Code/net/minecraft/world/level/block/MultifaceSpreader.java

package net.minecraft.world.level.block;

import com.google.common.annotations.VisibleForTesting;
import java.util.Optional;
import javax.annotation.Nullable;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.util.RandomSource;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.LevelAccessor;
import net.minecraft.world.level.block.state.BlockState;

public class MultifaceSpreader {
    public static final MultifaceSpreader.SpreadType[] DEFAULT_SPREAD_ORDER = new MultifaceSpreader.SpreadType[]{
        MultifaceSpreader.SpreadType.SAME_POSITION, MultifaceSpreader.SpreadType.SAME_PLANE, MultifaceSpreader.SpreadType.WRAP_AROUND
    };
    private final MultifaceSpreader.SpreadConfig config;

    public MultifaceSpreader(MultifaceBlock p_221590_) {
        this(new MultifaceSpreader.DefaultSpreaderConfig(p_221590_));
    }

    public MultifaceSpreader(MultifaceSpreader.SpreadConfig p_221592_) {
        this.config = p_221592_;
    }

    public boolean canSpreadInAnyDirection(BlockState p_221602_, BlockGetter p_221603_, BlockPos p_221604_, Direction p_221605_) {
        return Direction.stream()
            .anyMatch(p_221611_ -> this.getSpreadFromFaceTowardDirection(p_221602_, p_221603_, p_221604_, p_221605_, p_221611_, this.config::canSpreadInto).isPresent());
    }

    public Optional<MultifaceSpreader.SpreadPos> spreadFromRandomFaceTowardRandomDirection(BlockState p_221620_, LevelAccessor p_221621_, BlockPos p_221622_, RandomSource p_221623_) {
        return Direction.allShuffled(p_221623_)
            .stream()
            .filter(p_221680_ -> this.config.canSpreadFrom(p_221620_, p_221680_))
            .map(p_221629_ -> this.spreadFromFaceTowardRandomDirection(p_221620_, p_221621_, p_221622_, p_221629_, p_221623_, false))
            .filter(Optional::isPresent)
            .findFirst()
            .orElse(Optional.empty());
    }

    public long spreadAll(BlockState p_221658_, LevelAccessor p_221659_, BlockPos p_221660_, boolean p_221661_) {
        return Direction.stream()
            .filter(p_221670_ -> this.config.canSpreadFrom(p_221658_, p_221670_))
            .map(p_221667_ -> this.spreadFromFaceTowardAllDirections(p_221658_, p_221659_, p_221660_, p_221667_, p_221661_))
            .reduce(0L, Long::sum);
    }

    public Optional<MultifaceSpreader.SpreadPos> spreadFromFaceTowardRandomDirection(
        BlockState p_221631_, LevelAccessor p_221632_, BlockPos p_221633_, Direction p_221634_, RandomSource p_221635_, boolean p_221636_
    ) {
        return Direction.allShuffled(p_221635_)
            .stream()
            .map(p_221677_ -> this.spreadFromFaceTowardDirection(p_221631_, p_221632_, p_221633_, p_221634_, p_221677_, p_221636_))
            .filter(Optional::isPresent)
            .findFirst()
            .orElse(Optional.empty());
    }

    private long spreadFromFaceTowardAllDirections(BlockState p_221645_, LevelAccessor p_221646_, BlockPos p_221647_, Direction p_221648_, boolean p_221649_) {
        return Direction.stream()
            .map(p_221656_ -> this.spreadFromFaceTowardDirection(p_221645_, p_221646_, p_221647_, p_221648_, p_221656_, p_221649_))
            .filter(Optional::isPresent)
            .count();
    }

    @VisibleForTesting
    public Optional<MultifaceSpreader.SpreadPos> spreadFromFaceTowardDirection(
        BlockState p_221638_, LevelAccessor p_221639_, BlockPos p_221640_, Direction p_221641_, Direction p_221642_, boolean p_221643_
    ) {
        return this.getSpreadFromFaceTowardDirection(p_221638_, p_221639_, p_221640_, p_221641_, p_221642_, this.config::canSpreadInto)
            .flatMap(p_221600_ -> this.spreadToFace(p_221639_, p_221600_, p_221643_));
    }

    public Optional<MultifaceSpreader.SpreadPos> getSpreadFromFaceTowardDirection(
        BlockState p_221613_, BlockGetter p_221614_, BlockPos p_221615_, Direction p_221616_, Direction p_221617_, MultifaceSpreader.SpreadPredicate p_221618_
    ) {
        if (p_221617_.getAxis() == p_221616_.getAxis()) {
            return Optional.empty();
        } else if (this.config.isOtherBlockValidAsSource(p_221613_) || this.config.hasFace(p_221613_, p_221616_) && !this.config.hasFace(p_221613_, p_221617_)) {
            for (MultifaceSpreader.SpreadType multifacespreader$spreadtype : this.config.getSpreadTypes()) {
                MultifaceSpreader.SpreadPos multifacespreader$spreadpos = multifacespreader$spreadtype.getSpreadPos(p_221615_, p_221617_, p_221616_);
                if (p_221618_.test(p_221614_, p_221615_, multifacespreader$spreadpos)) {
                    return Optional.of(multifacespreader$spreadpos);
                }
            }

