Added missing javadoc

README.md

@@ -158,7 +158,7 @@ Here's a list of some (not all) of the features of eco:
 
 <h1 align="center">
   <br>
-    <a href="http://gamersupps.gg?afmc=Auxilor" target="_blank">
+    <a href="http://gamersupps.gg/discount/Auxilor?afmc=Auxilor" target="_blank">
       <img src="https://i.imgur.com/uFDpBAC.png" alt="supps banner">
     </a>
     <a href="https://dedimc.promo/Auxilor" target="_blank">

build.gradle

@@ -51,6 +51,9 @@ allprojects {
 
         // CombatLogX
         maven { url 'https://nexus.sirblobman.xyz/repository/public/' }
+
+        // Head Database
+        maven { url 'https://mvn.intellectualsites.com/content/groups/public/' }
     }
 
     dependencies {

eco-api/src/main/java/com/willfp/eco/core/EcoPlugin.java

@@ -305,10 +305,27 @@ public abstract class EcoPlugin extends JavaPlugin {
         this.logger = Eco.getHandler().createLogger(this);
         this.proxyFactory = this.proxyPackage.equalsIgnoreCase("") ? null : Eco.getHandler().createProxyFactory(this);
 
-        this.langYml = new LangYml(this);
+        this.langYml = this.createLangYml();
-        this.configYml = new ConfigYml(this);
+        this.configYml = this.createConfigYml();
 
         Eco.getHandler().addNewPlugin(this);
+
+        /*
+        The minimum eco version check was moved here because it's very common
+        to add a lot of code in the constructor of plugins; meaning that the plugin
+        can throw errors without it being obvious to the user that the reason is
+        because they have an outdated version of eco installed.
+         */
+
+        DefaultArtifactVersion runningVersion = new DefaultArtifactVersion(Eco.getHandler().getEcoPlugin().getDescription().getVersion());
+        DefaultArtifactVersion requiredVersion = new DefaultArtifactVersion(this.getMinimumEcoVersion());
+        if (!(runningVersion.compareTo(requiredVersion) > 0 || runningVersion.equals(requiredVersion))) {
+            this.getLogger().severe("You are running an outdated version of eco!");
+            this.getLogger().severe("You must be on at least" + this.getMinimumEcoVersion());
+            this.getLogger().severe("Download the newest version here:");
+            this.getLogger().severe("https://polymart.org/download/773/recent/JSpprMspkuyecf5y1wQ2Jn8OoLQSQ_IW");
+            Bukkit.getPluginManager().disablePlugin(this);
+        }
     }
 
     /**
@@ -336,16 +353,6 @@ public abstract class EcoPlugin extends JavaPlugin {
             });
         }
 
-        DefaultArtifactVersion runningVersion = new DefaultArtifactVersion(Eco.getHandler().getEcoPlugin().getDescription().getVersion());
-        DefaultArtifactVersion requiredVersion = new DefaultArtifactVersion(this.getMinimumEcoVersion());
-        if (!(runningVersion.compareTo(requiredVersion) > 0 || runningVersion.equals(requiredVersion))) {
-            this.getLogger().severe("You are running an outdated version of eco!");
-            this.getLogger().severe("You must be on at least" + this.getMinimumEcoVersion());
-            this.getLogger().severe("Download the newest version here:");
-            this.getLogger().severe("https://polymart.org/download/773/recent/JSpprMspkuyecf5y1wQ2Jn8OoLQSQ_IW");
-            Bukkit.getPluginManager().disablePlugin(this);
-        }
-
         if (this.getBStatsId() != 0) {
             Eco.getHandler().registerBStats(this);
         }
@@ -571,6 +578,28 @@ public abstract class EcoPlugin extends JavaPlugin {
      */
     protected abstract List<Listener> loadListeners();
 
+    /**
+     * Useful for custom LangYml implementations.
+     * <p>
+     * Override if needed.
+     *
+     * @return lang.yml.
+     */
+    protected LangYml createLangYml() {
+        return new LangYml(this);
+    }
+
+    /**
+     * Useful for custom ConfigYml implementations.
+     * <p>
+     * Override if needed.
+     *
+     * @return config.yml.
+     */
+    protected ConfigYml createConfigYml() {
+        return new ConfigYml(this);
+    }
+
     /**
      * Create the display module for the plugin.
      *

eco-api/src/main/java/com/willfp/eco/core/Handler.java

@@ -16,6 +16,7 @@ import com.willfp.eco.core.proxy.ProxyFactory;
 import com.willfp.eco.core.scheduling.Scheduler;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 import java.util.logging.Logger;
@@ -30,6 +31,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The scheduler.
      */
+    @NotNull
     Scheduler createScheduler(@NotNull EcoPlugin plugin);
 
     /**
@@ -38,6 +40,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The event manager.
      */
+    @NotNull
     EventManager createEventManager(@NotNull EcoPlugin plugin);
 
     /**
@@ -46,6 +49,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The factory.
      */
+    @NotNull
     NamespacedKeyFactory createNamespacedKeyFactory(@NotNull EcoPlugin plugin);
 
     /**
@@ -54,6 +58,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The factory.
      */
+    @NotNull
     MetadataValueFactory createMetadataValueFactory(@NotNull EcoPlugin plugin);
 
     /**
@@ -62,6 +67,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The factory.
      */
+    @NotNull
     RunnableFactory createRunnableFactory(@NotNull EcoPlugin plugin);
 
     /**
@@ -70,6 +76,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The factory.
      */
+    @NotNull
     ExtensionLoader createExtensionLoader(@NotNull EcoPlugin plugin);
 
     /**
@@ -78,6 +85,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The handler.
      */
+    @NotNull
     ConfigHandler createConfigHandler(@NotNull EcoPlugin plugin);
 
     /**
@@ -86,6 +94,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The logger.
      */
+    @NotNull
     Logger createLogger(@NotNull EcoPlugin plugin);
 
     /**
@@ -94,6 +103,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The integration.
      */
+    @NotNull
     PlaceholderIntegration createPAPIIntegration(@NotNull EcoPlugin plugin);
 
     /**
@@ -102,6 +112,7 @@ public interface Handler {
      * @param plugin The plugin.
      * @return The factory.
      */
+    @NotNull
     ProxyFactory createProxyFactory(@NotNull EcoPlugin plugin);
 
     /**
@@ -109,6 +120,7 @@ public interface Handler {
      *
      * @return The plugin.
      */
+    @NotNull
     EcoPlugin getEcoPlugin();
 
     /**
@@ -116,6 +128,7 @@ public interface Handler {
      *
      * @return The factory.
      */
+    @NotNull
     ConfigFactory getConfigFactory();
 
     /**
@@ -123,6 +136,7 @@ public interface Handler {
      *
      * @return The factory.
      */
+    @NotNull
     DropQueueFactory getDropQueueFactory();
 
     /**
@@ -130,6 +144,7 @@ public interface Handler {
      *
      * @return The factory.
      */
+    @NotNull
     GUIFactory getGUIFactory();
 
     /**
@@ -137,6 +152,7 @@ public interface Handler {
      *
      * @return The cleaner.
      */
+    @NotNull
     Cleaner getCleaner();
 
     /**
@@ -152,6 +168,7 @@ public interface Handler {
      * @param name The name.
      * @return The plugin.
      */
+    @Nullable
     EcoPlugin getPluginByName(@NotNull String name);
 
     /**
@@ -159,6 +176,7 @@ public interface Handler {
      *
      * @return A list of plugin names in lowercase.
      */
+    @NotNull
     List<String> getLoadedPlugins();
 
     /**
@@ -167,6 +185,7 @@ public interface Handler {
      * @param itemStack The base ItemStack.
      * @return The FastItemStack.
      */
+    @NotNull
     FastItemStack createFastItemStack(@NotNull ItemStack itemStack);
 
     /**

eco-api/src/main/java/com/willfp/eco/core/PluginDependent.java

@@ -9,11 +9,12 @@ import org.jetbrains.annotations.NotNull;
  *
  * @param <T> The eco plugin type.
  */
-public abstract class PluginDependent<T extends EcoPlugin> {
+public abstract class PluginDependent<@NotNull T extends EcoPlugin> {
     /**
      * The {@link EcoPlugin} that is stored.
      */
     @Getter(AccessLevel.PROTECTED)
+    @NotNull
     private final T plugin;
 
     /**

eco-api/src/main/java/com/willfp/eco/core/config/base/LangYml.java

@@ -2,6 +2,7 @@ package com.willfp.eco.core.config.base;
 
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.config.yaml.YamlBaseConfig;
+import com.willfp.eco.util.StringUtils;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -42,6 +43,18 @@ public class LangYml extends YamlBaseConfig {
      * @return The message with a prefix appended.
      */
     public String getMessage(@NotNull final String message) {
-        return getPrefix() + this.getString("messages." + message);
+        return getMessage(message, StringUtils.FormatOption.WITH_PLACEHOLDERS);
+    }
+
+    /**
+     * Get a chat message.
+     *
+     * @param message The key of the message.
+     * @param option  The format options.
+     * @return The message with a prefix appended.
+     */
+    public String getMessage(@NotNull final String message,
+                             @NotNull final StringUtils.FormatOption option) {
+        return getPrefix() + this.getString("messages." + message, option);
     }
 }

eco-api/src/main/java/com/willfp/eco/core/config/interfaces/Config.java

@@ -1,5 +1,6 @@
 package com.willfp.eco.core.config.interfaces;
 
+import com.willfp.eco.util.StringUtils;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -165,7 +166,9 @@ public interface Config extends Cloneable {
      * @return The found value, or an empty string if not found.
      */
     @NotNull
-    String getString(@NotNull String path);
+    default String getString(@NotNull String path) {
+        return getString(path, true);
+    }
 
     /**
      * Get a string from config.
@@ -175,8 +178,36 @@ public interface Config extends Cloneable {
      * @return The found value, or an empty string if not found.
      */
     @NotNull
+    default String getString(@NotNull String path,
+                             boolean format) {
+        return this.getString(path, format, StringUtils.FormatOption.WITH_PLACEHOLDERS);
+    }
+
+    /**
+     * Get a string from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param option The format option.
+     * @return The found value, or an empty string if not found.
+     */
+    @NotNull
+    default String getString(@NotNull String path,
+                             @NotNull final StringUtils.FormatOption option) {
+        return this.getString(path, true, option);
+    }
+
+    /**
+     * Get a string from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param format If the string should be formatted.
+     * @param option The format option.
+     * @return The found value, or an empty string if not found.
+     */
+    @NotNull
     String getString(@NotNull String path,
-                     boolean format);
+                     boolean format,
+                     @NotNull StringUtils.FormatOption option);
 
     /**
      * Get a string from config.
@@ -185,7 +216,9 @@ public interface Config extends Cloneable {
      * @return The found value, or null if not found.
      */
     @Nullable
-    String getStringOrNull(@NotNull String path);
+    default String getStringOrNull(@NotNull String path) {
+        return getStringOrNull(path, true);
+    }
 
     /**
      * Get a string from config.
@@ -195,8 +228,36 @@ public interface Config extends Cloneable {
      * @return The found value, or null if not found.
      */
     @Nullable
+    default String getStringOrNull(@NotNull String path,
+                                   boolean format) {
+        return this.getStringOrNull(path, format, StringUtils.FormatOption.WITH_PLACEHOLDERS);
+    }
+
+    /**
+     * Get a string from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param option The format option.
+     * @return The found value, or null if not found.
+     */
+    @Nullable
+    default String getStringOrNull(@NotNull String path,
+                                   @NotNull StringUtils.FormatOption option) {
+        return this.getStringOrNull(path, true, option);
+    }
+
+    /**
+     * Get a string from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param format If the string should be formatted.
+     * @param option The format option.
+     * @return The found value, or null if not found.
+     */
+    @Nullable
     String getStringOrNull(@NotNull String path,
-                           boolean format);
+                           boolean format,
+                           @NotNull StringUtils.FormatOption option);
 
     /**
      * Get a list of strings from config.
@@ -207,7 +268,9 @@ public interface Config extends Cloneable {
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
     @NotNull
-    List<String> getStrings(@NotNull String path);
+    default List<String> getStrings(@NotNull String path) {
+        return getStrings(path, true);
+    }
 
     /**
      * Get a list of strings from config.
@@ -217,8 +280,36 @@ public interface Config extends Cloneable {
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
     @NotNull
+    default List<String> getStrings(@NotNull String path,
+                                    boolean format) {
+        return this.getStrings(path, format, StringUtils.FormatOption.WITH_PLACEHOLDERS);
+    }
+
+    /**
+     * Get a list of strings from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param option The format option.
+     * @return The found value, or a blank {@link java.util.ArrayList} if not found.
+     */
+    @Nullable
+    default List<String> getStrings(@NotNull String path,
+                                    @NotNull StringUtils.FormatOption option) {
+        return getStrings(path, true, option);
+    }
+
+    /**
+     * Get a list of strings from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param format If the strings should be formatted.
+     * @param option The option.
+     * @return The found value, or a blank {@link java.util.ArrayList} if not found.
+     */
+    @NotNull
     List<String> getStrings(@NotNull String path,
-                            boolean format);
+                            boolean format,
+                            @NotNull StringUtils.FormatOption option);
 
