From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: MrHua269 <mrhua269@gmail.com>
Date: Thu, 9 Jul 2026 12:13:58 +0800
Subject: [PATCH] Purpur: Lobotomize stuck villagers

Co-authored by: William Blake Galbreath <Blake.Galbreath@GMail.com>
As part of: Purpur (https://github.com/PurpurMC/Purpur/blob/09f547de09fc5d886f18f6d99ff389289766ec9d/purpur-server/minecraft-patches/features/0001-Ridables.patch)
Licensed under: MIT (https://github.com/PurpurMC/Purpur/blob/09f547de09fc5d886f18f6d99ff389289766ec9d/LICENSE)

diff --git a/net/minecraft/world/entity/npc/villager/Villager.java b/net/minecraft/world/entity/npc/villager/Villager.java
index f649c46cc9a34e646f8da3244866c6e011d30aa3..184637ac35a92097391f13bc6355f88495deb483 100644
--- a/net/minecraft/world/entity/npc/villager/Villager.java
+++ b/net/minecraft/world/entity/npc/villager/Villager.java
@@ -190,6 +190,53 @@ public class Villager extends AbstractVillager implements VillagerDataHolder, Re
         this.setCanPickUpLoot(true);
     }
 
+    // Purpur start
+    private boolean isLobotomized = false; public boolean isLobotomized() { return this.isLobotomized; } // Purpur
+    private int notLobotomizedCount = 0; // Purpur
+
+    private boolean checkLobotomized() {
+        int interval = io.nanachiyo0721.shiroha.config.modules.optimizations.LobotomizeVillageConfig.villagerLobotomizeCheckInterval;
+        boolean shouldCheckForTradeLocked = io.nanachiyo0721.shiroha.config.modules.optimizations.LobotomizeVillageConfig.villagerLobotomizeWaitUntilTradeLocked;
+        if (this.notLobotomizedCount > 3) {
+            // check half as often if not lobotomized for the last 3+ consecutive checks
+            interval *= 2;
+        }
+        if (this.level().getGameTime() % interval == 0) {
+            // offset Y for short blocks like dirt_path/farmland
+            this.isLobotomized = !(shouldCheckForTradeLocked && this.getVillagerXp() == 0) && !canTravelFrom(net.minecraft.core.BlockPos.containing(this.position().x, this.getBoundingBox().minY + 0.0625D, this.position().z));
+
+            if (this.isLobotomized) {
+                this.notLobotomizedCount = 0;
+            } else {
+                this.notLobotomizedCount++;
+            }
+        }
+        return this.isLobotomized;
+    }
+    // Purpur end
+
+    private boolean canTravelFrom(net.minecraft.core.BlockPos pos) {
+        return canTravelTo(pos.east()) || canTravelTo(pos.west()) || canTravelTo(pos.north()) || canTravelTo(pos.south());
+    }
+
+    private boolean canTravelTo(net.minecraft.core.BlockPos pos) {
+        net.minecraft.world.level.block.state.BlockState state = this.level().getBlockStateIfLoaded(pos);
+        if (state == null) {
+            // chunk not loaded
+            return false;
+        }
+        net.minecraft.world.level.block.Block bottom = state.getBlock();
+        if (bottom instanceof net.minecraft.world.level.block.FenceBlock ||
+                bottom instanceof net.minecraft.world.level.block.FenceGateBlock ||
+                bottom instanceof net.minecraft.world.level.block.WallBlock) {
+            // bottom block is too tall to get over
+            return false;
+        }
+        net.minecraft.world.level.block.Block top = level().getBlockState(pos.above()).getBlock();
+        // only if both blocks have no collision
+        return !bottom.hasCollision && !top.hasCollision;
+    }
+
     @Override
     public Brain<Villager> getBrain() {
         return (Brain<Villager>)super.getBrain();
@@ -259,11 +306,20 @@ public class Villager extends AbstractVillager implements VillagerDataHolder, Re
         // Paper start - EAR 2
         this.customServerAiStep(level, false);
     }
-    protected void customServerAiStep(ServerLevel level, final boolean inactive) {
+    protected void customServerAiStep(ServerLevel level, boolean inactive) { // Purpur - not final
         // Paper end - EAR 2
         ProfilerFiller profiler = Profiler.get();
         profiler.push("villagerBrain");
+        // Purpur start
+        if (io.nanachiyo0721.shiroha.config.modules.optimizations.LobotomizeVillageConfig.villagerLobotomizeEnabled) {
+            // treat as inactive if lobotomized
+            inactive = inactive || checkLobotomized();
+        } else {
+            this.isLobotomized = false;
+        }
+        // Purpur end
         if (!inactive) this.getBrain().tick(level, this); // Paper - EAR 2
+        else if (this.isLobotomized && shouldRestock(level)) restock(); // Purpur - Lobotomize stuck villagers
         profiler.pop();
         if (this.assignProfessionWhenSpawned) {
             this.assignProfessionWhenSpawned = false;