so much progress

.gitignore

@@ -46,3 +46,5 @@ bin/
 /.idea/
 
 gradle.properties
+
+gradle.properties

src/main/java/io/github/znetworkw/znpcservers/commands/list/DefaultCommand.java

@@ -91,7 +91,7 @@ public class DefaultCommand extends Command {
             Configuration.MESSAGES.sendMessage(sender.getCommandSender(), ConfigurationValue.NOT_SUPPORTED_NPC_TYPE);
             return;
         }
-        ZNPCsPlus.createNPC(id, npcType, sender.getPlayer().getLocation(), name);
+        // ZNPCsPlus.createNPC(id, npcType, sender.getPlayer().getLocation(), name);
         Configuration.MESSAGES.sendMessage(sender.getCommandSender(), ConfigurationValue.SUCCESS);
     }
 
@@ -111,7 +111,7 @@ public class DefaultCommand extends Command {
             Configuration.MESSAGES.sendMessage(sender.getCommandSender(), ConfigurationValue.NPC_NOT_FOUND);
             return;
         }
-        ZNPCsPlus.deleteNPC(id);
+        // ZNPCsPlus.deleteNPC(id);
         Configuration.MESSAGES.sendMessage(sender.getCommandSender(), ConfigurationValue.SUCCESS);
     }
 

src/main/java/io/github/znetworkw/znpcservers/configuration/ConfigurationValue.java

@@ -18,7 +18,7 @@ public enum ConfigurationValue {
     SAVE_NPCS_DELAY_SECONDS("config", 600, Integer.class),
     MAX_PATH_LOCATIONS("config", 500, Integer.class),
     NAMING_METHOD("config", NamingType.DEFAULT, NamingType.class),
-    DEBUG_ENABLED("config", true, Boolean.class),
+    DEBUG_ENABLED("config", false, Boolean.class),
     LINE_SPACING("config", 0.3D, Double.class),
     ANIMATION_RGB("config", false, Boolean.class),
     CHECK_FOR_UPDATES("config", true, Boolean.class),

src/main/java/io/github/znetworkw/znpcservers/npc/task/NPCVisibilityTask.java

@@ -1,34 +0,0 @@
-package io.github.znetworkw.znpcservers.npc.task;
-
-import io.github.znetworkw.znpcservers.configuration.ConfigurationConstants;
-import io.github.znetworkw.znpcservers.npc.NPC;
-import io.github.znetworkw.znpcservers.npc.conversation.ConversationModel;
-import io.github.znetworkw.znpcservers.user.ZUser;
-import org.bukkit.Bukkit;
-import org.bukkit.entity.Player;
-import org.bukkit.plugin.Plugin;
-import org.bukkit.scheduler.BukkitRunnable;
-
-public class NPCVisibilityTask extends BukkitRunnable {
-    public NPCVisibilityTask(Plugin serversNPC) {
-        runTaskTimerAsynchronously(serversNPC, 60L, 10L);
-    }
-
-    public void run() {
-        int distSq = ConfigurationConstants.VIEW_DISTANCE * ConfigurationConstants.VIEW_DISTANCE;
-        for (NPC npc : NPC.all()) for (Player player : Bukkit.getOnlinePlayers()) {
-            ZUser zUser = ZUser.find(player);
-            boolean canSeeNPC = (player.getWorld() == npc.getLocation().getWorld() && player.getLocation().distanceSquared(npc.getLocation()) <= distSq);
-            if (npc.getViewers().contains(zUser) && !canSeeNPC) {
-                npc.delete(zUser);
-                continue;
-            }
-            if (canSeeNPC) {
-                if (!npc.getViewers().contains(zUser)) npc.spawn(zUser);
-                npc.getHologram().updateNames(zUser);
-                ConversationModel conversationStorage = npc.getNpcPojo().getConversation();
-                if (conversationStorage != null && conversationStorage.getConversationType() == ConversationModel.ConversationType.RADIUS) npc.tryStartConversation(player);
-            }
-        }
-    }
-}

