import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.Map;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.enchantments.Enchantment;
import org.bukkit.entity.EntityType;
import org.bukkit.inventory.ItemStack;

public class CSpawner {

    private static Class<?> _CRAFT_WORLD_CLASS, _TILE_ENTITY_MOB_SPAWNER_CLASS, _NBT_TAG_COMPOUND_CLASS,
            _NBT_TAG_LIST_CLASS, _NBT_BASE_CLASS;
    private static Constructor<?> _BLOCK_POSITION_CONSTRUCTOR, _NBT_TAG_LIST_CONSTRUCTOR, _NBT_TAG_COMPOUND_CONSTRUCTOR;
    private static Method _GET_HANDLE_METHOD, _GET_TILE_ENTITY_METHOD, _D_METHOD, _SET_SHORT_METHOD, _SET_STRING_METHOD,
            _SET_METHOD, _ADD_METHOD, _LOAD_METHOD;

    static {
        String name = Bukkit.getServer().getClass().getName();
        name = name.substring(name.indexOf("craftbukkit.") + "craftbukkit.".length());
        final String _VERSION = name.substring(0, name.indexOf("."));
        try {
            Class<?> _BLOCK_POSITION_CLASS = Class.forName("net.minecraft.server." + _VERSION + ".BlockPosition");
            _CRAFT_WORLD_CLASS = Class.forName("org.bukkit.craftbukkit." + _VERSION + ".CraftWorld");
            _TILE_ENTITY_MOB_SPAWNER_CLASS = Class
                    .forName("net.minecraft.server." + _VERSION + ".TileEntityMobSpawner");
            _NBT_TAG_COMPOUND_CLASS = Class.forName("net.minecraft.server." + _VERSION + ".NBTTagCompound");
            _NBT_TAG_LIST_CLASS = Class.forName("net.minecraft.server." + _VERSION + ".NBTTagList");
            _NBT_BASE_CLASS = Class.forName("net.minecraft.server." + _VERSION + ".NBTBase");

            _BLOCK_POSITION_CONSTRUCTOR = _BLOCK_POSITION_CLASS.getConstructor(double.class, double.class,
                    double.class);
            _NBT_TAG_LIST_CONSTRUCTOR = _NBT_TAG_LIST_CLASS.getConstructor();
            _NBT_TAG_COMPOUND_CONSTRUCTOR = _NBT_TAG_COMPOUND_CLASS.getConstructor();

            _GET_HANDLE_METHOD = _CRAFT_WORLD_CLASS.getMethod("getHandle");
            _GET_TILE_ENTITY_METHOD = Class.forName("net.minecraft.server." + _VERSION + ".WorldServer")
                    .getMethod("getTileEntity", _BLOCK_POSITION_CLASS);
            _D_METHOD = _TILE_ENTITY_MOB_SPAWNER_CLASS.getMethod("d");
            _SET_SHORT_METHOD = _NBT_TAG_COMPOUND_CLASS.getMethod("setShort", String.class, short.class);
            _SET_STRING_METHOD = _NBT_TAG_COMPOUND_CLASS.getMethod("setString", String.class, String.class);
            _SET_METHOD = _NBT_TAG_COMPOUND_CLASS.getMethod("set", String.class, _NBT_BASE_CLASS);
            _ADD_METHOD = _NBT_TAG_LIST_CLASS.getMethod("add", _NBT_BASE_CLASS);
            String[] split = _VERSION.split("_");
            if (Double.valueOf(split[1]) < 1.9) {
                _LOAD_METHOD = _TILE_ENTITY_MOB_SPAWNER_CLASS.getMethod("a", _NBT_TAG_COMPOUND_CLASS);
            } else {
                _LOAD_METHOD = _TILE_ENTITY_MOB_SPAWNER_CLASS.getMethod("load", _NBT_TAG_COMPOUND_CLASS);
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private Object _spawner;
    private Object _hands, _armor;
    private String _entityType;

    private int _maxRange, _maxMobs;

