content: package org.allaymc.server.block.component.sign;
  
  import org.allaymc.api.block.BlockBehavior;
  import org.allaymc.api.block.data.BlockFace;
  import org.allaymc.api.block.dto.Block;
  import org.allaymc.api.block.dto.PlayerInteractInfo;
  import org.allaymc.api.block.property.type.BlockPropertyTypes;
  import org.allaymc.api.block.type.BlockState;
  import org.allaymc.api.block.type.BlockType;
  import org.allaymc.api.world.Dimension;
  import org.allaymc.server.block.BlockPlaceHelper;
  import org.allaymc.server.block.component.BlockBaseComponentImpl;
  import org.joml.Vector3ic;
  
  import static org.allaymc.api.block.property.type.BlockPropertyTypes.HANGING;
  
  /**
   * @author daoge_cmd
   */
  public class BlockHangingSignBaseComponentImpl extends BlockBaseComponentImpl {
      public BlockHangingSignBaseComponentImpl(BlockType<? extends BlockBehavior> blockType) {
          super(blockType);
      }
  
      @Override
      public boolean place(Dimension dimension, BlockState blockState, Vector3ic placeBlockPos, PlayerInteractInfo placementInfo) {
          if (placementInfo == null) {
              return super.place(dimension, blockState, placeBlockPos, null);
          }
  
          var face = placementInfo.blockFace();
          if (face == BlockFace.UP) {
              return false;
          }
  
          if (face == BlockFace.DOWN) {
              blockState = blockState.setPropertyValue(HANGING, true);
              var upperBlock = dimension.getBlockState(BlockFace.UP.offsetPos(placeBlockPos));
              if (!upperBlock.getBlockStateData().isSolid()) {
                  return false;
              }
  
              var shape = upperBlock.getBlockStateData().collisionShape();
              var full = shape.isFull(BlockFace.DOWN);
              var centerFull = shape.isCenterFull(BlockFace.DOWN);
              if (placementInfo.player().isSneaking() || (centerFull && !full)) {
                  blockState = blockState.setPropertyValue(BlockPropertyTypes.ATTACHED_BIT, true);
                  blockState = BlockPlaceHelper.processGroundSignDirectionProperty(blockState, placeBlockPos, placementInfo);
              } else if (full) {
                  blockState = BlockPlaceHelper.processFacingDirectionProperty(blockState, placeBlockPos, placementInfo);
              } else {
                  return false;
              }
          } else {
              blockState = blockState.setPropertyValue(BlockPropertyTypes.FACING_DIRECTION, face.opposite().rotateY().ordinal());
          }
  
          return dimension.setBlockState(placeBlockPos.x(), placeBlockPos.y(), placeBlockPos.z(), blockState, placementInfo);
      }
  
      @Override
      public void onNeighborUpdate(Block block, Block neighbor, BlockFace face) {
          super.onNeighborUpdate(block, neighbor, face);
  
          if (!block.getPropertyValue(HANGING) || face != BlockFace.UP) {
              return;
          }
  
          var keep = true;
          if (!neighbor.getBlockStateData().isSolid()) {
              keep = false;
          } else {
              keep = neighbor.getBlockStateData().collisionShape().isCenterFull(BlockFace.DOWN);
          }
  
          if (!keep) {
              block.breakBlock();
          }
      }
  }
  