package com.hypixel.hytale.server.spawning.util;

import com.hypixel.fastutil.longs.Long2ObjectConcurrentHashMap;
import com.hypixel.hytale.component.Component;
import com.hypixel.hytale.component.ComponentType;
import com.hypixel.hytale.math.util.ChunkUtil;
import com.hypixel.hytale.math.util.MathUtil;
import com.hypixel.hytale.math.vector.Vector3d;
import com.hypixel.hytale.math.vector.Vector3i;
import com.hypixel.hytale.protocol.BlockMaterial;
import com.hypixel.hytale.server.core.asset.type.blocktype.config.BlockType;
import com.hypixel.hytale.server.core.asset.type.fluid.Fluid;
import com.hypixel.hytale.server.core.universe.world.World;
import com.hypixel.hytale.server.core.universe.world.accessor.ChunkAccessor;
import com.hypixel.hytale.server.core.universe.world.accessor.LocalCachedChunkAccessor;
import com.hypixel.hytale.server.core.universe.world.chunk.WorldChunk;
import com.hypixel.hytale.server.core.universe.world.storage.EntityStore;
import com.hypixel.hytale.server.npc.NPCPlugin;
import com.hypixel.hytale.server.npc.asset.builder.Builder;
import com.hypixel.hytale.server.npc.role.Role;
import com.hypixel.hytale.server.spawning.ISpawnableWithModel;
import com.hypixel.hytale.server.spawning.SpawnTestResult;
import com.hypixel.hytale.server.spawning.SpawningContext;
import com.hypixel.hytale.server.spawning.SpawningPlugin;
import com.hypixel.hytale.server.spawning.assets.spawns.config.RoleSpawnParameters;
import com.hypixel.hytale.server.spawning.suppression.component.ChunkSuppressionEntry;
import com.hypixel.hytale.server.spawning.suppression.component.SpawnSuppressionController;
import com.hypixel.hytale.server.spawning.wrappers.BeaconSpawnWrapper;
import it.unimi.dsi.fastutil.ints.Int2IntMap;
import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
import it.unimi.dsi.fastutil.ints.IntArrayList;
import it.unimi.dsi.fastutil.ints.IntLists;
import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
import it.unimi.dsi.fastutil.ints.IntSet;
import it.unimi.dsi.fastutil.objects.ObjectArrayList;
import it.unimi.dsi.fastutil.objects.ObjectArrays;
import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.BitSet;
import java.util.Comparator;
import java.util.Deque;
import java.util.concurrent.ThreadLocalRandom;
import java.util.logging.Level;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;

public class FloodFillPositionSelector implements Component<EntityStore> {
   private static final int MAX_SPAWN_POSITIONS_HINT = 30;
   private static final double SPAWN_POSITION_DENSITY = 0.1;
   private static final int CONCURRENT_POSITION_OPTION_MULTIPLIER = 3;
   private static final double MAX_FAILED_SPAWN_POSITION_RATIO = 0.25;
   private static final double IRREGULAR_MIN_SPAWNS_MULTIPLIER = 0.3;
   private static final double IRREGULAR_MAX_SPAWNS_MULTIPLIER = 5.0;
   private static final int NOT_CHECKED = -1;
   private static final int BLOCKED = -2;
   private static final int TOO_HIGH = Integer.MAX_VALUE;
   private static final int TOO_LOW = Integer.MIN_VALUE;
   private static final int MAX_RESOLUTION_DIVISOR = 8;
   private static final ThreadLocal<FloodFillPositionSelector.SortBufferProvider> sortBufferProvider = ThreadLocal.withInitial(
      FloodFillPositionSelector.SortBufferProvider::new
   );
   private static final Comparator<Object> WEIGHTED_POSITION_COMPARATOR = (entry1, entry2) -> Double.compare(
      ((FloodFillPositionSelector.WeightedPosition)entry2).getWeight(), ((FloodFillPositionSelector.WeightedPosition)entry1).getWeight()
   );
   private final World world;
   @Nullable
   private ChunkAccessor<WorldChunk> chunkAccessor;
   private final int size;
   private int minY;
   private int maxY;
   @Nonnull
   private final BeaconSpawnWrapper spawnWrapper;
   @Nonnull
   private final int[] roleIndexes;
   @Nonnull
   private final int[] heightGrid;
   @Nonnull
   private final Int2ObjectMap<BitSet> resolutionMaps;
   private final BitSet fullResolutionMap;
   private int desiredPositionCount;
   private final IntArrayList highResolutionOptions = new IntArrayList(4);
   private final Deque<int[]> floodFillQueue = new ArrayDeque<>();
   private final SpawningContext spawningContext = new SpawningContext();
   @Nullable
   private WorldChunk chunk;
   private final IntSet positionIndexes = new IntOpenHashSet();
   private final Int2ObjectMap<ObjectArrayList<FloodFillPositionSelector.WeightedPosition>> positionsByRole = new Int2ObjectOpenHashMap();
   private final Int2IntMap failedSpawnsByRole = new Int2IntOpenHashMap();
   private boolean hasRun;
   private FloodFillPositionSelector.Debug debug;
   private boolean irregularCase;
   private IntSet failedPositionTestIndexes;
   private double calculatePositionsAfter;

