ServerLevel.java.patch

--- a/net/minecraft/server/level/ServerLevel.java
+++ b/net/minecraft/server/level/ServerLevel.java
@@ -215,11 +_,17 @@
     private boolean handlingTick;
     private final List<CustomSpawner> customSpawners;
     private @Nullable EnderDragonFight dragonFight;
-    private final Int2ObjectMap<EnderDragonPart> dragonParts = new Int2ObjectOpenHashMap<>();
+    final Int2ObjectMap<net.neoforged.neoforge.entity.PartEntity<?>> dragonParts = new Int2ObjectOpenHashMap<>();
     private final StructureManager structureManager;
     private final StructureCheck structureCheck;
     private final boolean tickTime;
     private final LevelDebugSynchronizers debugSynchronizers = new LevelDebugSynchronizers(this);
+    // NeoForge: If present, this level uses its own seed instead of the server's global seed
+    private final java.util.OptionalLong seedOverride;
+    /// {@return the override for the seed, specified in the [LevelStem] this level was constructed from}, if any
+    public java.util.OptionalLong getSeedOverride() {
+        return this.seedOverride;
+    }
 
     public ServerLevel(
         MinecraftServer server,
@@ -233,10 +_,12 @@
         List<CustomSpawner> customSpawners,
         boolean tickTime
     ) {
+        // NeoForge: set seed override asap because things like the chunk cache constructor check level.getSeed()
+        this.seedOverride = levelStem.seedOverride();
+        biomeZoomSeed = net.minecraft.util.ExtraCodecs.fromOptionalLong.apply(levelStem.seedOverride()).map(net.minecraft.world.level.biome.BiomeManager::obfuscateSeed).orElse(biomeZoomSeed);
         super(levelData, dimension, server.registryAccess(), levelStem.type(), false, isDebug, biomeZoomSeed, server.getMaxChainedNeighborUpdates());
         this.tickTime = tickTime;
         this.server = server;
-        this.customSpawners = customSpawners;
         this.serverLevelData = levelData;
         ChunkGenerator generator = levelStem.generator();
         boolean syncWrites = server.forceSynchronousWrites();
@@ -279,7 +_,7 @@
 
         WorldGenSettings worldGenSettings = server.getWorldGenSettings();
         WorldOptions options = worldGenSettings.options();
-        long seed = options.seed();
+        long seed = seedOverride.orElse(options.seed()); // NeoForge: use the seed override here too
         this.structureCheck = new StructureCheck(
             this.chunkSource.chunkScanner(),
             this.registryAccess(),
@@ -303,6 +_,10 @@
         this.waypointManager = new ServerWaypointManager();
         this.environmentAttributes = EnvironmentAttributeSystem.builder().addDefaultLayers(this).build();
         this.updateSkyBrightness();
+
+        // Neo: Move the initialization of customSpawners to the end of costructor
+        // Providing a fully initialized ServerLevel instance for the ServerLevelEvent.CustomSpawners
+        this.customSpawners = net.neoforged.neoforge.event.EventHooks.getCustomSpawners(this, customSpawners);
     }
 
     @Deprecated
@@ -354,7 +_,11 @@
         if (this.sleepStatus.areEnoughSleeping(percentage) && this.sleepStatus.areEnoughDeepSleeping(percentage, this.players)) {
             Optional<Holder<WorldClock>> defaultClock = this.dimensionType().defaultClock();
             if (this.getGameRules().get(GameRules.ADVANCE_TIME) && defaultClock.isPresent()) {
-                this.server.clockManager().moveToTimeMarker(defaultClock.get(), ClockTimeMarkers.WAKE_UP_FROM_SLEEP);
+                // Neo: Allow mods to control how the clock is adjusted after sleep
+                var adjustment = net.neoforged.neoforge.event.EventHooks.onSleepFinished(this, new net.neoforged.neoforge.common.util.ClockAdjustment.Marker(ClockTimeMarkers.WAKE_UP_FROM_SLEEP));
+                if (adjustment != null) {
+                    adjustment.apply(this.server.clockManager(), defaultClock.get());
+                }
             }
 
             this.wakeUpAllPlayers();
@@ -392,7 +_,7 @@
 
         this.handlingTick = false;
         profiler.pop();
-        boolean isActive = this.chunkSource.hasActiveTickets();
+        boolean isActive = this.chunkSource.hasActiveTickets() || net.neoforged.neoforge.common.world.chunk.ForcedChunkManager.hasForcedChunks(this);
         if (isActive) {
             this.resetEmptyTime();
         }
@@ -429,7 +_,9 @@
                                     }
 
