Add below name scoreboard support

Fixes #1927

connector/src/main/java/org/geysermc/connector/entity/player/PlayerEntity.java

@@ -28,6 +28,7 @@ package org.geysermc.connector.entity.player;
 import com.github.steveice10.mc.auth.data.GameProfile;
 import com.github.steveice10.mc.protocol.data.game.entity.metadata.EntityMetadata;
 import com.github.steveice10.mc.protocol.data.game.entity.metadata.Pose;
+import com.github.steveice10.mc.protocol.data.game.scoreboard.ScoreboardPosition;
 import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
 import com.nukkitx.math.vector.Vector3f;
 import com.nukkitx.math.vector.Vector3i;
@@ -37,10 +38,7 @@ import com.nukkitx.protocol.bedrock.data.command.CommandPermission;
 import com.nukkitx.protocol.bedrock.data.entity.EntityData;
 import com.nukkitx.protocol.bedrock.data.entity.EntityFlag;
 import com.nukkitx.protocol.bedrock.data.entity.EntityLinkData;
-import com.nukkitx.protocol.bedrock.packet.AddPlayerPacket;
+import com.nukkitx.protocol.bedrock.packet.*;
-import com.nukkitx.protocol.bedrock.packet.MovePlayerPacket;
-import com.nukkitx.protocol.bedrock.packet.SetEntityLinkPacket;
-import com.nukkitx.protocol.bedrock.packet.UpdateAttributesPacket;
 import lombok.Getter;
 import lombok.Setter;
 import net.kyori.adventure.text.Component;
@@ -50,7 +48,10 @@ import org.geysermc.connector.entity.living.animal.tameable.ParrotEntity;
 import org.geysermc.connector.entity.type.EntityType;
 import org.geysermc.connector.network.session.GeyserSession;
 import org.geysermc.connector.network.translators.chat.MessageTranslator;
+import org.geysermc.connector.scoreboard.Objective;
+import org.geysermc.connector.scoreboard.Score;
 import org.geysermc.connector.scoreboard.Team;
+import org.geysermc.connector.scoreboard.UpdateType;
 
 import java.util.Collections;
 import java.util.UUID;
@@ -85,6 +86,12 @@ public class PlayerEntity extends LivingEntity {
 
     @Override
     public void spawnEntity(GeyserSession session) {
+        // Check to see if the player should have a belowname counterpart added
+        Objective objective = session.getWorldCache().getScoreboard().getObjectiveSlots().get(ScoreboardPosition.BELOW_NAME);
+        if (objective != null) {
+            setBelowNameText(session, objective);
+        }
+
         AddPlayerPacket addPlayerPacket = new AddPlayerPacket();
         addPlayerPacket.setUuid(uuid);
         addPlayerPacket.setUsername(username);
@@ -326,4 +333,34 @@ public class PlayerEntity extends LivingEntity {
         metadata.put(EntityData.BOUNDING_BOX_WIDTH, entityType.getWidth());
         metadata.put(EntityData.BOUNDING_BOX_HEIGHT, height);
     }
+
+    public void setBelowNameText(GeyserSession session, Objective objective) {
+        if (objective != null && objective.getUpdateType() != UpdateType.REMOVE) {
+            int amount;
+            Score score = objective.getScores().get(username);
+            if (score != null) {
+                amount = score.getCurrentData().getScore();
+            } else {
+                amount = 0;
+            }
+            String displayString = amount + " " + objective.getDisplayName();
+
+            metadata.put(EntityData.SCORE_TAG, displayString);
+            if (valid) {
+                // Already spawned - we still need to run the rest of this code because the spawn packet will be
+                // providing the information
+                SetEntityDataPacket packet = new SetEntityDataPacket();
+                packet.setRuntimeEntityId(geyserId);
+                packet.getMetadata().put(EntityData.SCORE_TAG, displayString);
+                session.sendUpstreamPacket(packet);
+            }
+        } else {
+            if (valid && metadata.remove(EntityData.SCORE_TAG) != null) {
+                SetEntityDataPacket packet = new SetEntityDataPacket();
+                packet.setRuntimeEntityId(geyserId);
+                packet.getMetadata().put(EntityData.SCORE_TAG, "");
+                session.sendUpstreamPacket(packet);
+            }
+        }
+    }
 }

connector/src/main/java/org/geysermc/connector/network/session/cache/EntityCache.java

