Paper/patches/server/0281-Fixes-and-additions-to-the-spawn-reason-API.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 24 Mar 2019 00:24:52 -0400
Subject: [PATCH] Fixes and additions to the spawn reason API

Expose an entities spawn reason on the entity.
Pre existing entities will return NATURAL if it was a non
persistenting Living Entity, SPAWNER for spawners,
or DEFAULT since data was not stored.

Additionally, add missing spawn reasons.

Co-authored-by: Jake Potrebic <jake.m.potrebic@gmail.com>
Co-authored-by: Doc <nachito94@msn.com>

diff --git a/src/main/java/net/minecraft/server/commands/SummonCommand.java b/src/main/java/net/minecraft/server/commands/SummonCommand.java
index bf72cf288ade52ee8cc41ca978f368b3ad575951..798999be50d26be357ef3c6d5b9383ce4d1048c1 100644
--- a/src/main/java/net/minecraft/server/commands/SummonCommand.java
+++ b/src/main/java/net/minecraft/server/commands/SummonCommand.java
@@ -57,6 +57,7 @@ public class SummonCommand {
             ServerLevel worldserver = source.getLevel();
             Entity entity = EntityType.loadEntityRecursive(nbttagcompound1, worldserver, (entity1) -> {
                 entity1.moveTo(pos.x, pos.y, pos.z, entity1.getYRot(), entity1.getXRot());
+                entity1.spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.COMMAND; // Paper - Entity#getEntitySpawnReason
                 return entity1;
             });
 
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index e9d08662c065d04a67918f0aa2cd4fde5798f2a6..a6a21def1ae0d35fa106da6242c49a0928e4eda5 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -1207,6 +1207,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
             return true;
         }
         // Paper end - extra debug info
+        if (entity.spawnReason == null) entity.spawnReason = spawnReason; // Paper - Entity#getEntitySpawnReason
         if (entity.isRemoved()) {
             // WorldServer.LOGGER.warn("Tried to add entity {} but it was marked as removed already", EntityTypes.getKey(entity.getType())); // CraftBukkit
             return false;
diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
index 2f1d075b8dbcf173c51f3e6396ccbc61b64f75df..79203d0e5cdb86d9e2fb22cdaeb8cf3a93e43dcc 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -223,6 +223,11 @@ public abstract class PlayerList {
             worldserver1 = worldserver;
         }
 
+        // Paper start - Entity#getEntitySpawnReason
+        if (optional.isEmpty()) {
+            player.spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DEFAULT; // set Player SpawnReason to DEFAULT on first login
+        }
+        // Paper end - Entity#getEntitySpawnReason
         player.setServerLevel(worldserver1);
         String s1 = connection.getLoggableAddress(this.server.logIPs());
 
@@ -348,7 +353,7 @@ public abstract class PlayerList {
             CompoundTag nbttagcompound = ((CompoundTag) optional.get()).getCompound("RootVehicle");
             ServerLevel finalWorldServer = worldserver1; // CraftBukkit - decompile error
             Entity entity = EntityType.loadEntityRecursive(nbttagcompound.getCompound("Entity"), worldserver1, (entity1) -> {
-                return !finalWorldServer.addWithUUID(entity1) ? null : entity1; // CraftBukkit - decompile error
+                return !finalWorldServer.addWithUUID(entity1, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.MOUNT) ? null : entity1; // CraftBukkit - decompile error // Paper - Entity#getEntitySpawnReason
             });
 
             if (entity != null) {
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index f330ddca00ed11bf76ae825820423b94920013b9..9d56aff2766b684f0fb20e93d504de1a7a564b11 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -247,6 +247,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
         }
     }
     // Paper end - Share random for entities to make them more random
+    public org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason spawnReason; // Paper - Entity#getEntitySpawnReason
 
     private CraftEntity bukkitEntity;
 
@@ -2274,6 +2275,9 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
                 }
                 nbttagcompound.put("Paper.Origin", this.newDoubleList(origin.getX(), origin.getY(), origin.getZ()));
             }
+            if (spawnReason != null) {
+                nbttagcompound.putString("Paper.SpawnReason", spawnReason.name());
+            }
             // Save entity's from mob spawner status
             if (spawnedViaMobSpawner) {
                 nbttagcompound.putBoolean("Paper.FromMobSpawner", true);
@@ -2420,6 +2424,26 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
             }
 
