Convert NBT tags between 1.20.1 <-> 1.20.2

src/main/java/com/moulberry/axiom/packet/HelloPacketListener.java

@@ -12,12 +12,15 @@ import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.data.*;
 import com.viaversion.viaversion.api.protocol.ProtocolPathEntry;
 import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
+import com.viaversion.viaversion.api.type.ByteBufReader;
+import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.libs.opennbt.tag.builtin.CompoundTag;
 import io.netty.buffer.Unpooled;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.format.NamedTextColor;
 import net.minecraft.SharedConstants;
 import net.minecraft.core.IdMapper;
+import net.minecraft.nbt.NbtIo;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.level.block.state.BlockState;
 import org.bukkit.Bukkit;
@@ -53,7 +56,7 @@ public class HelloPacketListener implements PluginMessageListener {
         FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(Unpooled.wrappedBuffer(message));
         int apiVersion = friendlyByteBuf.readVarInt();
         int dataVersion = friendlyByteBuf.readVarInt();
-        friendlyByteBuf.readNbt(); // Discard
+        ViaVersionHelper.skipTagUnknown(friendlyByteBuf, player);
 
         int serverDataVersion = SharedConstants.getCurrentVersion().getDataVersion().getVersion();
         if (dataVersion != serverDataVersion) {

src/main/java/com/moulberry/axiom/packet/ManipulateEntityPacketListener.java

@@ -4,6 +4,7 @@ import com.moulberry.axiom.AxiomPaper;
 import com.moulberry.axiom.NbtSanitization;
 import com.moulberry.axiom.integration.Integration;
 import com.moulberry.axiom.integration.plotsquared.PlotSquaredIntegration;
+import com.moulberry.axiom.viaversion.ViaVersionHelper;
 import io.netty.buffer.Unpooled;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
@@ -46,7 +47,7 @@ public class ManipulateEntityPacketListener implements PluginMessageListener {
 
     public record ManipulateEntry(UUID uuid, @Nullable Set<RelativeMovement> relativeMovementSet, @Nullable Vec3 position,
                                   float yaw, float pitch, CompoundTag merge, PassengerManipulation passengerManipulation, List<UUID> passengers) {
-        public static ManipulateEntry read(FriendlyByteBuf friendlyByteBuf) {
+        public static ManipulateEntry read(FriendlyByteBuf friendlyByteBuf, Player player) {
             UUID uuid = friendlyByteBuf.readUUID();
 
             int flags = friendlyByteBuf.readByte();
@@ -61,7 +62,7 @@ public class ManipulateEntityPacketListener implements PluginMessageListener {
                 pitch = friendlyByteBuf.readFloat();
             }
 
-            CompoundTag nbt = friendlyByteBuf.readNbt();
+            CompoundTag nbt = ViaVersionHelper.readTagUnknown(friendlyByteBuf, player);
 
             PassengerManipulation passengerManipulation = friendlyByteBuf.readEnum(PassengerManipulation.class);
             List<UUID> passengers = List.of();
@@ -93,7 +94,7 @@ public class ManipulateEntityPacketListener implements PluginMessageListener {
 
         FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(Unpooled.wrappedBuffer(message));
         List<ManipulateEntry> entries = friendlyByteBuf.readCollection(FriendlyByteBuf.limitValue(ArrayList::new, 1000),
-            ManipulateEntry::read);
+            buf -> ManipulateEntry.read(buf, player));
 
         ServerLevel serverLevel = ((CraftWorld)player.getWorld()).getHandle();
 

src/main/java/com/moulberry/axiom/packet/SetBlockBufferPacketListener.java

@@ -9,6 +9,7 @@ import com.moulberry.axiom.buffer.CompressedBlockEntity;
 import com.moulberry.axiom.integration.Integration;
 import com.moulberry.axiom.integration.SectionPermissionChecker;
 import com.moulberry.axiom.integration.plotsquared.PlotSquaredIntegration;
+import com.moulberry.axiom.viaversion.ViaVersionHelper;
 import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
 import it.unimi.dsi.fastutil.shorts.Short2ObjectMap;
 import net.minecraft.ChatFormatting;
@@ -77,7 +78,7 @@ public class SetBlockBufferPacketListener {
         boolean continuation = friendlyByteBuf.readBoolean();
 
         if (!continuation) {
-            friendlyByteBuf.readNbt(); // Discard sourceInfo
+            ViaVersionHelper.skipTagUnknown(friendlyByteBuf, player.getBukkitEntity());
         }
 
         RateLimiter rateLimiter = this.plugin.getBlockBufferRateLimiter(player.getUUID());

src/main/java/com/moulberry/axiom/packet/SpawnEntityPacketListener.java

@@ -4,6 +4,7 @@ import com.moulberry.axiom.AxiomPaper;
 import com.moulberry.axiom.NbtSanitization;
 import com.moulberry.axiom.integration.Integration;
 import com.moulberry.axiom.integration.plotsquared.PlotSquaredIntegration;
+import com.moulberry.axiom.viaversion.ViaVersionHelper;
 import io.netty.buffer.Unpooled;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
@@ -38,11 +39,6 @@ public class SpawnEntityPacketListener implements PluginMessageListener {
 
     private record SpawnEntry(UUID newUuid, double x, double y, double z, float yaw, float pitch,
                               @Nullable UUID copyFrom, CompoundTag tag) {
-        public SpawnEntry(FriendlyByteBuf friendlyByteBuf) {
-            this(friendlyByteBuf.readUUID(), friendlyByteBuf.readDouble(), friendlyByteBuf.readDouble(),
-                friendlyByteBuf.readDouble(), friendlyByteBuf.readFloat(), friendlyByteBuf.readFloat(),
-                friendlyByteBuf.readNullable(FriendlyByteBuf::readUUID), friendlyByteBuf.readNbt());
-        }
     }
 
     private static final Rotation[] ROTATION_VALUES = Rotation.values();
@@ -62,7 +58,10 @@ public class SpawnEntityPacketListener implements PluginMessageListener {
         }
 