   public static ComponentType<EntityStore, FloodFillPositionSelector> getComponentType() {
      return SpawningPlugin.get().getFloodFillPositionSelectorComponentType();
   }

   public FloodFillPositionSelector(World world, @Nonnull BeaconSpawnWrapper spawnWrapper) {
      this.world = world;
      int baseSize = MathUtil.ceil(spawnWrapper.getSpawnRadius()) * 2;
      this.size = (baseSize + 8 - 1) / 8 * 8;
      this.heightGrid = new int[this.size * this.size];
      Arrays.fill(this.heightGrid, -1);
      this.resolutionMaps = new Int2ObjectOpenHashMap();

      for (int i = 1; i <= 8; i *= 2) {
         this.resolutionMaps.put(i, new BitSet(this.heightGrid.length / i));
      }

      this.fullResolutionMap = (BitSet)this.resolutionMaps.get(1);
      this.spawnWrapper = spawnWrapper;
      RoleSpawnParameters[] roleSpawnParameters = spawnWrapper.getSpawn().getNPCs();
      this.roleIndexes = new int[roleSpawnParameters.length];

      for (int i = 0; i < this.roleIndexes.length; i++) {
         int roleIndex = NPCPlugin.get().getIndex(roleSpawnParameters[i].getId());
         this.roleIndexes[i] = roleIndex;
         this.positionsByRole.put(roleIndex, new ObjectArrayList());
      }

      this.debug = spawnWrapper.getSpawn().getDebug();
      if (this.debug != FloodFillPositionSelector.Debug.DISABLED) {
         this.failedPositionTestIndexes = new IntOpenHashSet();
      }
   }

   public void setCalculatePositionsAfter(double calculatePositionsAfter) {
      this.calculatePositionsAfter = calculatePositionsAfter;
   }

   public boolean tickCalculatePositionsAfter(float dt) {
      return (this.calculatePositionsAfter -= dt) <= 0.0;
   }

   public boolean hasPositionsForRole(int roleIndex) {
      return !((ObjectArrayList)this.positionsByRole.get(roleIndex)).isEmpty();
   }

   public boolean prepareSpawnContext(
      @Nonnull Vector3d playerPosition, int spawnsThisRound, int roleIndex, @Nonnull SpawningContext spawningContext, @Nonnull BeaconSpawnWrapper spawnWrapper
   ) {
      ObjectArrayList<FloodFillPositionSelector.WeightedPosition> positions = (ObjectArrayList<FloodFillPositionSelector.WeightedPosition>)this.positionsByRole
         .get(roleIndex);
      if (this.positionsByRole.isEmpty()) {
         return false;
      } else {
         double minDistanceFromPlayerSquared = spawnWrapper.getMinDistanceFromPlayerSquared();
         double targetDistanceFromPlayerSquared = spawnWrapper.getTargetDistanceFromPlayerSquared();

         for (int i = 0; i < positions.size(); i++) {
            FloodFillPositionSelector.WeightedPosition entry = (FloodFillPositionSelector.WeightedPosition)positions.get(i);
            double distance = playerPosition.distanceSquaredTo(entry.position);
            entry.weight = distance < minDistanceFromPlayerSquared
               ? 0.0
               : Math.max(0.0, targetDistanceFromPlayerSquared - Math.abs(distance - targetDistanceFromPlayerSquared));
         }

