@EventHandler(priority = EventPriority.MONITOR)
public void onSignChanged(SignChangeEvent e) {
    if (e.isCancelled() || e.getPlayer() == null
            || !plugin.getWorldManager().isSkyAssociatedWorld(e.getPlayer().getWorld())
            || !e.getLines()[0].equalsIgnoreCase("[usb]")
            || e.getLines()[1].trim().isEmpty()
            || !e.getPlayer().hasPermission("usb.island.signs.place")
            || !(e.getBlock().getType() == SkyBlockMenu.WALL_SIGN_MATERIAL)
            || !(e.getBlock().getState() instanceof Sign)
            ) {
        return;
    }
    Sign sign = (Sign) e.getBlock().getState();

    if(sign.getBlock().getState().getBlockData() instanceof WallSign) {
        WallSign data = (WallSign) sign.getBlock().getState().getBlockData();
        BlockFace attached = data.getFacing().getOppositeFace();
        Block wallBlock = sign.getBlock().getRelative(attached);
        if (isChest(wallBlock)) {
            logic.addSign(sign, e.getLines(), (Chest) wallBlock.getState());
        }
    }
}
 

@Override
public BlockFace getSignFacing(Block block) {
	if (block == null) {
		return null;
	}

	BlockState blockState = block.getState();
	if (blockState == null) {
		return null;
	}

	BlockData blockData = blockState.getBlockData();
	if (blockData == null) {
		return null;
	}

	if(blockData instanceof WallSign) {
		return ((WallSign) blockData).getFacing();
	} else if(blockData instanceof Sign) {
		return ((Sign) blockData).getRotation();
	}

	return null;
}
 

@Override
public boolean setSignFacing(Block block, BlockFace facing) {
	if (block == null || facing == null) {
		return false;
	}

	BlockState blockState = block.getState();
	if (blockState == null) {
		return false;
	}

	BlockData blockData = blockState.getBlockData();
	if (blockData == null) {
		return false;
	}

	if(blockData instanceof WallSign) {
		((WallSign) blockData).setFacing(facing);
	} else if(blockData instanceof Sign) {
		((Sign) blockData).setRotation(facing);
	} else {
		return false;
	}
	block.setBlockData(blockData);
	return true;
}
 

@Override
public Block getSignAttachedTo(Block block) {
	if (block == null) {
		return null;
	}

	BlockState blockState = block.getState();
	if (blockState == null) {
		return null;
	}

	org.bukkit.block.data.BlockData blockData = blockState.getBlockData();
	if (blockData == null) {
		return null;
	}

	if(blockData instanceof WallSign) {
		return block.getRelative(((WallSign) blockData).getFacing().getOppositeFace());
	} else if(blockData instanceof Sign) {
		return block.getRelative(BlockFace.DOWN);
	}

	return null;
}
 

/**
 * Create a shop use Shop and Info object.
 *
 * @param shop The shop object
 * @param info The info object
 */
public void createShop(@NotNull Shop shop, @NotNull Info info) {
    Player player = Bukkit.getPlayer(shop.getOwner());
    if (player == null) {
        throw new IllegalStateException("The owner creating the shop is offline or not exist");
    }
    ShopCreateEvent shopCreateEvent = new ShopCreateEvent(shop, player);
    if (Util.fireCancellableEvent(shopCreateEvent)) {
        Util.debugLog("Cancelled by plugin");
        return;
    }
    if (info.getSignBlock() != null && autoSign) {
        if (Util.isAir(info.getSignBlock().getType()) || info.getSignBlock().getType() == Material.WATER) {
            info.getSignBlock().setType(Util.getSignMaterial());
            BlockState bs = info.getSignBlock().getState();
            if (info.getSignBlock().getType() == Material.WATER && (bs.getBlockData() instanceof Waterlogged)) {
                Waterlogged waterable = (Waterlogged) bs.getBlockData();
                waterable.setWaterlogged(true); // Looks like sign directly put in water
            }
            if (bs.getBlockData() instanceof WallSign) {
                WallSign signBlockDataType = (WallSign) bs.getBlockData();
                BlockFace bf = info.getLocation().getBlock().getFace(info.getSignBlock());
                if (bf != null) {
                    signBlockDataType.setFacing(bf);
                    bs.setBlockData(signBlockDataType);
                }
            } else {
                plugin.getLogger().warning("Sign material " + bs.getType().name() + " not a WallSign, make sure you using correct sign material.");
            }
            bs.update(true);
        } else {
            if (!plugin.getConfig().getBoolean("shop.allow-shop-without-space-for-sign")) {
                MsgUtil.sendMessage(player, MsgUtil.getMessage("failed-to-put-sign", player));
                Util.debugLog("Sign cannot placed cause no enough space(Not air block)");
                return;
            }
        }
    }
    //load the shop finally
    shop.onLoad();
    //first init
    shop.setSignText();
    //sync add to prevent compete issue
    addShop(shop.getLocation().getWorld().getName(), shop);
    //save to database
    plugin.getDatabaseHelper().createShop(
            shop,
            null,
            e -> Bukkit.getScheduler().runTask(plugin, () -> {
                //also remove from memory when failed
                shop.delete(true);
                plugin.getLogger().warning("Shop create failed, trying to auto fix the database...");
                boolean backupSuccess = Util.backupDatabase();
                if (backupSuccess) {
                    plugin.getDatabaseHelper().removeShop(shop);
                } else {
                    plugin.getLogger().warning("Failed to backup the database, all changes will revert after a reboot.");
                }
            }));
}