     /**
      * Get a list of strings from config.
@@ -227,7 +318,9 @@ public interface Config extends Cloneable {
      * @return The found value, or null if not found.
      */
     @Nullable
-    List<String> getStringsOrNull(@NotNull String path);
+    default List<String> getStringsOrNull(@NotNull String path) {
+        return getStringsOrNull(path, true);
+    }
 
     /**
      * Get a list of strings from config.
@@ -237,8 +330,36 @@ public interface Config extends Cloneable {
      * @return The found value, or null if not found.
      */
     @Nullable
+    default List<String> getStringsOrNull(@NotNull String path,
+                                          boolean format) {
+        return getStringsOrNull(path, format, StringUtils.FormatOption.WITH_PLACEHOLDERS);
+    }
+
+    /**
+     * Get a list of strings from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param option The format option.
+     * @return The found value, or null if not found.
+     */
+    @Nullable
+    default List<String> getStringsOrNull(@NotNull String path,
+                                          @NotNull StringUtils.FormatOption option) {
+        return getStringsOrNull(path, true, option);
+    }
+
+    /**
+     * Get a list of strings from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param format If the strings should be formatted.
+     * @param option The format option.
+     * @return The found value, or null if not found.
+     */
+    @Nullable
     List<String> getStringsOrNull(@NotNull String path,
-                                  boolean format);
+                                  boolean format,
+                                  @NotNull StringUtils.FormatOption option);
 
     /**
      * Get a decimal from config.

eco-api/src/main/java/com/willfp/eco/core/config/wrapper/ConfigWrapper.java

@@ -1,6 +1,7 @@
 package com.willfp.eco.core.config.wrapper;
 
 import com.willfp.eco.core.config.interfaces.Config;
+import com.willfp.eco.util.StringUtils;
 import lombok.Getter;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -125,48 +126,33 @@ public abstract class ConfigWrapper<T extends Config> implements Config {
         return handle.getBoolsOrNull(path);
     }
 
-    @Override
-    public @NotNull String getString(@NotNull final String path) {
-        return handle.getString(path);
-    }
 
     @Override
     public @NotNull String getString(@NotNull final String path,
-                                     final boolean format) {
+                                     final boolean format,
-        return handle.getString(path, format);
+                                     @NotNull final StringUtils.FormatOption option) {
-    }
+        return handle.getString(path, format, option);
-
-    @Override
-    public @Nullable String getStringOrNull(@NotNull final String path) {
-        return handle.getStringOrNull(path);
     }
 
     @Override
     public @Nullable String getStringOrNull(@NotNull final String path,
-                                            final boolean format) {
+                                            final boolean format,
-        return handle.getStringOrNull(path, format);
+                                            @NotNull final StringUtils.FormatOption option) {
-    }
+        return handle.getStringOrNull(path, format, option);
-
-    @Override
-    public @NotNull List<String> getStrings(@NotNull final String path) {
-        return handle.getStrings(path);
     }
 
     @Override
     public @NotNull List<String> getStrings(@NotNull final String path,
-                                            final boolean format) {
+                                            final boolean format,
-        return handle.getStrings(path, format);
+                                            @NotNull final StringUtils.FormatOption option) {
-    }
+        return handle.getStrings(path, format, option);
-
-    @Override
-    public @Nullable List<String> getStringsOrNull(@NotNull final String path) {
-        return handle.getStringsOrNull(path);
     }
 
     @Override
     public @Nullable List<String> getStringsOrNull(@NotNull final String path,
-                                                   final boolean format) {
+                                                   final boolean format,
-        return handle.getStringsOrNull(path, format);
+                                                   @NotNull final StringUtils.FormatOption option) {
+        return handle.getStringsOrNull(path, format, option);
     }
 
     @Override

eco-api/src/main/java/com/willfp/eco/core/events/ArmorEquipEvent.java

@@ -16,7 +16,6 @@ import org.jetbrains.annotations.NotNull;
  *
  * @see ArmorChangeEvent
  */
-@Deprecated
 public class ArmorEquipEvent extends PlayerEvent {
     /**
      * Bukkit parity.

eco-api/src/main/java/com/willfp/eco/core/fast/FastItemStack.java

@@ -3,6 +3,7 @@ package com.willfp.eco.core.fast;
 import com.willfp.eco.core.Eco;
 import org.bukkit.Material;
 import org.bukkit.enchantments.Enchantment;
+import org.bukkit.inventory.ItemFlag;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -10,6 +11,7 @@ import org.jetbrains.annotations.Nullable;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Set;
 
 /**
  * FastItemStack contains methods to modify and read items faster than in default bukkit.
@@ -51,17 +53,47 @@ public interface FastItemStack {
     /**
      * Set the rework penalty.
      *
-     * @param cost      The rework penalty to set.
+     * @param cost The rework penalty to set.
      */
     void setRepairCost(int cost);
 
     /**
      * Get the rework penalty.
-     *.
+     * .
+     *
      * @return The rework penalty found on the item.
      */
     int getRepairCost();
 
+    /**
+     * Add ItemFlags.
+     *
+     * @param hideFlags The flags.
+     */
+    void addItemFlags(ItemFlag... hideFlags);
+
+    /**
+     * Remove ItemFlags.
+     *
+     * @param hideFlags The flags.
+     */
+    void removeItemFlags(ItemFlag... hideFlags);
+
+    /**
+     * Get the ItemFlags.
+     *
+     * @return The flags.
+     */
+    Set<ItemFlag> getItemFlags();
+
+    /**
+     * Test the item for a flag.
+     *
+     * @param flag The flag.
+     * @return If the flag is present.
+     */
+    boolean hasItemFlag(ItemFlag flag);
+
     /**
      * Get the Bukkit ItemStack again.
      *

eco-api/src/main/java/com/willfp/eco/core/gui/menu/Menu.java

@@ -2,12 +2,16 @@ package com.willfp.eco.core.gui.menu;
 
 import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.gui.slot.Slot;
+import org.bukkit.NamespacedKey;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.persistence.PersistentDataType;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
+import java.util.Set;
 
 /**
  * GUI version of {@link Inventory}.
@@ -55,6 +59,43 @@ public interface Menu {
      */
     List<ItemStack> getCaptiveItems(@NotNull Player player);
 
+    /**
+     * Write data.
+     *
+     * @param player The player.
+     * @param key    The key.
+     * @param type   The type.
+     * @param value  The value.
+     * @param <T>    The type.
+     * @param <Z>    The type.
+     */
+    <T, Z> void writeData(@NotNull Player player,
+                          @NotNull NamespacedKey key,
+                          @NotNull PersistentDataType<T, Z> type,
+                          @NotNull Z value);
+
+    /**
+     * Read data.
+     *
+     * @param player The player.
+     * @param key    The key.
+     * @param type   The type.
+     * @param <T>    The type.
+     * @param <Z>    The type.
+     * @return The data.
+     */
+    @Nullable <T, Z> T readData(@NotNull Player player,
+                                @NotNull NamespacedKey key,
+                                @NotNull PersistentDataType<T, Z> type);
+
+    /**
+     * Get all data keys for a player.
+     *
+     * @param player The player.
+     * @return The keys.
+     */
+    Set<NamespacedKey> getKeys(@NotNull Player player);
+
     /**
      * Create a builder with a given amount of rows.
      *

eco-api/src/main/java/com/willfp/eco/core/integrations/customitems/CustomItemsWrapper.java

@@ -1,9 +1,11 @@
 package com.willfp.eco.core.integrations.customitems;
 
+import com.willfp.eco.core.integrations.Integration;
+
 /**
  * Wrapper class for custom item integrations.
  */
-public interface CustomItemsWrapper {
+public interface CustomItemsWrapper extends Integration {
     /**
      * Register all the custom items for a specific plugin into eco.
      *

eco-api/src/main/java/com/willfp/eco/core/integrations/mcmmo/McmmoManager.java

@@ -16,7 +16,7 @@ public class McmmoManager {
     /**
      * A set of all registered integrations.
      */
-    private final Set<McmmoWrapper> regsistered = new HashSet<>();
+    private final Set<McmmoWrapper> registered = new HashSet<>();
 
     /**
      * Register a new integration.
@@ -24,7 +24,7 @@ public class McmmoManager {
      * @param integration The integration to register.
      */
     public void register(@NotNull final McmmoWrapper integration) {
-        regsistered.add(integration);
+        registered.add(integration);
     }
 
     /**
@@ -34,7 +34,7 @@ public class McmmoManager {
      * @return The bonus drop count.
      */
     public int getBonusDropCount(@NotNull final Block block) {
-        for (McmmoWrapper mcmmoWrapper : regsistered) {
+        for (McmmoWrapper mcmmoWrapper : registered) {
             return mcmmoWrapper.getBonusDropCount(block);
         }
         return 0;
@@ -47,7 +47,7 @@ public class McmmoManager {
      * @return If the event is fake.
      */
     public boolean isFake(@NotNull final Event event) {
-        for (McmmoWrapper mcmmoWrapper : regsistered) {
+        for (McmmoWrapper mcmmoWrapper : registered) {
             return mcmmoWrapper.isFake(event);
         }
         return false;

eco-api/src/main/java/com/willfp/eco/core/integrations/placeholder/PlaceholderManager.java

@@ -5,7 +5,9 @@ import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicReference;
@@ -18,7 +20,7 @@ public class PlaceholderManager {
     /**
      * All registered placeholders.
      */
-    private static final Set<PlaceholderEntry> REGISTERED_PLACEHOLDERS = new HashSet<>();
+    private static final Map<String, PlaceholderEntry> REGISTERED_PLACEHOLDERS = new HashMap<>();
 
     /**
      * All registered placeholder integrations.
@@ -41,8 +43,8 @@ public class PlaceholderManager {
      * @param expansion The {@link PlaceholderEntry} to register.
      */
     public static void registerPlaceholder(@NotNull final PlaceholderEntry expansion) {
-        REGISTERED_PLACEHOLDERS.removeIf(placeholderEntry -> placeholderEntry.getIdentifier().equalsIgnoreCase(expansion.getIdentifier()));
+        REGISTERED_PLACEHOLDERS.remove(expansion.getIdentifier());
-        REGISTERED_PLACEHOLDERS.add(expansion);
+        REGISTERED_PLACEHOLDERS.put(expansion.getIdentifier(), expansion);
     }
 
     /**
@@ -54,14 +56,15 @@ public class PlaceholderManager {
      */
     public static String getResult(@Nullable final Player player,
                                    @NotNull final String identifier) {
-        Optional<PlaceholderEntry> matching = REGISTERED_PLACEHOLDERS.stream().filter(expansion -> expansion.getIdentifier().equalsIgnoreCase(identifier)).findFirst();
+        PlaceholderEntry entry = REGISTERED_PLACEHOLDERS.get(identifier.toLowerCase());
-        if (matching.isEmpty()) {
+        if (entry == null) {
-            return null;
+            return "";
         }
-        PlaceholderEntry entry = matching.get();
+
         if (player == null && entry.requiresPlayer()) {
             return "";
         }
+
         return entry.getResult(player);
     }
 
@@ -74,8 +77,10 @@ public class PlaceholderManager {
      */
     public static String translatePlaceholders(@NotNull final String text,
                                                @Nullable final Player player) {
-        AtomicReference<String> translatedReference = new AtomicReference<>(text);
+        String processed = text;
-        REGISTERED_INTEGRATIONS.forEach(placeholderIntegration -> translatedReference.set(placeholderIntegration.translate(translatedReference.get(), player)));
+        for (PlaceholderIntegration integration : REGISTERED_INTEGRATIONS) {
-        return translatedReference.get();
+            processed = integration.translate(processed, player);
+        }
+        return processed;
     }
 }

eco-api/src/main/java/com/willfp/eco/core/integrations/shop/ShopManager.java

@@ -0,0 +1,36 @@
+package com.willfp.eco.core.integrations.shop;
+
+import lombok.experimental.UtilityClass;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Class to handle shop integrations.
+ */
+@UtilityClass
+public class ShopManager {
+    /**
+     * A set of all registered integrations.
+     */
+    private final Set<ShopWrapper> registered = new HashSet<>();
+
+    /**
+     * Register a new integration.
+     *
+     * @param integration The integration to register.
+     */
+    public void register(@NotNull final ShopWrapper integration) {
+        registered.add(integration);
+    }
+
+    /**
+     * Register eco item provider for shop plugins.
+     */
+    public void registerEcoProvider() {
+        for (ShopWrapper shopWrapper : registered) {
+            shopWrapper.registerEcoProvider();
+        }
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/integrations/shop/ShopWrapper.java

@@ -0,0 +1,11 @@
+package com.willfp.eco.core.integrations.shop;
+
+/**
+ * Wrapper class for shop integrations.
+ */
+public interface ShopWrapper {
+    /**
+     * Register eco item provider for shop plugins.
+     */
+    void registerEcoProvider();
+}

eco-api/src/main/java/com/willfp/eco/core/items/Items.java

@@ -1,7 +1,6 @@
 package com.willfp.eco.core.items;
 
