package net.minecraft.world.level.material;

import com.google.common.collect.Maps;
import it.unimi.dsi.fastutil.objects.Object2ByteLinkedOpenHashMap;
import it.unimi.dsi.fastutil.shorts.Short2BooleanFunction;
import it.unimi.dsi.fastutil.shorts.Short2BooleanMap;
import it.unimi.dsi.fastutil.shorts.Short2BooleanOpenHashMap;
import it.unimi.dsi.fastutil.shorts.Short2ObjectFunction;
import it.unimi.dsi.fastutil.shorts.Short2ObjectMap;
import it.unimi.dsi.fastutil.shorts.Short2ObjectOpenHashMap;
import java.util.Map;
import java.util.Map.Entry;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.tags.BlockTags;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.LevelAccessor;
import net.minecraft.world.level.LevelReader;
import net.minecraft.world.level.block.Block;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.DoorBlock;
import net.minecraft.world.level.block.IceBlock;
import net.minecraft.world.level.block.LiquidBlockContainer;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.block.state.StateDefinition.Builder;
import net.minecraft.world.level.block.state.properties.BlockStateProperties;
import net.minecraft.world.level.block.state.properties.BooleanProperty;
import net.minecraft.world.level.block.state.properties.IntegerProperty;
import net.minecraft.world.phys.Vec3;
import net.minecraft.world.phys.shapes.Shapes;
import net.minecraft.world.phys.shapes.VoxelShape;

public abstract class FlowingFluid extends Fluid {
	public static final BooleanProperty FALLING = BlockStateProperties.FALLING;
	public static final IntegerProperty LEVEL = BlockStateProperties.LEVEL_FLOWING;
	private static final int CACHE_SIZE = 200;
	private static final ThreadLocal<Object2ByteLinkedOpenHashMap<FlowingFluid.BlockStatePairKey>> OCCLUSION_CACHE = ThreadLocal.withInitial(
		() -> {
			Object2ByteLinkedOpenHashMap<FlowingFluid.BlockStatePairKey> object2ByteLinkedOpenHashMap = new Object2ByteLinkedOpenHashMap<FlowingFluid.BlockStatePairKey>(
				200
			) {
				@Override
				protected void rehash(int i) {
				}
			};
			object2ByteLinkedOpenHashMap.defaultReturnValue((byte)127);
			return object2ByteLinkedOpenHashMap;
		}
	);
	private final Map<FluidState, VoxelShape> shapes = Maps.<FluidState, VoxelShape>newIdentityHashMap();

	@Override
	protected void createFluidStateDefinition(Builder<Fluid, FluidState> builder) {
		builder.add(FALLING);
	}

	@Override
	public Vec3 getFlow(BlockGetter blockReader, BlockPos pos, FluidState fluidState) {
		double d = 0.0;
		double e = 0.0;
		BlockPos.MutableBlockPos mutableBlockPos = new BlockPos.MutableBlockPos();

		for (Direction direction : Direction.Plane.HORIZONTAL) {
			mutableBlockPos.setWithOffset(pos, direction);
			FluidState fluidState2 = blockReader.getFluidState(mutableBlockPos);
			if (this.affectsFlow(fluidState2)) {
				float f = fluidState2.getOwnHeight();
				float g = 0.0F;
				if (f == 0.0F) {
					if (!blockReader.getBlockState(mutableBlockPos).blocksMotion()) {
						BlockPos blockPos = mutableBlockPos.below();
						FluidState fluidState3 = blockReader.getFluidState(blockPos);
						if (this.affectsFlow(fluidState3)) {
							f = fluidState3.getOwnHeight();
							if (f > 0.0F) {
								g = fluidState.getOwnHeight() - (f - 0.8888889F);
							}
						}
					}
				} else if (f > 0.0F) {
					g = fluidState.getOwnHeight() - f;
				}

				if (g != 0.0F) {
					d += direction.getStepX() * g;
					e += direction.getStepZ() * g;
				}
			}
		}

