From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: William Blake Galbreath <blake.galbreath@gmail.com>
Date: Sat, 11 Jul 2020 19:41:34 -0500
Subject: [PATCH] Entity lifespan


diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 4475c9fb628cdd7175899370ba144d27f4148757..a4d3f1cbb5d832281d12ce7c27506c6eb037d38c 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -2860,6 +2860,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
             AABB axisalignedbb = entity.getBoundingBox();
 
             if (axisalignedbb.distanceToSqr(this.player.getEyePosition()) < ServerGamePacketListenerImpl.MAX_INTERACTION_DISTANCE) {
+                if (entity instanceof Mob mob) mob.ticksSinceLastInteraction = 0; // Purpur
                 packet.dispatch(new ServerboundInteractPacket.Handler() {
                     private void performInteraction(InteractionHand enumhand, ServerGamePacketListenerImpl.EntityInteraction playerconnection_a, PlayerInteractEntityEvent event) { // CraftBukkit
                         ItemStack itemstack = ServerGamePacketListenerImpl.this.player.getItemInHand(enumhand);
diff --git a/src/main/java/net/minecraft/world/entity/Mob.java b/src/main/java/net/minecraft/world/entity/Mob.java
index ef290c4f243e07a15a489ddd7461b4f182cb2345..9f68247ffc31b67e1eb66d3b6449c44fe8549d0d 100644
--- a/src/main/java/net/minecraft/world/entity/Mob.java
+++ b/src/main/java/net/minecraft/world/entity/Mob.java
@@ -133,6 +133,7 @@ public abstract class Mob extends LivingEntity implements Targeting {
     private BlockPos restrictCenter;
     private float restrictRadius;
 
+    public int ticksSinceLastInteraction; // Purpur
     public boolean aware = true; // CraftBukkit
 
     protected Mob(EntityType<? extends Mob> type, Level world) {
@@ -321,6 +322,7 @@ public abstract class Mob extends LivingEntity implements Targeting {
                 entityliving = null;
             }
         }
+        if (entityliving instanceof ServerPlayer) this.ticksSinceLastInteraction = 0; // Purpur
         this.target = entityliving;
         return true;
         // CraftBukkit end
@@ -368,8 +370,28 @@ public abstract class Mob extends LivingEntity implements Targeting {
         }
 
         this.level().getProfiler().pop();
+        incrementTicksSinceLastInteraction(); // Purpur
     }
 
+    // Purpur start
+    private void incrementTicksSinceLastInteraction() {
+        ++this.ticksSinceLastInteraction;
+        if (getRider() != null) {
+            this.ticksSinceLastInteraction = 0;
+            return;
+        }
+        if (this.level().purpurConfig.entityLifeSpan <= 0) {
+            return; // feature disabled
+        }
+        if (!this.removeWhenFarAway(0) || isPersistenceRequired() || requiresCustomPersistence() || hasCustomName()) {
+            return; // mob persistent
+        }
+        if (this.ticksSinceLastInteraction > this.level().purpurConfig.entityLifeSpan) {
+            this.discard();
+        }
+    }
+    // Purpur end
+
     @Override
     protected void playHurtSound(DamageSource source) {
         this.resetAmbientSoundTime();
@@ -559,6 +581,7 @@ public abstract class Mob extends LivingEntity implements Targeting {
         }
 
         nbt.putBoolean("Bukkit.Aware", this.aware); // CraftBukkit
+        nbt.putInt("Purpur.ticksSinceLastInteraction", this.ticksSinceLastInteraction); // Purpur
     }
 
     @Override
@@ -629,6 +652,11 @@ public abstract class Mob extends LivingEntity implements Targeting {
             this.aware = nbt.getBoolean("Bukkit.Aware");
         }
         // CraftBukkit end
+        // Purpur start
+        if (nbt.contains("Purpur.ticksSinceLastInteraction")) {
+            this.ticksSinceLastInteraction = nbt.getInt("Purpur.ticksSinceLastInteraction");
+        }
+        // Purpur end
     }
 
     @Override
@@ -1688,6 +1716,7 @@ public abstract class Mob extends LivingEntity implements Targeting {
             this.setLastHurtMob(target);
         }
 
+        if (target instanceof ServerPlayer) this.ticksSinceLastInteraction = 0; // Purpur
         return flag;
     }
 
diff --git a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
index c69147c1bc8e96c43a9496fd8c4fb4139682afd5..96203a380bbb4dc9aaffb6867ca1395d96795f43 100644
--- a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
+++ b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
@@ -127,6 +127,11 @@ public class PurpurWorldConfig {
         elytraDamagePerTridentBoost = getInt("gameplay-mechanics.elytra.damage-per-boost.trident", elytraDamagePerTridentBoost);
     }
 
+    public int entityLifeSpan = 0;
+    private void entitySettings() {
+        entityLifeSpan = getInt("gameplay-mechanics.entity-lifespan", entityLifeSpan);
+    }
+
     public List<Item> itemImmuneToCactus = new ArrayList<>();
     public List<Item> itemImmuneToExplosion = new ArrayList<>();
     public List<Item> itemImmuneToFire = new ArrayList<>();