Rewrite regenerateChunkRegion

src/main/java/carpet/mixins/BlockLightStorage_scarpetChunkCreationMixin.java

@@ -0,0 +1,65 @@
+package carpet.mixins;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import carpet.fakes.ChunkLightProviderInterface;
+import carpet.fakes.LightStorageInterface;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.ChunkSectionPos;
+import net.minecraft.util.math.Direction;
+import net.minecraft.world.LightType;
+import net.minecraft.world.chunk.ChunkNibbleArray;
+import net.minecraft.world.chunk.ChunkProvider;
+import net.minecraft.world.chunk.light.BlockLightStorage;
+import net.minecraft.world.chunk.light.BlockLightStorage.Data;
+import net.minecraft.world.chunk.light.ChunkLightProvider;
+import net.minecraft.world.chunk.light.LightStorage;
+
+@Mixin(BlockLightStorage.class)
+public abstract class BlockLightStorage_scarpetChunkCreationMixin extends LightStorage<Data> implements LightStorageInterface
+{
+    private BlockLightStorage_scarpetChunkCreationMixin(final LightType lightType, final ChunkProvider chunkProvider, final Data lightData)
+    {
+        super(lightType, chunkProvider, lightData);
+    }
+
+    @Override
+    public void processRelight(final ChunkLightProvider<?, ?> lightProvider, final long cPos)
+    {
+        final LevelPropagatorInterface levelPropagator = (LevelPropagatorInterface) lightProvider;
+
+        for (int y = -1; y < 17; ++y)
+        {
+            final long sectionPos = ChunkSectionPos.asLong(ChunkSectionPos.getX(cPos), y, ChunkSectionPos.getZ(cPos));
+            final long pos = BlockPos.asLong(ChunkSectionPos.getWorldCoord(ChunkSectionPos.getX(sectionPos)), ChunkSectionPos.getWorldCoord(y), ChunkSectionPos.getWorldCoord(ChunkSectionPos.getZ(sectionPos)));
+
+            if (!this.hasLight(sectionPos))
+                continue;
+
+            for (final Direction dir : Direction.Type.HORIZONTAL)
+            {
+                final ChunkNibbleArray neighborLightArray = this.getLightArray(ChunkSectionPos.offset(sectionPos, dir));
+
+                if (neighborLightArray == null)
+                    continue;
+
+                final int ox = 15 * Math.max(dir.getOffsetX(), 0);
+                final int oz = 15 * Math.max(dir.getOffsetZ(), 0);
+
+                final int dx = Math.abs(dir.getOffsetZ());
+                final int dz = Math.abs(dir.getOffsetX());
+
+                for (int t = 0; t < 16; ++t)
+                    for (int dy = 0; dy < 16; ++dy)
+                    {
+                        final long dst = BlockPos.add(pos, ox + t * dx, dy, oz + t * dz);
+                        final long src = BlockPos.offset(dst, dir);
+
+                        final int srcLevel = ((ChunkLightProviderInterface) lightProvider).callGetCurrentLevelFromArray(neighborLightArray, src);
+
+                        levelPropagator.invokeUpdateLevel(src, dst, levelPropagator.callGetPropagatedLevel(src, dst, srcLevel), true);
+                    }
+            }
+        }
+    }
+}

src/main/java/carpet/mixins/ChunkLightProvider_scarpetChunkCreationMixin.java

@@ -0,0 +1,36 @@
+package carpet.mixins;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.gen.Invoker;
+
+import carpet.fakes.ChunkLightProviderInterface;
+import carpet.fakes.Lighting_scarpetChunkCreationInterface;
+import net.minecraft.world.chunk.ChunkNibbleArray;
+import net.minecraft.world.chunk.light.ChunkLightProvider;
+import net.minecraft.world.chunk.light.LightStorage;
+
+@Mixin(ChunkLightProvider.class)
+public abstract class ChunkLightProvider_scarpetChunkCreationMixin implements Lighting_scarpetChunkCreationInterface, ChunkLightProviderInterface
+{
+    @Shadow
+    @Final
+    protected LightStorage<?> lightStorage;
+
+    @Override
+    public void removeLightData(final long pos)
+    {
+        ((Lighting_scarpetChunkCreationInterface) this.lightStorage).removeLightData(pos);
+    }
+
+    @Override
+    public void relight(final long pos)
+    {
+        ((Lighting_scarpetChunkCreationInterface) this.lightStorage).relight(pos);
+    }
+
+    @Override
+    @Invoker("getCurrentLevelFromArray")
+    public abstract int callGetCurrentLevelFromArray(ChunkNibbleArray array, long blockPos);
+}

src/main/java/carpet/mixins/ChunkTicketManager_scarpetChunkCreationMixin.java

@@ -0,0 +1,26 @@
+package carpet.mixins;
+
+import java.util.Set;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+import carpet.fakes.ChunkTicketManagerInterface;
+import net.minecraft.server.world.ChunkHolder;
+import net.minecraft.server.world.ChunkTicketManager;
+
+@Mixin(ChunkTicketManager.class)
+public abstract class ChunkTicketManager_scarpetChunkCreationMixin implements ChunkTicketManagerInterface
+{
+    @Shadow
+    @Final
+    private Set<ChunkHolder> chunkHolders;
+
+    @Override
+    public void replaceHolder(final ChunkHolder oldHolder, final ChunkHolder newHolder)
+    {
+        this.chunkHolders.remove(oldHolder);
+        this.chunkHolders.add(newHolder);
+    }
+}