		Vec3 vec3 = new Vec3(d, 0.0, e);
		if ((Boolean)fluidState.getValue(FALLING)) {
			for (Direction direction2 : Direction.Plane.HORIZONTAL) {
				mutableBlockPos.setWithOffset(pos, direction2);
				if (this.isSolidFace(blockReader, mutableBlockPos, direction2) || this.isSolidFace(blockReader, mutableBlockPos.above(), direction2)) {
					vec3 = vec3.normalize().add(0.0, -6.0, 0.0);
					break;
				}
			}
		}

		return vec3.normalize();
	}

	private boolean affectsFlow(FluidState state) {
		return state.isEmpty() || state.getType().isSame(this);
	}

	protected boolean isSolidFace(BlockGetter level, BlockPos neighborPos, Direction side) {
		BlockState blockState = level.getBlockState(neighborPos);
		FluidState fluidState = level.getFluidState(neighborPos);
		if (fluidState.getType().isSame(this)) {
			return false;
		} else if (side == Direction.UP) {
			return true;
		} else {
			return blockState.getBlock() instanceof IceBlock ? false : blockState.isFaceSturdy(level, neighborPos, side);
		}
	}

	protected void spread(ServerLevel level, BlockPos pos, BlockState blockState, FluidState fluidState) {
		if (!fluidState.isEmpty()) {
			BlockPos blockPos = pos.below();
			BlockState blockState2 = level.getBlockState(blockPos);
			FluidState fluidState2 = blockState2.getFluidState();
			if (this.canMaybePassThrough(level, pos, blockState, Direction.DOWN, blockPos, blockState2, fluidState2)) {
				FluidState fluidState3 = this.getNewLiquid(level, blockPos, blockState2);
				Fluid fluid = fluidState3.getType();
				if (fluidState2.canBeReplacedWith(level, blockPos, fluid, Direction.DOWN) && canHoldSpecificFluid(level, blockPos, blockState2, fluid)) {
					this.spreadTo(level, blockPos, blockState2, Direction.DOWN, fluidState3);
					if (this.sourceNeighborCount(level, pos) >= 3) {
						this.spreadToSides(level, pos, fluidState, blockState);
					}

					return;
				}
			}

			if (fluidState.isSource() || !this.isWaterHole(level, pos, blockState, blockPos, blockState2)) {
				this.spreadToSides(level, pos, fluidState, blockState);
			}
		}
	}

	private void spreadToSides(ServerLevel level, BlockPos pos, FluidState fluidState, BlockState blockState) {
		int i = fluidState.getAmount() - this.getDropOff(level);
		if ((Boolean)fluidState.getValue(FALLING)) {
			i = 7;
		}

		if (i > 0) {
			Map<Direction, FluidState> map = this.getSpread(level, pos, blockState);

			for (Entry<Direction, FluidState> entry : map.entrySet()) {
				Direction direction = (Direction)entry.getKey();
				FluidState fluidState2 = (FluidState)entry.getValue();
				BlockPos blockPos = pos.relative(direction);
				this.spreadTo(level, blockPos, level.getBlockState(blockPos), direction, fluidState2);
			}
		}
	}

	protected FluidState getNewLiquid(ServerLevel level, BlockPos pos, BlockState state) {
		int i = 0;
		int j = 0;
		BlockPos.MutableBlockPos mutableBlockPos = new BlockPos.MutableBlockPos();

		for (Direction direction : Direction.Plane.HORIZONTAL) {
			BlockPos blockPos = mutableBlockPos.setWithOffset(pos, direction);
			BlockState blockState = level.getBlockState(blockPos);
			FluidState fluidState = blockState.getFluidState();
			if (fluidState.getType().isSame(this) && canPassThroughWall(direction, level, pos, state, blockPos, blockState)) {
				if (fluidState.isSource()) {
					j++;
				}

				i = Math.max(i, fluidState.getAmount());
			}
		}

		if (j >= 2 && this.canConvertToSource(level)) {
			BlockState blockState2 = level.getBlockState(mutableBlockPos.setWithOffset(pos, Direction.DOWN));
			FluidState fluidState2 = blockState2.getFluidState();
			if (blockState2.isSolid() || this.isSourceBlockOfThisType(fluidState2)) {
				return this.getSource(false);
			}
		}