@@ -138,6 +138,10 @@ public class EntityCache {
         return playerEntities.remove(uuid);
     }
 
+    public Collection<PlayerEntity> getAllPlayerEntities() {
+        return playerEntities.values();
+    }
+
     public void addBossBar(UUID uuid, BossBar bossBar) {
         bossBars.put(uuid, bossBar);
         bossBar.addBossBar();

connector/src/main/java/org/geysermc/connector/network/translators/java/scoreboard/JavaScoreboardObjectiveTranslator.java

@@ -26,9 +26,11 @@
 package org.geysermc.connector.network.translators.java.scoreboard;
 
 import com.github.steveice10.mc.protocol.data.game.scoreboard.ObjectiveAction;
+import com.github.steveice10.mc.protocol.data.game.scoreboard.ScoreboardPosition;
 import com.github.steveice10.mc.protocol.packet.ingame.server.scoreboard.ServerScoreboardObjectivePacket;
 import org.geysermc.connector.GeyserConnector;
 import org.geysermc.connector.GeyserLogger;
+import org.geysermc.connector.entity.player.PlayerEntity;
 import org.geysermc.connector.network.session.GeyserSession;
 import org.geysermc.connector.network.session.cache.WorldCache;
 import org.geysermc.connector.network.translators.PacketTranslator;
@@ -63,7 +65,20 @@ public class JavaScoreboardObjectiveTranslator extends PacketTranslator<ServerSc
         switch (packet.getAction()) {
             case ADD, UPDATE -> objective.setDisplayName(MessageTranslator.convertMessage(packet.getDisplayName()))
                     .setType(packet.getType().ordinal());
-            case REMOVE -> scoreboard.unregisterObjective(packet.getName());
+            case REMOVE -> {
+                scoreboard.unregisterObjective(packet.getName());
+                if (objective != null && objective == scoreboard.getObjectiveSlots().get(ScoreboardPosition.BELOW_NAME)) {
+                    // Clear the score tag from all players
+                    for (PlayerEntity entity : session.getEntityCache().getAllPlayerEntities()) {
+                        if (!entity.isValid()) {
+                            // Player hasn't spawned yet - don't bother
+                            continue;
+                        }
+
+                        entity.setBelowNameText(session, null);
+                    }
+                }
+            }
         }
 
         if (objective == null || !objective.isActive()) {

connector/src/main/java/org/geysermc/connector/network/translators/java/scoreboard/JavaUpdateScoreTranslator.java

@@ -26,9 +26,13 @@
 package org.geysermc.connector.network.translators.java.scoreboard;
 
 import com.github.steveice10.mc.protocol.data.game.scoreboard.ScoreboardAction;
+import com.github.steveice10.mc.protocol.data.game.scoreboard.ScoreboardPosition;
 import com.github.steveice10.mc.protocol.packet.ingame.server.scoreboard.ServerUpdateScorePacket;
+import com.nukkitx.protocol.bedrock.data.entity.EntityData;
+import com.nukkitx.protocol.bedrock.packet.SetEntityDataPacket;
 import org.geysermc.connector.GeyserConnector;
 import org.geysermc.connector.GeyserLogger;
+import org.geysermc.connector.entity.player.PlayerEntity;
 import org.geysermc.connector.network.session.GeyserSession;
 import org.geysermc.connector.network.session.cache.WorldCache;
 import org.geysermc.connector.network.translators.PacketTranslator;
@@ -58,19 +62,40 @@ public class JavaUpdateScoreTranslator extends PacketTranslator<ServerUpdateScor
             return;
         }
 