         int targetNumberOfOptions = spawnsThisRound * 3;
         int size = positions.size();
         FloodFillPositionSelector.WeightedPosition[] sortBuffer = sortBufferProvider.get().getBuffer(size);
         System.arraycopy(positions.elements(), 0, sortBuffer, 0, size);
         ObjectArrays.mergeSort(positions.elements(), 0, size, WEIGHTED_POSITION_COMPARATOR, sortBuffer);
         double sum = 0.0;

         for (int i = 0; i < targetNumberOfOptions && i < positions.size(); i++) {
            FloodFillPositionSelector.WeightedPosition entry = (FloodFillPositionSelector.WeightedPosition)positions.get(i);
            if (entry.weight == 0.0) {
               break;
            }

            sum += entry.weight;
         }

         if (sum == 0.0) {
            return false;
         } else {
            sum = ThreadLocalRandom.current().nextDouble(sum);
            int selectedIndex = -1;
            FloodFillPositionSelector.WeightedPosition entry = null;

            for (int i = 0; i < targetNumberOfOptions && i < positions.size(); i++) {
               entry = (FloodFillPositionSelector.WeightedPosition)positions.get(i);
               selectedIndex = i;
               sum -= entry.weight;
               if (sum < 0.0) {
                  break;
               }
            }

            if (entry == null) {
               return false;
            } else {
               Vector3i position = entry.position;
               SpawnSuppressionController suppressionController = this.world
                  .getEntityStore()
                  .getStore()
                  .getResource(SpawnSuppressionController.getResourceType());
               long indexChunk = ChunkUtil.indexChunk(ChunkUtil.chunkCoordinate(position.x), ChunkUtil.chunkCoordinate(position.z));
               ChunkSuppressionEntry suppressionEntry = suppressionController.getChunkSuppressionMap().get(indexChunk);
               if ((suppressionEntry == null || !suppressionEntry.isSuppressingRoleAt(roleIndex, position.y))
                  && spawningContext.set(this.world, position.x, position.y, position.z)
                  && spawningContext.canSpawn() == SpawnTestResult.TEST_OK) {
                  return true;
               } else {
                  positions.remove(selectedIndex);
                  int totalFailed = this.failedSpawnsByRole.mergeInt(roleIndex, 1, Integer::sum);
                  if (totalFailed > positions.size() * 0.25) {
                     this.hasRun = false;
                  }

                  return false;
               }
            }
         }
      }
   }

   public boolean shouldRebuildCache() {
      return !this.hasRun;
   }

   public void forceRebuildCache() {
      this.hasRun = false;
   }

   public void init() {
      Arrays.fill(this.heightGrid, -1);

      for (int i = 1; i <= 8; i *= 2) {
         ((BitSet)this.resolutionMaps.get(i)).clear();
      }

      for (int role : this.roleIndexes) {
         ((ObjectArrayList)this.positionsByRole.get(role)).clear();
         this.failedSpawnsByRole.put(role, 0);
      }

      this.irregularCase = false;
   }

   public void buildPositionCache(@Nonnull Vector3d origin, @Nonnull FloodFillEntryPoolSimple pool) {
      int sizeHalf = this.size / 2;
      int worldX = MathUtil.floor(origin.getX());
      int worldY = MathUtil.floor(origin.getY());
      int worldZ = MathUtil.floor(origin.getZ());
      this.chunkAccessor = LocalCachedChunkAccessor.atWorldCoords(this.world, worldX, worldZ, sizeHalf);
      this.chunk = this.chunkAccessor.getChunkIfInMemory(ChunkUtil.indexChunkFromBlock(worldX, worldZ));
      if (this.chunk != null) {
         int[] yRange = this.spawnWrapper.getSpawn().getYRange();
         this.minY = Math.max(0, worldY + yRange[0]);
         this.maxY = Math.min(319, worldY + yRange[1]);
         this.floodFill(worldX, worldY, worldZ, sizeHalf, sizeHalf, pool);
         this.desiredPositionCount = Math.min(MathUtil.ceil(this.fullResolutionMap.cardinality() * 0.1), 30);
         if (this.desiredPositionCount > 0) {
            this.findPositions(worldX, worldZ);
         } else {
            SpawningPlugin.get().getLogger().at(Level.WARNING).log("Spawn beacon at: " + origin + " unable to find any suitable positions to check");
         }