		BlockPos blockPos2 = mutableBlockPos.setWithOffset(pos, Direction.UP);
		BlockState blockState3 = level.getBlockState(blockPos2);
		FluidState fluidState3 = blockState3.getFluidState();
		if (!fluidState3.isEmpty() && fluidState3.getType().isSame(this) && canPassThroughWall(Direction.UP, level, pos, state, blockPos2, blockState3)) {
			return this.getFlowing(8, true);
		} else {
			int k = i - this.getDropOff(level);
			return k <= 0 ? Fluids.EMPTY.defaultFluidState() : this.getFlowing(k, false);
		}
	}

	private static boolean canPassThroughWall(Direction direction, BlockGetter level, BlockPos pos, BlockState state, BlockPos spreadPos, BlockState spreadState) {
		VoxelShape voxelShape = spreadState.getCollisionShape(level, spreadPos);
		if (voxelShape == Shapes.block()) {
			return false;
		} else {
			VoxelShape voxelShape2 = state.getCollisionShape(level, pos);
			if (voxelShape2 == Shapes.block()) {
				return false;
			} else if (voxelShape2 == Shapes.empty() && voxelShape == Shapes.empty()) {
				return true;
			} else {
				Object2ByteLinkedOpenHashMap<FlowingFluid.BlockStatePairKey> object2ByteLinkedOpenHashMap;
				if (!state.getBlock().hasDynamicShape() && !spreadState.getBlock().hasDynamicShape()) {
					object2ByteLinkedOpenHashMap = (Object2ByteLinkedOpenHashMap<FlowingFluid.BlockStatePairKey>)OCCLUSION_CACHE.get();
				} else {
					object2ByteLinkedOpenHashMap = null;
				}

				FlowingFluid.BlockStatePairKey blockStatePairKey;
				if (object2ByteLinkedOpenHashMap != null) {
					blockStatePairKey = new FlowingFluid.BlockStatePairKey(state, spreadState, direction);
					byte b = object2ByteLinkedOpenHashMap.getAndMoveToFirst(blockStatePairKey);
					if (b != 127) {
						return b != 0;
					}
				} else {
					blockStatePairKey = null;
				}

				boolean bl = !Shapes.mergedFaceOccludes(voxelShape2, voxelShape, direction);
				if (object2ByteLinkedOpenHashMap != null) {
					if (object2ByteLinkedOpenHashMap.size() == 200) {
						object2ByteLinkedOpenHashMap.removeLastByte();
					}

					object2ByteLinkedOpenHashMap.putAndMoveToFirst(blockStatePairKey, (byte)(bl ? 1 : 0));
				}

				return bl;
			}
		}
	}

	public abstract Fluid getFlowing();

	public FluidState getFlowing(int level, boolean falling) {
		return this.getFlowing().defaultFluidState().setValue(LEVEL, level).setValue(FALLING, falling);
	}

	public abstract Fluid getSource();

	public FluidState getSource(boolean falling) {
		return this.getSource().defaultFluidState().setValue(FALLING, falling);
	}

	protected abstract boolean canConvertToSource(ServerLevel level);

	protected void spreadTo(LevelAccessor level, BlockPos pos, BlockState blockState, Direction direction, FluidState fluidState) {
		if (blockState.getBlock() instanceof LiquidBlockContainer liquidBlockContainer) {
			liquidBlockContainer.placeLiquid(level, pos, blockState, fluidState);
		} else {
			if (!blockState.isAir()) {
				this.beforeDestroyingBlock(level, pos, blockState);
			}

			level.setBlock(pos, fluidState.createLegacyBlock(), 3);
		}
	}

	protected abstract void beforeDestroyingBlock(LevelAccessor level, BlockPos pos, BlockState state);

	protected int getSlopeDistance(LevelReader level, BlockPos pos, int depth, Direction direction, BlockState state, FlowingFluid.SpreadContext spreadContext) {
		int i = 1000;

		for (Direction direction2 : Direction.Plane.HORIZONTAL) {
			if (direction2 != direction) {
				BlockPos blockPos = pos.relative(direction2);
				BlockState blockState = spreadContext.getBlockState(blockPos);
				FluidState fluidState = blockState.getFluidState();
				if (this.canPassThrough(level, this.getFlowing(), pos, state, direction2, blockPos, blockState, fluidState)) {
					if (spreadContext.isHole(blockPos)) {
						return depth;
					}

					if (depth < this.getSlopeFindDistance(level)) {
						int j = this.getSlopeDistance(level, blockPos, depth + 1, direction2.getOpposite(), blockState, spreadContext);
						if (j < i) {
							i = j;
						}
					}
				}
			}
		}

