AmiriEnchantSourceCode

package com.bawnorton.amirienchants;

import com.bawnorton.amirienchants.events.EventManager;
import org.bukkit.ChatColor;
import org.bukkit.plugin.java.JavaPlugin;

public class AmiriEnchants extends JavaPlugin {

    public static AmiriEnchants instance;

    @Override
    public void onEnable() {
        instance = this;
        new EventManager(instance);
        getServer().getConsoleSender().sendMessage(ChatColor.GREEN + "[AmiriEnchants] Enabled");
    }

    @Override
    public void onDisable() {
        getServer().getConsoleSender().sendMessage(ChatColor.RED + "[AmiriEnchants] Disabled");
    }
}

package com.bawnorton.amirienchants.events;

import com.bawnorton.amirienchants.AmiriEnchants;
import org.bukkit.Material;
import org.bukkit.enchantments.Enchantment;
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.PrepareAnvilEvent;
import org.bukkit.inventory.AnvilInventory;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.InventoryView;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.EnchantmentStorageMeta;
import org.bukkit.inventory.meta.ItemMeta;

import java.util.Hashtable;
import java.util.Map;

import static com.bawnorton.amirienchants.AmiriEnchants.instance;

public class EventManager implements Listener {

    private int repairCost = 0;
    private boolean expectTrident = false;
    private boolean expectBow = false;

    public EventManager(AmiriEnchants plugin) {
        plugin.getServer().getPluginManager().registerEvents(this, plugin);
    }

    @EventHandler
    public void onAnvilCraft(PrepareAnvilEvent event) {
        ItemStack[] components;
        try {
            components = event.getInventory().getContents();
        } catch (NullPointerException ignore) {
            return;
        }
        for (ItemStack component : components) {
            if (component == null) {
                return;
            }
        }
        try {
            if(components[0].getType() == Material.TRIDENT) {
                if(components[1].getType() == Material.ENCHANTED_BOOK || components[1].getType() == Material.TRIDENT || components[1].getType() == Material.BOOK) {
                    Map<Enchantment, Integer> enchants;
                    if(components[1].getType() == Material.ENCHANTED_BOOK) {
                        EnchantmentStorageMeta enchantedMeta = (EnchantmentStorageMeta) components[1].getItemMeta();
                        enchants = enchantedMeta.getStoredEnchants();
                    }
                    else {
                        ItemMeta enchantedMeta = components[1].getItemMeta();
                        enchants = enchantedMeta.getEnchants();
                    }

                    int length = enchants.size();
                    Hashtable<Enchantment, Integer> toEnchant = new Hashtable<>(length);
                    for(int i = 0; i < length; i++) {
                        Enchantment enchantment = (Enchantment) enchants.keySet().toArray()[i];
                        Integer level = (Integer) enchants.values().toArray()[i];
                        boolean canEnchant = enchantment.canEnchantItem(components[0]);
                        if(canEnchant || enchantment.equals(Enchantment.DAMAGE_ALL)) {
                            toEnchant.put(enchantment, level);
                        }
                    }
                    if(toEnchant.size() < 1) { return; }
                    ItemMeta meta = components[0].getItemMeta();
                    for(int i = 0; i < toEnchant.size(); i++) {
                        meta.addEnchant((Enchantment) toEnchant.keySet().toArray()[i], (Integer) toEnchant.values().toArray()[i], true);
                    }
                    ItemStack newItem = new ItemStack(components[0].getType(), 1);
                    newItem.setItemMeta(meta);
                    event.setResult(newItem);
                    int totalLength = length + components[0].getEnchantments().size();
                    repairCost = totalLength*5+totalLength%5;
                    expectTrident = true;
                    instance.getServer().getScheduler().runTask(instance, () -> event.getInventory().setRepairCost(repairCost));
                }
            }
            else if(components[0].getType() == Material.BOW) {
                if(components[1].getType() == Material.ENCHANTED_BOOK || components[1].getType() == Material.BOW || components[1].getType() == Material.BOOK) {
                    Map<Enchantment, Integer> enchants;
                    if(components[1].getType() == Material.ENCHANTED_BOOK) {
                        EnchantmentStorageMeta enchantedMeta = (EnchantmentStorageMeta) components[1].getItemMeta();
                        enchants = enchantedMeta.getStoredEnchants();
                    }
                    else {
                        ItemMeta enchantedMeta = components[1].getItemMeta();
                        enchants = enchantedMeta.getEnchants();
                    }
                    int length = enchants.size();
                    Hashtable<Enchantment, Integer> toEnchant = new Hashtable<>(length);
                    for(int i = 0; i < length; i++) {
                        Enchantment enchantment = (Enchantment) enchants.keySet().toArray()[i];
                        Integer level = (Integer) enchants.values().toArray()[i];
                        boolean canEnchant = enchantment.canEnchantItem(components[0]);
                        if(canEnchant || enchantment.equals(Enchantment.ARROW_INFINITE) || enchantment.equals(Enchantment.MENDING)) {
                            toEnchant.put(enchantment, level);
                        }
                    }
                    if(toEnchant.size() < 1) { return; }
                    ItemMeta meta = components[0].getItemMeta();
                    for(int i = 0; i < toEnchant.size(); i++) {
                        meta.addEnchant((Enchantment) toEnchant.keySet().toArray()[i], (Integer) toEnchant.values().toArray()[i], true);
                    }
                    ItemStack newItem = new ItemStack(components[0].getType(), 1);
                    newItem.setItemMeta(meta);
                    event.setResult(newItem);
                    int totalLength = length + components[0].getEnchantments().size();
                    repairCost = totalLength*5+totalLength%5;
                    expectBow = true;
                    instance.getServer().getScheduler().runTask(instance, () -> event.getInventory().setRepairCost(repairCost));
                }
            }

        } catch(NullPointerException ignore) {}
    }

    @EventHandler
    public void onInventoryClick(InventoryClickEvent event) {
        Inventory inv = event.getInventory();
        if (inv instanceof AnvilInventory) {
            InventoryView view = event.getView();
            int rawSlot = event.getRawSlot();
            if (rawSlot == view.convertSlot(rawSlot)) {
                if (rawSlot == 2) {
                    Player player = (Player) event.getWhoClicked();
                    ItemStack item = event.getCurrentItem();
                    if(item == null) { return; }
                    if(item.getType() == Material.TRIDENT && expectTrident) {
                        if(player.getLevel() >= repairCost) {
                            player.setLevel(player.getLevel() - repairCost);
                            event.setCursor(item);
                            view.setItem(0, null);
                            view.setItem(1, null);
                            view.setItem(2, null);

                        }
                    }
                    if(item.getType() == Material.BOW && expectBow) {
                        if(player.getLevel() >= repairCost) {
                            player.setLevel(player.getLevel() - repairCost);
                            event.setCursor(item);
                            view.setItem(0, null);
                            view.setItem(1, null);
                            view.setItem(2, null);

                        }
                    }
                }
            }
        }
    }
}