Implement villager trade leveling tweak

README.md

@@ -108,6 +108,7 @@ All changes are toggleable via the config file.
 * **Disable Fancy Missing Model:** Improves rendering performance by removing the resource location text on missing models
 * **Disable Narrator:** Disables the narrator functionality entirely
 * **Disable Sleeping:** Disables skipping night by using a bed while making it still able to set spawn
+* **Disable Villager Trade Leveling:** Disables leveling of villager careers, only allowing base level trades
 * **Disable Wither Targeting AI:** Disables withers targeting animals
 * **Easy Breeding:** Enables easy breeding of animals by tossing food on the ground
 * **End Portal Parallax:** Re-implements parallax rendering of the end portal from 1.11 and older

src/main/java/mod/acgaming/universaltweaks/config/UTConfig.java

@@ -661,6 +661,11 @@ public static class TweaksEntitiesCategory
         @Config.Comment("Disables creepers dropping music discs when slain by skeletons")
         public boolean utCreeperMusicDiscsToggle = false;
 
+        @Config.RequiresMcRestart
+        @Config.Name("Disable Villager Trade Leveling")
+        @Config.Comment("Disables leveling of villager careers, only allowing base level trades")
+        public boolean utVillagerTradeLevelingToggle = false;
+
         @Config.RequiresMcRestart
         @Config.Name("Disable Wither Targeting AI")
         @Config.Comment("Disables withers targeting animals")

src/main/java/mod/acgaming/universaltweaks/core/UTLoadingPlugin.java

@@ -188,6 +188,7 @@ public List<String> getMixinConfigs()
         configs.add("mixins.tweaks.entities.speed.boat.json");
         configs.add("mixins.tweaks.entities.speed.player.json");
         configs.add("mixins.tweaks.entities.taming.horse.json");
+        configs.add("mixins.tweaks.entities.trading.json");
         configs.add("mixins.tweaks.items.attackcooldown.server.json");
         configs.add("mixins.tweaks.items.eating.json");
         configs.add("mixins.tweaks.items.hardcorebuckets.json");
@@ -389,6 +390,8 @@ public boolean shouldMixinConfigQueue(String mixinConfig)
                 return UTConfig.TWEAKS_ENTITIES.PLAYER_SPEED.utPlayerSpeedToggle;
             case "mixins.tweaks.entities.taming.horse.json":
                 return UTConfig.TWEAKS_ENTITIES.UNDEAD_HORSES.utTamingUndeadHorsesToggle;
+            case "mixins.tweaks.entities.trading.json":
+                return UTConfig.TWEAKS_ENTITIES.utVillagerTradeLevelingToggle;
             case "mixins.tweaks.items.attackcooldown.server.json":
                 return UTConfig.TWEAKS_ITEMS.ATTACK_COOLDOWN.utAttackCooldownToggle;
             case "mixins.tweaks.items.eating.json":

src/main/java/mod/acgaming/universaltweaks/tweaks/entities/trading/mixin/UTVillagerRegistryMixin.java

@@ -0,0 +1,22 @@
+package mod.acgaming.universaltweaks.tweaks.entities.trading.mixin;
+
+import java.util.List;
+
+import net.minecraft.entity.passive.EntityVillager;
+import net.minecraftforge.fml.common.registry.VillagerRegistry;
+
+import mod.acgaming.universaltweaks.config.UTConfig;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+@Mixin(value = VillagerRegistry.VillagerCareer.class, remap = false)
+public class UTVillagerRegistryMixin
+{
+    @Inject(method = "getTrades", at = @At("RETURN"), cancellable = true)
+    public void utGetTrades(int level, CallbackInfoReturnable<List<EntityVillager.ITradeList>> cir)
+    {
+        if (UTConfig.TWEAKS_ENTITIES.utVillagerTradeLevelingToggle && level > 0) cir.setReturnValue(null);
+    }
+}

src/main/resources/mixins.tweaks.entities.trading.json

@@ -0,0 +1,7 @@
+{
+  "package": "mod.acgaming.universaltweaks.tweaks.entities.trading.mixin",
+  "refmap": "universaltweaks.refmap.json",
+  "minVersion": "0.8",
+  "compatibilityLevel": "JAVA_8",
+  "mixins": ["UTVillagerRegistryMixin"]
+}