src/main/java/carpet/mixins/LevelPropagatorInterface.java

@@ -0,0 +1,16 @@
+package carpet.mixins;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Invoker;
+
+import net.minecraft.world.chunk.light.LevelPropagator;
+
+@Mixin(LevelPropagator.class)
+public interface LevelPropagatorInterface
+{
+    @Invoker("updateLevel")
+    void invokeUpdateLevel(long sourceId, long id, int level, boolean decrease);
+
+    @Invoker("getPropagatedLevel")
+    int callGetPropagatedLevel(long sourceId, long targetId, int level);
+}

src/main/java/carpet/mixins/LightStorage_scarpetChunkCreationMixin.java

@@ -0,0 +1,115 @@
+package carpet.mixins;
+
+import java.util.Arrays;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import carpet.fakes.LightStorageInterface;
+import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
+import it.unimi.dsi.fastutil.longs.LongSet;
+import net.minecraft.util.math.ChunkSectionPos;
+import net.minecraft.world.chunk.ChunkNibbleArray;
+import net.minecraft.world.chunk.ChunkToNibbleArrayMap;
+import net.minecraft.world.chunk.light.ChunkLightProvider;
+import net.minecraft.world.chunk.light.LightStorage;
+
+@Mixin(LightStorage.class)
+public abstract class LightStorage_scarpetChunkCreationMixin implements LightStorageInterface
+{
+    @Shadow
+    protected abstract ChunkNibbleArray getLightArray(final long sectionPos, final boolean cached);
+
+    @Shadow
+    protected abstract void removeChunkData(final ChunkLightProvider<?, ?> storage, final long blockChunkPos);
+
+    @Shadow
+    @Final
+    protected LongSet field_15802;
+
+    @Shadow
+    @Final
+    protected ChunkToNibbleArrayMap<?> lightArrays;
+
+    @Shadow protected abstract boolean hasLight(final long sectionPos);
+
+    @Shadow
+    @Final
+    protected Long2ObjectMap<ChunkNibbleArray> lightArraysToAdd;
+
+    @Shadow protected abstract void setLightEnabled(final long l, final boolean bl);
+
+    @Unique
+    private final LongSet removedChunks = new LongOpenHashSet();
+
+    @Unique
+    private final LongSet relightChunks = new LongOpenHashSet();
+
+    @Override
+    public void removeLightData(final long pos)
+    {
+        this.removedChunks.add(pos);
+    }
+
+    @Override
+    public void relight(final long pos)
+    {
+        this.relightChunks.add(pos);
+    }
+
+    @Inject(
+        method = "updateLightArrays(Lnet/minecraft/world/chunk/light/ChunkLightProvider;ZZ)V",
+        at = @At("HEAD")
+    )
+    private void processData(final ChunkLightProvider<?, ?> lightProvider, final boolean doSkylight, final boolean skipEdgeLightPropagation, final CallbackInfo ci)
+    {
+        // Process light removal
+
+        for (final long cPos : this.removedChunks)
+        {
+            for (int y = -1; y < 17; ++y)
+            {
+                final long sectionPos = ChunkSectionPos.asLong(ChunkSectionPos.getX(cPos), y, ChunkSectionPos.getZ(cPos));
+
+                this.lightArraysToAdd.remove(sectionPos);
+
+                if (this.hasLight(sectionPos))
+                {
+                    this.removeChunkData(lightProvider, sectionPos);
+
+                    if (this.field_15802.add(sectionPos))
+                        this.lightArrays.replaceWithCopy(sectionPos);
+
+                    Arrays.fill(this.getLightArray(sectionPos, true).asByteArray(), (byte) 0);
+                }
+            }
+
+            this.processRemoveLightData(cPos);
+        }
+
+        this.removedChunks.clear();
+
+        // Process relighting
+
+        for (final long cPos : this.relightChunks)
+            this.processRelight(lightProvider, cPos);
+
+        this.relightChunks.clear();
+    }
+
+    @Override
+    public void processRemoveLightData(final long pos)
+    {
+    }
+
+    @Override
+    public void processRelight(final ChunkLightProvider<?, ?> lightProvider, final long pos)
+    {
+    }
+}

src/main/java/carpet/mixins/LightingProvider_scarpetChunkCreationMixin.java

@@ -0,0 +1,41 @@
+package carpet.mixins;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+import carpet.fakes.Lighting_scarpetChunkCreationInterface;
+import net.minecraft.world.chunk.light.ChunkLightProvider;
+import net.minecraft.world.chunk.light.LightingProvider;
+
+@Mixin(LightingProvider.class)
+public abstract class LightingProvider_scarpetChunkCreationMixin implements Lighting_scarpetChunkCreationInterface
+{
+    @Shadow
+    @Final
+    private ChunkLightProvider<?, ?> blockLightProvider;
+
+    @Shadow
+    @Final
+    private ChunkLightProvider<?, ?> skyLightProvider;
+
+    @Override
+    public void removeLightData(final long pos)
+    {
+        if (this.blockLightProvider != null)
+            ((Lighting_scarpetChunkCreationInterface) this.blockLightProvider).removeLightData(pos);
+
+        if (this.skyLightProvider != null)
+            ((Lighting_scarpetChunkCreationInterface) this.skyLightProvider).removeLightData(pos);
+    }
+
+    @Override
+    public void relight(final long pos)
+    {
+        if (this.blockLightProvider != null)
+            ((Lighting_scarpetChunkCreationInterface) this.blockLightProvider).relight(pos);
+
+        if (this.skyLightProvider != null)
+            ((Lighting_scarpetChunkCreationInterface) this.skyLightProvider).relight(pos);
+    }
+}

src/main/java/carpet/mixins/ServerLightingProvider_scarpetChunkCreationMixin.java

@@ -1,54 +1,84 @@
 package carpet.mixins;
 