         if (this.debug != FloodFillPositionSelector.Debug.DISABLED && (this.irregularCase || this.debug == FloodFillPositionSelector.Debug.ALL)) {
            for (int i = 2; i <= 8; i *= 2) {
               BitSet map = (BitSet)this.resolutionMaps.get(i);
               if (map.cardinality() > 0) {
                  SpawningPlugin.get().getLogger().at(Level.WARNING).log(this.debugDumpLowResolutionMap(map, this.size / i));
               }
            }

            SpawningPlugin.get().getLogger().at(Level.WARNING).log("Spawn beacon at: " + origin + (this.irregularCase ? " is an irregular case" : ""));
         }

         this.chunkAccessor = null;
         this.chunk = null;
         this.spawningContext.releaseFull();
         this.hasRun = true;
      }
   }

   private void floodFill(int worldX, int worldY, int worldZ, int setX, int setZ, @Nonnull FloodFillEntryPoolSimple pool) {
      if (this.chunk != null) {
         this.floodFillQueue.clear();
         int[] initialEntry = pool.allocate();
         initialEntry[0] = worldX;
         initialEntry[1] = worldY;
         initialEntry[2] = worldZ;
         initialEntry[3] = setX;
         initialEntry[4] = setZ;
         this.floodFillQueue.add(initialEntry);
         int chunkX = this.chunk.getX();
         int chunkZ = this.chunk.getZ();

         label66:
         while (!this.floodFillQueue.isEmpty()) {
            int[] state = this.floodFillQueue.poll();
            worldX = state[0];
            worldY = state[1];
            worldZ = state[2];
            setX = state[3];
            setZ = state[4];
            if (setX >= 0 && setX < this.size && setZ >= 0 && setZ < this.size) {
               int index = getPositionIndex(setX, setZ, this.size);
               if (this.heightGrid[index] != -1) {
                  pool.deallocate(state);
               } else {
                  if (!ChunkUtil.isInsideChunk(chunkX, chunkZ, worldX, worldZ)) {
                     WorldChunk newChunk = this.chunkAccessor.getChunkIfInMemory(ChunkUtil.indexChunkFromBlock(worldX, worldZ));
                     if (newChunk == null) {
                        this.heightGrid[index] = -2;
                        pool.deallocate(state);
                        continue;
                     }

                     this.chunk = newChunk;
                     chunkX = this.chunk.getX();
                     chunkZ = this.chunk.getZ();
                  }

                  int block = this.chunk.getBlock(worldX, worldY, worldZ);
                  if (block != 0 && BlockType.getAssetMap().getAsset(block).getMaterial() == BlockMaterial.Solid) {
                     while (block != 0) {
                        block = this.chunk.getBlock(worldX, ++worldY, worldZ);
                        if (worldY > this.maxY) {
                           this.heightGrid[index] = Integer.MAX_VALUE;
                           pool.deallocate(state);
                           continue label66;
                        }
                     }
                  } else {
                     while (block == 0) {
                        block = this.chunk.getBlock(worldX, --worldY, worldZ);
                        if (worldY < this.minY) {
                           this.heightGrid[index] = Integer.MIN_VALUE;
                           pool.deallocate(state);
                           continue label66;
                        }
                     }

                     worldY++;
                  }

                  this.heightGrid[index] = worldY;
                  this.fullResolutionMap.set(index);
                  state[0] = worldX + 1;
                  state[1] = worldY;
                  state[2] = worldZ;
                  state[3] = setX + 1;
                  state[4] = setZ;
                  this.floodFillQueue.add(state);
                  int[] entry2 = pool.allocate();
                  entry2[0] = worldX - 1;
                  entry2[1] = worldY;
                  entry2[2] = worldZ;
                  entry2[3] = setX - 1;
                  entry2[4] = setZ;
                  this.floodFillQueue.add(entry2);
                  int[] entry3 = pool.allocate();
                  entry3[0] = worldX;
                  entry3[1] = worldY;
                  entry3[2] = worldZ + 1;
                  entry3[3] = setX;
                  entry3[4] = setZ + 1;
                  this.floodFillQueue.add(entry3);
                  int[] entry4 = pool.allocate();
                  entry4[0] = worldX;
                  entry4[1] = worldY;
                  entry4[2] = worldZ - 1;
                  entry4[3] = setX;
                  entry4[4] = setZ - 1;
                  this.floodFillQueue.add(entry4);
               }
            } else {
               pool.deallocate(state);
            }
         }
      }
   }