src/main/java/io/github/znetworkw/znpcservers/reflection/Reflections.java

@@ -15,6 +15,7 @@ import java.lang.reflect.Method;
 import java.util.Collection;
 import java.util.List;
 import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * Class containing all of the lazy-loaded reflections that the plugin uses to access
@@ -657,4 +658,14 @@ public final class Reflections {
     public static final ReflectionLazyLoader<CommandMap> COMMAND_MAP_FIELD = new FieldReflection(new ReflectionBuilder(ReflectionPackage.BUKKIT)
             .withClassName("CraftServer")
             .withFieldName("commandMap")).valueLoader(Bukkit.getServer(), CommandMap.class);
+
+    public static final FieldReflection.ValueModifier<Integer> ENTITY_ID_MODIFIER = new FieldReflection(new ReflectionBuilder(ReflectionPackage.ENTITY)
+            .withClassName(ENTITY_CLASS)
+            .withFieldName("entityCount")
+            .setStrict(!Utils.versionNewer(14))).staticValueModifier(int.class);
+
+    public static final ReflectionLazyLoader<AtomicInteger> ATOMIC_ENTITY_ID_FIELD = new FieldReflection(new ReflectionBuilder(ReflectionPackage.ENTITY)
+            .withClassName(ENTITY_CLASS)
+            .withFieldName("entityCount")
+            .setStrict(Utils.versionNewer(14))).staticValueLoader(AtomicInteger.class);
 }

src/main/java/io/github/znetworkw/znpcservers/reflection/types/FieldReflection.java

@@ -44,25 +44,35 @@ public class FieldReflection extends ReflectionLazyLoader<Field> {
         logger.accept("Field Type: " + expectType);
     }
 
-    public FieldValueReflection<Object> staticValueLoader() {
+    public ValueReflection<Object> staticValueLoader() {
         return staticValueLoader(Object.class);
     }
 
     @SuppressWarnings("unused")
-    public <T> FieldValueReflection<T> staticValueLoader(Class<T> valueType) {
-        return new FieldValueReflection<>(this, possibleClassNames, null, strict);
+    public <T> ValueReflection<T> staticValueLoader(Class<T> valueType) {
+        return new ValueReflection<>(this, possibleClassNames, null, strict);
     }
 
     @SuppressWarnings("unused")
-    public <T> FieldValueReflection<T> valueLoader(Object obj, Class<T> valueType) {
-        return new FieldValueReflection<>(this, possibleClassNames, obj, strict);
+    public <T> ValueReflection<T> valueLoader(Object obj, Class<T> valueType) {
+        return new ValueReflection<>(this, possibleClassNames, obj, strict);
     }
 
-    private static class FieldValueReflection<T> extends ReflectionLazyLoader<T> {
-        private final Object obj;
-        private final FieldReflection fieldReflection;
+    @SuppressWarnings("unused")
+    public <T> ValueModifier<T> staticValueModifier(Class<T> valueType) {
+        return new ValueModifier<>(this, possibleClassNames, null, strict);
+    }
 
-        public FieldValueReflection(FieldReflection fieldReflection, List<String> className, Object obj, boolean strict) {
+    @SuppressWarnings("unused")
+    public <T> ValueModifier<T> valueModifier(Object obj, Class<T> valueType) {
+        return new ValueModifier<>(this, possibleClassNames, obj, strict);
+    }
+
+    public static class ValueReflection<T> extends ReflectionLazyLoader<T> {
+        protected final Object obj;
+        protected final FieldReflection fieldReflection;
+
+        private ValueReflection(FieldReflection fieldReflection, List<String> className, Object obj, boolean strict) {
             super(className, strict);
             this.obj = obj;
             this.fieldReflection = fieldReflection;
@@ -78,4 +88,27 @@ public class FieldReflection extends ReflectionLazyLoader<Field> {
             fieldReflection.printDebugInfo(logger);
         }
     }
+
+    public static class ValueModifier<T> extends ValueReflection<T> {
+        private ValueModifier(FieldReflection fieldReflection, List<String> className, Object obj, boolean strict) {
+            super(fieldReflection, className, obj, strict);
+        }
+
+        @Override
+        public T get() {
+            try {
+                return load();
+            } catch (IllegalAccessException | NoSuchFieldException e) {
+                throw new RuntimeException(e);
+            }
+        }
+
+        public void set(T value) {
+            try {
+                fieldReflection.get().set(obj, value);
+            } catch (IllegalAccessException e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
 }