-import carpet.fakes.ServerLightingProviderInterface;
-import it.unimi.dsi.fastutil.objects.ObjectList;
-import net.minecraft.server.world.ServerLightingProvider;
-import net.minecraft.util.math.ChunkPos;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.IntSupplier;
+
 import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.gen.Invoker;
 
-import java.util.concurrent.atomic.AtomicBoolean;
-
-import static java.lang.Thread.yield;
+import carpet.fakes.Lighting_scarpetChunkCreationInterface;
+import carpet.fakes.ServerLightingProviderInterface;
+import carpet.fakes.ThreadedAnvilChunkStorageInterface;
+import net.minecraft.server.world.ServerLightingProvider;
+import net.minecraft.server.world.ServerLightingProvider.Stage;
+import net.minecraft.server.world.ThreadedAnvilChunkStorage;
+import net.minecraft.util.Util;
+import net.minecraft.util.math.ChunkPos;
+import net.minecraft.util.math.ChunkSectionPos;
+import net.minecraft.world.chunk.Chunk;
+import net.minecraft.world.chunk.ChunkProvider;
+import net.minecraft.world.chunk.light.LightingProvider;
 
 @Mixin(ServerLightingProvider.class)
-public abstract class ServerLightingProvider_scarpetChunkCreationMixin implements ServerLightingProviderInterface
+public abstract class ServerLightingProvider_scarpetChunkCreationMixin extends LightingProvider implements ServerLightingProviderInterface
 {
+    private ServerLightingProvider_scarpetChunkCreationMixin(final ChunkProvider chunkProvider, final boolean hasBlockLight, final boolean hasSkyLight)
+    {
+        super(chunkProvider, hasBlockLight, hasSkyLight);
+    }
 
-    @Shadow protected abstract void updateChunkStatus(ChunkPos pos);
+    @Shadow
+    protected abstract void enqueue(final int x, final int z, final IntSupplier completedLevelSupplier, final Stage stage, final Runnable task);
 
-    @Shadow private volatile int taskBatchSize;
-
-    @Shadow public abstract void setTaskBatchSize(int taskBatchSize);
-
-    @Shadow @Final private AtomicBoolean field_18812;
-
-    @Shadow @Final private ObjectList pendingTasks;
-
-    @Shadow protected abstract void runTasks();
+    @Shadow
+    @Final
+    private ThreadedAnvilChunkStorage chunkStorage;
 
     @Override
-    public void publicUpdateChunkStatus(ChunkPos pos)
+    @Invoker("updateChunkStatus")
+    public abstract void invokeUpdateChunkStatus(ChunkPos pos);
+
+    @Override
+    public void removeLightData(final Chunk chunk)
     {
-        updateChunkStatus(pos);
+        final ChunkPos pos = chunk.getPos();
+        chunk.setLightOn(false);
+
+        this.enqueue(pos.x, pos.z, () -> 0, ServerLightingProvider.Stage.PRE_UPDATE, Util.debugRunnable(() -> {
+                super.setLightEnabled(pos, false);
+                ((Lighting_scarpetChunkCreationInterface) this).removeLightData(ChunkSectionPos.withZeroZ(ChunkSectionPos.asLong(pos.x, 0, pos.z)));
+            },
+            () -> "Remove light data " + pos
+        ));
     }
 
     @Override
-    public void flush()
+    public CompletableFuture<Void> relight(final Chunk chunk)
     {
-        try
-        {
-            while (!field_18812.compareAndSet(false, true)) yield();
-            if (pendingTasks.size() == 0) return;
-            int prevTaskBatchSize = taskBatchSize;
-            setTaskBatchSize(pendingTasks.size());
-            runTasks();
-            setTaskBatchSize(prevTaskBatchSize);
-        }
-        finally
-        {
-            this.field_18812.set(false);
-        }
+        final ChunkPos pos = chunk.getPos();
+
+        this.enqueue(pos.x, pos.z, () -> 0, ServerLightingProvider.Stage.PRE_UPDATE, Util.debugRunnable(() -> {
+                super.setLightEnabled(pos, true);
+
+                chunk.getLightSourcesStream().forEach(
+                    blockPos -> super.addLightSource(blockPos, chunk.getLuminance(blockPos))
+                );
+
+                ((Lighting_scarpetChunkCreationInterface) this).relight(ChunkSectionPos.withZeroZ(ChunkSectionPos.asLong(pos.x, 0, pos.z)));
+            },
+            () -> "Relight chunk " + pos
+        ));
+
+        return CompletableFuture.runAsync(
+            Util.debugRunnable(() -> {
+                    chunk.setLightOn(true);
+                    ((ThreadedAnvilChunkStorageInterface) this.chunkStorage).releaseRelightTicket(pos);
+                },
+                () -> "Release relight ticket " + pos
+            ),
+            runnable -> this.enqueue(pos.x, pos.z, () -> 0, ServerLightingProvider.Stage.POST_UPDATE, runnable)
+        );
     }
 }