   private void findPositions(int originX, int originZ) {
      int resolution = 1;

      int segments;
      do {
         resolution *= 2;
         segments = this.buildLowerResolutionMap(
            (BitSet)this.resolutionMaps.get(resolution), this.size / resolution, (BitSet)this.resolutionMaps.get(resolution / 2), this.size / (resolution / 2)
         );
      } while (resolution < 8 && segments / this.desiredPositionCount > 1);

      BitSet lowestResolutionMap = (BitSet)this.resolutionMaps.get(resolution);
      int openSpots = lowestResolutionMap.cardinality();
      if (openSpots < this.desiredPositionCount) {
         resolution /= 2;
         lowestResolutionMap = (BitSet)this.resolutionMaps.get(resolution);
      }

      int sizeHalf = this.size / 2;
      int offsetOriginX = originX - sizeHalf;
      int offsetOriginZ = originZ - sizeHalf;
      SpawnSuppressionController suppressionController = this.world.getEntityStore().getStore().getResource(SpawnSuppressionController.getResourceType());
      long chunkIndex = ChunkUtil.NOT_FOUND;
      ChunkSuppressionEntry suppressionEntry = null;
      Long2ObjectConcurrentHashMap<ChunkSuppressionEntry> chunkSuppressionMap = suppressionController.getChunkSuppressionMap();

      for (int roleIndex : this.roleIndexes) {
         Builder<Role> spawnable = NPCPlugin.get().tryGetCachedValidRole(roleIndex);
         if (spawnable != null
            && spawnable.isSpawnable()
            && spawnable instanceof ISpawnableWithModel
            && this.spawningContext.setSpawnable((ISpawnableWithModel)spawnable, true)) {
            ObjectArrayList<FloodFillPositionSelector.WeightedPosition> positionList = (ObjectArrayList<FloodFillPositionSelector.WeightedPosition>)this.positionsByRole
               .get(roleIndex);

            for (int i = lowestResolutionMap.nextSetBit(0); i >= 0; i = lowestResolutionMap.nextSetBit(i + 1)) {
               int chosenIndex = i;

               for (int currentResolution = resolution; currentResolution > 1; currentResolution /= 2) {
                  int nextResolution = currentResolution / 2;
                  chosenIndex = this.pickOpenSegment(
                     chosenIndex, this.size / currentResolution, (BitSet)this.resolutionMaps.get(nextResolution), this.size / nextResolution
                  );
               }

               int x = offsetOriginX + xFromIndex(chosenIndex, this.size);
               int y = this.heightGrid[chosenIndex];
               int z = offsetOriginZ + zFromIndex(chosenIndex, this.size);
               long newChunkIndex = ChunkUtil.indexChunk(ChunkUtil.chunkCoordinate(x), ChunkUtil.chunkCoordinate(z));
               if (chunkIndex != newChunkIndex) {
                  suppressionEntry = chunkSuppressionMap.get(newChunkIndex);
                  chunkIndex = newChunkIndex;
               }

               if (!this.canSpawn(x, y, z, roleIndex, suppressionEntry)) {
                  if (this.debug != FloodFillPositionSelector.Debug.DISABLED) {
                     this.failedPositionTestIndexes.add(chosenIndex);
                  }

                  int originalIndex = chosenIndex;
                  chosenIndex = this.shiftIndexAwayFromWall(chosenIndex);
                  if (chosenIndex == originalIndex) {
                     continue;
                  }

                  x = offsetOriginX + xFromIndex(chosenIndex, this.size);
                  y = this.heightGrid[chosenIndex];
                  z = offsetOriginZ + zFromIndex(chosenIndex, this.size);
                  newChunkIndex = ChunkUtil.indexChunk(ChunkUtil.chunkCoordinate(x), ChunkUtil.chunkCoordinate(z));
                  if (chunkIndex != newChunkIndex) {
                     suppressionEntry = chunkSuppressionMap.get(newChunkIndex);
                     chunkIndex = newChunkIndex;
                  }