+        // If this is the objective that is in use to show the below name text, we need to update the player
+        // attached to this score.
+        boolean isBelowName = objective != null && objective == scoreboard.getObjectiveSlots().get(ScoreboardPosition.BELOW_NAME);
+
         switch (packet.getAction()) {
-            case ADD_OR_UPDATE:
+            case ADD_OR_UPDATE -> {
                 objective.setScore(packet.getEntry(), packet.getValue());
-                break;
+                if (isBelowName) {
-            case REMOVE:
+                    // Update the below name score on this player
+                    setBelowName(session, objective, packet.getEntry(), packet.getValue());
+                }
+            }
+            case REMOVE -> {
+                if (packet.getObjective().isEmpty()) {
+                    // An empty objective name means all scores are reset for that player (/scoreboard players reset PLAYERNAME)
+                    Objective belowName = scoreboard.getObjectiveSlots().get(ScoreboardPosition.BELOW_NAME);
+                    if (belowName != null) {
+                        setBelowName(session, belowName, packet.getEntry(), 0);
+                    }
+                }
+
                 if (objective != null) {
                     objective.removeScore(packet.getEntry());
+
+                    if (isBelowName) {
+                        // Update the score on this player to now reflect 0
+                        setBelowName(session, objective, packet.getEntry(), 0);
+                    }
                 } else {
                     for (Objective objective1 : scoreboard.getObjectives()) {
                         objective1.removeScore(packet.getEntry());
                     }
                 }
-                break;
+            }
         }
 
         // ScoreboardUpdater will handle it for us if the packets per second
@@ -79,4 +104,43 @@ public class JavaUpdateScoreTranslator extends PacketTranslator<ServerUpdateScor
             scoreboard.onUpdate();
         }
     }
+
+    /**
+     * @param objective the objective that currently resides on the below name display slot
+     */
+    private void setBelowName(GeyserSession session, Objective objective, String username, int count) {
+        PlayerEntity entity = getPlayerEntity(session, username);
+        if (entity == null) {
+            return;
+        }
+
+        String displayString = count + " " + objective.getDisplayName();
+
+        // Of note: unlike Bedrock, if there is an objective in the below name slot, everyone has a display
+        entity.getMetadata().put(EntityData.SCORE_TAG, displayString);
+        SetEntityDataPacket entityDataPacket = new SetEntityDataPacket();
+        entityDataPacket.setRuntimeEntityId(entity.getGeyserId());
+        entityDataPacket.getMetadata().put(EntityData.SCORE_TAG, displayString);
+        session.sendUpstreamPacket(entityDataPacket);
+    }
+
+    private PlayerEntity getPlayerEntity(GeyserSession session, String username) {
+        // We don't care about the session player, because... they're not going to be seeing their own score
+        if (session.getPlayerEntity().getUsername().equals(username)) {
+            return null;
+        }
+
+        for (PlayerEntity entity : session.getEntityCache().getAllPlayerEntities()) {
+            if (entity.getUsername().equals(username)) {
+                if (entity.isValid()) {
+                    return entity;
+                } else {
+                    // The below name text will be applied on spawn
+                    return null;
+                }
+            }
+        }
+
+        return null;
+    }
 }

connector/src/main/java/org/geysermc/connector/scoreboard/Scoreboard.java

@@ -33,6 +33,7 @@ import com.nukkitx.protocol.bedrock.packet.SetScorePacket;
 import lombok.Getter;
 import org.geysermc.connector.GeyserConnector;
 import org.geysermc.connector.GeyserLogger;
+import org.geysermc.connector.entity.player.PlayerEntity;
 import org.geysermc.connector.network.session.GeyserSession;
 import org.geysermc.connector.utils.LanguageUtils;
 
@@ -49,7 +50,8 @@ public final class Scoreboard {
     private final AtomicLong nextId = new AtomicLong(0);
 
     private final Map<String, Objective> objectives = new ConcurrentHashMap<>();
-    private final Map<ScoreboardPosition, Objective> objectiveSlots = new HashMap<>();
+    @Getter
+    private final Map<ScoreboardPosition, Objective> objectiveSlots = new EnumMap<>(ScoreboardPosition.class);
     private final Map<String, Team> teams = new ConcurrentHashMap<>(); // updated on multiple threads
 
     private int lastAddScoreCount = 0;
@@ -103,6 +105,19 @@ public final class Scoreboard {
             objective.pendingRemove();
         }
         objectiveSlots.put(displaySlot, objective);
+
+        if (displaySlot == ScoreboardPosition.BELOW_NAME) {
+            // Display the below name score option to all players
+            // Of note: unlike Bedrock, if there is an objective in the below name slot, everyone has a display
+            for (PlayerEntity entity : session.getEntityCache().getAllPlayerEntities()) {
+                if (!entity.isValid()) {
+                    // Player hasn't spawned yet - don't bother, it'll be done then
+                    continue;
+                }
+
+                entity.setBelowNameText(session, objective);
+            }
+        }
     }
 
     public Team registerNewTeam(String teamName, String[] players) {