some changes

build.gradle

@@ -10,6 +10,7 @@ repositories {
 }
 
 dependencies {
+    implementation 'org.jetbrains:annotations:24.0.0'
     testImplementation platform('org.junit:junit-bom:5.9.1')
     testImplementation 'org.junit.jupiter:junit-jupiter'
     implementation(

src/main/java/tokarotik/giftapi/Main.java

@@ -1,36 +1,49 @@
 package tokarotik.giftapi;
 
 import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerQuitEvent;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.plugin.java.JavaPlugin;
 
+import tokarotik.giftapi.NBT.cache.CacheManager;
 import tokarotik.giftapi.dev.GiftCommand;
 
 public class Main extends JavaPlugin implements Listener
 {
+    private CacheManager cacheManager;
     private APIManager apiManager;
 
     @Override
-    public void onEnable() {
+    public void onEnable()
+    {
         saveDefaultConfig();
 
-        getLogger().info("GiftAPI enabled!");
-
-        saveDefaultConfig();
+        cacheManager = new CacheManager(54);
         apiManager = new APIManager(this, getConfig());
 
-        if (getConfig().getBoolean(ConfigPaths.DEVTEST, false))
-        {
-            this.getCommand("gift").setExecutor(new GiftCommand(apiManager));
-        }
+        this.getCommand("gift").setExecutor(new GiftCommand(apiManager)); // DELETE FOR RELEASE
+
+        getServer().getPluginManager().registerEvents(this, this); // bullshit
+
+        getLogger().info("GiftAPI enabled!");
     }
 
     @Override
-    public void onDisable() {
+    public void onDisable()
+    {
+        cacheManager.disable();
+
         getLogger().info("GiftAPI disabled!");
     }
 
+    @EventHandler
+    public void onPlayerQuit(PlayerQuitEvent event)
+    {
+        cacheManager.playerQuit(event.getPlayer().getName());
+    }
+
     // if failed to add, return false
     // if successfully added, return true
     public boolean add(Player player, ItemStack item)

src/main/java/tokarotik/giftapi/NBT/NBTManager.java

@@ -3,6 +3,7 @@ package tokarotik.giftapi.NBT;
 import net.minecraft.server.v1_6_R3.EntityPlayer;
 import net.minecraft.server.v1_6_R3.NBTTagCompound;
 import org.bukkit.entity.Player;
+import tokarotik.giftapi.NBT.cache.BasicNBT;
 
 public class NBTManager
 {

src/main/java/tokarotik/giftapi/NBT/WorldNBTSynchronizer.java

@@ -1,40 +0,0 @@
-package tokarotik.giftapi.NBT;
-
-import net.minecraft.server.v1_6_R3.EntityPlayer;
-import net.minecraft.server.v1_6_R3.NBTTagCompound;
-import org.bukkit.Bukkit;
-import org.bukkit.World;
-import org.bukkit.entity.Player;
-
-public class WorldNBTSynchronizer
-{
-    public static String getWorld(EntityPlayer entityPlayer, String worldName)
-    {
-        BasicNBT basicNBT = new BasicNBT(worldName);
-
-        return worldName;
-    }
-
-    private static boolean hasPlayer(String playerName, String worldName)
-    {
-        World world = Bukkit.getWorld(worldName);
-
-        for (Player player : world.getPlayers())
-        {
-            if (player.getName() == playerName) { return true; }
-        }
-
-        return false;
-    }
-
-    private static boolean hasGiftApiNBT(EntityPlayer entityPlayer, String worldName)
-    {
-        BasicNBT basicNBT = new BasicNBT(worldName);
-
-        NBTTagCompound tag = basicNBT.readPlayerNBT(entityPlayer);
-
-        return true;
-    }
-
-
-}

src/main/java/tokarotik/giftapi/NBT/cache/BasicNBT.java

@@ -1,4 +1,4 @@
-package tokarotik.giftapi.NBT;
+package tokarotik.giftapi.NBT.cache;
 
 import net.minecraft.server.v1_6_R3.EntityPlayer;
 import net.minecraft.server.v1_6_R3.NBTCompressedStreamTools;
@@ -58,7 +58,7 @@ public class BasicNBT {
         }
     }
 
-    public EntityPlayer getPlayer(Player player)
+    public static EntityPlayer getPlayer(Player player)
     {
         return ((CraftPlayer) player).getHandle();
     }