                                     profiler.push("tick");
-                                    this.guardEntityTick(this::tickNonPassenger, entity);
+                                    if (!entity.isRemoved() && !(entity instanceof net.neoforged.neoforge.entity.PartEntity)) {
+                                        this.guardEntityTick(this::tickNonPassenger, entity);
+                                    }
                                     profiler.pop();
                                 }
                             }
@@ -569,6 +_,7 @@
         BlockPos topPos = this.getHeightmapPos(Heightmap.Types.MOTION_BLOCKING, pos);
         BlockPos belowPos = topPos.below();
         Biome biome = this.getBiome(topPos).value();
+        if (this.isAreaLoaded(belowPos, 1)) // Forge: check area to avoid loading neighbors in unloaded chunks
         if (biome.shouldFreeze(this, belowPos)) {
             this.setBlockAndUpdate(belowPos, Blocks.ICE.defaultBlockState());
         }
@@ -771,15 +_,19 @@
                 .broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.THUNDER_LEVEL_CHANGE, this.thunderLevel), this.dimension());
         }
 
+        /* The function in use here has been replaced in order to only send the weather info to players in the correct dimension,
+         * rather than to all players on the server. This is what causes the client-side rain, as the
+         * client believes that it has started raining locally, rather than in another dimension.
+         */
         if (wasRaining != this.isRaining()) {
             if (wasRaining) {
-                this.server.getPlayerList().broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.STOP_RAINING, 0.0F));
+                this.server.getPlayerList().broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.STOP_RAINING, 0.0F), this.dimension());
             } else {
-                this.server.getPlayerList().broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.START_RAINING, 0.0F));
+                this.server.getPlayerList().broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.START_RAINING, 0.0F), this.dimension());
             }
 
-            this.server.getPlayerList().broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.RAIN_LEVEL_CHANGE, this.rainLevel));
-            this.server.getPlayerList().broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.THUNDER_LEVEL_CHANGE, this.thunderLevel));
+            this.server.getPlayerList().broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.RAIN_LEVEL_CHANGE, this.rainLevel), this.dimension());
+            this.server.getPlayerList().broadcastAll(new ClientboundGameEventPacket(ClientboundGameEventPacket.THUNDER_LEVEL_CHANGE, this.thunderLevel), this.dimension());
         }
     }
 
@@ -817,7 +_,11 @@
         entity.tickCount++;
         profiler.push(entity.typeHolder()::getRegisteredName);
         profiler.incrementCounter("tickNonPassenger");
-        entity.tick();
+        // Neo: Permit cancellation of Entity#tick via EntityTickEvent.Pre
+        if (!net.neoforged.neoforge.event.EventHooks.fireEntityTickPre(entity).isCanceled()) {
+            entity.tick();
+            net.neoforged.neoforge.event.EventHooks.fireEntityTickPost(entity);
+        }
         profiler.pop();
 
         for (Entity passenger : entity.getPassengers()) {
@@ -880,6 +_,7 @@
             } else {
                 this.entityManager.autoSave();
             }
+            net.neoforged.neoforge.common.NeoForge.EVENT_BUS.post(new net.neoforged.neoforge.event.level.LevelEvent.Save(this));
         }
     }
 
@@ -969,6 +_,7 @@
     }
 
     private void addPlayer(ServerPlayer player) {
+        if (net.neoforged.neoforge.common.NeoForge.EVENT_BUS.post(new net.neoforged.neoforge.event.entity.EntityJoinLevelEvent(player, this)).isCanceled()) return;
         Entity existing = this.getEntity(player.getUUID());
         if (existing != null) {
             LOGGER.warn("Force-added player with duplicate UUID {}", player.getUUID());
@@ -976,7 +_,8 @@
             this.removePlayerImmediately((ServerPlayer)existing, Entity.RemovalReason.DISCARDED);
         }
 
