From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Encode42 <me@encode42.dev>
Date: Tue, 8 Dec 2020 17:15:15 -0500
Subject: [PATCH] Configurable chance for wolves to spawn rabid

Configurable chance to spawn a wolf that is rabid.
Rabid wolves attack all players, mobs, and animals.

diff --git a/src/main/java/net/minecraft/world/entity/animal/Wolf.java b/src/main/java/net/minecraft/world/entity/animal/Wolf.java
index 2267f8da1c27ff54b2ced59ef15eb45357b7075d..073014d44a3ccfca9bb5a387843e22917de13bb4 100644
--- a/src/main/java/net/minecraft/world/entity/animal/Wolf.java
+++ b/src/main/java/net/minecraft/world/entity/animal/Wolf.java
@@ -104,6 +104,37 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
 
         return entitytypes == EntityType.SHEEP || entitytypes == EntityType.RABBIT || entitytypes == EntityType.FOX;
     };
+    // Purpur start - rabid wolf spawn chance
+    private boolean isRabid = false;
+    private static final Predicate<LivingEntity> RABID_PREDICATE = entity -> entity instanceof net.minecraft.server.level.ServerPlayer || entity instanceof Mob;
+    private final net.minecraft.world.entity.ai.goal.Goal PATHFINDER_VANILLA = new NonTameRandomTargetGoal<>(this, Animal.class, false, PREY_SELECTOR);
+    private final net.minecraft.world.entity.ai.goal.Goal PATHFINDER_RABID = new NonTameRandomTargetGoal<>(this, LivingEntity.class, false, RABID_PREDICATE);
+    private static final class AvoidRabidWolfGoal extends AvoidEntityGoal<Wolf> {
+        private final Wolf wolf;
+
+        public AvoidRabidWolfGoal(Wolf wolf, float distance, double minSpeed, double maxSpeed) {
+            super(wolf, Wolf.class, distance, minSpeed, maxSpeed);
+            this.wolf = wolf;
+        }
+
+        @Override
+        public boolean canUse() {
+            return super.canUse() && !this.wolf.isRabid() && this.toAvoid != null && this.toAvoid.isRabid(); // wolves which are not rabid run away from rabid wolves
+        }
+
+        @Override
+        public void start() {
+            this.wolf.setTarget(null);
+            super.start();
+        }
+
+        @Override
+        public void tick() {
+            this.wolf.setTarget(null);
+            super.tick();
+        }
+    }
+    // Purpur end
     private static final float START_HEALTH = 8.0F;
     private static final float TAME_HEALTH = 40.0F;
     private static final float ARMOR_REPAIR_UNIT = 0.125F;
@@ -156,6 +187,30 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
         return this.level().purpurConfig.wolfBreedingTicks;
     }
 
+    public boolean isRabid() {
+        return this.isRabid;
+    }
+
+    public void setRabid(boolean isRabid) {
+        this.isRabid = isRabid;
+        updatePathfinders(true);
+    }
+
+    public void updatePathfinders(boolean modifyEffects) {
+        this.targetSelector.removeGoal(PATHFINDER_VANILLA);
+        this.targetSelector.removeGoal(PATHFINDER_RABID);
+        if (this.isRabid) {
+            setOwnerUUID(null);
+            setTame(false, true);
+            this.targetSelector.addGoal(5, PATHFINDER_RABID);
+            if (modifyEffects) this.addEffect(new net.minecraft.world.effect.MobEffectInstance(net.minecraft.world.effect.MobEffects.CONFUSION, 1200));
+        } else {
+            this.targetSelector.addGoal(5, PATHFINDER_VANILLA);
+            this.stopBeingAngry();
+            if (modifyEffects) this.removeEffect(net.minecraft.world.effect.MobEffects.CONFUSION);
+        }
+    }
+
     @Override
     protected void registerGoals() {
         this.goalSelector.addGoal(1, new FloatGoal(this));
@@ -163,6 +218,7 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
         this.goalSelector.addGoal(1, new Wolf.WolfPanicGoal(this, 1.5D));
         this.goalSelector.addGoal(2, new SitWhenOrderedToGoal(this));
         this.goalSelector.addGoal(3, new Wolf.WolfAvoidEntityGoal<>(this, Llama.class, 24.0F, 1.5D, 1.5D));
+        this.goalSelector.addGoal(3, new AvoidRabidWolfGoal(this, 24.0F, 1.5D, 1.5D)); // Purpur
         this.goalSelector.addGoal(4, new LeapAtTargetGoal(this, 0.4F));
         this.goalSelector.addGoal(5, new MeleeAttackGoal(this, 1.0D, true));
         this.goalSelector.addGoal(6, new FollowOwnerGoal(this, 1.0D, 10.0F, 2.0F, false));
@@ -176,7 +232,7 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
         this.targetSelector.addGoal(2, new OwnerHurtTargetGoal(this));
         this.targetSelector.addGoal(3, (new HurtByTargetGoal(this, new Class[0])).setAlertOthers());
         this.targetSelector.addGoal(4, new NearestAttackableTargetGoal<>(this, Player.class, 10, true, false, this::isAngryAt));
-        this.targetSelector.addGoal(5, new NonTameRandomTargetGoal<>(this, Animal.class, false, Wolf.PREY_SELECTOR));
+        // this.targetSelector.addGoal(5, new NonTameRandomTargetGoal<>(this, Animal.class, false, Wolf.PREY_SELECTOR)); // Purpur - moved to updatePathfinders()
         this.targetSelector.addGoal(6, new NonTameRandomTargetGoal<>(this, Turtle.class, false, Turtle.BABY_ON_LAND_SELECTOR));
         this.targetSelector.addGoal(7, new NearestAttackableTargetGoal<>(this, AbstractSkeleton.class, false));
         this.targetSelector.addGoal(8, new ResetUniversalAngerTargetGoal<>(this, true));
@@ -219,6 +275,7 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
     public void addAdditionalSaveData(CompoundTag nbt) {
         super.addAdditionalSaveData(nbt);
         nbt.putByte("CollarColor", (byte) this.getCollarColor().getId());
+        nbt.putBoolean("Purpur.IsRabid", this.isRabid); // Purpur
         nbt.putString("variant", ((ResourceKey) this.getVariant().unwrapKey().orElse(WolfVariants.PALE)).location().toString());
         this.addPersistentAngerSaveData(nbt);
     }
@@ -234,6 +291,10 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
         if (nbt.contains("CollarColor", 99)) {
             this.setCollarColor(DyeColor.byId(nbt.getInt("CollarColor")));
         }
+        // Purpur start
+        this.isRabid = nbt.getBoolean("Purpur.IsRabid");
+        this.updatePathfinders(false);
+        // Purpur end
 