src/main/java/lol/pyr/znpcsplus/ZNPCsPlus.java

@@ -10,19 +10,20 @@ import io.github.znetworkw.znpcservers.configuration.Configuration;
 import io.github.znetworkw.znpcservers.configuration.ConfigurationConstants;
 import io.github.znetworkw.znpcservers.listeners.InventoryListener;
 import io.github.znetworkw.znpcservers.listeners.PlayerListener;
-import io.github.znetworkw.znpcservers.npc.NPC;
-import io.github.znetworkw.znpcservers.npc.NPCModel;
 import io.github.znetworkw.znpcservers.npc.NPCPath;
-import io.github.znetworkw.znpcservers.npc.NPCType;
 import io.github.znetworkw.znpcservers.npc.interaction.InteractionPacketListener;
 import io.github.znetworkw.znpcservers.npc.task.NPCPositionTask;
 import io.github.znetworkw.znpcservers.npc.task.NPCSaveTask;
-import io.github.znetworkw.znpcservers.npc.task.NPCVisibilityTask;
 import io.github.znetworkw.znpcservers.user.ZUser;
 import io.github.znetworkw.znpcservers.utility.BungeeUtils;
 import io.github.znetworkw.znpcservers.utility.SchedulerUtils;
 import io.github.znetworkw.znpcservers.utility.itemstack.ItemStackSerializer;
 import io.github.znetworkw.znpcservers.utility.location.ZLocation;
+import lol.pyr.znpcsplus.entity.PacketLocation;
+import lol.pyr.znpcsplus.npc.NPC;
+import lol.pyr.znpcsplus.npc.NPCRegistry;
+import lol.pyr.znpcsplus.npc.NPCType;
+import lol.pyr.znpcsplus.tasks.NPCVisibilityTask;
 import lol.pyr.znpcsplus.updater.UpdateChecker;
 import lol.pyr.znpcsplus.updater.UpdateNotificationListener;
 import net.kyori.adventure.platform.bukkit.BukkitAudiences;
@@ -30,13 +31,12 @@ import org.apache.commons.io.FileUtils;
 import org.bstats.bukkit.Metrics;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
-import org.bukkit.Location;
+import org.bukkit.World;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.plugin.java.JavaPlugin;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.Collections;
 import java.util.logging.Logger;
 
 public class ZNPCsPlus extends JavaPlugin {
@@ -56,25 +56,6 @@ public class ZNPCsPlus extends JavaPlugin {
 
     private boolean enabled = false;
 
-    public static NPC createNPC(int id, NPCType npcType, Location location, String name) {
-        NPC find = NPC.find(id);
-        if (find != null)
-            return find;
-        NPCModel pojo = new NPCModel(id).withHologramLines(Collections.singletonList(name))
-                .withHologramHeight(npcType.getHoloHeight())
-                .withLocation(new ZLocation(location))
-                .withNpcType(npcType);
-        ConfigurationConstants.NPC_LIST.add(pojo);
-        return new NPC(pojo, true);
-    }
-
-    public static void deleteNPC(int npcID) {
-        NPC npc = NPC.find(npcID);
-        if (npc == null) throw new IllegalStateException("can't find npc:  " + npcID);
-        NPC.unregister(npcID);
-        ConfigurationConstants.NPC_LIST.remove(npc.getNpcPojo());
-    }
-
     @Override
     public void onLoad() {
         PacketEvents.setAPI(SpigotPacketEventsBuilder.build(this));
@@ -146,6 +127,21 @@ public class ZNPCsPlus extends JavaPlugin {
         enabled = true;
         log(ChatColor.WHITE + " * Loading complete! (" + (System.currentTimeMillis() - before) + "ms)");
         log("");
+
+        if (ConfigurationConstants.DEBUG_ENABLED) {
+            int wrap = 20;
+            int x = 0;
+            int z = 0;
+            World world = Bukkit.getWorld("world");
+            if (world == null) world = Bukkit.getWorlds().get(0);
+            for (NPCType type : NPCType.values()) {
+                NPCRegistry.register("debug_npc" + (z * wrap + x), new NPC(world, type, new PacketLocation(x * 3, 200, z * 3, 0, 0)));
+                if (x++ > wrap) {
+                    x = 0;
+                    z++;
+                }
+            }
+        }
     }
 
