Replace home-made legacy hover event serializer with Adventure's implementation

This technically can break backwards compatibility, but this seems to be very unlikely to be the practice in reality. (The Velocity implementation probably wasn't correct, anyway.)

gradle/libs.versions.toml

@@ -12,7 +12,8 @@ spotless = "com.diffplug.spotless:6.25.0"
 
 [libraries]
 adventure-bom = "net.kyori:adventure-bom:4.17.0"
-adventure-facet = "net.kyori:adventure-platform-facet:4.3.2"
+adventure-text-serializer-json-legacy-impl = "net.kyori:adventure-text-serializer-json-legacy-impl:4.17.0"
+adventure-facet = "net.kyori:adventure-platform-facet:4.3.4"
 asm = "org.ow2.asm:asm:9.6"
 auto-service = "com.google.auto.service:auto-service:1.0.1"
 auto-service-annotations = "com.google.auto.service:auto-service-annotations:1.0.1"

proxy/build.gradle.kts

@@ -127,7 +127,7 @@ dependencies {
     runtimeOnly(libs.disruptor)
     implementation(libs.fastutil)
     implementation(platform(libs.adventure.bom))
-    implementation("net.kyori:adventure-nbt")
+    implementation(libs.adventure.text.serializer.json.legacy.impl)
     implementation(libs.adventure.facet)
     implementation(libs.completablefutures)
     implementation(libs.nightconfig)

proxy/src/main/java/com/velocitypowered/proxy/protocol/ProtocolUtils.java

@@ -25,7 +25,6 @@ import com.velocitypowered.api.proxy.crypto.IdentifiedKey;
 import com.velocitypowered.api.util.GameProfile;
 import com.velocitypowered.proxy.crypto.IdentifiedKeyImpl;
 import com.velocitypowered.proxy.protocol.netty.MinecraftDecoder;
-import com.velocitypowered.proxy.protocol.util.VelocityLegacyHoverEventSerializer;
 import com.velocitypowered.proxy.util.except.QuietDecoderException;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufInputStream;
@@ -47,6 +46,7 @@ import net.kyori.adventure.nbt.BinaryTagTypes;
 import net.kyori.adventure.nbt.CompoundBinaryTag;
 import net.kyori.adventure.text.serializer.gson.GsonComponentSerializer;
 import net.kyori.adventure.text.serializer.json.JSONOptions;
+import net.kyori.adventure.text.serializer.json.legacyimpl.NBTLegacyHoverEventSerializer;
 import net.kyori.option.OptionState;
 
 /**
@@ -58,8 +58,7 @@ public enum ProtocolUtils {
   private static final GsonComponentSerializer PRE_1_16_SERIALIZER =
       GsonComponentSerializer.builder()
           .downsampleColors()
-          .emitLegacyHoverEvent()
+          .legacyHoverEventSerializer(NBTLegacyHoverEventSerializer.get())
-          .legacyHoverEventSerializer(VelocityLegacyHoverEventSerializer.INSTANCE)
           .options(
               OptionState.optionState()
               // before 1.16
@@ -74,7 +73,7 @@ public enum ProtocolUtils {
           .build();
   private static final GsonComponentSerializer PRE_1_20_3_SERIALIZER =
           GsonComponentSerializer.builder()
-          .legacyHoverEventSerializer(VelocityLegacyHoverEventSerializer.INSTANCE)
+          .legacyHoverEventSerializer(NBTLegacyHoverEventSerializer.get())
           .options(
               OptionState.optionState()
               // after 1.16
@@ -89,7 +88,7 @@ public enum ProtocolUtils {
           .build();
   private static final GsonComponentSerializer MODERN_SERIALIZER =
       GsonComponentSerializer.builder()
-          .legacyHoverEventSerializer(VelocityLegacyHoverEventSerializer.INSTANCE)
+          .legacyHoverEventSerializer(NBTLegacyHoverEventSerializer.get())
           .options(
               OptionState.optionState()
               // after 1.16

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/VelocityLegacyHoverEventSerializer.java