                  if (!this.canSpawn(x, y, z, roleIndex, suppressionEntry)) {
                     if (this.debug != FloodFillPositionSelector.Debug.DISABLED) {
                        this.failedPositionTestIndexes.add(chosenIndex);
                     }
                     continue;
                  }
               }

               if (this.positionIndexes.add(chosenIndex)) {
                  positionList.add(new FloodFillPositionSelector.WeightedPosition(x, y, z));
               }

               if (i == Integer.MAX_VALUE) {
                  break;
               }
            }

            int positionCount = this.positionIndexes.size();
            if (this.debug != FloodFillPositionSelector.Debug.DISABLED
               && (positionCount < this.desiredPositionCount * 0.3 || positionCount > this.desiredPositionCount * 5.0)) {
               this.irregularCase = true;
            }

            if (this.irregularCase || this.debug == FloodFillPositionSelector.Debug.ALL) {
               SpawningPlugin.get().getLogger().at(Level.WARNING).log("Role: " + NPCPlugin.get().getName(roleIndex));
               SpawningPlugin.get().getLogger().at(Level.WARNING).log(this.debugDumpBaseFloodFill());
               this.failedPositionTestIndexes.clear();
            }

            this.positionIndexes.clear();
         }
      }
   }

   private int buildLowerResolutionMap(@Nonnull BitSet targetMap, int mapSize, @Nonnull BitSet parentMap, int parentMapSize) {
      for (int x = 0; x < mapSize; x++) {
         for (int z = 0; z < mapSize; z++) {
            int parentX = x * 2;
            int parentZ = z * 2;
            int index = getPositionIndex(parentX, parentZ, parentMapSize);
            if (parentMap.get(index) || parentMap.get(index + 1) || parentMap.get(index + parentMapSize) || parentMap.get(index + parentMapSize + 1)) {
               targetMap.set(getPositionIndex(x, z, mapSize));
            }
         }
      }

      return targetMap.cardinality();
   }

   private int pickOpenSegment(int lowResolutionIndex, int lowResolutionMapSize, @Nonnull BitSet higherResolutionMap, int highResolutionMapSize) {
      int x = xFromIndex(lowResolutionIndex, lowResolutionMapSize);
      int z = zFromIndex(lowResolutionIndex, lowResolutionMapSize);
      int parentX = x * 2;
      int parentZ = z * 2;
      int originIndex = getPositionIndex(parentX, parentZ, highResolutionMapSize);
      if (higherResolutionMap.get(originIndex)) {
         this.highResolutionOptions.add(originIndex);
      }

      int index = originIndex + 1;
      if (higherResolutionMap.get(index)) {
         this.highResolutionOptions.add(index);
      }

      index = originIndex + highResolutionMapSize;
      if (higherResolutionMap.get(index)) {
         this.highResolutionOptions.add(index);
      }

      index = originIndex + highResolutionMapSize + 1;
      if (higherResolutionMap.get(index)) {
         this.highResolutionOptions.add(index);
      }

      if (this.highResolutionOptions.size() > 1) {
         IntLists.shuffle(this.highResolutionOptions, ThreadLocalRandom.current());
      }

      index = this.highResolutionOptions.getInt(0);
      this.highResolutionOptions.clear();
      return index;
   }

   private int shiftIndexAwayFromWall(int index) {
      int newIndex = index;
      int checkIndex = index - 1;
      if (checkIndex < 0 || !this.fullResolutionMap.get(checkIndex)) {
         newIndex = index + 1;
      }

      checkIndex = index + 1;
      if (checkIndex >= this.fullResolutionMap.size() || !this.fullResolutionMap.get(checkIndex)) {
         newIndex--;
      }

      checkIndex = index - this.size;
      if (checkIndex < 0 || !this.fullResolutionMap.get(checkIndex)) {
         newIndex += this.size;
      }

      checkIndex = index + this.size;
      if (checkIndex >= this.fullResolutionMap.size() || !this.fullResolutionMap.get(checkIndex)) {
         newIndex -= this.size;
      }