		return i;
	}

	boolean isWaterHole(BlockGetter level, BlockPos pos, BlockState state, BlockPos belowPos, BlockState belowState) {
		if (!canPassThroughWall(Direction.DOWN, level, pos, state, belowPos, belowState)) {
			return false;
		} else {
			return belowState.getFluidState().getType().isSame(this) ? true : canHoldFluid(level, belowPos, belowState, this.getFlowing());
		}
	}

	private boolean canPassThrough(
		BlockGetter level, Fluid fluid, BlockPos pos, BlockState state, Direction direction, BlockPos spreadPos, BlockState spreadState, FluidState fluidState
	) {
		return this.canMaybePassThrough(level, pos, state, direction, spreadPos, spreadState, fluidState)
			&& canHoldSpecificFluid(level, spreadPos, spreadState, fluid);
	}

	private boolean canMaybePassThrough(
		BlockGetter level, BlockPos pos, BlockState state, Direction direction, BlockPos spreadPos, BlockState spreadState, FluidState fluidState
	) {
		return !this.isSourceBlockOfThisType(fluidState) && canHoldAnyFluid(spreadState) && canPassThroughWall(direction, level, pos, state, spreadPos, spreadState);
	}

	private boolean isSourceBlockOfThisType(FluidState state) {
		return state.getType().isSame(this) && state.isSource();
	}

	protected abstract int getSlopeFindDistance(LevelReader level);

	/**
	 * Returns the number of immediately adjacent source blocks of the same fluid that lie on the horizontal plane.
	 */
	private int sourceNeighborCount(LevelReader level, BlockPos pos) {
		int i = 0;

		for (Direction direction : Direction.Plane.HORIZONTAL) {
			BlockPos blockPos = pos.relative(direction);
			FluidState fluidState = level.getFluidState(blockPos);
			if (this.isSourceBlockOfThisType(fluidState)) {
				i++;
			}
		}

		return i;
	}

	protected Map<Direction, FluidState> getSpread(ServerLevel level, BlockPos pos, BlockState state) {
		int i = 1000;
		Map<Direction, FluidState> map = Maps.newEnumMap(Direction.class);
		FlowingFluid.SpreadContext spreadContext = null;

		for (Direction direction : Direction.Plane.HORIZONTAL) {
			BlockPos blockPos = pos.relative(direction);
			BlockState blockState = level.getBlockState(blockPos);
			FluidState fluidState = blockState.getFluidState();
			if (this.canMaybePassThrough(level, pos, state, direction, blockPos, blockState, fluidState)) {
				FluidState fluidState2 = this.getNewLiquid(level, blockPos, blockState);
				if (canHoldSpecificFluid(level, blockPos, blockState, fluidState2.getType())) {
					if (spreadContext == null) {
						spreadContext = new FlowingFluid.SpreadContext(level, pos);
					}

					int j;
					if (spreadContext.isHole(blockPos)) {
						j = 0;
					} else {
						j = this.getSlopeDistance(level, blockPos, 1, direction.getOpposite(), blockState, spreadContext);
					}

					if (j < i) {
						map.clear();
					}

					if (j <= i) {
						if (fluidState.canBeReplacedWith(level, blockPos, fluidState2.getType(), direction)) {
							map.put(direction, fluidState2);
						}

						i = j;
					}
				}
			}
		}

		return map;
	}

	private static boolean canHoldAnyFluid(BlockState state) {
		Block block = state.getBlock();
		if (block instanceof LiquidBlockContainer) {
			return true;
		} else {
			return state.blocksMotion()
				? false
				: !(block instanceof DoorBlock)
					&& !state.is(BlockTags.SIGNS)
					&& !state.is(Blocks.LADDER)
					&& !state.is(Blocks.SUGAR_CANE)
					&& !state.is(Blocks.BUBBLE_COLUMN)
					&& !state.is(Blocks.NETHER_PORTAL)
					&& !state.is(Blocks.END_PORTAL)
					&& !state.is(Blocks.END_GATEWAY)
					&& !state.is(Blocks.STRUCTURE_VOID);
		}
	}

	private static boolean canHoldFluid(BlockGetter level, BlockPos pos, BlockState state, Fluid fluid) {
		return canHoldAnyFluid(state) && canHoldSpecificFluid(level, pos, state, fluid);
	}

	private static boolean canHoldSpecificFluid(BlockGetter level, BlockPos pos, BlockState state, Fluid fluid) {
		return state.getBlock() instanceof LiquidBlockContainer liquidBlockContainer ? liquidBlockContainer.canPlaceLiquid(null, level, pos, state, fluid) : true;
	}

	protected abstract int getDropOff(LevelReader level);

	protected int getSpreadDelay(Level level, BlockPos pos, FluidState currentState, FluidState newState) {
		return this.getTickDelay(level);
	}