-import com.willfp.eco.core.items.builder.ItemBuilder;
+import com.willfp.eco.core.items.args.LookupArgParser;
-import com.willfp.eco.core.items.builder.ItemStackBuilder;
 import com.willfp.eco.core.recipe.parts.EmptyTestableItem;
 import com.willfp.eco.core.recipe.parts.MaterialTestableItem;
 import com.willfp.eco.core.recipe.parts.ModifiedTestableItem;
@@ -10,16 +9,19 @@ import com.willfp.eco.util.NamespacedKeyUtils;
 import lombok.experimental.UtilityClass;
 import org.bukkit.Material;
 import org.bukkit.NamespacedKey;
-import org.bukkit.enchantments.Enchantment;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
+import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Predicate;
 
 /**
  * Class to manage all custom and vanilla items.
@@ -29,19 +31,33 @@ public final class Items {
     /**
      * All recipe parts.
      */
-    private static final Map<NamespacedKey, CustomItem> REGISTRY = new HashMap<>();
+    private static final Map<NamespacedKey, CustomItem> REGISTRY = new ConcurrentHashMap<>();
 
     /**
-     * Register a new recipe part.
+     * All recipe parts.
+     */
+    private static final List<LookupArgParser> ARG_PARSERS = new ArrayList<>();
+
+    /**
+     * Register a new custom item.
      *
-     * @param key  The key of the recipe part.
+     * @param key  The key of the item.
-     * @param part The recipe part.
+     * @param part The item.
      */
     public void registerCustomItem(@NotNull final NamespacedKey key,
                                    @NotNull final CustomItem part) {
         REGISTRY.put(key, part);
     }
 
+    /**
+     * Register a new arg parser.
+     *
+     * @param parser The parser.
+     */
+    public void registerArgParser(@NotNull final LookupArgParser parser) {
+        ARG_PARSERS.add(parser);
+    }
+
     /**
      * Remove an item.
      *
@@ -52,12 +68,27 @@ public final class Items {
     }
 
     /**
-     * Lookup item from string.
+     * This is the backbone of the entire eco item system.
      * <p>
-     * Used for recipes.
+     * You can lookup a TestableItem for any material, custom item,
+     * or item in general, and it will return it with any modifiers
+     * passed as parameters. This includes stack size (item amount)
+     * and enchantments that should be present on the item.
+     * <p>
+     * If you want to get an ItemStack instance from this, then just call
+     * {@link TestableItem#getItem()}.
+     * <p>
+     * The advantages of the testable item system are that there is the inbuilt
+     * {@link TestableItem#matches(ItemStack)} - this allows to check if any item
+     * is that testable item; which may sound negligible but actually it allows for
+     * much more power an flexibility. For example, you can have an item with an
+     * extra metadata tag, extra lore lines, different display name - and it
+     * will still work as long as the test passes. This is very important
+     * for custom crafting recipes where other plugins may add metadata
+     * values or the play may rename the item.
      *
-     * @param key The string to test.
+     * @param key The lookup string.
-     * @return The found testable item, or an empty item if not found.
+     * @return The testable item, or an {@link EmptyTestableItem}.
      */
     public TestableItem lookup(@NotNull final String key) {
         if (key.contains("?")) {
@@ -79,6 +110,8 @@ public final class Items {
 
         TestableItem item = null;
 
+        int stackAmount = 1;
+
         String[] split = args[0].toLowerCase().split(":");
 
         if (split.length == 1) {
@@ -92,71 +125,84 @@ public final class Items {
         if (split.length == 2) {
             CustomItem part = REGISTRY.get(NamespacedKeyUtils.create(split[0], split[1]));
 
+            /*
+            Legacy id:amount format
+            This has been superseded by id amount
+             */
             if (part == null) {
                 Material material = Material.getMaterial(split[0].toUpperCase());
                 if (material == null || material == Material.AIR) {
                     return new EmptyTestableItem();
                 }
-                item = new TestableStack(new MaterialTestableItem(material), Integer.parseInt(split[1]));
+                item = new MaterialTestableItem(material);
+                stackAmount = Integer.parseInt(split[1]);
             } else {
                 item = part;
             }
         }
 
+        /*
+        Legacy namespace:id:amount format
+        This has been superseded by namespace:id amount
+         */
         if (split.length == 3) {
             CustomItem part = REGISTRY.get(NamespacedKeyUtils.create(split[0], split[1]));
-            item = part == null ? new EmptyTestableItem() : new TestableStack(part, Integer.parseInt(split[2]));
+            if (part == null) {
+                return new EmptyTestableItem();
+            }
+            item = part;
+            stackAmount = Integer.parseInt(split[2]);
         }
 
+        boolean usingNewStackFormat = false;
+
+        if (args.length >= 2) {
+            try {
+                stackAmount = Integer.parseInt(args[1]);
+                usingNewStackFormat = true;
+            } catch (NumberFormatException ignored) {
+            }
+        }
+
+        // Marked as redundant but i am covering all bases here
         if (item == null || item instanceof EmptyTestableItem) {
             return new EmptyTestableItem();
         }
 
-        String[] enchantArgs = Arrays.copyOfRange(args, 1, args.length);
+        ItemStack example = item.getItem();
+        ItemMeta meta = example.getItemMeta();
+        assert meta != null;
 
-        Map<Enchantment, Integer> requiredEnchantments = new HashMap<>();
+        String[] modifierArgs = Arrays.copyOfRange(args, usingNewStackFormat ? 2 : 1, args.length);
 
-        for (String enchantArg : enchantArgs) {
+        List<Predicate<ItemStack>> predicates = new ArrayList<>();
-            String[] enchantArgSplit = enchantArg.split(":");
 
-            Enchantment enchantment = Enchantment.getByKey(NamespacedKey.minecraft(enchantArgSplit[0].toLowerCase()));
+        for (LookupArgParser argParser : ARG_PARSERS) {
-            int level = Integer.parseInt(enchantArgSplit[1]);
+            predicates.add(argParser.parseArguments(modifierArgs, meta));
-
-            requiredEnchantments.put(enchantment, level);
         }
 
-        if (requiredEnchantments.isEmpty()) {
+        example.setItemMeta(meta);
+        if (!predicates.isEmpty()) {
+            item = new ModifiedTestableItem(
+                    item,
+                    test -> {
+                        for (Predicate<ItemStack> predicate : predicates) {
+                            if (!predicate.test(test)) {
+                                return false;
+                            }
+                        }
+
+                        return true;
+                    },
+                    example
+            );
+        }
+
+        if (stackAmount <= 1) {
             return item;
+        } else {
+            return new TestableStack(item, stackAmount);
         }
-
-        ItemBuilder builder = new ItemStackBuilder(item.getItem());
-        requiredEnchantments.forEach(builder::addEnchantment);
-        ItemStack example = builder.build();
-
-        return new ModifiedTestableItem(
-                item,
-                itemStack -> {
-                    if (!itemStack.hasItemMeta()) {
-                        return false;
-                    }
-
-                    ItemMeta meta = itemStack.getItemMeta();
-
-                    assert meta != null;
-
-                    for (Map.Entry<Enchantment, Integer> entry : requiredEnchantments.entrySet()) {
-                        if (!meta.hasEnchant(entry.getKey())) {
-                            return false;
-                        }
-                        if (meta.getEnchantLevel(entry.getKey()) < entry.getValue()) {
-                            return false;
-                        }
-                    }
-
-                    return true;
-                },
-                example
-        );
     }
 
     /**
@@ -174,6 +220,22 @@ public final class Items {
         return false;
     }
 
+    /**
+     * Get custom item from item.
+     *
+     * @param itemStack The item.
+     * @return The custom item, or null if not exists.
+     */
+    @Nullable
+    public CustomItem getCustomItem(@NotNull final ItemStack itemStack) {
+        for (CustomItem item : REGISTRY.values()) {
+            if (item.matches(itemStack)) {
+                return item;
+            }
+        }
+        return null;
+    }
+
     /**
      * Get all registered custom items.
      *

eco-api/src/main/java/com/willfp/eco/core/items/args/EnchantmentArgParser.java

@@ -0,0 +1,78 @@
+package com.willfp.eco.core.items.args;
+
+import org.bukkit.NamespacedKey;
+import org.bukkit.enchantments.Enchantment;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.EnchantmentStorageMeta;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Predicate;
+
+/**
+ * Parses enchantment arguments.
+ */
+public class EnchantmentArgParser implements LookupArgParser {
+    @Override
+    public Predicate<ItemStack> parseArguments(@NotNull final String[] args,
+                                               @NotNull final ItemMeta meta) {
+        Map<Enchantment, Integer> requiredEnchantments = new HashMap<>();
+
+        for (String enchantArg : args) {
+            String[] enchantArgSplit = enchantArg.split(":");
+
+            Enchantment enchantment = Enchantment.getByKey(NamespacedKey.minecraft(enchantArgSplit[0].toLowerCase()));
+            if (enchantment == null) {
+                continue;
+            }
+
+            if (enchantArgSplit.length < 2) {
+                continue;
+            }
+
+            int level = Integer.parseInt(enchantArgSplit[1]);
+
+            requiredEnchantments.put(enchantment, level);
+        }
+
+        if (meta instanceof EnchantmentStorageMeta storageMeta) {
+            requiredEnchantments.forEach((enchantment, integer) -> storageMeta.addStoredEnchant(enchantment, integer, true));
+        } else {
+            requiredEnchantments.forEach((enchantment, integer) -> meta.addEnchant(enchantment, integer, true));
+        }
+
+        return test -> {
+            if (!test.hasItemMeta()) {
+                return false;
+            }
+
+            ItemMeta testMeta = test.getItemMeta();
+
+            assert testMeta != null;
+
+            if (testMeta instanceof EnchantmentStorageMeta storageMeta) {
+                for (Map.Entry<Enchantment, Integer> entry : requiredEnchantments.entrySet()) {
+                    if (!storageMeta.hasStoredEnchant(entry.getKey())) {
+                        return false;
+                    }
+                    if (storageMeta.getStoredEnchantLevel(entry.getKey()) < entry.getValue()) {
+                        return false;
+                    }
+                }
+            } else {
+                for (Map.Entry<Enchantment, Integer> entry : requiredEnchantments.entrySet()) {
+                    if (!testMeta.hasEnchant(entry.getKey())) {
+                        return false;
+                    }
+                    if (testMeta.getEnchantLevel(entry.getKey()) < entry.getValue()) {
+                        return false;
+                    }
+                }
+            }
+
+            return true;
+        };
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/items/args/LookupArgParser.java

@@ -0,0 +1,24 @@
+package com.willfp.eco.core.items.args;
+
+import com.willfp.eco.core.items.TestableItem;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.function.Predicate;
+
+/**
+ * An argument parser should generate the predicate as well
+ * as modify the ItemMeta for {@link TestableItem#getItem()}.
+ */
+public interface LookupArgParser {
+    /**
+     * Parse the arguments.
+     *
+     * @param args The arguments.
+     * @param meta The ItemMeta to modify.
+     * @return The predicate test to apply to the modified item.
+     */
+    Predicate<ItemStack> parseArguments(@NotNull String[] args,
+                                        @NotNull ItemMeta meta);
+}

eco-api/src/main/java/com/willfp/eco/core/items/args/TextureArgParser.java

@@ -0,0 +1,54 @@
+package com.willfp.eco.core.items.args;
+
+import com.willfp.eco.util.SkullUtils;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.bukkit.inventory.meta.SkullMeta;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.function.Predicate;
+
+/**
+ * Parse skull textures.
+ */
+public class TextureArgParser implements LookupArgParser {
+    @Override
+    public Predicate<ItemStack> parseArguments(@NotNull final String[] args,
+                                               @NotNull final ItemMeta meta) {
+        String skullTexture = null;
+
+        for (String arg : args) {
+            String[] argSplit = arg.split(":");
+            if (!argSplit[0].equalsIgnoreCase("texture")) {
+                continue;
+            }
+
+            if (argSplit.length < 2) {
+                continue;
+            }
+
+            skullTexture = argSplit[1];
+        }
+
+        if (meta instanceof SkullMeta skullMeta && skullTexture != null) {
+            SkullUtils.setSkullTexture(skullMeta, skullTexture);
+        }
+
+        String finalSkullTexture = skullTexture;
+        return test -> {
+            if (!test.hasItemMeta()) {
+                return false;
+            }
+
+            ItemMeta testMeta = test.getItemMeta();
+
+            assert testMeta != null;
+
+            if (testMeta instanceof SkullMeta skullMeta && finalSkullTexture != null) {
+                return finalSkullTexture.equalsIgnoreCase(SkullUtils.getSkullTexture(skullMeta));
+            }
+
+            return true;
+        };
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/recipe/parts/MaterialTestableItem.java

@@ -2,6 +2,7 @@ package com.willfp.eco.core.recipe.parts;
 
 import com.willfp.eco.core.items.TestableItem;
 import lombok.Getter;
+import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
@@ -23,6 +24,8 @@ public class MaterialTestableItem implements TestableItem {
      * @param material The material.
      */
     public MaterialTestableItem(@NotNull final Material material) {
+        Validate.isTrue(material != Material.AIR, "You can't have air as the type!");
+
         this.material = material;
     }
 

eco-api/src/main/java/com/willfp/eco/core/recipe/parts/ModifiedTestableItem.java

@@ -17,6 +17,7 @@ public class ModifiedTestableItem implements TestableItem {
     /**
      * The item.
      */
+    @Getter
     private final TestableItem handle;
 