src/main/java/carpet/mixins/SkyLightStorage_scarpetChunkCreationMixin.java

@@ -0,0 +1,109 @@
+package carpet.mixins;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+import carpet.fakes.ChunkLightProviderInterface;
+import carpet.fakes.LightStorageInterface;
+import it.unimi.dsi.fastutil.longs.LongSet;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.ChunkSectionPos;
+import net.minecraft.util.math.Direction;
+import net.minecraft.world.LightType;
+import net.minecraft.world.chunk.ChunkNibbleArray;
+import net.minecraft.world.chunk.ChunkProvider;
+import net.minecraft.world.chunk.light.BlockLightStorage.Data;
+import net.minecraft.world.chunk.light.ChunkLightProvider;
+import net.minecraft.world.chunk.light.LightStorage;
+import net.minecraft.world.chunk.light.SkyLightStorage;
+
+@Mixin(SkyLightStorage.class)
+public abstract class SkyLightStorage_scarpetChunkCreationMixin extends LightStorage<Data> implements LightStorageInterface
+{
+    protected SkyLightStorage_scarpetChunkCreationMixin(final LightType lightType, final ChunkProvider chunkProvider, final Data lightData)
+    {
+        super(lightType, chunkProvider, lightData);
+    }
+
+    @Shadow
+    @Final
+    private LongSet pendingSkylightUpdates;
+
+    @Shadow
+    @Final
+    private LongSet field_15816;
+
+    @Shadow
+    @Final
+    private LongSet field_15820;
+
+    @Shadow protected abstract boolean isAboveTopmostLightArray(final long pos);
+
+    @Shadow protected abstract boolean isLightEnabled(final long sectionPos);
+
+    @Override
+    public void processRemoveLightData(final long cPos)
+    {
+        for (int y = -1; y < 17; ++y)
+        {
+            final long sectionPos = ChunkSectionPos.asLong(ChunkSectionPos.getX(cPos), y, ChunkSectionPos.getZ(cPos));
+
+            this.pendingSkylightUpdates.remove(sectionPos);
+            this.field_15816.remove(sectionPos);
+
+            this.field_15820.remove(sectionPos);
+        }
+    }
+
+    @Override
+    public void processRelight(final ChunkLightProvider<?, ?> lightProvider, final long cPos)
+    {
+        final LevelPropagatorInterface levelPropagator = (LevelPropagatorInterface) lightProvider;
+
+        for (int y = -1; y < 17; ++y)
+        {
+            final long sectionPos = ChunkSectionPos.asLong(ChunkSectionPos.getX(cPos), y, ChunkSectionPos.getZ(cPos));
+            final long pos = BlockPos.asLong(ChunkSectionPos.getWorldCoord(ChunkSectionPos.getX(sectionPos)), ChunkSectionPos.getWorldCoord(y), ChunkSectionPos.getWorldCoord(ChunkSectionPos.getZ(sectionPos)));
+
+            if (!this.hasLight(sectionPos))
+                continue;
+
+            for (final Direction dir : Direction.Type.HORIZONTAL)
+            {
+                long neighborCeilingSectionPos = ChunkSectionPos.offset(sectionPos, dir);
+                final ChunkNibbleArray neighborLightArray = this.getLightArray(neighborCeilingSectionPos);
+
+                ChunkNibbleArray neighborCeilingLightArray = neighborLightArray;
+
+                while (neighborCeilingLightArray == null && !this.isAboveTopmostLightArray(neighborCeilingSectionPos))
+                {
+                    neighborCeilingSectionPos = ChunkSectionPos.offset(neighborCeilingSectionPos, Direction.UP);
+                    neighborCeilingLightArray = this.getLightArray(neighborCeilingSectionPos);
+                }
+
+                final int ox = 15 * Math.max(dir.getOffsetX(), 0);
+                final int oz = 15 * Math.max(dir.getOffsetZ(), 0);
+
+                final int dx = Math.abs(dir.getOffsetZ());
+                final int dz = Math.abs(dir.getOffsetX());
+
+                for (int t = 0; t < 16; ++t)
+                    for (int dy = 0; dy < 16; ++dy)
+                    {
+                        final long dst = BlockPos.add(pos, ox + t * dx, dy, oz + t * dz);
+                        long src = BlockPos.offset(dst, dir);
+
+                        if (neighborLightArray == null)
+                            src = BlockPos.asLong(BlockPos.unpackLongX(src), ChunkSectionPos.getWorldCoord(ChunkSectionPos.getY(neighborCeilingSectionPos)), BlockPos.unpackLongZ(src));
+
+                        final int srcLevel = neighborCeilingLightArray != null ?
+                            ((ChunkLightProviderInterface) lightProvider).callGetCurrentLevelFromArray(neighborCeilingLightArray, src)
+                            : this.isLightEnabled(ChunkSectionPos.withZeroZ(neighborCeilingSectionPos)) ? 0 : 15;
+
+                        levelPropagator.invokeUpdateLevel(src, dst, levelPropagator.callGetPropagatedLevel(src, dst, srcLevel), true);
+                    }
+            }
+        }
+    }
+}

src/main/java/carpet/mixins/ThreadedAnvilChunkStorage_scarpetChunkCreationMixin.java

@@ -1,222 +1,402 @@
 package carpet.mixins;
 