src/main/java/tokarotik/giftapi/NBT/cache/CacheManager.java

@@ -0,0 +1,92 @@
+package tokarotik.giftapi.NBT.cache;
+
+import net.minecraft.server.v1_6_R3.EntityPlayer;
+import net.minecraft.server.v1_6_R3.NBTTagCompound;
+import net.minecraft.server.v1_6_R3.NBTTagList;
+import org.bukkit.entity.Player;
+import tokarotik.giftapi.NBT.page.PageManager;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class CacheManager
+{
+    private final Map<Player, PageManager> world_map = new HashMap<>();
+    private final Map<Player, PageManager> nether_map = new HashMap<>();
+    private final Map<Player, PageManager> end_map = new HashMap<>();
+
+    private final int max_stack;
+
+    public CacheManager(int max_stack)
+    {
+        this.max_stack = max_stack;
+    }
+
+    public PageManager load(Player player)
+    {
+        String worldPlayer = player.getWorld().getName();
+        Map<Player, PageManager> hashMap = getWorlMap(worldPlayer);
+        EntityPlayer entityPlayer = BasicNBT.getPlayer(player);
+
+
+        // if player was loaded early
+        if (hashMap.containsKey(player))
+        {
+            return hashMap.get(player);
+        }
+
+        // if world in what is player has giftapi
+        if (WorldNBTSynchronizer.hasAll(entityPlayer, worldPlayer))
+        {
+            NBTTagCompound compound = new BasicNBT(worldPlayer).readPlayerNBT(entityPlayer);
+            NBTTagList list = compound.getList("giftapi");
+
+            PageManager new_pages = new PageManager(list, this.max_stack);
+            hashMap.put(player, new_pages);
+
+            return new_pages;
+        }
+
+        String world = WorldNBTSynchronizer.getWorldWhatHasPlayer(entityPlayer);
+
+        // if world in what is player hasn't giftapi, but in another has
+        if (world != null)
+        {
+            NBTTagCompound compound = new BasicNBT(world).readPlayerNBT(entityPlayer);
+            NBTTagList list = compound.getList("giftapi");
+
+            PageManager new_pages = new PageManager(list, this.max_stack);
+            hashMap.put(player, new_pages);
+
+            return new_pages;
+        }
+
+        // if player doesn't have any saved apiconfig NBT
+        PageManager new_pages = new PageManager(this.max_stack);
+        hashMap.put(player, new_pages);
+
+        return new_pages;
+    }
+
+    public void disable()
+    {
+
+    }
+
+    public void playerQuit(String playerName)
+    {
+
+    }
+
+    private Map<Player, PageManager> getWorlMap(String worldName)
+    {
+        switch(worldName)
+        {
+            case "world": { return this.world_map; }
+            case "world_nether": { return this.nether_map; }
+            case "world_the_end": { return this.end_map; }
+        }
+
+        return null;
+    }
+}

src/main/java/tokarotik/giftapi/NBT/cache/WorldNBTSynchronizer.java

@@ -0,0 +1,83 @@
+package tokarotik.giftapi.NBT.cache;
+
+import net.minecraft.server.v1_6_R3.EntityPlayer;
+import net.minecraft.server.v1_6_R3.NBTTagCompound;
+import org.bukkit.Bukkit;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.Nullable;
+import tokarotik.giftapi.NBT.cache.BasicNBT;
+
+public class WorldNBTSynchronizer
+{
+    public static void getWorld(EntityPlayer entityPlayer, String worldName)
+    {
+        if (hasAll(entityPlayer, worldName)) { return; }
+
+
+    }
+
+    public static boolean isPlayerEmpty(EntityPlayer entityPlayer)
+    {
+        return getWorldWhatHasPlayer(entityPlayer) == null;
+    }
+
+    @Nullable
+    public static String getWorldWhatHasPlayer(EntityPlayer entityPlayer)
+    {
+        for (World world : Bukkit.getWorlds())
+        {
+            String worldName = world.getName();
+
+            if (hasAll(entityPlayer, worldName))
+            {
+                return worldName;
+            }
+        }
+
+        return null;
+    }
+
+    public static boolean hasAll(EntityPlayer entityPlayer, String worldName)
+    {
+        boolean isHasPlayer = hasPlayer(entityPlayer.getName(), worldName);
+        if (!isHasPlayer) { return false; }
+
+        boolean isHasNBT = hasGiftApiNBT(entityPlayer, worldName);
+        return isHasNBT;
+    }
+
+    private static boolean hasPlayer(String playerName, String worldName)
+    {
+        World world = Bukkit.getWorld(worldName);
+
+        for (Player player : world.getPlayers())
+        {
+            if (player.getName() == playerName) { return true; }
+        }
+
+        return false;
+    }
+
+    private static boolean hasGiftApiNBT(EntityPlayer entityPlayer, String worldName)
+    {
+        BasicNBT basicNBT = new BasicNBT(worldName);
+
+        NBTTagCompound tag = basicNBT.readPlayerNBT(entityPlayer);
+
+        if (tag.hasKey("giftapi")) // if exists giftapi tag in player
+        {
+            try
+            {
+                tag.getList("giftapi");
+                return true;
+            }
+
+            catch(Exception ignored){} // if giftapi is not type list, throw exception and for what I used construction try-catch.
+        }
+
+        return false;
+    }
+
+
+}

src/main/java/tokarotik/giftapi/NBT/page/PageManager.java

@@ -18,7 +18,9 @@ public class PageManager
 
     public PageManager(int max_stack)
     {
+
         this.max_stack = max_stack;
+        this.tag = new NBTTagList("giftapi");
     }
 
     public NBTTagList getTag()