-        this.entityManager.addNewEntity(player);
+        this.entityManager.addNewEntityWithoutEvent(player);
+        player.onAddedToLevel();
     }
 
     private boolean addEntity(Entity entity) {
@@ -984,7 +_,12 @@
             LOGGER.warn("Tried to add entity {} but it was marked as removed already", entity.typeHolder().getRegisteredName());
             return false;
         } else {
-            return this.entityManager.addNewEntity(entity);
+            if (this.entityManager.addNewEntity(entity)) {
+                entity.onAddedToLevel();
+                return true;
+            } else {
+                return false;
+            }
         }
     }
 
@@ -1025,6 +_,12 @@
     public void playSeededSound(
         @Nullable Entity except, double x, double y, double z, Holder<SoundEvent> sound, SoundSource source, float volume, float pitch, long seed
     ) {
+        net.neoforged.neoforge.event.PlayLevelSoundEvent.AtPosition event = net.neoforged.neoforge.event.EventHooks.onPlaySoundAtPosition(this, x, y, z, sound, source, volume, pitch);
+        if (event.isCanceled() || event.getSound() == null) return;
+        sound = event.getSound();
+        source = event.getSource();
+        volume = event.getNewVolume();
+        pitch = event.getNewPitch();
         this.server
             .getPlayerList()
             .broadcast(
@@ -1042,6 +_,12 @@
     public void playSeededSound(
         @Nullable Entity except, Entity sourceEntity, Holder<SoundEvent> sound, SoundSource source, float volume, float pitch, long seed
     ) {
+        net.neoforged.neoforge.event.PlayLevelSoundEvent.AtEntity event = net.neoforged.neoforge.event.EventHooks.onPlaySoundAtEntity(sourceEntity, sound, source, volume, pitch);
+        if (event.isCanceled() || event.getSound() == null) return;
+        sound = event.getSound();
+        source = event.getSource();
+        volume = event.getNewVolume();
+        pitch = event.getNewPitch();
         this.server
             .getPlayerList()
             .broadcast(
@@ -1100,6 +_,7 @@
 
     @Override
     public void gameEvent(Holder<GameEvent> gameEvent, Vec3 position, GameEvent.Context context) {
+        if (!net.neoforged.neoforge.common.CommonHooks.onVanillaGameEvent(this, gameEvent, position, context)) return;
         this.gameEventDispatcher.post(gameEvent, position, context);
     }
 
@@ -1138,6 +_,7 @@
 
     @Override
     public void updateNeighborsAt(BlockPos pos, Block sourceBlock) {
+        net.neoforged.neoforge.event.EventHooks.onNeighborNotify(this, pos, this.getBlockState(pos), java.util.EnumSet.allOf(Direction.class), false).isCanceled();
         this.updateNeighborsAt(pos, sourceBlock, ExperimentalRedstoneUtils.initialOrientation(this, null, null));
     }
 
@@ -1148,6 +_,10 @@
 
     @Override
     public void updateNeighborsAtExceptFromFacing(BlockPos pos, Block blockObject, Direction skipDirection, @Nullable Orientation orientation) {
+        java.util.EnumSet<Direction> directions = java.util.EnumSet.allOf(Direction.class);
+        directions.remove(skipDirection);
+        if (net.neoforged.neoforge.event.EventHooks.onNeighborNotify(this, pos, this.getBlockState(pos), directions, false).isCanceled())
+            return;
         this.neighborUpdater.updateNeighborsAtExceptFromFacing(pos, blockObject, skipDirection, orientation);
     }
 
@@ -1194,7 +_,7 @@
         Explosion.BlockInteraction blockInteraction = switch (interactionType) {
             case NONE -> Explosion.BlockInteraction.KEEP;
             case BLOCK -> this.getDestroyType(GameRules.BLOCK_EXPLOSION_DROP_DECAY);
-            case MOB -> this.getGameRules().get(GameRules.MOB_GRIEFING)
+            case MOB -> net.neoforged.neoforge.event.EventHooks.canEntityGrief(this, source)
                 ? this.getDestroyType(GameRules.MOB_EXPLOSION_DROP_DECAY)
                 : Explosion.BlockInteraction.KEEP;
             case TNT -> this.getDestroyType(GameRules.TNT_EXPLOSION_DROP_DECAY);
@@ -1202,6 +_,7 @@
         };
         Vec3 center = new Vec3(x, y, z);
         ServerExplosion explosion = new ServerExplosion(this, source, damageSource, damageCalculator, center, r, fire, blockInteraction);
+        if (net.neoforged.neoforge.event.EventHooks.onExplosionStart(this, explosion)) return;
         int blockCount = explosion.explode();
         ParticleOptions explosionParticle = explosion.isSmall() ? smallExplosionParticles : largeExplosionParticles;
 