     @Override

src/main/java/lol/pyr/znpcsplus/entity/EntityIDProvider.java

@@ -0,0 +1,15 @@
+package lol.pyr.znpcsplus.entity;
+
+import io.github.znetworkw.znpcservers.reflection.Reflections;
+import io.github.znetworkw.znpcservers.utility.Utils;
+
+public class EntityIDProvider {
+    public static int reserve() {
+        if (Utils.versionNewer(14)) return Reflections.ATOMIC_ENTITY_ID_FIELD.get().incrementAndGet();
+        else {
+            int id = Reflections.ENTITY_ID_MODIFIER.get();
+            Reflections.ENTITY_ID_MODIFIER.set(id + 1);
+            return id;
+        }
+    }
+}

src/main/java/lol/pyr/znpcsplus/entity/PacketEntity.java

@@ -0,0 +1,46 @@
+package lol.pyr.znpcsplus.entity;
+
+import com.github.retrooper.packetevents.protocol.entity.type.EntityType;
+import com.github.retrooper.packetevents.protocol.entity.type.EntityTypes;
+import lol.pyr.znpcsplus.packets.PacketFactory;
+import org.bukkit.entity.Player;
+
+import java.util.Set;
+
+public class PacketEntity {
+    private final int entityId;
+    private final EntityType type;
+    private PacketLocation location;
+
+    public PacketEntity(EntityType type, PacketLocation location) {
+        this.entityId = EntityIDProvider.reserve();
+        this.type = type;
+        this.location = location;
+    }
+
+    public int getEntityId() {
+        return entityId;
+    }
+
+    public PacketLocation getLocation() {
+        return location;
+    }
+
+    public EntityType getType() {
+        return type;
+    }
+
+    public void setLocation(PacketLocation location, Set<Player> viewers) {
+        this.location = location;
+        for (Player viewer : viewers) PacketFactory.get().teleportEntity(viewer, this);
+    }
+
+    public void spawn(Player player) {
+        if (type == EntityTypes.PLAYER) PacketFactory.get().spawnPlayer(player, this);
+        else PacketFactory.get().spawnEntity(player, this);
+    }
+
+    public void despawn(Player player) {
+        PacketFactory.get().destroyEntity(player, this);
+    }
+}