     /**

eco-api/src/main/java/com/willfp/eco/core/recipe/parts/TestableStack.java

@@ -1,17 +1,12 @@
 package com.willfp.eco.core.recipe.parts;
 
-import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.items.TestableItem;
 import lombok.Getter;
 import org.apache.commons.lang.Validate;
 import org.bukkit.inventory.ItemStack;
-import org.bukkit.inventory.meta.ItemMeta;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import java.util.ArrayList;
-import java.util.List;
-
 /**
  * Stacks of items.
  */
@@ -19,6 +14,7 @@ public class TestableStack implements TestableItem {
     /**
      * The item.
      */
+    @Getter
     private final TestableItem handle;
 
     /**
@@ -35,7 +31,8 @@ public class TestableStack implements TestableItem {
      */
     public TestableStack(@NotNull final TestableItem item,
                          final int amount) {
-        Validate.isTrue(!(item instanceof TestableStack));
+        Validate.isTrue(!(item instanceof TestableStack), "You can't stack a stack!");
+        Validate.isTrue(!(item instanceof EmptyTestableItem), "You can't stack air!");
 
         this.handle = item;
         this.amount = amount;
@@ -55,19 +52,7 @@ public class TestableStack implements TestableItem {
     @Override
     public ItemStack getItem() {
         ItemStack temp = handle.getItem().clone();
-        ItemMeta meta = temp.getItemMeta();
-        assert meta != null;
-
-        List<String> lore = meta.hasLore() ? meta.getLore() : new ArrayList<>();
-        assert lore != null;
-        lore.add("");
-        String add = Eco.getHandler().getEcoPlugin().getLangYml().getString("multiple-in-craft");
-        add = add.replace("%amount%", String.valueOf(amount));
-        lore.add(add);
-        meta.setLore(lore);
-        temp.setItemMeta(meta);
         temp.setAmount(amount);
-
         return temp;
     }
 }

eco-api/src/main/java/com/willfp/eco/core/recipe/recipes/ShapedCraftingRecipe.java

@@ -1,16 +1,19 @@
 package com.willfp.eco.core.recipe.recipes;
 
+import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.PluginDependent;
 import com.willfp.eco.core.items.TestableItem;
 import com.willfp.eco.core.recipe.Recipes;
 import com.willfp.eco.core.recipe.parts.EmptyTestableItem;
+import com.willfp.eco.core.recipe.parts.TestableStack;
 import lombok.Getter;
 import org.bukkit.Bukkit;
 import org.bukkit.NamespacedKey;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.RecipeChoice;
 import org.bukkit.inventory.ShapedRecipe;
+import org.bukkit.inventory.meta.ItemMeta;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
@@ -87,7 +90,23 @@ public final class ShapedCraftingRecipe extends PluginDependent<EcoPlugin> imple
         displayedRecipe.shape("012", "345", "678");
         for (int i = 0; i < 9; i++) {
             char character = String.valueOf(i).toCharArray()[0];
-            displayedRecipe.setIngredient(character, new RecipeChoice.ExactChoice(parts.get(i).getItem()));
+            ItemStack item = parts.get(i).getItem();
+
+            if (parts.get(i) instanceof TestableStack) {
+                ItemMeta meta = item.getItemMeta();
+                assert meta != null;
+
+                List<String> lore = meta.hasLore() ? meta.getLore() : new ArrayList<>();
+                assert lore != null;
+                lore.add("");
+                String add = Eco.getHandler().getEcoPlugin().getLangYml().getString("multiple-in-craft");
+                add = add.replace("%amount%", String.valueOf(item.getAmount()));
+                lore.add(add);
+                meta.setLore(lore);
+                item.setItemMeta(meta);
+            }
+
+            displayedRecipe.setIngredient(character, new RecipeChoice.ExactChoice(item));
         }
 
         Bukkit.getServer().addRecipe(shapedRecipe);

eco-api/src/main/java/com/willfp/eco/util/ArrowUtils.java

@@ -19,7 +19,7 @@ public class ArrowUtils {
      * Get the bow from an arrow.
      *
      * @param arrow The arrow.
-     * @return The bow.
+     * @return The bow, or null if no bow.
      */
     @Nullable
     public ItemStack getBow(@NotNull final Arrow arrow) {

eco-api/src/main/java/com/willfp/eco/util/BlockUtils.java

@@ -63,6 +63,7 @@ public class BlockUtils {
      * @param limit            The maximum size of vein to return.
      * @return A set of all {@link Block}s.
      */
+    @NotNull
     public Set<Block> getVein(@NotNull final Block start,
                               @NotNull final List<Material> allowedMaterials,
                               final int limit) {

eco-api/src/main/java/com/willfp/eco/util/ListUtils.java

@@ -1,6 +1,8 @@
 package com.willfp.eco.util;
 
 import lombok.experimental.UtilityClass;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -18,8 +20,9 @@ public class ListUtils {
      * @param <T>     The type of the object stored in the list.
      * @return The list, filled will null objects.
      */
-    public <T> List<List<T>> create2DList(final int rows,
+    @NotNull
-                                          final int columns) {
+    public <@Nullable T> List<List<T>> create2DList(final int rows,
+                                                    final int columns) {
         List<List<T>> list = new ArrayList<>(rows);
         while (list.size() < rows) {
             List<T> row = new ArrayList<>(columns);

eco-api/src/main/java/com/willfp/eco/util/MenuUtils.java

@@ -2,6 +2,7 @@ package com.willfp.eco.util;
 
 import com.willfp.eco.core.tuples.Pair;
 import lombok.experimental.UtilityClass;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Utilities / API methods for menus.
@@ -14,6 +15,7 @@ public class MenuUtils {
      * @param slot The slot.
      * @return The pair of row and columns.
      */
+    @NotNull
     public Pair<Integer, Integer> convertSlotToRowColumn(final int slot) {
         int row = Math.floorDiv(slot, 9);
         int column = slot - row * 9;

eco-api/src/main/java/com/willfp/eco/util/NamespacedKeyUtils.java

@@ -17,6 +17,7 @@ public class NamespacedKeyUtils {
      * @param string The string.
      * @return The key.
      */
+    @NotNull
     public NamespacedKey createEcoKey(@NotNull final String string) {
         return Objects.requireNonNull(NamespacedKey.fromString("eco:" + string));
     }
@@ -28,6 +29,7 @@ public class NamespacedKeyUtils {
      * @param key       The key.
      * @return The key.
      */
+    @NotNull
     public NamespacedKey create(@NotNull final String namespace,
                                 @NotNull final String key) {
         return Objects.requireNonNull(NamespacedKey.fromString(namespace + ":" + key));

eco-api/src/main/java/com/willfp/eco/util/NumberUtils.java

@@ -1,5 +1,6 @@
 package com.willfp.eco.util;
 
+import lombok.experimental.NonFinal;
 import lombok.experimental.UtilityClass;
 import org.jetbrains.annotations.NotNull;
 
@@ -109,6 +110,7 @@ public class NumberUtils {
      * @param number The number to convert.
      * @return The number, converted to a roman numeral.
      */
+    @NotNull
     public String toNumeral(final int number) {
         if (number >= 1 && number <= 4096) {
             int l = NUMERALS.floorKey(number);
@@ -199,6 +201,7 @@ public class NumberUtils {
      * @param toFormat The number to format.
      * @return Formatted.
      */
+    @NotNull
     public String format(final double toFormat) {
         DecimalFormat df = new DecimalFormat("0.00");
         String formatted = df.format(toFormat);

eco-api/src/main/java/com/willfp/eco/util/SkullUtils.java

@@ -5,8 +5,10 @@ import org.apache.commons.lang.Validate;
 import org.bukkit.inventory.meta.SkullMeta;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.function.BiConsumer;
+import java.util.function.Function;
 
 /**
  * Utilities / API methods for player heads.
@@ -23,6 +25,11 @@ public class SkullUtils {
      */
     private BiConsumer<SkullMeta, String> metaSetConsumer = null;
 
+    /**
+     * The meta get function.
+     */
+    private Function<SkullMeta, String> metaGetConsumer = null;
+
     /**
      * Set the texture of a skull from base64.
      *
@@ -37,16 +44,33 @@ public class SkullUtils {
         metaSetConsumer.accept(meta, base64);
     }
 
+    /**
+     * Get the texture of a skull - in base64.
+     *
+     * @param meta The meta to modify.
+     * @return The texture, potentially null.
+     */
+    @Nullable
+    public String getSkullTexture(@NotNull final SkullMeta meta) {
+        Validate.isTrue(initialized, "Must be initialized!");
+        Validate.notNull(metaGetConsumer, "Must be initialized!");
+
+        return metaGetConsumer.apply(meta);
+    }
+
     /**
      * Initialize the skull texture function.
      *
-     * @param function The function.
+     * @param function  The function.
+     * @param function2 Get function.
      */
     @ApiStatus.Internal
-    public void initialize(@NotNull final BiConsumer<SkullMeta, String> function) {
+    public void initialize(@NotNull final BiConsumer<SkullMeta, String> function,
+                           @NotNull final Function<SkullMeta, String> function2) {
         Validate.isTrue(!initialized, "Already initialized!");
 
         metaSetConsumer = function;
+        metaGetConsumer = function2;
         initialized = true;
     }
 }

eco-api/src/main/java/com/willfp/eco/util/StringUtils.java

@@ -12,7 +12,7 @@ import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import java.awt.*;
+import java.awt.Color;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -57,58 +57,137 @@ public class StringUtils {
             .build();
 
     /**
-     * Format a list of strings - converts Placeholders and Color codes.
+     * Format a list of strings.
+     * <p>
+     * Converts color codes and placeholders.
+     *
+     * @param list The messages to format.
+     * @return The message, formatted.
+     */
+    @NotNull
+    public List<String> formatList(@NotNull final List<String> list) {
+        return formatList(list, (Player) null);
+    }
+
+    /**
+     * Format a list of strings.
+     * <p>
+     * Coverts color codes and placeholders for a player.
      *
      * @param list   The messages to format.
      * @param player The player to translate placeholders with respect to.
      * @return The message, format.
      */
+    @NotNull
     public List<String> formatList(@NotNull final List<String> list,
                                    @Nullable final Player player) {
+        return formatList(list, player, FormatOption.WITH_PLACEHOLDERS);
+    }
+
+    /**
+     * Format a list of strings.
+     * <p>
+     * Converts color codes and placeholders if specified.
+     *
+     * @param list   The messages to format.
+     * @param option The format option.
+     * @return The message, formatted.
+     */
+    @NotNull
+    public List<String> formatList(@NotNull final List<String> list,
+                                   @NotNull final FormatOption option) {
+        return formatList(list, null, option);
+    }
+
+    /**
+     * Format a list of strings.
+     * <p>
+     * Coverts color codes and placeholders for a player if specified.
+     *
+     * @param list   The messages to format.
+     * @param player The player to translate placeholders with respect to.
+     * @param option The options.
+     * @return The message, format.
+     */
+    @NotNull
+    public List<String> formatList(@NotNull final List<String> list,
+                                   @Nullable final Player player,
+                                   @NotNull final FormatOption option) {
         List<String> translated = new ArrayList<>();
         for (String string : list) {
-            translated.add(format(string, player));
+            translated.add(format(string, player, option));
         }
 
         return translated;
     }
 
     /**
-     * Format a list of strings - converts Placeholders and Color codes.
+     * Format a string.
-     *
+     * <p>
-     * @param list The messages to format.
+     * Converts color codes and placeholders.
-     * @return The message, formatted.
-     */
-    public List<String> formatList(@NotNull final List<String> list) {
-        return formatList(list, null);
-    }
-
-    /**
-     * Format a string - converts Placeholders and Color codes.
-     *
-     * @param message The message to format.
-     * @param player  The player to translate placeholders with respect to.
-     * @return The message, formatted.
-     */
-    public String format(@NotNull final String message,
-                         @Nullable final Player player) {
-        String processedMessage = message;
-        processedMessage = translateGradients(processedMessage);
-        processedMessage = PlaceholderManager.translatePlaceholders(processedMessage, player);
-        processedMessage = translateHexColorCodes(processedMessage);
-        processedMessage = ChatColor.translateAlternateColorCodes('&', processedMessage);
-        return processedMessage;
-    }
-
-    /**
-     * Format a string without respect to a player.
      *
      * @param message The message to translate.
      * @return The message, formatted.
      * @see StringUtils#format(String, Player)
      */
+    @NotNull
     public String format(@NotNull final String message) {
-        return format(message, null);
+        return format(message, (Player) null);
+    }
+
+    /**
+     * Format a string.
+     * <p>
+     * Converts color codes and placeholders for a player.
+     *
+     * @param message The message to format.
+     * @param player  The player to translate placeholders with respect to.
+     * @return The message, formatted.
+     */
+    @NotNull
+    public String format(@NotNull final String message,
+                         @Nullable final Player player) {
+        return format(message, player, FormatOption.WITH_PLACEHOLDERS);
+    }
+
+    /**
+     * Format a string.
+     * <p>
+     * Converts color codes and placeholders if specified.
+     *
+     * @param message The message to translate.
+     * @param option  The format option.
+     * @return The message, formatted.
+     * @see StringUtils#format(String, Player)
+     */
+    @NotNull
+    public String format(@NotNull final String message,
+                         @NotNull final FormatOption option) {
+        return format(message, null, option);
+    }
+
+    /**
+     * Format a string.
+     * <p>
+     * Coverts color codes and placeholders for a player if specified.
+     *
+     * @param message The message to format.
+     * @param player  The player to translate placeholders with respect to.
+     * @param option  The format options.
+     * @return The message, formatted.
+     */
+    @NotNull
+    public String format(@NotNull final String message,
+                         @Nullable final Player player,
+                         @NotNull final FormatOption option) {
+        String processedMessage = message;
+        processedMessage = translateGradients(processedMessage);
+        if (option == FormatOption.WITH_PLACEHOLDERS) {
+            processedMessage = PlaceholderManager.translatePlaceholders(processedMessage, player);
+        }
+        processedMessage = translateHexColorCodes(processedMessage);
+        processedMessage = ChatColor.translateAlternateColorCodes('&', processedMessage);
+        return processedMessage;
     }
 