	@Override
	public void tick(ServerLevel level, BlockPos pos, BlockState blockState, FluidState fluidState) {
		if (!fluidState.isSource()) {
			FluidState fluidState2 = this.getNewLiquid(level, pos, level.getBlockState(pos));
			int i = this.getSpreadDelay(level, pos, fluidState, fluidState2);
			if (fluidState2.isEmpty()) {
				fluidState = fluidState2;
				blockState = Blocks.AIR.defaultBlockState();
				level.setBlock(pos, blockState, 3);
			} else if (fluidState2 != fluidState) {
				fluidState = fluidState2;
				blockState = fluidState2.createLegacyBlock();
				level.setBlock(pos, blockState, 3);
				level.scheduleTick(pos, fluidState2.getType(), i);
			}
		}

		this.spread(level, pos, blockState, fluidState);
	}

	protected static int getLegacyLevel(FluidState state) {
		return state.isSource() ? 0 : 8 - Math.min(state.getAmount(), 8) + (state.getValue(FALLING) ? 8 : 0);
	}

	private static boolean hasSameAbove(FluidState fluidState, BlockGetter level, BlockPos pos) {
		return fluidState.getType().isSame(level.getFluidState(pos.above()).getType());
	}

	@Override
	public float getHeight(FluidState state, BlockGetter level, BlockPos pos) {
		return hasSameAbove(state, level, pos) ? 1.0F : state.getOwnHeight();
	}

	@Override
	public float getOwnHeight(FluidState state) {
		return state.getAmount() / 9.0F;
	}

	@Override
	public abstract int getAmount(FluidState state);

	@Override
	public VoxelShape getShape(FluidState state, BlockGetter level, BlockPos pos) {
		return state.getAmount() == 9 && hasSameAbove(state, level, pos)
			? Shapes.block()
			: (VoxelShape)this.shapes.computeIfAbsent(state, fluidState -> Shapes.box(0.0, 0.0, 0.0, 1.0, fluidState.getHeight(level, pos), 1.0));
	}

	record BlockStatePairKey(BlockState first, BlockState second, Direction direction) {
		public boolean equals(Object object) {
			return object instanceof FlowingFluid.BlockStatePairKey blockStatePairKey
				&& this.first == blockStatePairKey.first
				&& this.second == blockStatePairKey.second
				&& this.direction == blockStatePairKey.direction;
		}

		public int hashCode() {
			int i = System.identityHashCode(this.first);
			i = 31 * i + System.identityHashCode(this.second);
			return 31 * i + this.direction.hashCode();
		}
	}

	protected class SpreadContext {
		private final BlockGetter level;
		private final BlockPos origin;
		private final Short2ObjectMap<BlockState> stateCache = new Short2ObjectOpenHashMap<>();
		private final Short2BooleanMap holeCache = new Short2BooleanOpenHashMap();

		SpreadContext(final BlockGetter level, final BlockPos origin) {
			this.level = level;
			this.origin = origin;
		}

		public BlockState getBlockState(BlockPos pos) {
			return this.getBlockState(pos, this.getCacheKey(pos));
		}

		private BlockState getBlockState(BlockPos pos, short cacheKey) {
			return this.stateCache.computeIfAbsent(cacheKey, (Short2ObjectFunction<? extends BlockState>)(s -> this.level.getBlockState(pos)));
		}

		public boolean isHole(BlockPos pos) {
			return this.holeCache.computeIfAbsent(this.getCacheKey(pos), (Short2BooleanFunction)(s -> {
				BlockState blockState = this.getBlockState(pos, s);
				BlockPos blockPos2 = pos.below();
				BlockState blockState2 = this.level.getBlockState(blockPos2);
				return FlowingFluid.this.isWaterHole(this.level, pos, blockState, blockPos2, blockState2);
			}));
		}

		private short getCacheKey(BlockPos pos) {
			int i = pos.getX() - this.origin.getX();
			int j = pos.getZ() - this.origin.getZ();
			return (short)((i + 128 & 0xFF) << 8 | j + 128 & 0xFF);
		}
	}
}