         this.readPersistentAngerSaveData(this.level(), nbt);
     }
@@ -252,6 +313,12 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
         }
 
         this.setVariant(holder1);
+
+        // Purpur start
+        this.isRabid = world.getLevel().purpurConfig.wolfNaturalRabid > 0.0D && random.nextDouble() <= world.getLevel().purpurConfig.wolfNaturalRabid;
+        this.updatePathfinders(false);
+        // Purpur end
+
         return super.finalizeSpawn(world, difficulty, spawnReason, (SpawnGroupData) entityData);
     }
 
@@ -295,6 +362,11 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
     public void tick() {
         super.tick();
         if (this.isAlive()) {
+            // Purpur start
+            if (this.age % 300 == 0 && this.isRabid()) {
+                this.addEffect(new net.minecraft.world.effect.MobEffectInstance(net.minecraft.world.effect.MobEffects.CONFUSION, 400));
+            }
+            // Purpur end
             this.interestedAngleO = this.interestedAngle;
             if (this.isInterested()) {
                 this.interestedAngle += (1.0F - this.interestedAngle) * 0.4F;
@@ -541,6 +613,19 @@ public class Wolf extends TamableAnimal implements NeutralMob, VariantHolder<Hol
             itemstack.consume(1, player);
             this.tryToTame(player);
             return InteractionResult.SUCCESS;
+        // Purpur start
+        } else if (this.level().purpurConfig.wolfMilkCuresRabies && itemstack.getItem() == Items.MILK_BUCKET && this.isRabid()) {
+            if (!player.isCreative()) {
+                player.setItemInHand(hand, new ItemStack(Items.BUCKET));
+            }
+            this.setRabid(false);
+            for (int i = 0; i < 10; ++i) {
+                ((ServerLevel) level()).sendParticles(((ServerLevel) level()).players(), null, ParticleTypes.HAPPY_VILLAGER,
+                        getX() + random.nextFloat(), getY() + (random.nextFloat() * 1.5), getZ() + random.nextFloat(), 1,
+                        random.nextGaussian() * 0.05D, random.nextGaussian() * 0.05D, random.nextGaussian() * 0.05D, 0, true);
+            }
+            return InteractionResult.SUCCESS;
+        // Purpur end
         } else {
             return super.mobInteract(player, hand);
         }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftWolf.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftWolf.java
index 86574da257731de7646a712ed73384955fe35aa3..e223234dd64b0e41441c3b9f649f0b64dc6d98c4 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftWolf.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftWolf.java
@@ -146,4 +146,16 @@ public class CraftWolf extends CraftTameableAnimal implements Wolf {
             return this.getKey().hashCode();
         }
     }
+
+    // Purpur start
+    @Override
+    public boolean isRabid() {
+        return getHandle().isRabid();
+    }
+
+    @Override
+    public void setRabid(boolean isRabid) {
+        getHandle().setRabid(isRabid);
+    }
+    // Purpur end
 }
diff --git a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
index 43e02a35c742aced64c0b9700da9a71c15532478..1a82ac75760dbddca5b37cb97b27cee18c831b83 100644
--- a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
+++ b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
@@ -1962,6 +1962,8 @@ public class PurpurWorldConfig {
     public boolean wolfRidableInWater = true;
     public boolean wolfControllable = true;
     public double wolfMaxHealth = 8.0D;
+    public boolean wolfMilkCuresRabies = true;
+    public double wolfNaturalRabid = 0.0D;
     public int wolfBreedingTicks = 6000;
     private void wolfSettings() {
         wolfRidable = getBoolean("mobs.wolf.ridable", wolfRidable);
@@ -1973,6 +1975,8 @@ public class PurpurWorldConfig {
             set("mobs.wolf.attributes.max_health", oldValue);
         }
         wolfMaxHealth = getDouble("mobs.wolf.attributes.max_health", wolfMaxHealth);
+        wolfMilkCuresRabies = getBoolean("mobs.wolf.milk-cures-rabid-wolves", wolfMilkCuresRabies);
+        wolfNaturalRabid = getDouble("mobs.wolf.spawn-rabid-chance", wolfNaturalRabid);
         wolfBreedingTicks = getInt("mobs.wolf.breeding-delay-ticks", wolfBreedingTicks);
     }