     private static String translateHexColorCodes(@NotNull final String message) {
@@ -213,6 +292,7 @@ public class StringUtils {
      * @param object The object to convert to string.
      * @return The object stringified.
      */
+    @NotNull
     public String internalToString(@Nullable final Object object) {
         if (object == null) {
             return "null";
@@ -238,6 +318,7 @@ public class StringUtils {
      * @param prefix The substring to remove.
      * @return The string with the prefix removed.
      */
+    @NotNull
     public String removePrefix(@NotNull final String string,
                                @NotNull final String prefix) {
         if (string.startsWith(prefix)) {
@@ -252,6 +333,7 @@ public class StringUtils {
      * @param legacy The legacy string.
      * @return The JSON String.
      */
+    @NotNull
     public String legacyToJson(@NotNull final String legacy) {
         return GsonComponentSerializer.gson().serialize(
                 Component.empty().decoration(TextDecoration.ITALIC, false).append(
@@ -266,9 +348,25 @@ public class StringUtils {
      * @param json The JSON string.
      * @return The legacy string.
      */
+    @NotNull
     public String jsonToLegacy(@NotNull final String json) {
         return LEGACY_COMPONENT_SERIALIZER.serialize(
                 GsonComponentSerializer.gson().deserialize(json)
         );
     }
+
+    /**
+     * Options for formatting.
+     */
+    public enum FormatOption {
+        /**
+         * Completely formatted.
+         */
+        WITH_PLACEHOLDERS,
+
+        /**
+         * Completely formatted without placeholders.
+         */
+        WITHOUT_PLACEHOLDERS
+    }
 }

eco-api/src/main/java/com/willfp/eco/util/TeamUtils.java

@@ -43,6 +43,7 @@ public class TeamUtils {
      * @param color The color to find the team for.
      * @return The team.
      */
+    @NotNull
     public Team fromChatColor(@NotNull final ChatColor color) {
         if (CHAT_COLOR_TEAMS.containsKey(color)) {
             return CHAT_COLOR_TEAMS.get(color);
@@ -70,6 +71,7 @@ public class TeamUtils {
      * @param material The material to find the team from.
      * @return The team.
      */
+    @NotNull
     public Team getMaterialColorTeam(@NotNull final Material material) {
         return fromChatColor(MATERIAL_COLORS.getOrDefault(material, ChatColor.WHITE));
     }

eco-api/src/main/java/com/willfp/eco/util/VectorUtils.java

@@ -44,6 +44,7 @@ public class VectorUtils {
      * @param vec The vector to simplify.
      * @return The vector, simplified.
      */
+    @NotNull
     public Vector simplifyVector(@NotNull final Vector vec) {
         double x = Math.abs(vec.getX());
         double y = Math.abs(vec.getY());
@@ -76,6 +77,7 @@ public class VectorUtils {
      * @param radius The radius.
      * @return An array of {@link Vector}s.
      */
+    @NotNull
     public Vector[] getCircle(final int radius) {
         Vector[] cached = CIRCLE_CACHE.get(radius);
         if (cached != null) {
@@ -112,6 +114,7 @@ public class VectorUtils {
      * @param radius The radius of the square.
      * @return An array of {@link Vector}s.
      */
+    @NotNull
     public Vector[] getSquare(final int radius) {
         List<Vector> vectors = new ArrayList<>();
 
@@ -136,6 +139,7 @@ public class VectorUtils {
      * @param radius The radius of the cube.
      * @return An array of {@link Vector}s.
      */
+    @NotNull
     public Vector[] getCube(final int radius) {
         List<Vector> vectors = new ArrayList<>();
 

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/config/json/EcoJSONConfigWrapper.kt

@@ -11,9 +11,9 @@ import java.util.*
 open class EcoJSONConfigWrapper : JSONConfig {
     val handle: Gson = GsonBuilder().setPrettyPrinting().create()
 
-    val values: MutableMap<String, Any?> = HashMap()
+    val values = mutableMapOf<String, Any?>()
 
-    private val cache: MutableMap<String, Any> = HashMap()
+    private val cache = mutableMapOf<String, Any>()
 
     fun init(values: Map<String, Any?>) {
         this.values.clear()
@@ -138,17 +138,17 @@ open class EcoJSONConfigWrapper : JSONConfig {
 
     override fun getSubsections(path: String): List<JSONConfig> {
         val subsections = getSubsectionsOrNull(path)
-        return subsections ?: ArrayList()
+        return subsections ?: mutableListOf()
     }
 
     override fun getSubsectionsOrNull(path: String): List<JSONConfig>? {
         val maps = getOfKnownType(path, Any::class.java) as List<Map<String, Any>>?
             ?: return null
-        val configs: MutableList<JSONConfig> = ArrayList()
+        val configs = mutableListOf<JSONConfig>()
         for (map in maps) {
             configs.add(EcoJSONConfigSection(map))
         }
-        return configs
+        return configs.toMutableList()
     }
 
     override fun getInt(path: String): Int {
@@ -170,11 +170,11 @@ open class EcoJSONConfigWrapper : JSONConfig {
         return Objects.requireNonNullElse(getOfKnownType(path, Int::class.java), def)
     }
 
-    override fun getInts(path: String): List<Int> {
+    override fun getInts(path: String): MutableList<Int> {
-        return Objects.requireNonNullElse(getOfKnownType(path, Any::class.java), ArrayList<Any>()) as List<Int>
+        return (Objects.requireNonNullElse(getOfKnownType(path, Any::class.java), emptyList<Int>()) as List<Int>).toMutableList()
     }
 
-    override fun getIntsOrNull(path: String): List<Int>? {
+    override fun getIntsOrNull(path: String): MutableList<Int>? {
         return if (has(path)) {
             getInts(path)
         } else {
@@ -194,11 +194,11 @@ open class EcoJSONConfigWrapper : JSONConfig {
         }
     }
 
-    override fun getBools(path: String): List<Boolean> {
+    override fun getBools(path: String): MutableList<Boolean> {
-        return Objects.requireNonNullElse(getOfKnownType(path, Any::class.java), ArrayList<Any>()) as List<Boolean>
+        return (Objects.requireNonNullElse(getOfKnownType(path, Any::class.java), emptyList<Boolean>()) as List<Boolean>).toMutableList()
     }
 
-    override fun getBoolsOrNull(path: String): List<Boolean>? {
+    override fun getBoolsOrNull(path: String): MutableList<Boolean>? {
         return if (has(path)) {
             getBools(path)
         } else {
@@ -206,64 +206,44 @@ open class EcoJSONConfigWrapper : JSONConfig {
         }
     }
 
-    override fun getString(path: String): String {
-        return getString(path, true)
-    }
-
     override fun getString(
         path: String,
-        format: Boolean
+        format: Boolean,
+        option: StringUtils.FormatOption
     ): String {
         val string = getOfKnownType(path, String::class.java) ?: ""
-        return if (format) StringUtils.format(string) else string
+        return if (format) StringUtils.format(string, option) else string
-    }
-
-    override fun getStringOrNull(path: String): String? {
-        return if (has(path)) {
-            getString(path)
-        } else {
-            null
-        }
     }
 
     override fun getStringOrNull(
         path: String,
-        format: Boolean
+        format: Boolean,
+        option: StringUtils.FormatOption
     ): String? {
         return if (has(path)) {
-            getString(path, format)
+            getString(path, format, option)
         } else {
             null
         }
     }
 
-    override fun getStrings(path: String): List<String> {
-        return getStrings(path, true)
-    }
-
     override fun getStrings(
         path: String,
-        format: Boolean
+        format: Boolean,
-    ): List<String> {
+        option: StringUtils.FormatOption
+    ): MutableList<String> {
         val strings =
-            Objects.requireNonNullElse(getOfKnownType(path, Any::class.java), ArrayList<Any>()) as List<String>
+            (Objects.requireNonNullElse(getOfKnownType(path, Any::class.java), emptyList<String>()) as List<String>).toMutableList()
-        return if (format) StringUtils.formatList(strings) else strings
+        return if (format) StringUtils.formatList(strings, option) else strings
-    }
-
-    override fun getStringsOrNull(path: String): List<String>? {
-        return if (has(path)) {
-            getStrings(path)
-        } else {
-            null
-        }
     }
 
     override fun getStringsOrNull(
         path: String,
-        format: Boolean
+        format: Boolean,
-    ): List<String>? {
+        option: StringUtils.FormatOption
+    ): MutableList<String>? {
         return if (has(path)) {
-            getStrings(path, format)
+            getStrings(path, format, option)
         } else {
             null
         }
@@ -281,11 +261,11 @@ open class EcoJSONConfigWrapper : JSONConfig {
         }
     }
 
-    override fun getDoubles(path: String): List<Double> {
+    override fun getDoubles(path: String): MutableList<Double> {
-        return Objects.requireNonNullElse(getOfKnownType(path, Any::class.java), ArrayList<Any>()) as List<Double>
+        return (Objects.requireNonNullElse(getOfKnownType(path, Any::class.java), emptyList<Double>()) as List<Double>).toMutableList()
     }
 
-    override fun getDoublesOrNull(path: String): List<Double>? {
+    override fun getDoublesOrNull(path: String): MutableList<Double>? {
         return if (has(path)) {
             getDoubles(path)
         } else {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/config/json/EcoLoadableJSONConfig.kt

@@ -27,7 +27,6 @@ class EcoLoadableJSONConfig(
     }
 
     override fun createFile() {
-        val resourcePath = resourcePath
         val inputStream = source.getResourceAsStream(resourcePath)!!
         val outFile = File(this.plugin.dataFolder, resourcePath)
         val lastIndex = resourcePath.lastIndexOf('/')
@@ -37,11 +36,7 @@ class EcoLoadableJSONConfig(
         }
         if (!outFile.exists()) {
             val out: OutputStream = FileOutputStream(outFile)
-            val buf = ByteArray(1024)
+            inputStream.copyTo(out, 1024)
-            var len: Int
-            while (inputStream.read(buf).also { len = it } > 0) {
-                out.write(buf, 0, len)
-            }
             out.close()
             inputStream.close()
         }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/config/updating/EcoConfigHandler.kt

@@ -1,7 +1,6 @@
 package com.willfp.eco.internal.config.updating
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.config.interfaces.LoadableConfig
 import com.willfp.eco.core.config.updating.ConfigHandler
 import com.willfp.eco.core.config.updating.ConfigUpdater
@@ -14,14 +13,14 @@ import org.reflections.scanners.MethodAnnotationsScanner
 import java.lang.reflect.Modifier
 
 class EcoConfigHandler(
-    plugin: EcoPlugin
+    private val plugin: EcoPlugin
-) : PluginDependent<EcoPlugin>(plugin), ConfigHandler {
+) : ConfigHandler {
     private val reflections: Reflections = Reflections(
         this.plugin::class.java.classLoader,
         MethodAnnotationsScanner()
     )
 
-    private val configs: MutableList<LoadableConfig> = ArrayList()
+    private val configs = mutableListOf<LoadableConfig>()
 
     override fun callUpdate() {
         for (method in reflections.getMethodsAnnotatedWith(ConfigUpdater::class.java)) {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/config/yaml/EcoLoadableYamlConfig.kt

@@ -31,7 +31,6 @@ open class EcoLoadableYamlConfig(
     }
 
     final override fun createFile() {
-        val resourcePath = resourcePath
         val inputStream = source.getResourceAsStream(resourcePath)!!
         val outFile = File(this.plugin.dataFolder, resourcePath)
         val lastIndex = resourcePath.lastIndexOf('/')
@@ -41,11 +40,7 @@ open class EcoLoadableYamlConfig(
         }
         if (!outFile.exists()) {
             val out: OutputStream = FileOutputStream(outFile)
-            val buf = ByteArray(1024)
+            inputStream.copyTo(out, 1024)
-            var len: Int
-            while (inputStream.read(buf).also { len = it } > 0) {
-                out.write(buf, 0, len)
-            }
             out.close()
             inputStream.close()
         }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/config/yaml/EcoYamlConfigWrapper.kt