      return this.fullResolutionMap.get(newIndex) ? newIndex : index;
   }

   private boolean canSpawn(int x, int y, int z, int roleIndex, @Nullable ChunkSuppressionEntry suppressionEntry) {
      if (!this.spawnWrapper.getSpawn().isOverrideSpawnSuppressors() && suppressionEntry != null && suppressionEntry.isSuppressingRoleAt(roleIndex, y)) {
         return false;
      } else if (!this.spawningContext.set(this.world, x, y, z)
         || this.spawningContext.canSpawn() != SpawnTestResult.TEST_OK
         || !this.spawnWrapper.withinLightRange(this.spawningContext)) {
         return false;
      } else if (this.spawningContext.ySpawn > this.maxY) {
         return false;
      } else {
         IntSet spawnBlockSet = this.spawnWrapper.getSpawnBlockSet(roleIndex);
         int spawnFluidTag = this.spawnWrapper.getSpawnFluidTag(roleIndex);
         if (spawnBlockSet == null && spawnFluidTag == Integer.MIN_VALUE) {
            return true;
         } else {
            return spawnBlockSet != null && spawnBlockSet.contains(this.spawningContext.groundBlockId)
               ? true
               : spawnFluidTag != Integer.MIN_VALUE && Fluid.getAssetMap().getIndexesForTag(spawnFluidTag).contains(this.spawningContext.groundFluidId);
         }
      }
   }

   @Nonnull
   private String debugDumpBaseFloodFill() {
      StringBuilder sb = new StringBuilder();
      int sizeHalf = this.size / 2;
      int centre = getPositionIndex(sizeHalf, sizeHalf, this.size);

      for (int z = 0; z < this.size; z++) {
         for (int x = 0; x < this.size; x++) {
            int index = getPositionIndex(x, z, this.size);
            if (index == centre) {
               sb.append('B');
            } else if (this.positionIndexes.contains(index)) {
               sb.append('S');
            } else if (this.failedPositionTestIndexes.contains(index)) {
               sb.append('F');
            } else {
               switch (this.heightGrid[index]) {
                  case Integer.MIN_VALUE:
                     sb.append('v');
                     break;
                  case -2:
                  case -1:
                     sb.append('X');
                     break;
                  case Integer.MAX_VALUE:
                     sb.append('^');
                     break;
                  default:
                     sb.append('.');
               }
            }

            sb.append(' ');
         }

         sb.append('\n');
      }

      return sb.toString();
   }

   @Nonnull
   private String debugDumpLowResolutionMap(@Nonnull BitSet map, int size) {
      StringBuilder sb = new StringBuilder();

      for (int z = 0; z < size; z++) {
         for (int x = 0; x < size; x++) {
            sb.append((char)(map.get(getPositionIndex(x, z, size)) ? '.' : 'X')).append(' ');
         }

         sb.append('\n');
      }

      return sb.toString();
   }

   public static int getPositionIndex(int x, int z, int size) {
      return x * size + z;
   }

   public static int xFromIndex(int index, int size) {
      return index / size;
   }

   public static int zFromIndex(int index, int size) {
      return index % size;
   }

   @Nonnull
   @Override
   public Component<EntityStore> clone() {
      FloodFillPositionSelector selector = new FloodFillPositionSelector(this.world, this.spawnWrapper);
      selector.init();
      return selector;
   }

   public static enum Debug {
      DISABLED,
      IRREGULARITIES,
      ALL;
   }

   public static class SortBufferProvider {
      protected FloodFillPositionSelector.WeightedPosition[] buffer = new FloodFillPositionSelector.WeightedPosition[10];

      public FloodFillPositionSelector.WeightedPosition[] getBuffer(int size) {
         if (size <= this.buffer.length) {
            return this.buffer;
         } else {
            this.buffer = (FloodFillPositionSelector.WeightedPosition[])ObjectArrays.grow(this.buffer, size);
            return this.buffer;
         }
      }
   }

   private static class WeightedPosition {
      @Nonnull
      private final Vector3i position;
      private double weight;

      private WeightedPosition(int x, int y, int z) {
         this.position = new Vector3i(x, y, z);
      }

      public double getWeight() {
         return this.weight;
      }
   }
}