fix: Working Implementation

backend/fabric/build.gradle.kts

@@ -10,9 +10,9 @@ dependencies {
     mappings(loom.officialMojangMappings())
     modImplementation(libs.fabric.loader)
     modImplementation(libs.fabric.api)
-    include(libs.mixinsextras)
-    implementation(libs.mixinsextras)
-    annotationProcessor(libs.mixinsextras)
+//    include(libs.mixinsextras)
+//    implementation(libs.mixinsextras)
+//    annotationProcessor(libs.mixinsextras)
 
     shadeModule(projects.signedvelocityBackendCommon)
 }

backend/fabric/src/main/java/io/github/_4drian3d/signedvelocity/fabric/SignedVelocity.java

@@ -3,13 +3,17 @@
 import io.github._4drian3d.signedvelocity.common.SignedQueue;
 import net.fabricmc.api.DedicatedServerModInitializer;
 import net.minecraft.resources.ResourceLocation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public final class SignedVelocity implements DedicatedServerModInitializer {
+    public static final Logger LOGGER = LoggerFactory.getLogger("SignedVelocity");
     public static final ResourceLocation CHANNEL = new ResourceLocation("signedvelocity", "main");
     public static final SignedQueue CHAT_QUEUE = new SignedQueue();
     public static final SignedQueue COMMAND_QUEUE = new SignedQueue();
 
     @Override
     public void onInitializeServer() {
+        LOGGER.info("Started SignedVelocity");
     }
 }

backend/fabric/src/main/java/io/github/_4drian3d/signedvelocity/fabric/mixins/ChatCommandPacketMixin.java

@@ -0,0 +1,22 @@
+package io.github._4drian3d.signedvelocity.fabric.mixins;
+
+import io.github._4drian3d.signedvelocity.fabric.model.SignedChatCommandPacket;
+import net.minecraft.network.protocol.game.ServerboundChatCommandPacket;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+
+@Mixin(ServerboundChatCommandPacket.class)
+public class ChatCommandPacketMixin implements SignedChatCommandPacket {
+    @Unique
+    private boolean signedVelocity$handled = false;
+
+    @Override
+    public boolean signedVelocity$handled() {
+        return this.signedVelocity$handled;
+    }
+
+    @Override
+    public void signedVelocity$handled(boolean handled) {
+        this.signedVelocity$handled = handled;
+    }
+}

backend/fabric/src/main/java/io/github/_4drian3d/signedvelocity/fabric/mixins/PlayerChatMixin.java

@@ -0,0 +1,22 @@
+package io.github._4drian3d.signedvelocity.fabric.mixins;
+
+import io.github._4drian3d.signedvelocity.fabric.model.SignedPlayerChatMessage;
+import net.minecraft.network.chat.PlayerChatMessage;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+
+@Mixin(PlayerChatMessage.class)
+public class PlayerChatMixin implements SignedPlayerChatMessage {
+    @Unique
+    public boolean signedVelocity$handled;
+
+    @Override
+    public boolean signedVelocity$handled() {
+        return signedVelocity$handled;
+    }
+
+    @Override
+    public void signedVelocity$handled(boolean handled) {
+        signedVelocity$handled = handled;
+    }
+}

backend/fabric/src/main/java/io/github/_4drian3d/signedvelocity/fabric/mixins/PlayerListMixin.java

@@ -0,0 +1,50 @@
+package io.github._4drian3d.signedvelocity.fabric.mixins;
+
+import io.github._4drian3d.signedvelocity.common.SignedResult;
+import io.github._4drian3d.signedvelocity.fabric.SignedVelocity;
+import io.github._4drian3d.signedvelocity.fabric.model.SignedPlayerChatMessage;
+import net.minecraft.network.chat.ChatType;
+import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.PlayerChatMessage;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.players.PlayerList;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import static java.util.Objects.requireNonNull;
+
+@Mixin(value = PlayerList.class, priority = 1)
+public abstract class PlayerListMixin {
+    @Shadow
+    public abstract void broadcastChatMessage(PlayerChatMessage playerChatMessage, ServerPlayer serverPlayer, ChatType.Bound bound);
+
+    @Inject(
+            method = "broadcastChatMessage(Lnet/minecraft/network/chat/PlayerChatMessage;Lnet/minecraft/server/level/ServerPlayer;Lnet/minecraft/network/chat/ChatType$Bound;)V",
+            at = @At("HEAD"), cancellable = true)
+    public void signedVelocity$handleChat(
+            PlayerChatMessage playerChatMessage,
+            ServerPlayer serverPlayer,
+            ChatType.Bound bound,
+            CallbackInfo ci
+    ) {
+        requireNonNull(serverPlayer);
+        if (!((SignedPlayerChatMessage)(Object)playerChatMessage).signedVelocity$handled()) {
+            ((SignedPlayerChatMessage)(Object)playerChatMessage).signedVelocity$handled(true);
+            final SignedResult result = SignedVelocity.CHAT_QUEUE.dataFrom(serverPlayer.getUUID())
+                    .nextResult().join();
+            // Cancelled Result
+            if (result.cancelled()) {
+                ci.cancel();
+                return;
+            }
+            final String modified = result.message();
+            // Modified Result
+            if (modified != null) {
+                this.broadcastChatMessage(playerChatMessage.withUnsignedContent(Component.literal(modified)), serverPlayer, bound);
+            }
+        }
+    }
+}

backend/fabric/src/main/java/io/github/_4drian3d/signedvelocity/fabric/mixins/ServerCommonPacketListenerMixin.java