-import carpet.fakes.ChunkHolderInterface;
-import carpet.fakes.ServerLightingProviderInterface;
-import carpet.fakes.ThreadedAnvilChunkStorageInterface;
-import carpet.script.utils.WorldTools;
-import com.mojang.datafixers.util.Either;
-import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
-import it.unimi.dsi.fastutil.longs.LongSet;
-import net.minecraft.server.WorldGenerationProgressListener;
-import net.minecraft.server.world.ChunkHolder;
-import net.minecraft.server.world.ChunkTaskPrioritySystem;
-import net.minecraft.server.world.ServerLightingProvider;
-import net.minecraft.server.world.ServerWorld;
-import net.minecraft.server.world.ThreadedAnvilChunkStorage;
-import net.minecraft.util.math.ChunkPos;
-import net.minecraft.util.thread.ThreadExecutor;
-import net.minecraft.world.chunk.Chunk;
-import net.minecraft.world.chunk.ChunkStatus;
-import net.minecraft.world.chunk.WorldChunk;
-import net.minecraft.world.storage.RegionFile;
-import org.spongepowered.asm.mixin.Final;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
-
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Queue;
+import java.util.Map.Entry;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.function.IntFunction;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.tuple.Pair;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import com.mojang.datafixers.util.Either;
+
+import carpet.fakes.ChunkHolderInterface;
+import carpet.fakes.ChunkTicketManagerInterface;
+import carpet.fakes.ServerLightingProviderInterface;
+import carpet.fakes.ThreadedAnvilChunkStorageInterface;
+import carpet.script.utils.WorldTools;
+import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.longs.LongSet;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
+import net.minecraft.server.WorldGenerationProgressListener;
+import net.minecraft.server.world.ChunkHolder;
+import net.minecraft.server.world.ChunkHolder.Unloaded;
+import net.minecraft.server.world.ChunkTaskPrioritySystem;
+import net.minecraft.server.world.ChunkTicketType;
+import net.minecraft.server.world.ServerLightingProvider;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.server.world.ThreadedAnvilChunkStorage;
+import net.minecraft.server.world.ThreadedAnvilChunkStorage.TicketManager;
+import net.minecraft.util.Util;
+import net.minecraft.util.math.ChunkPos;
+import net.minecraft.util.thread.ThreadExecutor;
+import net.minecraft.world.chunk.Chunk;
+import net.minecraft.world.chunk.ChunkStatus;
+import net.minecraft.world.chunk.WorldChunk;
+import net.minecraft.world.storage.RegionFile;
 
 import static carpet.script.CarpetEventServer.Event.CHUNK_GENERATED;
 
 @Mixin(ThreadedAnvilChunkStorage.class)
 public abstract class ThreadedAnvilChunkStorage_scarpetChunkCreationMixin implements ThreadedAnvilChunkStorageInterface
 {
-    @Shadow @Final private ServerWorld world;
+    @Shadow
+    @Final
+    private ServerWorld world;
 
-    @Shadow @Final private LongSet loadedChunks;
+    @Shadow
+    @Final
+    private LongSet loadedChunks;
 
-    @Shadow @Final private LongSet unloadedChunks;
+    @Shadow
+    @Final
+    private Long2ObjectLinkedOpenHashMap<ChunkHolder> currentChunkHolders;
 
-    @Shadow @Final private Long2ObjectLinkedOpenHashMap<ChunkHolder> currentChunkHolders;
+    @Shadow
+    private boolean chunkHolderListDirty;
 
-    @Shadow @Final private Long2ObjectLinkedOpenHashMap<ChunkHolder> field_18807;
+    @Shadow
+    @Final
+    private ServerLightingProvider serverLightingProvider;
 
-    @Shadow private boolean chunkHolderListDirty;
+    @Shadow
+    @Final
+    private ChunkTaskPrioritySystem chunkTaskPrioritySystem;
 
-    @Shadow protected abstract void method_20458(long l, ChunkHolder chunkHolder);
+    @Shadow
+    @Final
+    private ThreadExecutor<Runnable> mainThreadExecutor;
 
-    @Shadow @Final private Queue<Runnable> field_19343;
+    @Shadow
+    @Final
+    private WorldGenerationProgressListener worldGenerationProgressListener;
 
-    @Shadow @Final private ServerLightingProvider serverLightingProvider;
+    @Shadow
+    @Final
+    private TicketManager ticketManager;
 
-    @Shadow @Final private ChunkTaskPrioritySystem chunkTaskPrioritySystem;
+    @Shadow
+    protected abstract boolean updateHolderMap();
 
-    @Shadow protected abstract CompletableFuture<Either<Chunk, ChunkHolder.Unloaded>> convertToFullChunk(ChunkHolder chunkHolder);
-
-    @Shadow public abstract CompletableFuture<Either<Chunk, ChunkHolder.Unloaded>> createChunkFuture(ChunkHolder chunkHolder, ChunkStatus chunkStatus);
-
-    @Shadow @Final private ThreadExecutor<Runnable> mainThreadExecutor;
-
-    @Shadow protected abstract boolean save(Chunk chunk);
-
-    @Shadow @Final private WorldGenerationProgressListener worldGenerationProgressListener;
+    @Shadow
+    protected abstract CompletableFuture<Either<List<Chunk>, Unloaded>> createChunkRegionFuture(final ChunkPos centerChunk, final int margin, final IntFunction<ChunkStatus> distanceToStatus);
 
     //in method_20617
     //method_19534(Lnet/minecraft/server/world/ChunkHolder;Lnet/minecraft/world/chunk/Chunk;)Ljava/util/concurrent/CompletableFuture;
     // incmopatibility with optifine makes this mixin fail.
     @Inject(method = "method_19534", require = 0, at = @At(
-            value = "INVOKE",
-            target = "Lnet/minecraft/server/world/ThreadedAnvilChunkStorage;convertToFullChunk(Lnet/minecraft/server/world/ChunkHolder;)Ljava/util/concurrent/CompletableFuture;",
-            shift = At.Shift.AFTER
+        value = "INVOKE",
+        target = "Lnet/minecraft/server/world/ThreadedAnvilChunkStorage;convertToFullChunk(Lnet/minecraft/server/world/ChunkHolder;)Ljava/util/concurrent/CompletableFuture;",
+        shift = At.Shift.AFTER
     ))
-    private void onChunkGenerated(ChunkHolder chunkHolder, Chunk chunk, CallbackInfoReturnable<CompletableFuture> cir)
+    private void onChunkGenerated(final ChunkHolder chunkHolder, final Chunk chunk, final CallbackInfoReturnable<CompletableFuture> cir)
     {
         if (CHUNK_GENERATED.isNeeded())
-            world.getServer().execute( () -> CHUNK_GENERATED.onChunkGenerated(world, chunk) );
+            this.world.getServer().execute(() -> CHUNK_GENERATED.onChunkGenerated(this.world, chunk));
+    }
+
+    @Unique
+    private void addTicket(final ChunkPos pos, final ChunkStatus status)
+    {
+        this.ticketManager.addTicketWithLevel(ChunkTicketType.UNKNOWN, pos, 33 + ChunkStatus.getTargetGenerationRadius(status), pos);
+    }
+
+    @Unique
+    private void addTicket(final ChunkPos pos)
+    {
+        this.addTicket(pos, ChunkStatus.EMPTY);
+    }
+
+    @Unique
+    private void addRelightTicket(final ChunkPos pos)
+    {
+        this.ticketManager.addTicket(ChunkTicketType.LIGHT, pos, 1, pos);
     }
 
