minecraft-src/net/minecraft/world/level/block/DetectorRailBlock.java

package net.minecraft.world.level.block;

import com.mojang.serialization.MapCodec;
import java.util.List;
import java.util.function.Predicate;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.util.RandomSource;
import net.minecraft.world.Container;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.EntitySelector;
import net.minecraft.world.entity.InsideBlockEffectApplier;
import net.minecraft.world.entity.vehicle.AbstractMinecart;
import net.minecraft.world.entity.vehicle.MinecartCommandBlock;
import net.minecraft.world.inventory.AbstractContainerMenu;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.state.BlockBehaviour;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.block.state.StateDefinition;
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.EnumProperty;
import net.minecraft.world.level.block.state.properties.Property;
import net.minecraft.world.level.block.state.properties.RailShape;
import net.minecraft.world.phys.AABB;

public class DetectorRailBlock extends BaseRailBlock {
	public static final MapCodec<DetectorRailBlock> CODEC = simpleCodec(DetectorRailBlock::new);
	public static final EnumProperty<RailShape> SHAPE = BlockStateProperties.RAIL_SHAPE_STRAIGHT;
	public static final BooleanProperty POWERED = BlockStateProperties.POWERED;
	private static final int PRESSED_CHECK_PERIOD = 20;

	@Override
	public MapCodec<DetectorRailBlock> codec() {
		return CODEC;
	}

	public DetectorRailBlock(BlockBehaviour.Properties properties) {
		super(true, properties);
		this.registerDefaultState(this.stateDefinition.any().setValue(POWERED, false).setValue(SHAPE, RailShape.NORTH_SOUTH).setValue(WATERLOGGED, false));
	}

	@Override
	protected boolean isSignalSource(BlockState state) {
		return true;
	}

	@Override
	protected void entityInside(BlockState state, Level level, BlockPos pos, Entity entity, InsideBlockEffectApplier effectApplier) {
		if (!level.isClientSide) {
			if (!(Boolean)state.getValue(POWERED)) {
				this.checkPressed(level, pos, state);
			}
		}
	}

	@Override
	protected void tick(BlockState state, ServerLevel level, BlockPos pos, RandomSource random) {
		if ((Boolean)state.getValue(POWERED)) {
			this.checkPressed(level, pos, state);
		}
	}

	@Override
	protected int getSignal(BlockState state, BlockGetter level, BlockPos pos, Direction direction) {
		return state.getValue(POWERED) ? 15 : 0;
	}

	@Override
	protected int getDirectSignal(BlockState state, BlockGetter level, BlockPos pos, Direction direction) {
		if (!(Boolean)state.getValue(POWERED)) {
			return 0;
		} else {
			return direction == Direction.UP ? 15 : 0;
		}
	}

	private void checkPressed(Level level, BlockPos pos, BlockState state) {
		if (this.canSurvive(state, level, pos)) {
			boolean bl = (Boolean)state.getValue(POWERED);
			boolean bl2 = false;
			List<AbstractMinecart> list = this.getInteractingMinecartOfType(level, pos, AbstractMinecart.class, entity -> true);
			if (!list.isEmpty()) {
				bl2 = true;
			}

			if (bl2 && !bl) {
				BlockState blockState = state.setValue(POWERED, true);
				level.setBlock(pos, blockState, 3);
				this.updatePowerToConnected(level, pos, blockState, true);
				level.updateNeighborsAt(pos, this);
				level.updateNeighborsAt(pos.below(), this);
				level.setBlocksDirty(pos, state, blockState);
			}

			if (!bl2 && bl) {
				BlockState blockState = state.setValue(POWERED, false);
				level.setBlock(pos, blockState, 3);
				this.updatePowerToConnected(level, pos, blockState, false);
				level.updateNeighborsAt(pos, this);
				level.updateNeighborsAt(pos.below(), this);
				level.setBlocksDirty(pos, state, blockState);
			}

			if (bl2) {
				level.scheduleTick(pos, this, 20);
			}

			level.updateNeighbourForOutputSignal(pos, this);
		}
	}

	protected void updatePowerToConnected(Level level, BlockPos pos, BlockState state, boolean powered) {
		RailState railState = new RailState(level, pos, state);

		for (BlockPos blockPos : railState.getConnections()) {
			BlockState blockState = level.getBlockState(blockPos);
			level.neighborChanged(blockState, blockPos, blockState.getBlock(), null, false);
		}
	}

	@Override
	protected void onPlace(BlockState state, Level level, BlockPos pos, BlockState oldState, boolean movedByPiston) {
		if (!oldState.is(state.getBlock())) {
			BlockState blockState = this.updateState(state, level, pos, movedByPiston);
			this.checkPressed(level, pos, blockState);
		}
	}

	@Override
	public Property<RailShape> getShapeProperty() {
		return SHAPE;
	}

	@Override
	protected boolean hasAnalogOutputSignal(BlockState state) {
		return true;
	}

	@Override
	protected int getAnalogOutputSignal(BlockState state, Level level, BlockPos pos) {
		if ((Boolean)state.getValue(POWERED)) {
			List<MinecartCommandBlock> list = this.getInteractingMinecartOfType(level, pos, MinecartCommandBlock.class, entity -> true);
			if (!list.isEmpty()) {
				return ((MinecartCommandBlock)list.get(0)).getCommandBlock().getSuccessCount();
			}

			List<AbstractMinecart> list2 = this.getInteractingMinecartOfType(level, pos, AbstractMinecart.class, EntitySelector.CONTAINER_ENTITY_SELECTOR);
			if (!list2.isEmpty()) {
				return AbstractContainerMenu.getRedstoneSignalFromContainer((Container)list2.get(0));
			}
		}

		return 0;
	}

	private <T extends AbstractMinecart> List<T> getInteractingMinecartOfType(Level level, BlockPos pos, Class<T> cartType, Predicate<Entity> filter) {
		return level.getEntitiesOfClass(cartType, this.getSearchBB(pos), filter);
	}

	private AABB getSearchBB(BlockPos pos) {
		double d = 0.2;
		return new AABB(pos.getX() + 0.2, pos.getY(), pos.getZ() + 0.2, pos.getX() + 1 - 0.2, pos.getY() + 1 - 0.2, pos.getZ() + 1 - 0.2);
	}

	@Override
	protected BlockState rotate(BlockState state, Rotation rotation) {
		RailShape railShape = state.getValue(SHAPE);
		RailShape railShape2 = this.rotate(railShape, rotation);
		return state.setValue(SHAPE, railShape2);
	}

	@Override
	protected BlockState mirror(BlockState state, Mirror mirror) {
		RailShape railShape = state.getValue(SHAPE);
		RailShape railShape2 = this.mirror(railShape, mirror);
		return state.setValue(SHAPE, railShape2);
	}

	@Override
	protected void createBlockStateDefinition(StateDefinition.Builder<Block, BlockState> builder) {
		builder.add(SHAPE, POWERED, WATERLOGGED);
	}
}