@@ -1,10 +1,11 @@
 package io.github._4drian3d.signedvelocity.fabric.mixins;
 
+import com.google.common.io.ByteArrayDataInput;
+import com.google.common.io.ByteStreams;
 import io.github._4drian3d.signedvelocity.common.SignedQueue;
 import io.github._4drian3d.signedvelocity.common.SignedResult;
 import io.github._4drian3d.signedvelocity.fabric.SignedVelocity;
 import net.fabricmc.fabric.impl.networking.payload.PacketByteBufPayload;
-import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.protocol.common.ServerboundCustomPayloadPacket;
 import org.spongepowered.asm.mixin.Mixin;
 import net.minecraft.server.network.ServerCommonPacketListenerImpl;
@@ -19,10 +20,10 @@ public abstract class ServerCommonPacketListenerMixin {
     @Inject(at = @At("HEAD"), method = "handleCustomPayload", cancellable = true)
     private void signedVelocity$onPluginMessage(ServerboundCustomPayloadPacket packet, CallbackInfo ci) {
         if (packet.payload() instanceof PacketByteBufPayload payload && payload.id().equals(SignedVelocity.CHANNEL)) {
-            final FriendlyByteBuf input = payload.data();
-            final UUID playerId = UUID.fromString(input.readUtf());
-            final String source = input.readUtf();
-            final String result = input.readUtf();
+            final ByteArrayDataInput input = ByteStreams.newDataInput(payload.data().unwrap().array());
+            final UUID playerId = UUID.fromString(input.readUTF());
+            final String source = input.readUTF();
+            final String result = input.readUTF();
 
             final SignedQueue queue = switch (source) {
                 case "COMMAND_RESULT" -> SignedVelocity.COMMAND_QUEUE;
@@ -31,7 +32,7 @@ public abstract class ServerCommonPacketListenerMixin {
             };
             final SignedResult resulted = switch (result) {
                 case "CANCEL" -> SignedResult.cancel();
-                case "MODIFY" -> SignedResult.modify(input.readUtf());
+                case "MODIFY" -> SignedResult.modify(input.readUTF());
                 case "ALLOWED" -> SignedResult.allowed();
                 default -> throw new IllegalArgumentException("Invalid result " + result);
             };

backend/fabric/src/main/java/io/github/_4drian3d/signedvelocity/fabric/mixins/ServerGamePacketListenerMixin.java

@@ -0,0 +1,58 @@
+package io.github._4drian3d.signedvelocity.fabric.mixins;
+
+import io.github._4drian3d.signedvelocity.common.SignedResult;
+import io.github._4drian3d.signedvelocity.fabric.SignedVelocity;
+import io.github._4drian3d.signedvelocity.fabric.model.SignedChatCommandPacket;
+import net.minecraft.network.chat.LastSeenMessages;
+import net.minecraft.network.protocol.game.ServerboundChatCommandPacket;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.network.ServerGamePacketListenerImpl;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(value = ServerGamePacketListenerImpl.class, priority = 1)
+public abstract class ServerGamePacketListenerMixin {
+    @Shadow
+    public ServerPlayer player;
+
+    @Shadow
+    protected abstract void performChatCommand(ServerboundChatCommandPacket serverboundChatCommandPacket, LastSeenMessages lastSeenMessages);
+
+    @Inject(
+            method = "performChatCommand",
+            at = @At("HEAD"),
+            cancellable = true)
+    public void signedVelocity$handleChatCommand(
+            ServerboundChatCommandPacket packet,
+            LastSeenMessages lastSeenMessages,
+            CallbackInfo ci
+    ) {
+        if (!((SignedChatCommandPacket)(Object) packet).signedVelocity$handled()) {
+            return;
+        }
+        ((SignedChatCommandPacket)(Object) packet).signedVelocity$handled(true);
+        final SignedResult result = SignedVelocity.COMMAND_QUEUE.dataFrom(player.getUUID())
+                .nextResult().join();
+        if (result.cancelled()) {
+            ci.cancel();
+            return;
+        }
+        final String modified = result.toModify();
+        if (modified != null) {
+            // TODO: verify
+            this.performChatCommand(
+                    new ServerboundChatCommandPacket(
+                            modified,
+                            packet.timeStamp(),
+                            packet.salt(),
+                            packet.argumentSignatures(),
+                            packet.lastSeenMessages()
+                    ),
+                    lastSeenMessages
+            );
+        }
+    }
+}

backend/fabric/src/main/java/io/github/_4drian3d/signedvelocity/fabric/model/SignedChatCommandPacket.java

@@ -0,0 +1,7 @@
+package io.github._4drian3d.signedvelocity.fabric.model;
+
+public interface SignedChatCommandPacket {
+    boolean signedVelocity$handled();
+
+    void signedVelocity$handled(boolean handled);
+}

backend/fabric/src/main/java/io/github/_4drian3d/signedvelocity/fabric/model/SignedPlayerChatMessage.java

@@ -0,0 +1,7 @@
+package io.github._4drian3d.signedvelocity.fabric.model;
+
+public interface SignedPlayerChatMessage {
+    boolean signedVelocity$handled();
+
+    void signedVelocity$handled(boolean handled);
+}