             spawnedViaMobSpawner = nbt.getBoolean("Paper.FromMobSpawner"); // Restore entity's from mob spawner status
+            if (nbt.contains("Paper.SpawnReason")) {
+                String spawnReasonName = nbt.getString("Paper.SpawnReason");
+                try {
+                    spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.valueOf(spawnReasonName);
+                } catch (Exception ignored) {
+                    LOGGER.error("Unknown SpawnReason " + spawnReasonName + " for " + this);
+                }
+            }
+            if (spawnReason == null) {
+                if (spawnedViaMobSpawner) {
+                    spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.SPAWNER;
+                } else if (this instanceof Mob && (this instanceof net.minecraft.world.entity.animal.Animal || this instanceof net.minecraft.world.entity.animal.AbstractFish) && !((Mob) this).removeWhenFarAway(0.0)) {
+                    if (!nbt.getBoolean("PersistenceRequired")) {
+                        spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.NATURAL;
+                    }
+                }
+            }
+            if (spawnReason == null) {
+                spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DEFAULT;
+            }
             // Paper end
 
         } catch (Throwable throwable) {
diff --git a/src/main/java/net/minecraft/world/entity/EntityType.java b/src/main/java/net/minecraft/world/entity/EntityType.java
index 69a661f01e43d17262fd2845dde5528416bbe456..c0062c8f83641ff30e79a309c0bb9930ba4b422a 100644
--- a/src/main/java/net/minecraft/world/entity/EntityType.java
+++ b/src/main/java/net/minecraft/world/entity/EntityType.java
@@ -366,7 +366,7 @@ public class EntityType<T extends Entity> implements FeatureElement, EntityTypeT
     @Nullable
     public T spawn(ServerLevel world, @Nullable ItemStack stack, @Nullable Player player, BlockPos pos, MobSpawnType spawnReason, boolean alignPosition, boolean invertY) {
         // CraftBukkit start
-        return this.spawn(world, stack, player, pos, spawnReason, alignPosition, invertY, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.SPAWNER_EGG);
+        return this.spawn(world, stack, player, pos, spawnReason, alignPosition, invertY, spawnReason == MobSpawnType.DISPENSER ? org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DISPENSE_EGG : org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.SPAWNER_EGG); // Paper - use correct spawn reason for dispenser spawn eggs
     }
 
     @Nullable
diff --git a/src/main/java/net/minecraft/world/entity/OminousItemSpawner.java b/src/main/java/net/minecraft/world/entity/OminousItemSpawner.java
index 146cbec9e64b6c77759aadd0d0c4e989018e9aef..4c4545b3732d4c08afdb7bc1913169a96e82825c 100644
--- a/src/main/java/net/minecraft/world/entity/OminousItemSpawner.java
+++ b/src/main/java/net/minecraft/world/entity/OminousItemSpawner.java
@@ -89,7 +89,7 @@ public class OminousItemSpawner extends Entity {
                 entity = new ItemEntity(level, this.getX(), this.getY(), this.getZ(), itemStack);
             }
 
-            level.addFreshEntity(entity);
+            level.addFreshEntity(entity, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.OMINOUS_ITEM_SPAWNER); // Paper - Fixes and additions to the SpawnReason API
             level.levelEvent(3021, this.blockPosition(), 1);
             level.gameEvent(entity, GameEvent.ENTITY_PLACE, this.position());
             this.setItem(ItemStack.EMPTY);
diff --git a/src/main/java/net/minecraft/world/entity/projectile/DragonFireball.java b/src/main/java/net/minecraft/world/entity/projectile/DragonFireball.java
index 1dade7a4fbdf190661e4431496349444467509cc..3e869620db35d38db39fbeed715b898ef9d2743c 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/DragonFireball.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/DragonFireball.java
@@ -65,7 +65,7 @@ public class DragonFireball extends AbstractHurtingProjectile {
 
                 if (new com.destroystokyo.paper.event.entity.EnderDragonFireballHitEvent((org.bukkit.entity.DragonFireball) this.getBukkitEntity(), list.stream().map(LivingEntity::getBukkitLivingEntity).collect(java.util.stream.Collectors.toList()), (org.bukkit.entity.AreaEffectCloud) entityareaeffectcloud.getBukkitEntity()).callEvent()) { // Paper - EnderDragon Events
                 this.level().levelEvent(2006, this.blockPosition(), this.isSilent() ? -1 : 1);
-                this.level().addFreshEntity(entityareaeffectcloud);
+                this.level().addFreshEntity(entityareaeffectcloud, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.EXPLOSION); // Paper - use correct spawn reason
                 } else entityareaeffectcloud.discard(null); // Paper - EnderDragon Events
                 this.discard(EntityRemoveEvent.Cause.HIT); // CraftBukkit - add Bukkit remove cause
             }
diff --git a/src/main/java/net/minecraft/world/level/BaseSpawner.java b/src/main/java/net/minecraft/world/level/BaseSpawner.java
index ee897b8c9462dbb3d7be9a2994753155065ce205..1d0964a7f544735a0213d5c7832c71f53db139a9 100644
--- a/src/main/java/net/minecraft/world/level/BaseSpawner.java
+++ b/src/main/java/net/minecraft/world/level/BaseSpawner.java
@@ -191,6 +191,7 @@ public abstract class BaseSpawner {
                         }
 