@@ -10,7 +10,7 @@ import java.io.StringReader
 @Suppress("UNCHECKED_CAST")
 open class EcoYamlConfigWrapper<T : ConfigurationSection> : Config {
     lateinit var handle: T
-    private val cache: MutableMap<String, Any?> = HashMap()
+    private val cache = mutableMapOf<String, Any?>()
 
     protected fun init(config: T): Config {
         handle = config
@@ -98,16 +98,16 @@ open class EcoYamlConfigWrapper<T : ConfigurationSection> : Config {
         }
     }
 
-    override fun getInts(path: String): List<Int> {
+    override fun getInts(path: String): MutableList<Int> {
         return if (cache.containsKey(path)) {
-            cache[path] as List<Int>
+            (cache[path] as MutableList<Int>).toMutableList()
         } else {
-            cache[path] = if (has(path)) ArrayList(handle.getIntegerList(path)) else ArrayList<Any>()
+            cache[path] = if (has(path)) ArrayList(handle.getIntegerList(path)) else mutableListOf<Int>()
             getInts(path)
         }
     }
 
-    override fun getIntsOrNull(path: String): List<Int>? {
+    override fun getIntsOrNull(path: String): MutableList<Int>? {
         return if (has(path)) {
             getInts(path)
         } else {
@@ -132,17 +132,17 @@ open class EcoYamlConfigWrapper<T : ConfigurationSection> : Config {
         }
     }
 
-    override fun getBools(path: String): List<Boolean> {
+    override fun getBools(path: String): MutableList<Boolean> {
         return if (cache.containsKey(path)) {
-            cache[path] as List<Boolean>
+            (cache[path] as MutableList<Boolean>).toMutableList()
         } else {
             cache[path] =
-                if (has(path)) ArrayList(handle.getBooleanList(path)) else ArrayList<Any>()
+                if (has(path)) ArrayList(handle.getBooleanList(path)) else mutableListOf<Boolean>()
             getBools(path)
         }
     }
 
-    override fun getBoolsOrNull(path: String): List<Boolean>? {
+    override fun getBoolsOrNull(path: String): MutableList<Boolean>? {
         return if (has(path)) {
             getBools(path)
         } else {
@@ -150,92 +150,80 @@ open class EcoYamlConfigWrapper<T : ConfigurationSection> : Config {
         }
     }
 
-    override fun getString(path: String): String {
-        return getString(path, true)
-    }
-
     override fun getString(
         path: String,
-        format: Boolean
+        format: Boolean,
+        option: StringUtils.FormatOption
     ): String {
-        if (format) {
+        if (format && option == StringUtils.FormatOption.WITHOUT_PLACEHOLDERS) {
             return if (cache.containsKey("$path\$FMT")) {
                 cache["$path\$FMT"] as String
             } else {
                 val string: String = handle.getString(path, "")!!
-                cache["$path\$FMT"] = StringUtils.format(string)
+                cache["$path\$FMT"] = StringUtils.format(string, option)
-                getString(path, format)
+                getString(path, format, option)
             }
         } else {
-            return if (cache.containsKey(path)) {
+            val string = if (cache.containsKey(path)) {
                 cache[path] as String
             } else {
                 cache[path] = handle.getString(path, "")!!
-                getString(path)
+                getString(path, format, option)
             }
-        }
-    }
 
-    override fun getStringOrNull(path: String): String? {
+            return if (format) StringUtils.format(string) else string
-        return if (has(path)) {
-            getString(path)
-        } else {
-            null
         }
     }
 
     override fun getStringOrNull(
         path: String,
-        format: Boolean
+        format: Boolean,
+        option: StringUtils.FormatOption
     ): String? {
         return if (has(path)) {
-            getString(path, format)
+            getString(path, format, option)
         } else {
             null
         }
     }
 
-    override fun getStrings(path: String): List<String> {
-        return getStrings(path, true)
-    }
-
     override fun getStrings(
         path: String,
-        format: Boolean
+        format: Boolean,
-    ): List<String> {
+        option: StringUtils.FormatOption
-        if (format) {
+    ): MutableList<String> {
+        if (format && option == StringUtils.FormatOption.WITHOUT_PLACEHOLDERS) {
             return if (cache.containsKey("$path\$FMT")) {
-                cache["$path\$FMT"] as List<String>
+                (cache["$path\$FMT"] as MutableList<String>).toMutableList()
             } else {
-                val list = if (has(path)) handle.getStringList(path) else ArrayList()
+                val list = if (has(path)) handle.getStringList(path) else mutableListOf<String>()
-                cache["$path\$FMT"] = StringUtils.formatList(list);
+                cache["$path\$FMT"] = StringUtils.formatList(list, option)
-                getStrings(path, true)
+                getStrings(path, true, option)
             }
         } else {
-            return if (cache.containsKey(path)) {
+            val strings = if (cache.containsKey(path)) {
-                cache[path] as List<String>
+                (cache[path] as MutableList<String>).toMutableList()
             } else {
                 cache[path] =
-                    if (has(path)) ArrayList(handle.getStringList(path)) else ArrayList<Any>()
+                    if (has(path)) ArrayList(handle.getStringList(path)) else mutableListOf<String>()
-                getStrings(path, false)
+                getStrings(path, false, option)
             }
-        }
-    }
 
-    override fun getStringsOrNull(path: String): List<String>? {
+            return if (format) {
-        return if (has(path)) {
+                StringUtils.formatList(strings, StringUtils.FormatOption.WITH_PLACEHOLDERS)
-            getStrings(path)
+            } else {
-        } else {
+                strings
-            null
+            }
         }
     }
 
     override fun getStringsOrNull(
         path: String,
-        format: Boolean
+        format: Boolean,
-    ): List<String>? {
+        option: StringUtils.FormatOption
+    ): MutableList<String>? {
         return if (has(path)) {
-            getStrings(path, format)
+            getStrings(path, format, option)
         } else {
             null
         }
@@ -258,16 +246,16 @@ open class EcoYamlConfigWrapper<T : ConfigurationSection> : Config {
         }
     }
 
-    override fun getDoubles(path: String): List<Double> {
+    override fun getDoubles(path: String): MutableList<Double> {
         return if (cache.containsKey(path)) {
-            cache[path] as List<Double>
+            (cache[path] as MutableList<Double>).toMutableList()
         } else {
-            cache[path] = if (has(path)) ArrayList(handle.getDoubleList(path)) else ArrayList<Any>()
+            cache[path] = if (has(path)) ArrayList(handle.getDoubleList(path)) else emptyList<Double>()
             getDoubles(path)
         }
     }
 
-    override fun getDoublesOrNull(path: String): List<Double>? {
+    override fun getDoublesOrNull(path: String): MutableList<Double>? {
         return if (has(path)) {
             getDoubles(path)
         } else {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/drops/impl/EcoDropQueue.kt

@@ -13,8 +13,8 @@ import org.bukkit.inventory.ItemStack
 import org.bukkit.util.Vector
 
 open class EcoDropQueue(player: Player) : InternalDropQueue {
-    val items: MutableList<ItemStack>
+    val items = mutableListOf<ItemStack>()
-    var xp: Int
+    var xp: Int = 0
     val player: Player
     var loc: Location
     var hasTelekinesis = false
@@ -79,8 +79,6 @@ open class EcoDropQueue(player: Player) : InternalDropQueue {
     }
 
     init {
-        items = ArrayList()
-        xp = 0
         this.player = player
         loc = player.location
     }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/events/EcoEventManager.kt

@@ -1,13 +1,12 @@
 package com.willfp.eco.internal.events
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.events.EventManager
 import org.bukkit.Bukkit
 import org.bukkit.event.HandlerList
 import org.bukkit.event.Listener
 
-class EcoEventManager constructor(plugin: EcoPlugin) : PluginDependent<EcoPlugin>(plugin), EventManager {
+class EcoEventManager (private val plugin: EcoPlugin) : EventManager {
     override fun registerListener(listener: Listener) {
         Bukkit.getPluginManager().registerEvents(listener, plugin)
     }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/extensions/EcoExtensionLoader.kt

@@ -2,7 +2,6 @@ package com.willfp.eco.internal.extensions
 
 import com.google.common.collect.ImmutableSet
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.config.yaml.YamlTransientConfig
 import com.willfp.eco.core.extensions.Extension
 import com.willfp.eco.core.extensions.ExtensionLoader
@@ -16,9 +15,9 @@ import java.net.URL
 import java.net.URLClassLoader
 
 class EcoExtensionLoader(
-    plugin: EcoPlugin
+    private val plugin: EcoPlugin
-) : PluginDependent<EcoPlugin>(plugin), ExtensionLoader {
+) : ExtensionLoader {
-    private val extensions: MutableMap<Extension, URLClassLoader> = HashMap()
+    private val extensions = mutableMapOf<Extension, URLClassLoader>()
 
     override fun loadExtensions() {
         val dir = File(this.plugin.dataFolder, "/extensions")
@@ -43,7 +42,7 @@ class EcoExtensionLoader(
 
     @Throws(MalformedExtensionException::class)
     private fun loadExtension(extensionJar: File) {
-        lateinit var url : URL
+        lateinit var url: URL
 
         try {
             url = extensionJar.toURI().toURL()
@@ -53,7 +52,7 @@ class EcoExtensionLoader(
 
         val classLoader = URLClassLoader(arrayOf(url), this.plugin::class.java.classLoader)
         val ymlIn = classLoader.getResourceAsStream("extension.yml")
-            ?: throw MalformedExtensionException ("No extension.yml found in " + extensionJar.name)
+            ?: throw MalformedExtensionException("No extension.yml found in " + extensionJar.name)
 
         val extensionYml = YamlTransientConfig(YamlConfiguration.loadConfiguration(InputStreamReader(ymlIn)))
 
@@ -64,7 +63,7 @@ class EcoExtensionLoader(
 
 
         if (mainClass == null) {
-            throw MalformedExtensionException ("Invalid extension.yml found in " + extensionJar.name)
+            throw MalformedExtensionException("Invalid extension.yml found in " + extensionJar.name)
         }
 
         if (name == null) {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/factory/EcoMetadataValueFactory.kt

@@ -1,11 +1,10 @@
 package com.willfp.eco.internal.factory
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.factory.MetadataValueFactory
 import org.bukkit.metadata.FixedMetadataValue
 
-class EcoMetadataValueFactory(plugin: EcoPlugin) : PluginDependent<EcoPlugin>(plugin), MetadataValueFactory {
+class EcoMetadataValueFactory(private val plugin: EcoPlugin) : MetadataValueFactory {
     override fun create(value: Any): FixedMetadataValue {
         return FixedMetadataValue(plugin, value)
     }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/factory/EcoNamespacedKeyFactory.kt

@@ -1,11 +1,10 @@
 package com.willfp.eco.internal.factory
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.factory.NamespacedKeyFactory
 import org.bukkit.NamespacedKey
 
-class EcoNamespacedKeyFactory(plugin: EcoPlugin) : PluginDependent<EcoPlugin>(plugin), NamespacedKeyFactory {
+class EcoNamespacedKeyFactory(private val plugin: EcoPlugin) : NamespacedKeyFactory {
     override fun create(key: String): NamespacedKey {
         return NamespacedKey(plugin, key)
     }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/factory/EcoRunnableFactory.kt

@@ -1,13 +1,12 @@
 package com.willfp.eco.internal.factory
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.factory.RunnableFactory
 import com.willfp.eco.core.scheduling.RunnableTask
 import com.willfp.eco.internal.scheduling.EcoRunnableTask
 import java.util.function.Consumer
 
-class EcoRunnableFactory(plugin: EcoPlugin) : PluginDependent<EcoPlugin>(plugin), RunnableFactory {
+class EcoRunnableFactory(private val plugin: EcoPlugin) : RunnableFactory {
     override fun create(consumer: Consumer<RunnableTask>): RunnableTask {
         return object : EcoRunnableTask(plugin) {
             override fun run() {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/fast/EcoFastItemStack.kt

@@ -1,6 +1,7 @@
 package com.willfp.eco.internal.fast
 
 import com.willfp.eco.core.fast.FastItemStack
+import org.bukkit.inventory.ItemFlag
 import org.bukkit.inventory.ItemStack
 
 abstract class EcoFastItemStack<T: Any>(
@@ -10,4 +11,8 @@ abstract class EcoFastItemStack<T: Any>(
     override fun unwrap(): ItemStack {
         return bukkit
     }
+
+    fun getBitModifier(hideFlag: ItemFlag): Int {
+        return 1 shl hideFlag.ordinal
+    }
 }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/menu/EcoMenu.kt

@@ -6,11 +6,14 @@ import com.willfp.eco.core.gui.slot.Slot
 import com.willfp.eco.internal.gui.slot.EcoSlot
 import com.willfp.eco.util.StringUtils
 import org.bukkit.Bukkit
+import org.bukkit.NamespacedKey
 import org.bukkit.entity.Player
 import org.bukkit.event.inventory.InventoryCloseEvent
 import org.bukkit.inventory.Inventory
 import org.bukkit.inventory.ItemStack
+import org.bukkit.persistence.PersistentDataType
 