     @Override
-    public Map<String, Integer> regenerateChunkRegion(List<ChunkPos> requestedChunks)
+    public void releaseRelightTicket(final ChunkPos pos)
     {
-        Map<String, Integer> report = new HashMap<>();
-        report.put("requested_chunks",requestedChunks.size());
-        //flushning all tasks on the thread executor so all futures are ready - we don't want any deadlocks
-        mainThreadExecutor.runTasks(() -> mainThreadExecutor.getTaskCount() == 0);
-        // save all pending chunks
-        // hopefully that would flush all chunk writes, including current chunk, if exists
-        Runnable runnable;
-        while((runnable = field_19343.poll()) != null) {
-            runnable.run();
-        }
+        this.mainThreadExecutor.send(Util.debugRunnable(
+            () -> this.ticketManager.removeTicket(ChunkTicketType.LIGHT, pos, 1, pos),
+            () -> "release relight ticket " + pos
+        ));
+    }
 
-        Set<ChunkPos> loadedChunks = new HashSet<>();
-        for (ChunkPos pos: requestedChunks)
+    @Unique
+    private void tickTicketManager()
+    {
+        this.ticketManager.tick((ThreadedAnvilChunkStorage) (Object) this);
+    }
+
+    @Unique
+    private Set<ChunkPos> getExistingChunks(final Set<ChunkPos> requestedChunks)
+    {
+        final Map<String, RegionFile> regionCache = new HashMap<>();
+        final Set<ChunkPos> ret = new HashSet<>();
+
+        for (final ChunkPos pos : requestedChunks)
+            if (WorldTools.canHasChunk(this.world, pos, regionCache, true))
+                ret.add(pos);
+
+        return ret;
+    }
+
+    @Unique
+    private Set<ChunkPos> loadExistingChunksFromDisk(final Set<ChunkPos> requestedChunks)
+    {
+        final Set<ChunkPos> existingChunks = this.getExistingChunks(requestedChunks);
+        for (final ChunkPos pos : existingChunks)
+            this.currentChunkHolders.get(pos.toLong()).createFuture(ChunkStatus.EMPTY, (ThreadedAnvilChunkStorage) (Object) this);
+
+        return existingChunks;
+    }
+
+    @Unique
+    private Set<ChunkPos> loadExistingChunks(final Set<ChunkPos> requestedChunks, final Object2IntMap<String> report)
+    {
+        if (report != null)
+            report.put("requested_chunks", requestedChunks.size());
+
+        // Load all relevant ChunkHolders into this.currentChunkHolders
+        // This will not trigger loading from disk yet
+
+        for (final ChunkPos pos : requestedChunks)
+            this.addTicket(pos);
+
+        this.tickTicketManager();
+
+        // Fetch all currently loaded chunks
+
+        final Set<ChunkPos> loadedChunks = requestedChunks.stream().filter(
+            pos -> this.currentChunkHolders.get(pos.toLong()).getCompletedChunk() != null // all relevant ChunkHolders exist
+        ).collect(Collectors.toSet());
+
+        if (report != null)
+            report.put("loaded_chunks", loadedChunks.size());
+
+        // Load remaining chunks from disk
+
+        final Set<ChunkPos> unloadedChunks = new HashSet<>(requestedChunks);
+        unloadedChunks.removeAll(loadedChunks);
+
+        final Set<ChunkPos> existingChunks = this.loadExistingChunksFromDisk(unloadedChunks);
+
+        existingChunks.addAll(loadedChunks);
+
+        return existingChunks;
+    }
+
+    @Unique
+    private Set<ChunkPos> loadExistingChunks(final Set<ChunkPos> requestedChunks)
+    {
+        return this.loadExistingChunks(requestedChunks, null);
+    }
+
+    @Unique
+    private void waitFor(final Future<?> future)
+    {
+        this.mainThreadExecutor.runTasks(future::isDone);
+    }
+
+    @Unique
+    private void waitFor(final List<? extends CompletableFuture<?>> futures)
+    {
+        this.waitFor(Util.combine(futures));
+    }
+
+    @Unique
+    private Chunk getCurrentChunk(final ChunkPos pos)
+    {
+        final CompletableFuture<Chunk> future = this.currentChunkHolders.get(pos.toLong()).getFuture();
+        this.waitFor(future);
+
+        return future.join();
+    }
+
+    @Override
+    public Map<String, Integer> regenerateChunkRegion(final List<ChunkPos> requestedChunksList)
+    {
+        final Object2IntMap<String> report = new Object2IntOpenHashMap<>();
+        final Set<ChunkPos> requestedChunks = new HashSet<>(requestedChunksList);
+
+        // Load requested chunks
+
+        final Set<ChunkPos> existingChunks = this.loadExistingChunks(requestedChunks, report);
+
+        // Finish pending generation stages
+        // This ensures that no generation events will be put back on the main thread after the chunks have been deleted
+
+        final Set<Chunk> affectedChunks = new HashSet<>();
+
+        for (final ChunkPos pos : existingChunks)
+            affectedChunks.add(this.getCurrentChunk(pos));
+
+        report.put("affected_chunks", affectedChunks.size());
+
+        // Load neighbors for light removal
+
+        final Set<ChunkPos> neighbors = new HashSet<>();
+
+        for (final Chunk chunk : affectedChunks)
         {
-            Chunk chunk = world.getChunk(pos.x, pos.z, ChunkStatus.FULL, false);
-            if (chunk != null && chunk.getStatus() != ChunkStatus.EMPTY)
-                loadedChunks.add(pos);
-        }
-        report.put("loaded_chunks", loadedChunks.size());
+            final ChunkPos pos = chunk.getPos();
 
