProtocolVersion implements Ordered<ProtocolVersion> {
    * @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 3948d0875..f1fc2d49f 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 class HandshakeSessionHandler implements MinecraftSessionHandler {
   }
 
   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 d253d3594..951d60986 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 @@ public class ServerListPingHandler {
    */
   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();