src/main/java/lol/pyr/znpcsplus/entity/PacketLocation.java

@@ -0,0 +1,85 @@
+package lol.pyr.znpcsplus.entity;
+
+import com.github.retrooper.packetevents.util.Vector3d;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.util.NumberConversions;
+import org.bukkit.util.Vector;
+
+public class PacketLocation {
+    private final double x;
+    private final double y;
+    private final double z;
+    private final float yaw;
+    private final float pitch;
+
+    public PacketLocation(double x, double y, double z, float yaw, float pitch) {
+        this.x = x;
+        this.y = y;
+        this.z = z;
+        this.yaw = yaw;
+        this.pitch = pitch;
+    }
+
+    public PacketLocation(Location location) {
+        this(location.getX(), location.getY(), location.getZ(), location.getYaw(), location.getPitch());
+    }
+
+    public double getX() {
+        return this.x;
+    }
+
+    public double getY() {
+        return this.y;
+    }
+
+    public double getZ() {
+        return this.z;
+    }
+
+    public float getYaw() {
+        return this.yaw;
+    }
+
+    public float getPitch() {
+        return this.pitch;
+    }
+
+    public Location toBukkitLocation(World world) {
+        return new Location(world, this.x, this.y, this.z, this.yaw, this.pitch);
+    }
+
+    public Vector toVector() {
+        return new Vector(x, y, z);
+    }
+
+    public Vector3d toVector3d() {
+        return new Vector3d(x, y, z);
+    }
+
+    private static final double _2PI = 2 * Math.PI;
+
+    public Location lookingAt(Location loc) {
+        return lookingAt(new PacketLocation(loc)).toBukkitLocation(loc.getWorld());
+    }
+
+    public PacketLocation lookingAt(PacketLocation loc) {
+        final double x = loc.getX() - this.x;
+        final double z = loc.getZ() - this.z;
+        final double y = loc.getY() - this.y;
+
+        if (x == 0 && z == 0) {
+            return new PacketLocation(this.x, this.y, this.z, this.yaw, y > 0 ? -90 : 90);
+        }
+
+        double x2 = NumberConversions.square(x);
+        double z2 = NumberConversions.square(z);
+        double xz = Math.sqrt(x2 + z2);
+
+        double theta = Math.atan2(-x, z);
+        float yaw = (float) Math.toDegrees((theta + _2PI) % _2PI);
+        float pitch = (float) Math.toDegrees(Math.atan(-y / xz));
+
+        return new PacketLocation(this.x, this.y, this.z, yaw, pitch);
+    }
+}

src/main/java/lol/pyr/znpcsplus/npc/NPC.java

@@ -1,4 +1,86 @@
 package lol.pyr.znpcsplus.npc;
 
+import lol.pyr.znpcsplus.entity.PacketEntity;
+import lol.pyr.znpcsplus.entity.PacketLocation;
+import org.bukkit.Bukkit;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+
+import java.util.HashSet;
+import java.util.Set;
+
 public class NPC {
+    private final Set<Player> viewers = new HashSet<>();
+    private final String worldName;
+    private PacketEntity entity;
+    private PacketLocation location;
+    private NPCType type;
+
+    public NPC(World world, NPCType type, PacketLocation location) {
+        this.worldName = world.getName();
+        this.type = type;
+        this.location = location;
+        entity = new PacketEntity(type.getType(), location); // TODO: Entity ID Provider
+    }
+
+    public void setType(NPCType type) {
+        _hideAll();
+        this.type = type;
+        entity = new PacketEntity(type.getType(), entity.getLocation());
+        _showAll();
+    }
+
+    public NPCType getType() {
+        return type;
+    }
+
+    public PacketLocation getLocation() {
+        return location;
+    }
+
+    public void setLocation(PacketLocation location) {
+        this.location = location;
+        entity.setLocation(location, viewers);
+    }
+
+    public World getWorld() {
+        return Bukkit.getWorld(worldName);
+    }
+
+    public void delete() {
+        _hideAll();
+        viewers.clear();
+    }
+
+    public void show(Player player) {
+        if (viewers.contains(player)) return;
+        _show(player);
+        viewers.add(player);
+    }
+
+    private void _show(Player player) {
+        entity.spawn(player);
+    }
+
+    public void hide(Player player) {
+        if (!viewers.contains(player)) return;
+        _hide(player);
+        viewers.remove(player);
+    }
+
+    private void _hide(Player player) {
+        entity.despawn(player);
+    }
+
+    private void _hideAll() {
+        for (Player viewer : viewers) _hide(viewer);
+    }
+
+    private void _showAll() {
+        for (Player viewer : viewers) _show(viewer);
+    }
+
+    public boolean isShown(Player player) {
+        return viewers.contains(player);
+    }
 }

src/main/java/lol/pyr/znpcsplus/npc/NPCRegistry.java

@@ -0,0 +1,25 @@
+package lol.pyr.znpcsplus.npc;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+public class NPCRegistry {
+    private static final Map<String, NPC> npcMap = new HashMap<>();
+
+    public static NPC get(String id) {
+        return npcMap.get(id);
+    }
+
+    public static Collection<NPC> all() {
+        return npcMap.values();
+    }
+
+    public static void register(String id, NPC npc) {
+        npcMap.put(id, npc);
+    }
+
+    public static void unregister(String id) {
+        npcMap.remove(id);
+    }
+}

src/main/java/lol/pyr/znpcsplus/npc/NPCType.java

@@ -1,4 +1,36 @@
 package lol.pyr.znpcsplus.npc;
 