-        Map<ChunkPos,ChunkStatus> targetStatus = new HashMap<>();
-        Map<String, RegionFile> regionCache = new HashMap<>();
-        for (ChunkPos pos: requestedChunks)
-        {
-            if (!WorldTools.canHasChunk(world, pos, regionCache, true)) continue;
-            Chunk chunk = world.getChunk(pos.x, pos.z, ChunkStatus.EMPTY, true);
-            if (chunk == null || chunk.getStatus() == ChunkStatus.EMPTY)
-                continue;
-            //unloaded areas can have unknown skirt chunk area
-            targetStatus.put(pos, loadedChunks.contains(pos)?chunk.getStatus():ChunkStatus.STRUCTURE_STARTS);
-        }
-        regionCache.clear();
-        report.put("affected_chunks", targetStatus.size());
-
-
-        for (ChunkPos chpos : targetStatus.keySet())
-        {
-            Long id = chpos.toLong();
-            //chunk is currently in memory in some shape or form / loaded / unloaded / queued / cached
-            ChunkHolder chunkHolder = currentChunkHolders.remove(id);
-            int currentLevel = ThreadedAnvilChunkStorage.MAX_LEVEL;
-            if (chunkHolder != null)
-            {
-                currentLevel = chunkHolder.getLevel()-1;
-                //method_20458(id, chunkHolder); // saving chunk // skipping entities etc
-                Chunk chunk = null;
-                try
-                {
-                    // fingers crossed
-                    chunk = chunkHolder.getFuture().get();
-                }
-                catch (InterruptedException | ExecutionException e)
-                {
-                }
-                // if (field_18807.remove(id, chunkHolder) && chunk != null) {
-                if (chunk != null)
-                {
-                    if (chunk instanceof WorldChunk)
+            for (int x = -1; x <= 1; ++x)
+                for (int z = -1; z <= 1; ++z)
+                    if (x != 0 || z != 0)
                     {
-                        ((WorldChunk) chunk).setLoadedToWorld(false);
+                        final ChunkPos nPos = new ChunkPos(pos.x + x, pos.z + z);
+                        if (!requestedChunks.contains(nPos))
+                            neighbors.add(nPos);
                     }
-                    save(chunk);
-                    if (this.loadedChunks.remove(id) && chunk instanceof WorldChunk)
-                    {
-                        WorldChunk worldChunk = (WorldChunk) chunk;
-                        //apparently that doesn't remove them for the client
-                        this.world.unloadEntities(worldChunk);
-                    }
-                    ((ServerLightingProviderInterface)this.serverLightingProvider).publicUpdateChunkStatus(chunk.getPos()); // we might need that as some point
-                    serverLightingProvider.tick();
-                    worldGenerationProgressListener.setChunkStatus(chunk.getPos(), (ChunkStatus) null);
-                }
-            }
-            unloadedChunks.remove(id);
-            loadedChunks.remove(id);
-            field_18807.remove(id);
-            ChunkHolder newHolder = new ChunkHolder(chpos, currentLevel,serverLightingProvider, chunkTaskPrioritySystem, (ChunkHolder.PlayersWatchingChunkProvider) this);
-            ((ChunkHolderInterface)newHolder).setDefaultProtoChunk(chpos, mainThreadExecutor);
-            this.currentChunkHolders.put(id, newHolder);
-            //removed holders
-            field_18807.put(id, newHolder);
-            //loadedChunks.add(id);
-
         }
-        //getting rid of all signs
+
+        this.loadExistingChunks(neighbors);
+
+        // Determine affected neighbors
+
+        final Set<Chunk> affectedNeighbors = new HashSet<>();
+
+        for (final ChunkPos pos : neighbors)
+        {
+            final Chunk chunk = this.getCurrentChunk(pos);
+
+            if (chunk.getStatus().isAtLeast(ChunkStatus.LIGHT.getPrevious()))
+                affectedNeighbors.add(chunk);
+        }
+
+        // Unload affected chunks
+
+        for (final Chunk chunk : affectedChunks)
+        {
+            final ChunkPos pos = chunk.getPos();
+
+            if (chunk instanceof WorldChunk)
+                ((WorldChunk) chunk).setLoadedToWorld(false);
+
+            if (this.loadedChunks.remove(pos.toLong()) && chunk instanceof WorldChunk)
+                this.world.unloadEntities((WorldChunk) chunk);
+
+            ((ServerLightingProviderInterface) this.serverLightingProvider).invokeUpdateChunkStatus(pos);
+            ((ServerLightingProviderInterface) this.serverLightingProvider).removeLightData(chunk);
+
+            this.worldGenerationProgressListener.setChunkStatus(pos, null);
+        }
+
+        // Replace ChunkHolders
+
+        for (final Chunk chunk : affectedChunks)
+        {
+            final ChunkPos cPos = chunk.getPos();
+            final long pos = cPos.toLong();
+
+            final ChunkHolder oldHolder = this.currentChunkHolders.remove(pos);
+            final ChunkHolder newHolder = new ChunkHolder(cPos, oldHolder.getLevel(), this.serverLightingProvider, this.chunkTaskPrioritySystem, (ChunkHolder.PlayersWatchingChunkProvider) this);
+            ((ChunkHolderInterface) newHolder).setDefaultProtoChunk(cPos, this.mainThreadExecutor);
+            this.currentChunkHolders.put(pos, newHolder);
+
+            ((ChunkTicketManagerInterface) this.ticketManager).replaceHolder(oldHolder, newHolder);
+        }
+
         this.chunkHolderListDirty = true;
-        // not needed right now
-        mainThreadExecutor.runTasks(() -> mainThreadExecutor.getTaskCount() == 0);
-        ((ServerLightingProviderInterface)this.serverLightingProvider).flush();
-        //worldgenExecutor.
-        // save all pending chunks / potentially only one max - ours
-        // hopefully that would flush all chunk writes, including current chink
-        while ((runnable = field_19343.poll()) != null)
+        this.updateHolderMap();
+
+        // Remove light for affected neighbors
+
+        for (final Chunk chunk : affectedNeighbors)
+            ((ServerLightingProviderInterface) this.serverLightingProvider).removeLightData(chunk);
+
+        // Schedule relighting of neighbors
+
+        for (final Chunk chunk : affectedNeighbors)
+            this.addRelightTicket(chunk.getPos());
+
+        this.tickTicketManager();
+
+        final List<CompletableFuture<?>> lightFutures = new ArrayList<>();
+
+        for (final Chunk chunk : affectedNeighbors)
         {
-            runnable.run();
+            final ChunkPos pos = chunk.getPos();
+
+            lightFutures.add(this.createChunkRegionFuture(pos, 1, (pos_) -> ChunkStatus.LIGHT).thenCompose(
+                either -> either.map(
+                    list -> ((ServerLightingProviderInterface) this.serverLightingProvider).relight(chunk),
+                    unloaded -> {
+                        this.releaseRelightTicket(pos);
+                        return CompletableFuture.completedFuture(null);
+                    }
+                )
+            ));
         }
 
