NPC.java

package me.danielthumaniel.NPCInvis;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.craftbukkit.libs.org.apache.commons.codec.binary.Base64;
import org.bukkit.craftbukkit.v1_15_R1.CraftServer;
import org.bukkit.craftbukkit.v1_15_R1.CraftWorld;
import org.bukkit.craftbukkit.v1_15_R1.entity.CraftPlayer;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;

import com.mojang.authlib.GameProfile;
import com.mojang.authlib.properties.Property;
import com.mojang.authlib.properties.PropertyMap;

import net.minecraft.server.v1_15_R1.EntityPlayer;
import net.minecraft.server.v1_15_R1.MinecraftServer;
import net.minecraft.server.v1_15_R1.PacketPlayOutEntityDestroy;
import net.minecraft.server.v1_15_R1.PacketPlayOutEntityHeadRotation;
import net.minecraft.server.v1_15_R1.PacketPlayOutNamedEntitySpawn;
import net.minecraft.server.v1_15_R1.PacketPlayOutPlayerInfo;
import net.minecraft.server.v1_15_R1.PlayerConnection;
import net.minecraft.server.v1_15_R1.PlayerInteractManager;
import net.minecraft.server.v1_15_R1.WorldServer;

public class NPC implements Listener {

    public static List<EntityPlayer> NPC = new ArrayList<EntityPlayer>();
    public static Map<UUID, EntityPlayer> npcPlayers = new HashMap<UUID, EntityPlayer>();
    public static Map<EntityPlayer, Integer> destroyable = new HashMap<EntityPlayer, Integer>();

    public static String texture = "";

    public static void createNPC(Player player) {
        MinecraftServer server = ((CraftServer) Bukkit.getServer()).getServer();
        WorldServer world = ((CraftWorld) Bukkit.getWorld(player.getWorld().getName())).getHandle();
        UUID uuid = UUID.randomUUID();
        GameProfile gameProfile = new GameProfile(uuid, "me");
        EntityPlayer npc = new EntityPlayer(server, world, gameProfile, new PlayerInteractManager(world));
        Location loc = player.getLocation();
        npc.setLocation(loc.getX(), loc.getY(), loc.getZ(), loc.getYaw(), loc.getPitch());

        // Skins start
            // get npc property map and grab it's textures
        PropertyMap npcMap = gameProfile.getProperties();
        Property npcProperty = npcMap.get("textures").iterator().next();
            // get player's property map and grab it's textures
        GameProfile playerProfile = ((CraftPlayer) player).getHandle().getProfile();
        PropertyMap playerMap = playerProfile.getProperties();
        Property playerProperty = playerMap.get("textures").iterator().next();
            // decode the texture value
        String base64 = playerProperty.getValue();
        String decoded = new String(Base64.decodeBase64(base64));

        texture = decoded;

        String textureValue;
        String textureSignature;

            // remove npc's textures and apply the player's textures to it
        npcMap.remove("textures", npcProperty);
        npcMap.put("textures", new Property("textures", textureValue, textureSignature));

        // Skins end

        addNPCPacket(npc);
        NPC.add(npc);
        npcPlayers.put(player.getUniqueId(), npc);
        destroyable.put(npc, npc.getId());
    }

    public static void addNPCPacket(EntityPlayer npc) {
        for (Player player : Bukkit.getOnlinePlayers()) {
            PlayerConnection connection = ((CraftPlayer) player).getHandle().playerConnection;
            connection.sendPacket(new PacketPlayOutPlayerInfo(PacketPlayOutPlayerInfo.EnumPlayerInfoAction.ADD_PLAYER, npc));
            connection.sendPacket(new PacketPlayOutNamedEntitySpawn(npc));
            connection.sendPacket(new PacketPlayOutEntityHeadRotation(npc, (byte) (npc.yaw * 256 / 360)));
        }
    }

    public static void addJoinPacket(Player player) {
        for (EntityPlayer npc : NPC) {
            PlayerConnection connection = ((CraftPlayer) player).getHandle().playerConnection;
            connection.sendPacket(new PacketPlayOutPlayerInfo(PacketPlayOutPlayerInfo.EnumPlayerInfoAction.ADD_PLAYER, npc));
            connection.sendPacket(new PacketPlayOutNamedEntitySpawn(npc));
            connection.sendPacket(new PacketPlayOutEntityHeadRotation(npc, (byte) (npc.yaw * 256 / 360)));
        }
    }

    public static void destroyNPCPacket(Player player) {
        EntityPlayer npc = (EntityPlayer) npcPlayers.get(player.getUniqueId());
        PacketPlayOutEntityDestroy removeEntity = new PacketPlayOutEntityDestroy(new int[]{destroyable.get(npc)});

        for (Player p : Bukkit.getOnlinePlayers()) {
            PlayerConnection connection = ((CraftPlayer) p).getHandle().playerConnection;
            connection.sendPacket(removeEntity);
        }
        NPC.remove(npc);
        npcPlayers.remove(player.getUniqueId());
    }

    public static void removeTabList(Player player) {
        EntityPlayer npc = (EntityPlayer) npcPlayers.get(player.getUniqueId());
        PacketPlayOutPlayerInfo removeTabList = new PacketPlayOutPlayerInfo(PacketPlayOutPlayerInfo.EnumPlayerInfoAction.REMOVE_PLAYER, npc);
        for (Player p : Bukkit.getOnlinePlayers()) {
            PlayerConnection connection = ((CraftPlayer) p).getHandle().playerConnection;
            connection.sendPacket(removeTabList);
        }
    }


    @EventHandler
    public static void onJoin(PlayerJoinEvent event) {
        if (NPC == null)
            return;
        if (NPC.isEmpty())
            return;
        addJoinPacket(event.getPlayer());
    }

}