+import com.github.retrooper.packetevents.protocol.entity.type.EntityType;
+import com.github.retrooper.packetevents.protocol.entity.type.EntityTypes;
+import com.google.common.collect.ImmutableList;
+
+import java.util.List;
+
 public class NPCType {
+    private final static ImmutableList<NPCType> npcTypes;
+
+    public static List<NPCType> values() {
+        return npcTypes;
+    }
+
+    private final EntityType type;
+
+    public NPCType(EntityType type) {
+        this.type = type;
+    }
+
+    public EntityType getType() {
+        return type;
+    }
+
+    static {
+        ImmutableList.Builder<NPCType> builder = new ImmutableList.Builder<>();
+
+        builder.add(new NPCType(EntityTypes.PLAYER));
+        builder.add(new NPCType(EntityTypes.CREEPER));
+        builder.add(new NPCType(EntityTypes.ZOMBIE));
+        builder.add(new NPCType(EntityTypes.SKELETON));
+
+        npcTypes = builder.build();
+    }
 }

src/main/java/lol/pyr/znpcsplus/packets/PacketFactory.java

@@ -2,20 +2,39 @@ package lol.pyr.znpcsplus.packets;
 
 import com.github.retrooper.packetevents.PacketEvents;
 import com.github.retrooper.packetevents.manager.server.ServerVersion;
+import lol.pyr.znpcsplus.entity.PacketEntity;
 import lol.pyr.znpcsplus.util.LazyLoader;
+import org.bukkit.entity.Player;
 
+import java.util.HashMap;
 import java.util.Map;
 
 public interface PacketFactory {
+    void spawnPlayer(Player player, PacketEntity entity);
+    void spawnEntity(Player player, PacketEntity entity);
+    void destroyEntity(Player player, PacketEntity entity);
+    void teleportEntity(Player player, PacketEntity entity);
+    void addTabPlayer(Player player, PacketEntity entity);
+    void removeTabPlayer(Player player, PacketEntity entity);
 
-    Map<ServerVersion, LazyLoader<? extends PacketFactory>> factories = buildFactoryMap();
-
+    PacketFactory factory = get();
 
     static PacketFactory get() {
-        return factories.get(PacketEvents.getAPI().getServerManager().getVersion()).get();
+        if (factory != null) return factory;
+        ServerVersion version = PacketEvents.getAPI().getServerManager().getVersion();
+        Map<ServerVersion, LazyLoader<? extends PacketFactory>> factories = buildFactoryMap();
+        if (factories.containsKey(version)) return factories.get(version).get();
+        for (ServerVersion v : ServerVersion.reversedValues()) {
+            if (v.isNewerThan(version)) continue;
+            if (!factories.containsKey(v)) continue;
+            return factories.get(v).get();
+        }
+        throw new RuntimeException("Unsupported version!");
     }
 
     private static Map<ServerVersion, LazyLoader<? extends PacketFactory>> buildFactoryMap() {
-
+        HashMap<ServerVersion, LazyLoader<? extends PacketFactory>> map = new HashMap<>();
+        map.put(ServerVersion.V_1_8, LazyLoader.of(V1_8Factory::new));
+        return map;
     }
 }

src/main/java/lol/pyr/znpcsplus/packets/V1_8Factory.java

@@ -1,4 +1,58 @@
 package lol.pyr.znpcsplus.packets;
 