-        for (ChunkStatus status : ChunkStatus.createOrderedList())
+        // Force generation to previous states
+        // This ensures that the world is in a consistent state after this method
+        // Also, this is needed to ensure chunks are saved to disk
+
+        final Map<ChunkPos, ChunkStatus> targetGenerationStatus = affectedChunks.stream().collect(
+            Collectors.toMap(Chunk::getPos, Chunk::getStatus)
+        );
+
+        for (final Entry<ChunkPos, ChunkStatus> entry : targetGenerationStatus.entrySet())
+            this.addTicket(entry.getKey(), entry.getValue());
+
+        this.tickTicketManager();
+
+        final List<Pair<ChunkStatus, CompletableFuture<?>>> targetGenerationFutures = new ArrayList<>();
+
+        for (final Entry<ChunkPos, ChunkStatus> entry : targetGenerationStatus.entrySet())
+            targetGenerationFutures.add(Pair.of(
+                entry.getValue(),
+                this.currentChunkHolders.get(entry.getKey().toLong()).createFuture(entry.getValue(), (ThreadedAnvilChunkStorage) (Object) this)
+            ));
+
+        final Map<ChunkStatus, List<CompletableFuture<?>>> targetGenerationFuturesGrouped = targetGenerationFutures.stream().collect(
+            Collectors.groupingBy(
+                Pair::getKey,
+                Collectors.mapping(
+                    Entry::getValue,
+                    Collectors.toList()
+                )
+            )
+        );
+
+        for (final ChunkStatus status : ChunkStatus.createOrderedList())
         {
-            report.put("layer_count_"+status.getId(),targetStatus.size());
-            long start = System.currentTimeMillis();
-            //if (status == ChunkStatus.LIGHT)
-            //{
-            //    serverLightingProvider.setTaskBatchSize(targetStatus.size() + 20);
-            //}
-            for (ChunkPos chpos : new ArrayList<>(targetStatus.keySet()))
-            {
-                if (targetStatus.get(chpos) == status)
-                    targetStatus.remove(chpos);
-                world.getChunk(chpos.x, chpos.z, status);
-                if (status == ChunkStatus.FULL)
-                    convertToFullChunk(currentChunkHolders.get(chpos.toLong()));
-            }
-            if (status == ChunkStatus.LIGHT)
-            { // default task batch size after initial generation is done
-                //serverLightingProvider.setTaskBatchSize(5);
-                ((ServerLightingProviderInterface)this.serverLightingProvider).flush();
-            }
-            report.put("layer_time_"+status.getId(), (int) (System.currentTimeMillis()-start));
+            final List<CompletableFuture<?>> futures = targetGenerationFuturesGrouped.get(status);
+
+            if (futures == null)
+                continue;
+
+            report.put("layer_count_" + status.getId(), futures.size());
+            final long start = System.currentTimeMillis();
+
+            this.waitFor(futures);
+
+            report.put("layer_time_" + status.getId(), (int) (System.currentTimeMillis() - start));
         }
 
-        mainThreadExecutor.runTasks(() -> mainThreadExecutor.getTaskCount() == 0);
-        //worldgenExecutor.
-        // save all pending chunks / potentially only one max - ours
-        // hopefully that would flush all chunk writes, including current chink
-        while ((runnable = field_19343.poll()) != null)
-        {
-            runnable.run();
-        }
+        report.put("relight_count", lightFutures.size());
+        final long relightStart = System.currentTimeMillis();
+
+        this.waitFor(lightFutures);
+
+        report.put("relight_time", (int) (System.currentTimeMillis() - relightStart));
+
         return report;
     }
 }