+@Suppress("UNCHECKED_CAST")
 class EcoMenu(
     private val rows: Int,
     val slots: List<MutableList<EcoSlot>>,
@@ -60,6 +63,7 @@ class EcoMenu(
 
     fun handleClose(event: InventoryCloseEvent) {
         onClose.handle(event, this)
+        MenuHandler.unregisterMenu(event.inventory)
     }
 
     override fun getRows(): Int {
@@ -72,7 +76,31 @@ class EcoMenu(
 
     override fun getCaptiveItems(player: Player): MutableList<ItemStack> {
         val inventory = MenuHandler.getExtendedInventory(player.openInventory.topInventory)
-        inventory ?: return ArrayList()
+        inventory ?: return mutableListOf()
         return inventory.captiveItems
     }
+
+    override fun <T : Any, Z : Any> writeData(
+        player: Player,
+        key: NamespacedKey,
+        type: PersistentDataType<T, Z>,
+        value: Z
+    ) {
+        val inventory = MenuHandler.getExtendedInventory(player.openInventory.topInventory)
+        inventory ?: return
+        inventory.data[key] = value
+        inventory.refresh(player)
+    }
+
+    override fun <T : Any, Z : Any> readData(player: Player, key: NamespacedKey, type: PersistentDataType<T, Z>): T? {
+        val inventory = MenuHandler.getExtendedInventory(player.openInventory.topInventory)
+        inventory ?: return null
+        return inventory.data[key] as T?
+    }
+
+    override fun getKeys(player: Player): MutableSet<NamespacedKey> {
+        val inventory = MenuHandler.getExtendedInventory(player.openInventory.topInventory)
+        inventory ?: return HashSet()
+        return inventory.data.keys
+    }
 }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/menu/EcoMenuBuilder.kt

@@ -61,10 +61,10 @@ class EcoMenuBuilder(private val rows: Int) : MenuBuilder {
             }
         }
 
-        val finalSlots: MutableList<MutableList<EcoSlot>> = ArrayList()
+        val finalSlots = mutableListOf<MutableList<EcoSlot>>()
 
         for (row in tempSlots) {
-            val tempRow = ArrayList<EcoSlot>()
+            val tempRow = mutableListOf<EcoSlot>()
             for (slot in row) {
                 var tempSlot = slot
                 if (tempSlot is FillerSlot) {

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/menu/ExtendedInventory.kt

@@ -3,6 +3,7 @@ package com.willfp.eco.internal.gui.menu
 import com.willfp.eco.internal.gui.slot.EcoCaptivatorSlot
 import com.willfp.eco.util.MenuUtils
 import com.willfp.eco.util.StringUtils
+import org.bukkit.NamespacedKey
 import org.bukkit.entity.Player
 import org.bukkit.inventory.Inventory
 import org.bukkit.inventory.ItemStack
@@ -11,7 +12,8 @@ class ExtendedInventory(
     val inventory: Inventory,
     private val menu: EcoMenu
 ) {
-    val captiveItems: MutableList<ItemStack> = ArrayList()
+    val captiveItems = mutableListOf<ItemStack>()
+    val data = mutableMapOf<NamespacedKey, Any>()
 
     fun refresh(player: Player) {
         captiveItems.clear()

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/menu/MenuHandler.kt

@@ -4,28 +4,28 @@ import com.willfp.eco.core.gui.menu.Menu
 import org.bukkit.inventory.Inventory
 
 object MenuHandler {
-    private val MENUS: MutableMap<ExtendedInventory, EcoMenu> = HashMap()
+    private val menus = mutableMapOf<ExtendedInventory, EcoMenu>()
-    private val INVS: MutableMap<Inventory, ExtendedInventory> = HashMap()
+    private val inventories = mutableMapOf<Inventory, ExtendedInventory>()
 
     fun registerMenu(
         inventory: Inventory,
         menu: EcoMenu
     ) {
         val extendedInventory = ExtendedInventory(inventory, menu)
-        INVS[inventory] = extendedInventory
+        inventories[inventory] = extendedInventory
-        MENUS[extendedInventory] = menu
+        menus[extendedInventory] = menu
     }
 
     fun unregisterMenu(inventory: Inventory) {
-        MENUS.remove(INVS[inventory])
+        menus.remove(inventories[inventory])
-        INVS.remove(inventory)
+        inventories.remove(inventory)
     }
 
     fun getMenu(inventory: Inventory): Menu? {
-        return MENUS[INVS[inventory]]
+        return menus[inventories[inventory]]
     }
 
     fun getExtendedInventory(inventory: Inventory): ExtendedInventory? {
-        return INVS[inventory]
+        return inventories[inventory]
     }
 }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/slot/EcoCaptivatorSlot.kt

@@ -15,7 +15,7 @@ class EcoCaptivatorSlot : EcoSlot(
     { _, _, _ -> }
 ) {
     companion object {
-        val plugin = Eco.getHandler().ecoPlugin!!
+        val plugin = Eco.getHandler().ecoPlugin
 
         val allowMovingItem = SlotHandler { event, _, _ ->
             event.isCancelled = false

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/slot/EcoSlotBuilder.kt

@@ -8,7 +8,7 @@ import com.willfp.eco.core.gui.slot.functional.SlotProvider
 
 class EcoSlotBuilder(private val provider: SlotProvider) : SlotBuilder {
     private var captive = false
-    var modifier: SlotModifier = SlotModifier{ player, menu, _ -> provider.provide(player, menu)}
+    private var modifier: SlotModifier = SlotModifier{ player, menu, _ -> provider.provide(player, menu)}
 
     private var onLeftClick =
         SlotHandler { _, _, _ -> run { } }

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/proxy/EcoProxyFactory.kt

@@ -1,7 +1,6 @@
-package com.willfp.eco.internal.proxy;
+package com.willfp.eco.internal.proxy
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.proxy.AbstractProxy
 import com.willfp.eco.core.proxy.ProxyConstants
 import com.willfp.eco.core.proxy.ProxyFactory
@@ -11,8 +10,8 @@ import java.net.URLClassLoader
 import java.util.*
 
 class EcoProxyFactory(
-    plugin: EcoPlugin
+    private val plugin: EcoPlugin
-) : PluginDependent<EcoPlugin>(plugin), ProxyFactory {
+) : ProxyFactory {
     private val proxyClassLoader: ClassLoader = plugin::class.java.classLoader
     private val cache: MutableMap<Class<out AbstractProxy>, AbstractProxy> = IdentityHashMap()
 

eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/scheduling/EcoScheduler.kt

@@ -1,12 +1,11 @@
 package com.willfp.eco.internal.scheduling
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.scheduling.Scheduler
 import org.bukkit.Bukkit
 import org.bukkit.scheduler.BukkitTask
 
-class EcoScheduler(plugin: EcoPlugin) : PluginDependent<EcoPlugin>(plugin), Scheduler {
+class EcoScheduler(private val plugin: EcoPlugin) : Scheduler {
     override fun runLater(
         runnable: Runnable,
         ticksLater: Long

eco-core/core-nms/v1_16_R3/src/main/kotlin/com/willfp/eco/proxy/v1_16_R3/Skull.kt

@@ -1,32 +1,43 @@
 package com.willfp.eco.proxy.v1_16_R3
+
 import com.mojang.authlib.GameProfile
 import com.mojang.authlib.properties.Property
-import org.bukkit.inventory.meta.SkullMeta
 import com.willfp.eco.proxy.SkullProxy
+import org.bukkit.inventory.meta.SkullMeta
+import java.lang.reflect.Field
 import java.lang.reflect.Method
 import java.util.*
 
 class Skull : SkullProxy {
     private lateinit var setProfile: Method
+    private lateinit var profile: Field
 
     override fun setSkullTexture(
         meta: SkullMeta,
         base64: String
     ) {
-        try {
+        if (!this::setProfile.isInitialized) {
-            if (!this::setProfile.isInitialized) {
+            setProfile = meta.javaClass.getDeclaredMethod("setProfile", GameProfile::class.java)
-                setProfile = meta.javaClass.getDeclaredMethod("setProfile", GameProfile::class.java)
+            setProfile.isAccessible = true
-                setProfile.isAccessible = true
-            }
-            val uuid = UUID(
-                base64.substring(base64.length - 20).hashCode().toLong(),
-                base64.substring(base64.length - 10).hashCode().toLong()
-            )
-            val profile = GameProfile(uuid, "eco")
-            profile.properties.put("textures", Property("textures", base64))
-            setProfile.invoke(meta, profile)
-        } catch (e: ReflectiveOperationException) {
-            e.printStackTrace()
         }
+        val uuid = UUID(
+            base64.substring(base64.length - 20).hashCode().toLong(),
+            base64.substring(base64.length - 10).hashCode().toLong()
+        )
+        val profile = GameProfile(uuid, "eco")
+        profile.properties.put("textures", Property("textures", base64))
+        setProfile.invoke(meta, profile)
+    }
+
+    override fun getSkullTexture(
+        meta: SkullMeta
+    ): String? {
+        if (!this::profile.isInitialized) {
+            profile = meta.javaClass.getDeclaredField("profile")
+            profile.isAccessible = true
+        }
+        val profile = profile[meta] as GameProfile?
+        val property = profile?.properties?.get("textures") as Property?
+        return property?.value
     }
 }

eco-core/core-nms/v1_16_R3/src/main/kotlin/com/willfp/eco/proxy/v1_16_R3/VillagerTrade.kt

@@ -1,9 +1,9 @@
 package com.willfp.eco.proxy.v1_16_R3
 import com.willfp.eco.core.display.Display
+import com.willfp.eco.proxy.VillagerTradeProxy
 import org.bukkit.craftbukkit.v1_16_R3.inventory.CraftMerchantRecipe
 import org.bukkit.entity.Player
 import org.bukkit.inventory.MerchantRecipe
-import com.willfp.eco.proxy.VillagerTradeProxy
 import java.lang.reflect.Field
 
 class VillagerTrade : VillagerTradeProxy {
@@ -15,7 +15,7 @@ class VillagerTrade : VillagerTradeProxy {
     ): MerchantRecipe {
         val oldRecipe = recipe as CraftMerchantRecipe
         val newRecipe = CraftMerchantRecipe(
-            Display.display(recipe.getResult().clone()),
+            Display.display(recipe.getResult().clone(), player),
             recipe.getUses(),
             recipe.getMaxUses(),
             recipe.hasExperienceReward(),

eco-core/core-nms/v1_16_R3/src/main/kotlin/com/willfp/eco/proxy/v1_16_R3/fast/NMSFastItemStack.kt

@@ -8,7 +8,7 @@ import org.bukkit.craftbukkit.v1_16_R3.inventory.CraftItemStack
 import org.bukkit.craftbukkit.v1_16_R3.util.CraftMagicNumbers
 import org.bukkit.craftbukkit.v1_16_R3.util.CraftNamespacedKey
 import org.bukkit.enchantments.Enchantment
-import java.lang.reflect.Field
+import org.bukkit.inventory.ItemFlag
 import kotlin.experimental.and
 
 class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemStack<ItemStack>(
@@ -96,12 +96,59 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
         }
     }
 
+    override fun addItemFlags(vararg hideFlags: ItemFlag) {
+        for (flag in hideFlags) {
+            this.flagBits = this.flagBits or getBitModifier(flag)
+        }
+
+        apply()
+    }
+
+    override fun removeItemFlags(vararg hideFlags: ItemFlag) {
+        for (flag in hideFlags) {
+            this.flagBits = this.flagBits and getBitModifier(flag)
+        }
+
+        apply()
+    }
+
+    override fun getItemFlags(): MutableSet<ItemFlag> {
+        val flags = mutableSetOf<ItemFlag>()
+
+        var flagArr: Array<ItemFlag>
+        val size = ItemFlag.values().also { flagArr = it }.size
+
+        for (i in 0 until size) {
+            val flag = flagArr[i]
+            if (this.hasItemFlag(flag)) {
+                flags.add(flag)
+            }
+        }
+
+        return flags
+    }
+
+    override fun hasItemFlag(flag: ItemFlag): Boolean {
+        val bitModifier = getBitModifier(flag)
+        return this.flagBits and bitModifier == bitModifier
+    }
+
+    private var flagBits: Int
+        get() =
+            if (handle.hasTag() && handle.tag!!.hasKeyOfType(
+                    "HideFlags",
+                    99
+                )
+            ) handle.tag!!.getInt("HideFlags") else 0
+        set(value) =
+            handle.orCreateTag.setInt("HideFlags", value)
+
     override fun getRepairCost(): Int {
-        return handle.repairCost;
+        return handle.repairCost
     }
 
     override fun setRepairCost(cost: Int) {
-        handle.repairCost = cost;
+        handle.repairCost = cost
     }
 
     private fun apply() {
@@ -109,28 +156,4 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
             bukkit.itemMeta = CraftItemStack.asCraftMirror(handle).itemMeta
         }
     }
-
-    companion object {
-        private var field: Field
-
-        init {
-            lateinit var temp: Field
-            try {
-                val handleField = CraftItemStack::class.java.getDeclaredField("handle")
-                handleField.isAccessible = true
-                temp = handleField
-            } catch (e: ReflectiveOperationException) {
-                e.printStackTrace()
-            }
-            field = temp
-        }
-
-        fun getNMSStack(itemStack: org.bukkit.inventory.ItemStack): ItemStack? {
-            return if (itemStack !is CraftItemStack) {
-                CraftItemStack.asNMSCopy(itemStack)
-            } else {
-                field.get(itemStack) as ItemStack
-            }
-        }
-    }
 }

eco-core/core-nms/v1_17_R1/src/main/kotlin/com/willfp/eco/proxy/v1_17_R1/Skull.kt

