Fix updating villager trade experience (#3906)

* Fix villager experience not updating

Remove unnecessary fake trade experience stuff

* Hide trade level for wandering traders

core/src/main/java/org/geysermc/geyser/entity/type/player/SessionPlayerEntity.java

@@ -67,10 +67,6 @@ public class SessionPlayerEntity extends PlayerEntity {
      */
     @Getter
     private boolean isRidingInFront;
-    /**
-     * Used for villager inventory emulation.
-     */
-    private int fakeTradeXp;
 
     public SessionPlayerEntity(GeyserSession session) {
         super(session, -1, 1, null, Vector3f.ZERO, Vector3f.ZERO, 0, 0, 0, null, null);
@@ -175,11 +171,6 @@ public class SessionPlayerEntity extends PlayerEntity {
         this.isRidingInFront = position != null && position.getX() > 0;
     }
 
-    public void addFakeTradeExperience(int tradeXp) {
-        fakeTradeXp += tradeXp;
-        dirtyMetadata.put(EntityDataTypes.TRADE_EXPERIENCE, fakeTradeXp);
-    }
-
     @Override
     public AttributeData createHealthAttribute() {
         // Max health must be divisible by two in bedrock

core/src/main/java/org/geysermc/geyser/inventory/MerchantContainer.java

@@ -30,6 +30,7 @@ import com.github.steveice10.mc.protocol.data.game.inventory.VillagerTrade;
 import com.github.steveice10.mc.protocol.packet.ingame.clientbound.inventory.ClientboundMerchantOffersPacket;
 import lombok.Getter;
 import lombok.Setter;
+import org.cloudburstmc.protocol.bedrock.data.entity.EntityDataTypes;
 import org.geysermc.geyser.entity.type.Entity;
 import org.geysermc.geyser.session.GeyserSession;
 
@@ -40,6 +41,8 @@ public class MerchantContainer extends Container {
     private VillagerTrade[] villagerTrades;
     @Getter @Setter
     private ClientboundMerchantOffersPacket pendingOffersPacket;
+    @Getter @Setter
+    private int tradeExperience;
 
     public MerchantContainer(String title, int id, int size, ContainerType containerType, PlayerInventory playerInventory) {
         super(title, id, size, containerType, playerInventory);
@@ -49,9 +52,10 @@ public class MerchantContainer extends Container {
         if (villagerTrades != null && slot >= 0 && slot < villagerTrades.length) {
             VillagerTrade trade = villagerTrades[slot];
             setItem(2, GeyserItemStack.from(trade.getOutput()), session);
-            // TODO this logic doesn't add up
+
-            session.getPlayerEntity().addFakeTradeExperience(trade.getXp());
+            tradeExperience += trade.getXp();
-            session.getPlayerEntity().updateBedrockMetadata();
+            villager.getDirtyMetadata().put(EntityDataTypes.TRADE_EXPERIENCE, tradeExperience);
+            villager.updateBedrockMetadata();
         }
     }
 }

core/src/main/java/org/geysermc/geyser/translator/protocol/java/inventory/JavaMerchantOffersTranslator.java

@@ -73,9 +73,17 @@ public class JavaMerchantOffersTranslator extends PacketTranslator<ClientboundMe
     public static void openMerchant(GeyserSession session, ClientboundMerchantOffersPacket packet, MerchantContainer merchantInventory) {
         // Retrieve the fake villager involved in the trade, and update its metadata to match with the window information
         merchantInventory.setVillagerTrades(packet.getTrades());
+        merchantInventory.setTradeExperience(packet.getExperience());
+
         Entity villager = merchantInventory.getVillager();
+        if (packet.isRegularVillager()) {
             villager.getDirtyMetadata().put(EntityDataTypes.TRADE_TIER, packet.getVillagerLevel() - 1);
             villager.getDirtyMetadata().put(EntityDataTypes.MAX_TRADE_TIER, 4);
+        } else {
+            // Don't show trade level for wandering traders
+            villager.getDirtyMetadata().put(EntityDataTypes.TRADE_TIER, 0);
+            villager.getDirtyMetadata().put(EntityDataTypes.MAX_TRADE_TIER, 0);
+        }
         villager.getDirtyMetadata().put(EntityDataTypes.TRADE_EXPERIENCE, packet.getExperience());
         villager.updateBedrockMetadata();