Class DCase

package com.ac.dc;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Random;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.event.inventory.InventoryCloseEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;

public class DCase implements Listener
{
    private static Case plugin;
    public static int keys = 0;
    private HashMap<Player, Integer> tasks = new HashMap<>();
    private int task;
    public static List<String> itemlist = new ArrayList<>();
    private static  HashMap<String, Integer> keysofaccount = new HashMap<>();
    public static List<String> names = new ArrayList<>();

    public DCase(Case plugin) {
        DCase.plugin = plugin;
    }

    public static void open(Player p)
    {
        Inventory casE = Bukkit.createInventory(null, 9, ChatColor.RED + "Opening case");
        ItemStack keyi = new ItemStack(131);
        ItemMeta meta = keyi.getItemMeta();
        List<String> list = new ArrayList<String>();
        String arg = "Ключей: " + keys;
        list.add(arg);
        meta.setLore(list);
        meta.setDisplayName(ChatColor.GOLD + "ключ");
        keyi.setItemMeta(meta);
        casE.setItem(4, keyi);
        p.openInventory(casE);
    }

    @EventHandler
    public void addGroup(InventoryClickEvent e)
    {
        Inventory inv = e.getInventory();
        if(inv.getName().equalsIgnoreCase("Getting prize"))
        {
            if(e.getCurrentItem().getType() == Material.AIR) return;
            Bukkit.getScheduler().runTaskLater(plugin, () ->{
                e.getWhoClicked().closeInventory();
            }, 1L);
        }
    }

    @EventHandler
    public void onClick(InventoryClickEvent e)
    {
        Player p = (Player) e.getWhoClicked();
        Inventory inv = e.getInventory();
        if(inv.getName().equalsIgnoreCase(ChatColor.RED + "Opening case"))
        {
            if(e.getCurrentItem().getType() == Material.AIR) return;
            e.setCancelled(true);
            if(!e.getCurrentItem().getItemMeta().hasDisplayName()) return;
            if(e.getCurrentItem().getTypeId() != 131) return;
            if(!e.getCurrentItem().getItemMeta().getDisplayName().equals(ChatColor.GOLD + "ключ")) return;
            if(keys == 0) return;
            removeKey(p);
            this.spinmenu(p);

        }
        if(inv.getName().equalsIgnoreCase("Opening..."))
        {
            if(e.getCurrentItem().getType() == Material.AIR) return;
            e.setCancelled(true);
        }
    }

    public void spinmenu(final Player p)
    {
        List<ItemStack> items = new ArrayList<>();
        Inventory spin = Bukkit.createInventory(null, 9, "Opening...");
        Random r = new Random();
            for(String item : itemlist)
            {
                ItemStack item1 = new ItemStack(Material.getMaterial(item.toUpperCase()));
                ItemMeta meta = item1.getItemMeta();
                for(String name : names)
                {
                    meta.setDisplayName(name);
                    item1.setItemMeta(meta);
                }
                items.add(item1);
            }
        task = Bukkit.getScheduler().scheduleSyncRepeatingTask(plugin, () -> {
            int index = r.nextInt(itemlist.size());
            ItemStack item = items.get(index);
            ItemMeta meta = item.getItemMeta();
            String name = names.get(index).replace("&", "\u00a7");
            meta.setDisplayName(name);
            item.setItemMeta(meta);
            spin.setItem(4, items.get(index));

        }, 0, 2);

        tasks.put(p, Bukkit.getScheduler().scheduleSyncDelayedTask(plugin, () -> {
            Bukkit.getScheduler().cancelTask(task);
            tasks.remove(p);
            int index = r.nextInt(itemlist.size());
            ItemStack item = items.get(index);
            getPrize(p, item);
        }, 60));
            p.openInventory(spin);
        }

    public void getPrize(Player p,ItemStack item)
    {
            Inventory inv = Bukkit.createInventory(null, 9, "Getting prize");
            inv.setItem(4, item);

        p.openInventory(inv);
    }

    @EventHandler
    public void onClose(InventoryCloseEvent e) {
        Player player = (Player) e.getPlayer();
        if (e.getInventory().getName().equalsIgnoreCase("Getting prize")) {
            if (tasks.containsKey(player)) {
                Bukkit.getScheduler().cancelTask(tasks.get(player));
                Bukkit.getScheduler().cancelTask(task);
                tasks.remove(player);
            }
        }
    }

    public static void addKey(Player p,int amount)
    {
        keys = keys + amount;
        keysofaccount.put(p.getName(), keys);
    }

    public void removeKey(Player p)
    {
        keys = keys - 1;
        keysofaccount.put(p.getName(), keys);
    }
}