    public CSpawner(Location location) {
        try {
            Object blockPosition = _BLOCK_POSITION_CONSTRUCTOR.newInstance(location.getBlockX(), location.getBlockY(),
                    location.getBlockZ());
            Object craftWorld = _CRAFT_WORLD_CLASS.cast(location.getWorld());
            Object serverWorld = _GET_HANDLE_METHOD.invoke(craftWorld);
            this._spawner = _GET_TILE_ENTITY_METHOD.invoke(serverWorld, blockPosition);
            this._entityType = "zombie";
            this._maxMobs = 20;
            this._maxRange = 20;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void setEntityType(EntityType entityType) {
        this._entityType = entityType.name().toLowerCase();
    }

    public void setSpawnRange(int range) {
        this._maxRange = range;
    }

    public void setMaxNearbyEntities(int max) {
        this._maxMobs = max;
    }

    public void setArmor(ItemStack helmetItem, ItemStack chestplateItem, ItemStack leggingsItem, ItemStack bootsItem) {
        try {
            this._armor = _NBT_TAG_LIST_CONSTRUCTOR.newInstance();

            Object helmet = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();
            Object chestplate = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();
            Object leggings = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();
            Object boots = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();

            setItemOnTag(helmet, helmetItem);
            setItemOnTag(chestplate, chestplateItem);
            setItemOnTag(leggings, leggingsItem);
            setItemOnTag(boots, bootsItem);

            _ADD_METHOD.invoke(this._armor, boots);
            _ADD_METHOD.invoke(this._armor, leggings);
            _ADD_METHOD.invoke(this._armor, chestplate);
            _ADD_METHOD.invoke(this._armor, helmet);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void setHands(ItemStack mainHandItem, ItemStack offHandItem) {
        try {
            this._hands = _NBT_TAG_LIST_CONSTRUCTOR.newInstance();

            Object mainHand = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();
            Object offHand = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();

            setItemOnTag(mainHand, mainHandItem);
            setItemOnTag(offHand, offHandItem);

            _ADD_METHOD.invoke(this._hands, mainHand);
            _ADD_METHOD.invoke(this._hands, offHand);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @SuppressWarnings("deprecation")
    private void setItemOnTag(Object tag, ItemStack item) {
        try {
            if (item != null) {
                _SET_STRING_METHOD.invoke(tag, "id", "minecraft:" + item.getType().toString().toLowerCase());
                _SET_SHORT_METHOD.invoke(tag, "Count", (short) item.getAmount());
                Map<Enchantment, Integer> enchants = item.getEnchantments();
                if (!enchants.isEmpty()) {
                    Object enchantments = _NBT_TAG_LIST_CONSTRUCTOR.newInstance();
                    for (Enchantment enchant : enchants.keySet()) {
                        Object e = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();
                        _SET_SHORT_METHOD.invoke(e, "id", (short) enchant.getId());
                        _SET_SHORT_METHOD.invoke(e, "lvl", (short) enchants.get(enchant).intValue());
                    }
                    Object ench = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();
                    _SET_METHOD.invoke(ench, "ench", enchantments);
                    _SET_METHOD.invoke(tag, "tag", ench);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void load() {
        try {
            Object spawnerTag = _D_METHOD.invoke(this._spawner);
            Object spawnData = _NBT_TAG_COMPOUND_CONSTRUCTOR.newInstance();
            _SET_STRING_METHOD.invoke(spawnData, "id", this._entityType);
            _SET_SHORT_METHOD.invoke(spawnerTag, "SpawnRange", (short) _maxRange);
            _SET_SHORT_METHOD.invoke(spawnerTag, "MaxNearbyEntities", (short) _maxMobs);
            if (this._hands != null) {
                _SET_METHOD.invoke(spawnData, "HandItems", this._hands);
            }
            if (this._armor != null) {
                _SET_METHOD.invoke(spawnData, "ArmorItems", this._armor);
            }
            _SET_METHOD.invoke(spawnerTag, "SpawnData", spawnData);
            _LOAD_METHOD.invoke(this._spawner, spawnerTag);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}