                         entity.spawnedViaMobSpawner = true; // Paper
+                        entity.spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.SPAWNER; // Paper - Entity#getEntitySpawnReason
                         flag = true; // Paper
                         // CraftBukkit start
                         if (org.bukkit.craftbukkit.event.CraftEventFactory.callSpawnerSpawnEvent(entity, pos).isCancelled()) {
diff --git a/src/main/java/net/minecraft/world/level/block/FrogspawnBlock.java b/src/main/java/net/minecraft/world/level/block/FrogspawnBlock.java
index 211b7809f099678bc3bd64bd29fd9c4d19e3ab0d..b968129b9a93fdf771caba5f768456070543ba6a 100644
--- a/src/main/java/net/minecraft/world/level/block/FrogspawnBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/FrogspawnBlock.java
@@ -111,7 +111,7 @@ public class FrogspawnBlock extends Block {
                 int k = random.nextInt(1, 361);
                 tadpole.moveTo(d, (double)pos.getY() - 0.5, e, (float)k, 0.0F);
                 tadpole.setPersistenceRequired();
-                world.addFreshEntity(tadpole);
+                world.addFreshEntity(tadpole, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.EGG); // Paper - use correct spawn reason
             }
         }
     }
diff --git a/src/main/java/net/minecraft/world/level/block/SnifferEggBlock.java b/src/main/java/net/minecraft/world/level/block/SnifferEggBlock.java
index 1eda49c9ce8ee009cb08b18f02f59b37c2118628..14a5cd54820243f4ca59857b0d67c1e86457d590 100644
--- a/src/main/java/net/minecraft/world/level/block/SnifferEggBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/SnifferEggBlock.java
@@ -73,7 +73,7 @@ public class SnifferEggBlock extends Block {
                 Vec3 vec3 = pos.getCenter();
                 sniffer.setBaby(true);
                 sniffer.moveTo(vec3.x(), vec3.y(), vec3.z(), Mth.wrapDegrees(world.random.nextFloat() * 360.0F), 0.0F);
-                world.addFreshEntity(sniffer);
+                world.addFreshEntity(sniffer, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.EGG); // Paper - use correct spawn reason
             }
         }
     }
diff --git a/src/main/java/net/minecraft/world/level/block/entity/SculkShriekerBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/SculkShriekerBlockEntity.java
index dbc0b69603dcffbf3d41d79719aa0f2b7da4a131..dd86f5ec5b2051aeea4e19ff97146362b1e8d019 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/SculkShriekerBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/SculkShriekerBlockEntity.java
@@ -189,7 +189,7 @@ public class SculkShriekerBlockEntity extends BlockEntity implements GameEventLi
 
     private boolean trySummonWarden(ServerLevel world) {
         return this.warningLevel >= 4
-            && SpawnUtil.trySpawnMob(EntityType.WARDEN, MobSpawnType.TRIGGERED, world, this.getBlockPos(), 20, 5, 6, SpawnUtil.Strategy.ON_TOP_OF_COLLIDER)
+            && SpawnUtil.trySpawnMob(EntityType.WARDEN, MobSpawnType.TRIGGERED, world, this.getBlockPos(), 20, 5, 6, SpawnUtil.Strategy.ON_TOP_OF_COLLIDER, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.NATURAL, null) // Paper - Entity#getEntitySpawnReason
                 .isPresent();
     }
 
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
index bddf98bdf60473eb1d2e533cf533ed7eee797aaa..ce70c8fddbe63d0af2b1f988ce9a2b40c5d48066 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
@@ -1018,4 +1018,11 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
         return this.getHandle().spawnedViaMobSpawner;
     }
     // Paper end - Entity#fromMobSpawner
+
+    // Paper start - entity spawn reason API
+    @Override
+    public org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason getEntitySpawnReason() {
+        return getHandle().spawnReason;
+    }
+    // Paper end - entity spawn reason API
 }