@@ -1379,7 +_,7 @@
     }
 
     @Override
-    public Collection<EnderDragonPart> dragonParts() {
+    public Collection<net.neoforged.neoforge.entity.PartEntity<?>> dragonParts() {
         return this.dragonParts.values();
     }
 
@@ -1640,7 +_,8 @@
 
     @Override
     public long getSeed() {
-        return this.server.getWorldGenSettings().options().seed();
+        // NeoForge: use seed override if present, otherwise default to vanilla global seed
+        return this.getSeedOverride().orElseGet(() -> this.server.getWorldGenSettings().options().seed());
     }
 
     public @Nullable EnderDragonFight getDragonFight() {
@@ -1906,8 +_,8 @@
                 ServerLevel.this.navigatingMobs.add(mob);
             }
 
-            if (entity instanceof EnderDragon dragon) {
-                for (EnderDragonPart subEntity : dragon.getSubEntities()) {
+            if (entity.isMultipartEntity()) {
+                for(net.neoforged.neoforge.entity.PartEntity<?> subEntity : entity.getParts()) {
                     ServerLevel.this.dragonParts.put(subEntity.getId(), subEntity);
                 }
             }
@@ -1927,25 +_,57 @@
                 if (ServerLevel.this.isUpdatingNavigations) {
                     String message = "onTrackingStart called during navigation iteration";
                     Util.logAndPauseIfInIde(
-                        "onTrackingStart called during navigation iteration", new IllegalStateException("onTrackingStart called during navigation iteration")
+                              "onTrackingStart called during navigation iteration", new IllegalStateException("onTrackingStart called during navigation iteration")
                     );
                 }
 
                 ServerLevel.this.navigatingMobs.remove(mob);
             }
 
-            if (entity instanceof EnderDragon dragon) {
-                for (EnderDragonPart subEntity : dragon.getSubEntities()) {
+            if (entity.isMultipartEntity()) {
+                for(net.neoforged.neoforge.entity.PartEntity<?> subEntity : entity.getParts()) {
                     ServerLevel.this.dragonParts.remove(subEntity.getId());
                 }
             }
 
             entity.updateDynamicGameEventListener(DynamicGameEventListener::remove);
             ServerLevel.this.debugSynchronizers.dropEntity(entity);
+
+            entity.onRemovedFromLevel();
+            net.neoforged.neoforge.common.NeoForge.EVENT_BUS.post(new net.neoforged.neoforge.event.entity.EntityLeaveLevelEvent(entity, ServerLevel.this));
         }
 
         public void onSectionChange(Entity entity) {
             entity.updateDynamicGameEventListener(DynamicGameEventListener::move);
         }
+    }
+
+    private final net.neoforged.neoforge.capabilities.CapabilityListenerHolder capListenerHolder = new net.neoforged.neoforge.capabilities.CapabilityListenerHolder();
+
+    @Override
+    public void invalidateCapabilities(BlockPos pos) {
+        capListenerHolder.invalidatePos(pos);
+    }
+
+    @Override
+    public void invalidateCapabilities(ChunkPos pos) {
+        capListenerHolder.invalidateChunk(pos);
+    }
+
+    /**
+     * Register a listener for capability invalidation.
+     * @see net.neoforged.neoforge.capabilities.ICapabilityInvalidationListener
+     */
+    public void registerCapabilityListener(BlockPos pos, net.neoforged.neoforge.capabilities.ICapabilityInvalidationListener listener) {
+        capListenerHolder.addListener(pos, listener);
+    }
+
+    /**
+     * Internal method, used to clean capability listeners that are not referenced.
+     * Do not call.
+     */
+    @org.jetbrains.annotations.ApiStatus.Internal
+    public void cleanCapabilityListenerReferences() {
+        capListenerHolder.clean();
     }
 }