         FriendlyByteBuf friendlyByteBuf = new FriendlyByteBuf(Unpooled.wrappedBuffer(message));
-        List<SpawnEntry> entries = friendlyByteBuf.readCollection(FriendlyByteBuf.limitValue(ArrayList::new, 1000), SpawnEntry::new);
+        List<SpawnEntry> entries = friendlyByteBuf.readCollection(FriendlyByteBuf.limitValue(ArrayList::new, 1000),
+            buf -> new SpawnEntry(buf.readUUID(), buf.readDouble(), buf.readDouble(),
+                buf.readDouble(), buf.readFloat(), buf.readFloat(),
+                buf.readNullable(FriendlyByteBuf::readUUID), ViaVersionHelper.readTagUnknown(buf, player)));
 
         ServerLevel serverLevel = ((CraftWorld)player.getWorld()).getHandle();
 

src/main/java/com/moulberry/axiom/viaversion/ViaVersionHelper.java

@@ -6,13 +6,22 @@ import com.viaversion.viaversion.api.data.BiMappings;
 import com.viaversion.viaversion.api.data.MappingData;
 import com.viaversion.viaversion.api.data.Mappings;
 import com.viaversion.viaversion.api.protocol.ProtocolPathEntry;
+import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
+import com.viaversion.viaversion.api.type.Type;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.format.NamedTextColor;
 import net.minecraft.SharedConstants;
 import net.minecraft.core.IdMapper;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.state.BlockState;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
@@ -92,4 +101,64 @@ public class ViaVersionHelper {
         return newBlockRegistry;
     }
 
+    private static final int UNNAMED_COMPOUND_TAG_CHANGE_VERSION = ProtocolVersion.v1_20_2.getVersion();
+
+    public static void skipTagUnknown(FriendlyByteBuf friendlyByteBuf, Player player) {
+        if (Bukkit.getPluginManager().isPluginEnabled("ViaVersion")) {
+            int playerVersion = Via.getAPI().getPlayerVersion(player.getUniqueId());
+            try {
+                ViaVersionHelper.skipTagViaVersion(friendlyByteBuf, playerVersion);
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        } else {
+            friendlyByteBuf.readNbt(); // Discard
+        }
+    }
+
+    public static CompoundTag readTagUnknown(FriendlyByteBuf friendlyByteBuf, Player player) {
+        if (Bukkit.getPluginManager().isPluginEnabled("ViaVersion")) {
+            int playerVersion = Via.getAPI().getPlayerVersion(player.getUniqueId());
+            try {
+                return ViaVersionHelper.readTagViaVersion(friendlyByteBuf, playerVersion);
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        } else {
+            return friendlyByteBuf.readNbt();
+        }
+    }
+
+    public static void skipTagViaVersion(FriendlyByteBuf friendlyByteBuf, int playerVersion) throws Exception {
+        getTagType(playerVersion).read(friendlyByteBuf);
+    }
+
+    public static CompoundTag readTagViaVersion(FriendlyByteBuf friendlyByteBuf, int playerVersion) throws Exception {
+        Type<com.viaversion.viaversion.libs.opennbt.tag.builtin.CompoundTag> from = getTagType(playerVersion);
+        Type<com.viaversion.viaversion.libs.opennbt.tag.builtin.CompoundTag> to = getTagType(SharedConstants.getProtocolVersion());
+
+        return readTagViaVersion(friendlyByteBuf, from, to);
+    }
+
+    private static Type<com.viaversion.viaversion.libs.opennbt.tag.builtin.CompoundTag> getTagType(int version) {
+        if (version < UNNAMED_COMPOUND_TAG_CHANGE_VERSION) {
+            return Type.NAMED_COMPOUND_TAG;
+        } else {
+            return Type.COMPOUND_TAG;
+        }
+    }
+
+    private static CompoundTag readTagViaVersion(FriendlyByteBuf friendlyByteBuf,
+            Type<com.viaversion.viaversion.libs.opennbt.tag.builtin.CompoundTag> from,
+            Type<com.viaversion.viaversion.libs.opennbt.tag.builtin.CompoundTag> to) throws Exception {
+        if (from == to) {
+            return friendlyByteBuf.readNbt();
+        }
+
+        com.viaversion.viaversion.libs.opennbt.tag.builtin.CompoundTag tag = from.read(friendlyByteBuf);
+        ByteBuf buffer = Unpooled.buffer();
+        to.write(buffer, tag);
+        return new FriendlyByteBuf(buffer).readNbt();
+    }
+
 }