ItemEconomy/src/main/java/ru/themixray/itemeconomy/Main.java

package ru.themixray.itemeconomy;

import com.google.common.io.ByteArrayDataInput;
import net.milkbowl.vault.economy.Economy;
import org.bukkit.Bukkit;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.inventory.ItemStack;
import org.bukkit.plugin.ServicePriority;
import org.bukkit.plugin.java.JavaPlugin;
import org.bukkit.scheduler.BukkitRunnable;

import java.io.IOException;
import java.util.*;

public class Main extends JavaPlugin {
    public static HashMap<String, List<ItemStack>> addItems = new HashMap<>();

    @Override
    public void onEnable() {
        Config.loadConfig(new UnrealConfig(this, getDataFolder(), "config.yml"));
        Bukkit.getServicesManager().register(Economy.class, new VaultLayer(), this, ServicePriority.High);
        new BukkitRunnable() {
            public void run() {
                new HashMap<>(addItems).forEach((k, v) -> {
                    Player player = Bukkit.getPlayerExact(k);

                    if (player != null) {
                        for (ItemStack item : v) {
                            addItems(player, item);
                        }

                        addItems.remove(k);
                    }
                });
            }
        }.runTaskTimer(this, 20, 20);
    }

    @Override
    public void onDisable() {
        super.onDisable();
    }

    public static List<ItemStack> getInventory(Player player) {
        return Arrays.stream(player.getInventory().getContents()).map(o -> o == null ? new ItemStack(Material.AIR) : o).toList();
    }

    public static boolean removeItems(String playerName, Material type, int amount) {
        System.out.println("try remove item "+type+" "+amount+" from "+playerName);
        ItemStack item = new ItemStack(type, amount);

        Player player = Bukkit.getPlayerExact(playerName);

        if (player == null) {
            return false;
        } else {
            return removeItems(player, item);
        }
    }

    public static void addItems(String playerName, Material type, int amount) {
        System.out.println("try add item "+type+" "+amount+" to "+playerName);
        ItemStack item = new ItemStack(type, amount);

        Player player = Bukkit.getPlayerExact(playerName);

        if (player == null) {
            List<ItemStack> items = addItems.getOrDefault(playerName, new ArrayList<>());
            items.add(item);
            addItems.put(playerName, items);
        } else {
            addItems(player, item);
        }
    }

    private static boolean removeItems(Player player, ItemStack item) {
        System.out.println("remove item "+item.getType()+" "+item.getAmount()+" from "+player.getName());
        if (player.getInventory().all(item.getType()).values().stream().mapToInt(ItemStack::getAmount).sum() < item.getAmount()) return false;
        return player.getInventory().removeItem(item).isEmpty();
    }

    private static void addItems(Player player, ItemStack item) {
        System.out.println("add item "+item.getType()+" "+item.getAmount()+" from "+player.getName());
        HashMap<Integer, ItemStack> nope = player.getInventory().addItem(item);
        for (ItemStack v:nope.values()) player.getWorld().dropItemNaturally(player.getLocation(), v);
    }
}