package io.github.eirikh1996;

import org.bukkit.Material;
import org.bukkit.block.Block;
import org.bukkit.block.Sign;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.block.Action;
import org.bukkit.event.player.PlayerInteractEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.InventoryHolder;
import org.bukkit.inventory.ItemStack;
import org.bukkit.plugin.java.JavaPlugin;
import org.bukkit.scheduler.BukkitRunnable;

public class Test extends JavaPlugin implements Listener {
    @Override
    public void onEnable() {
        getServer().getPluginManager().registerEvents(this,this);
    }

    @EventHandler
    public void onBlockClick(PlayerInteractEvent event){
        if (!event.getAction().equals(Action.RIGHT_CLICK_BLOCK)){
            return;
        }
        if (!event.getItem().getType().equals(Material.WOODEN_SHOVEL)){
            return;
        }
        event.setCancelled(true);
        if (event.getClickedBlock().getState() instanceof Sign){
            final Block block = event.getClickedBlock();
            new BukkitRunnable() {
                @Override
                public void run() {
                    Sign sign = (Sign) block.getState();
                    Player p = event.getPlayer();
                    p.sendMessage(event.getClickedBlock().getType().name() + ": ");
                    for (String s : sign.getLines()){
                        if (s == null) continue;
                        p.sendMessage(s);
                    }
                }
            }.runTaskAsynchronously(this);

        }
    }
}

[19:25:04] [Craft Scheduler Thread - 0/WARN]: [Test] Plugin Test v1.0 generated an exception while executing task 40
java.lang.NullPointerException: null
        at org.bukkit.craftbukkit.v1_14_R1.block.CraftSign.load(CraftSign.java:30) ~[spigot-1.14.jar:git-Spigot-1eece4f-dadc539]
        at org.bukkit.craftbukkit.v1_14_R1.block.CraftSign.load(CraftSign.java:1) ~[spigot-1.14.jar:git-Spigot-1eece4f-dadc539]
        at org.bukkit.craftbukkit.v1_14_R1.block.CraftBlockEntityState.<init>(CraftBlockEntityState.java:30) ~[spigot-1.14.jar:git-Spigot-1eece4f-dadc539]
        at org.bukkit.craftbukkit.v1_14_R1.block.CraftSign.<init>(CraftSign.java:19) ~[spigot-1.14.jar:git-Spigot-1eece4f-dadc539]
        at org.bukkit.craftbukkit.v1_14_R1.block.CraftBlock.getState(CraftBlock.java:330) ~[spigot-1.14.jar:git-Spigot-1eece4f-dadc539]
        at io.github.eirikh1996.Test$1.run(Test.java:37) ~[?:?]
        at org.bukkit.craftbukkit.v1_14_R1.scheduler.CraftTask.run(CraftTask.java:81) ~[spigot-1.14.jar:git-Spigot-1eece4f-dadc539]
        at org.bukkit.craftbukkit.v1_14_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:54) [spigot-1.14.jar:git-Spigot-1eece4f-dadc539]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_201]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_201]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_201]