            return Optional.empty();
        } else {
            return Optional.empty();
        }
    }

    public Optional<MultifaceSpreader.SpreadPos> spreadToFace(LevelAccessor p_221594_, MultifaceSpreader.SpreadPos p_221595_, boolean p_221596_) {
        BlockState blockstate = p_221594_.getBlockState(p_221595_.pos());
        return this.config.placeBlock(p_221594_, p_221595_, blockstate, p_221596_) ? Optional.of(p_221595_) : Optional.empty();
    }

    public static class DefaultSpreaderConfig implements MultifaceSpreader.SpreadConfig {
        protected MultifaceBlock block;

        public DefaultSpreaderConfig(MultifaceBlock p_221683_) {
            this.block = p_221683_;
        }

        @Nullable
        @Override
        public BlockState getStateForPlacement(BlockState p_221694_, BlockGetter p_221695_, BlockPos p_221696_, Direction p_221697_) {
            return this.block.getStateForPlacement(p_221694_, p_221695_, p_221696_, p_221697_);
        }

        protected boolean stateCanBeReplaced(BlockGetter p_221688_, BlockPos p_221689_, BlockPos p_221690_, Direction p_221691_, BlockState p_221692_) {
            return p_221692_.isAir() || p_221692_.is(this.block) || p_221692_.is(Blocks.WATER) && p_221692_.getFluidState().isSource();
        }

        @Override
        public boolean canSpreadInto(BlockGetter p_221685_, BlockPos p_221686_, MultifaceSpreader.SpreadPos p_221687_) {
            BlockState blockstate = p_221685_.getBlockState(p_221687_.pos());
            return this.stateCanBeReplaced(p_221685_, p_221686_, p_221687_.pos(), p_221687_.face(), blockstate)
                && this.block.isValidStateForPlacement(p_221685_, blockstate, p_221687_.pos(), p_221687_.face());
        }
    }

    public interface SpreadConfig {
        @Nullable
        BlockState getStateForPlacement(BlockState p_221707_, BlockGetter p_221708_, BlockPos p_221709_, Direction p_221710_);

        boolean canSpreadInto(BlockGetter p_221698_, BlockPos p_221699_, MultifaceSpreader.SpreadPos p_221700_);

        default MultifaceSpreader.SpreadType[] getSpreadTypes() {
            return MultifaceSpreader.DEFAULT_SPREAD_ORDER;
        }

        default boolean hasFace(BlockState p_221712_, Direction p_221713_) {
            return MultifaceBlock.hasFace(p_221712_, p_221713_);
        }

        default boolean isOtherBlockValidAsSource(BlockState p_221706_) {
            return false;
        }

        default boolean canSpreadFrom(BlockState p_221715_, Direction p_221716_) {
            return this.isOtherBlockValidAsSource(p_221715_) || this.hasFace(p_221715_, p_221716_);
        }

        default boolean placeBlock(LevelAccessor p_221702_, MultifaceSpreader.SpreadPos p_221703_, BlockState p_221704_, boolean p_221705_) {
            BlockState blockstate = this.getStateForPlacement(p_221704_, p_221702_, p_221703_.pos(), p_221703_.face());
            if (blockstate != null) {
                if (p_221705_) {
                    p_221702_.getChunk(p_221703_.pos()).markPosForPostprocessing(p_221703_.pos());
                }

                return p_221702_.setBlock(p_221703_.pos(), blockstate, 2);
            } else {
                return false;
            }
        }
    }

    public record SpreadPos(BlockPos pos, Direction face) {
    }

    @FunctionalInterface
    public interface SpreadPredicate {
        boolean test(BlockGetter p_221729_, BlockPos p_221730_, MultifaceSpreader.SpreadPos p_221731_);
    }

    public static enum SpreadType {
        SAME_POSITION {
            @Override
            public MultifaceSpreader.SpreadPos getSpreadPos(BlockPos p_221751_, Direction p_221752_, Direction p_221753_) {
                return new MultifaceSpreader.SpreadPos(p_221751_, p_221752_);
            }
        },
        SAME_PLANE {
            @Override
            public MultifaceSpreader.SpreadPos getSpreadPos(BlockPos p_221758_, Direction p_221759_, Direction p_221760_) {
                return new MultifaceSpreader.SpreadPos(p_221758_.relative(p_221759_), p_221760_);
            }
        },
        WRAP_AROUND {
            @Override
            public MultifaceSpreader.SpreadPos getSpreadPos(BlockPos p_221765_, Direction p_221766_, Direction p_221767_) {
                return new MultifaceSpreader.SpreadPos(p_221765_.relative(p_221766_).relative(p_221767_), p_221766_.getOpposite());
            }
        };

        public abstract MultifaceSpreader.SpreadPos getSpreadPos(BlockPos p_221741_, Direction p_221742_, Direction p_221743_);
    }
}