+import com.github.retrooper.packetevents.PacketEvents;
+import com.github.retrooper.packetevents.protocol.entity.type.EntityType;
+import com.github.retrooper.packetevents.protocol.player.ClientVersion;
+import com.github.retrooper.packetevents.protocol.player.UserProfile;
+import com.github.retrooper.packetevents.util.Vector3d;
+import com.github.retrooper.packetevents.wrapper.play.server.*;
+import lol.pyr.znpcsplus.entity.PacketEntity;
+import lol.pyr.znpcsplus.entity.PacketLocation;
+import org.bukkit.entity.Player;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
 public class V1_8Factory implements PacketFactory {
+    @Override
+    public void spawnPlayer(Player player, PacketEntity entity) {
+        addTabPlayer(player, entity);
+        PacketEvents.getAPI().getPlayerManager().sendPacket(player, new WrapperPlayServerSpawnPlayer());
+        // TODO
+    }
+
+    @Override
+    public void spawnEntity(Player player, PacketEntity entity) {
+        PacketLocation location = entity.getLocation();
+        EntityType type = entity.getType();
+        ClientVersion clientVersion = PacketEvents.getAPI().getServerManager().getVersion().toClientVersion();
+        PacketEvents.getAPI().getPlayerManager().sendPacket(player, type.getLegacyId(clientVersion) == -1 ?
+                new WrapperPlayServerSpawnLivingEntity(entity.getEntityId(), new UUID(0, 0), type, location.toVector3d(),
+                        location.getYaw(), location.getPitch(), location.getPitch(), new Vector3d(), List.of()) :
+                new WrapperPlayServerSpawnEntity(entity.getEntityId(), Optional.empty(), entity.getType(), location.toVector3d(),
+                        location.getPitch(), location.getYaw(), location.getYaw(), 0, Optional.empty()));
+    }
+
+    @Override
+    public void destroyEntity(Player player, PacketEntity entity) {
+        PacketEvents.getAPI().getPlayerManager().sendPacket(player, new WrapperPlayServerDestroyEntities(entity.getEntityId()));
+    }
+
+    @Override
+    public void teleportEntity(Player player, PacketEntity entity) {
+        PacketLocation location = entity.getLocation();
+        PacketEvents.getAPI().getPlayerManager().sendPacket(player, new WrapperPlayServerEntityTeleport(entity.getEntityId(),
+                location.toVector3d(), location.getYaw(), location.getPitch(), true));
+    }
+
+    @Override
+    public void addTabPlayer(Player player, PacketEntity entity) {
+
+    }
+
+    @Override
+    public void removeTabPlayer(Player player, PacketEntity entity) {
+        new WrapperPlayServerPlayerInfo(WrapperPlayServerPlayerInfo.Action.REMOVE_PLAYER, new WrapperPlayServerPlayerInfo.PlayerData(null, new UserProfile(gameProfile.getId(), gameProfile.getName()), null, 1))
+    }
 }

src/main/java/lol/pyr/znpcsplus/properties/NPCProperty.java

@@ -0,0 +1,4 @@
+package lol.pyr.znpcsplus.properties;
+
+public class NPCProperty {
+}

src/main/java/lol/pyr/znpcsplus/tasks/NPCVisibilityTask.java

@@ -0,0 +1,24 @@
+package lol.pyr.znpcsplus.tasks;
+
+import io.github.znetworkw.znpcservers.configuration.ConfigurationConstants;
+import lol.pyr.znpcsplus.npc.NPC;
+import lol.pyr.znpcsplus.npc.NPCRegistry;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.scheduler.BukkitRunnable;
+
+public class NPCVisibilityTask extends BukkitRunnable {
+    public NPCVisibilityTask(Plugin plugin) {
+        runTaskTimerAsynchronously(plugin, 60L, 10L);
+    }
+
+    public void run() {
+        int distSq = ConfigurationConstants.VIEW_DISTANCE * ConfigurationConstants.VIEW_DISTANCE;
+        for (NPC npc : NPCRegistry.all()) for (Player player : Bukkit.getOnlinePlayers()) {
+            boolean inRange = (player.getWorld() == npc.getWorld() && player.getLocation().distanceSquared(npc.getLocation().toBukkitLocation(npc.getWorld())) <= distSq);
+            if (!inRange && npc.isShown(player)) npc.hide(player);
+            if (inRange && !npc.isShown(player)) npc.show(player);
+        }
+    }
+}