@@ -1,123 +0,0 @@
-/*
- * Copyright (C) 2020-2023 Velocity Contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package com.velocitypowered.proxy.protocol.util;
-
-import java.io.IOException;
-import java.util.UUID;
-import net.kyori.adventure.key.Key;
-import net.kyori.adventure.nbt.CompoundBinaryTag;
-import net.kyori.adventure.nbt.TagStringIO;
-import net.kyori.adventure.nbt.api.BinaryTagHolder;
-import net.kyori.adventure.text.Component;
-import net.kyori.adventure.text.event.HoverEvent;
-import net.kyori.adventure.text.event.HoverEvent.ShowEntity;
-import net.kyori.adventure.text.event.HoverEvent.ShowItem;
-import net.kyori.adventure.text.serializer.gson.LegacyHoverEventSerializer;
-import net.kyori.adventure.text.serializer.plain.PlainTextComponentSerializer;
-import net.kyori.adventure.util.Codec.Decoder;
-import net.kyori.adventure.util.Codec.Encoder;
-import org.checkerframework.checker.nullness.qual.NonNull;
-
-/**
- * An implementation of {@link LegacyHoverEventSerializer} that implements the interface in the most
- * literal, albeit "incompatible" way possible.
- */
-public class VelocityLegacyHoverEventSerializer implements LegacyHoverEventSerializer {
-
-  public static final LegacyHoverEventSerializer INSTANCE =
-      new VelocityLegacyHoverEventSerializer();
-
-  private VelocityLegacyHoverEventSerializer() {
-
-  }
-
-  private static Key legacyIdToFakeKey(byte id) {
-    return Key.key("velocity", "legacy_hover/id_" + id);
-  }
-
-  @Override
-  public HoverEvent.@NonNull ShowItem deserializeShowItem(@NonNull Component input)
-      throws IOException {
-    String snbt = PlainTextComponentSerializer.plainText().serialize(input);
-    CompoundBinaryTag item = TagStringIO.get().asCompound(snbt);
-
-    Key key;
-    String idIfString = item.getString("id", "");
-    if (idIfString.isEmpty()) {
-      key = legacyIdToFakeKey(item.getByte("id"));
-    } else {
-      key = Key.key(idIfString);
-    }
-
-    byte count = item.getByte("Count", (byte) 1);
-    return ShowItem.of(key, count, BinaryTagHolder.binaryTagHolder(snbt));
-  }
-
-  @Override
-  public HoverEvent.@NonNull ShowEntity deserializeShowEntity(@NonNull Component input,
-      Decoder<Component, String, ? extends RuntimeException> componentDecoder) throws IOException {
-    String snbt = PlainTextComponentSerializer.plainText().serialize(input);
-    CompoundBinaryTag item = TagStringIO.get().asCompound(snbt);
-
-    Component name;
-    try {
-      name = componentDecoder.decode(item.getString("name"));
-    } catch (Exception e) {
-      name = Component.text(item.getString("name"));
-    }
-
-    return ShowEntity.of(Key.key(item.getString("type")),
-        UUID.fromString(item.getString("id")),
-        name);
-  }
-
-  @Override
-  public @NonNull Component serializeShowItem(HoverEvent.@NonNull ShowItem input)
-      throws IOException {
-    final CompoundBinaryTag.Builder builder = CompoundBinaryTag.builder()
-        .putByte("Count", (byte) input.count());
-
-    String keyAsString = input.item().asString();
-    if (keyAsString.startsWith("velocity:legacy_hover/id_")) {
-      builder.putByte("id", Byte.parseByte(keyAsString
-          .substring("velocity:legacy_hover/id_".length())));
-    } else {
-      builder.putString("id", keyAsString);
-    }
-
-    BinaryTagHolder nbt = input.nbt();
-    if (nbt != null) {
-      builder.put("tag", TagStringIO.get().asCompound(nbt.string()));
-    }
-
-    return Component.text(TagStringIO.get().asString(builder.build()));
-  }
-
-  @Override
-  public @NonNull Component serializeShowEntity(HoverEvent.@NonNull ShowEntity input,
-      Encoder<Component, String, ? extends RuntimeException> componentEncoder) throws IOException {
-    CompoundBinaryTag.Builder tag = CompoundBinaryTag.builder()
-        .putString("id", input.id().toString())
-        .putString("type", input.type().asString());
-    Component name = input.name();
-    if (name != null) {
-      tag.putString("name", componentEncoder.encode(name));
-    }
-    return Component.text(TagStringIO.get().asString(tag.build()));
-  }
-}