@@ -4,30 +4,40 @@ import com.mojang.authlib.GameProfile
 import com.mojang.authlib.properties.Property
 import com.willfp.eco.proxy.SkullProxy
 import org.bukkit.inventory.meta.SkullMeta
+import java.lang.reflect.Field
 import java.lang.reflect.Method
 import java.util.*
 
 class Skull : SkullProxy {
     private lateinit var setProfile: Method
+    private lateinit var profile: Field
 
     override fun setSkullTexture(
         meta: SkullMeta,
         base64: String
     ) {
-        try {
+        if (!this::setProfile.isInitialized) {
-            if (!this::setProfile.isInitialized) {
+            setProfile = meta.javaClass.getDeclaredMethod("setProfile", GameProfile::class.java)
-                setProfile = meta.javaClass.getDeclaredMethod("setProfile", GameProfile::class.java)
+            setProfile.isAccessible = true
-                setProfile.isAccessible = true
-            }
-            val uuid = UUID(
-                base64.substring(base64.length - 20).hashCode().toLong(),
-                base64.substring(base64.length - 10).hashCode().toLong()
-            )
-            val profile = GameProfile(uuid, "eco")
-            profile.properties.put("textures", Property("textures", base64))
-            setProfile.invoke(meta, profile)
-        } catch (e: ReflectiveOperationException) {
-            e.printStackTrace()
         }
+        val uuid = UUID(
+            base64.substring(base64.length - 20).hashCode().toLong(),
+            base64.substring(base64.length - 10).hashCode().toLong()
+        )
+        val profile = GameProfile(uuid, "eco")
+        profile.properties.put("textures", Property("textures", base64))
+        setProfile.invoke(meta, profile)
+    }
+
+    override fun getSkullTexture(
+        meta: SkullMeta
+    ): String? {
+        if (!this::profile.isInitialized) {
+            profile = meta.javaClass.getDeclaredField("profile")
+            profile.isAccessible = true
+        }
+        val profile = profile[meta] as GameProfile?
+        val property = profile?.properties?.get("textures") as Property?
+        return property?.value
     }
 }

eco-core/core-nms/v1_17_R1/src/main/kotlin/com/willfp/eco/proxy/v1_17_R1/VillagerTrade.kt

@@ -1,15 +1,15 @@
 package com.willfp.eco.proxy.v1_17_R1
 
 import com.willfp.eco.core.display.Display
+import com.willfp.eco.proxy.VillagerTradeProxy
 import net.minecraft.world.item.trading.MerchantOffer
 import org.bukkit.craftbukkit.v1_17_R1.inventory.CraftMerchantRecipe
 import org.bukkit.entity.Player
 import org.bukkit.inventory.MerchantRecipe
-import com.willfp.eco.proxy.VillagerTradeProxy
 import java.lang.reflect.Field
 
 class VillagerTrade : VillagerTradeProxy {
-    private var handle: Field
+    private val handle: Field = CraftMerchantRecipe::class.java.getDeclaredField("handle")
 
     override fun displayTrade(
         recipe: MerchantRecipe,
@@ -17,7 +17,7 @@ class VillagerTrade : VillagerTradeProxy {
     ): MerchantRecipe {
         val oldRecipe = recipe as CraftMerchantRecipe
         val newRecipe = CraftMerchantRecipe(
-            Display.display(recipe.getResult().clone()),
+            Display.display(recipe.getResult().clone(), player),
             recipe.getUses(),
             recipe.getMaxUses(),
             recipe.hasExperienceReward(),
@@ -32,21 +32,10 @@ class VillagerTrade : VillagerTradeProxy {
     }
 
     private fun getHandle(recipe: CraftMerchantRecipe): MerchantOffer {
-        try {
+        return handle[recipe] as MerchantOffer
-            return handle[recipe] as MerchantOffer
-        } catch (e: IllegalAccessException) {
-            e.printStackTrace()
-        }
-        throw IllegalArgumentException("Not CMR")
     }
 
     init {
-        try {
+        handle.isAccessible = true
-            handle = CraftMerchantRecipe::class.java.getDeclaredField("handle")
-            handle.isAccessible = true
-        } catch (e: NoSuchFieldException) {
-            e.printStackTrace()
-            throw RuntimeException("Error!")
-        }
     }
 }

eco-core/core-nms/v1_17_R1/src/main/kotlin/com/willfp/eco/proxy/v1_17_R1/fast/NMSFastItemStack.kt

@@ -13,6 +13,7 @@ import org.bukkit.craftbukkit.v1_17_R1.inventory.CraftItemStack
 import org.bukkit.craftbukkit.v1_17_R1.util.CraftMagicNumbers
 import org.bukkit.craftbukkit.v1_17_R1.util.CraftNamespacedKey
 import org.bukkit.enchantments.Enchantment
+import org.bukkit.inventory.ItemFlag
 import kotlin.experimental.and
 
 class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemStack<ItemStack>(
@@ -115,12 +116,59 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
         }
     }
 
+    override fun addItemFlags(vararg hideFlags: ItemFlag) {
+        for (flag in hideFlags) {
+            this.flagBits = this.flagBits or getBitModifier(flag)
+        }
+
+        apply()
+    }
+
+    override fun removeItemFlags(vararg hideFlags: ItemFlag) {
+        for (flag in hideFlags) {
+            this.flagBits = this.flagBits and getBitModifier(flag)
+        }
+
+        apply()
+    }
+
+    override fun getItemFlags(): MutableSet<ItemFlag> {
+        val flags = mutableSetOf<ItemFlag>()
+
+        var flagArr: Array<ItemFlag>
+        val size = ItemFlag.values().also { flagArr = it }.size
+
+        for (i in 0 until size) {
+            val flag = flagArr[i]
+            if (this.hasItemFlag(flag)) {
+                flags.add(flag)
+            }
+        }
+
+        return flags
+    }
+
+    override fun hasItemFlag(flag: ItemFlag): Boolean {
+        val bitModifier = getBitModifier(flag)
+        return this.flagBits and bitModifier == bitModifier
+    }
+
+    private var flagBits: Int
+        get() =
+            if (handle.hasTag() && handle.tag!!.contains(
+                    "HideFlags",
+                    99
+                )
+            ) handle.tag!!.getInt("HideFlags") else 0
+        set(value) =
+            handle.orCreateTag.putInt("HideFlags", value)
+
     override fun getRepairCost(): Int {
-        return handle.baseRepairCost;
+        return handle.baseRepairCost
     }
 
     override fun setRepairCost(cost: Int) {
-        handle.setRepairCost(cost);
+        handle.setRepairCost(cost)
     }
 
     private fun apply() {

eco-core/core-plugin/build.gradle

@@ -20,8 +20,9 @@ dependencies {
     compileOnly 'com.gmail.nossr50.mcMMO:mcMMO:2.1.157'
     compileOnly 'me.clip:placeholderapi:2.10.9'
     compileOnly 'com.willfp:Oraxen:e1f4003d8d'
-
+    compileOnly 'com.github.brcdev-minecraft:shopgui-api:2.2.0'
-    compileOnly 'com.github.LoneDev6:API-ItemsAdder:2.3.8'
+    compileOnly 'com.github.LoneDev6:API-ItemsAdder:2.4.7'
+    compileOnly 'me.arcaniax:HeadDatabase-API:1.2.0'
 
     // CombatLogX V10 + NewbieHelper Expansion
     compileOnly 'com.SirBlobman.combatlogx:CombatLogX-API:10.0.0.0-SNAPSHOT'

eco-core/core-plugin/src/main/java/com/willfp/eco/spigot/recipes/ShapedRecipeListener.java

@@ -6,6 +6,7 @@ import com.willfp.eco.core.items.Items;
 import com.willfp.eco.core.items.TestableItem;
 import com.willfp.eco.core.recipe.Recipes;
 import com.willfp.eco.core.recipe.parts.MaterialTestableItem;
+import com.willfp.eco.core.recipe.parts.ModifiedTestableItem;
 import com.willfp.eco.core.recipe.parts.TestableStack;
 import com.willfp.eco.core.recipe.recipes.CraftingRecipe;
 import com.willfp.eco.core.recipe.recipes.ShapedCraftingRecipe;
@@ -97,16 +98,65 @@ public class ShapedRecipeListener extends PluginDependent<EcoPlugin> implements
             return;
         }
 
-        this.getPlugin().getScheduler().runLater(() -> {
+        boolean isStackedRecipe = false;
-            for (int i = 0; i < 9; i++) {
-                ItemStack inMatrix = event.getInventory().getMatrix()[i];
-                TestableItem inRecipe = matched.getParts().get(i);
 
-                if (inRecipe instanceof TestableStack testableStack) {
+        int upperBound = 64;
+        for (int i = 0; i < 9; i++) {
+            ItemStack inMatrix = event.getInventory().getMatrix()[i];
+            TestableItem inRecipe = matched.getParts().get(i);
+
+            if (inRecipe instanceof TestableStack testableStack) {
+                int max = Math.floorDiv(inMatrix.getAmount(), testableStack.getAmount());
+                if (max < upperBound) {
+                    upperBound = max;
+                }
+                isStackedRecipe = true;
+            } else if (inMatrix != null) {
+                int max = inMatrix.getAmount();
+                if (max < upperBound) {
+                    upperBound = max;
+                }
+            }
+        }
+
+        if (!isStackedRecipe) {
+            return;
+        }
+
+        int toGivePerRecipe = event.getRecipe().getResult().getAmount();
+        int maxStackSize = event.getRecipe().getResult().getMaxStackSize();
+        while (toGivePerRecipe * upperBound > maxStackSize) {
+            upperBound--;
+        }
+
+        for (int i = 0; i < 9; i++) {
+            ItemStack inMatrix = event.getInventory().getMatrix()[i];
+            TestableItem inRecipe = matched.getParts().get(i);
+
+            if (inRecipe instanceof TestableStack testableStack) {
+                if (event.isShiftClick()) {
+                    int amount = inMatrix.getAmount() + 1;
+                    for (int j = 0; j < upperBound; j++) {
+                        amount -= testableStack.getAmount();
+                    }
+                    inMatrix.setAmount(amount);
+                } else {
                     inMatrix.setAmount(inMatrix.getAmount() - (testableStack.getAmount() - 1));
                 }
             }
-        }, 1);
+        }
+
+        int finalUpperBound = upperBound;
+
+        if (event.isShiftClick()) {
+            ItemStack result = event.getInventory().getResult();
+            if (result == null) {
+                return;
+            }
+
+            result.setAmount(result.getAmount() * finalUpperBound);
+            event.getInventory().setResult(result);
+        }
     }
 
     @EventHandler
@@ -130,6 +180,22 @@ public class ShapedRecipeListener extends PluginDependent<EcoPlugin> implements
                     return;
                 }
             }
+            if (part instanceof ModifiedTestableItem modified) {
+                if (modified.getHandle() instanceof MaterialTestableItem) {
+                    if (Items.isCustomItem(itemStack)) {
+                        event.getInventory().setResult(new ItemStack(Material.AIR));
+                        return;
+                    }
+                }
+            }
+            if (part instanceof TestableStack modified) {
+                if (modified.getHandle() instanceof MaterialTestableItem) {
+                    if (Items.isCustomItem(itemStack)) {
+                        event.getInventory().setResult(new ItemStack(Material.AIR));
+                        return;
+                    }
+                }
+            }
         }
     }
     
@@ -156,6 +222,24 @@ public class ShapedRecipeListener extends PluginDependent<EcoPlugin> implements
                     return;
                 }
             }
+            if (part instanceof ModifiedTestableItem modified) {
+                if (modified.getHandle() instanceof MaterialTestableItem) {
+                    if (Items.isCustomItem(itemStack)) {
+                        event.getInventory().setResult(new ItemStack(Material.AIR));
+                        event.setResult(Event.Result.DENY);
+                        event.setCancelled(true);
+                        return;
+                    }
+                }
+            }
+            if (part instanceof TestableStack modified) {
+                if (modified.getHandle() instanceof MaterialTestableItem) {
+                    if (Items.isCustomItem(itemStack)) {
+                        event.getInventory().setResult(new ItemStack(Material.AIR));
+                        return;
+                    }
+                }
+            }
         }
     }
     

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/EcoHandler.kt

@@ -31,9 +31,9 @@ import com.willfp.eco.internal.integrations.PlaceholderIntegrationPAPI
 import com.willfp.eco.internal.logging.EcoLogger
 import com.willfp.eco.internal.proxy.EcoProxyFactory
 import com.willfp.eco.internal.scheduling.EcoScheduler
+import com.willfp.eco.proxy.FastItemStackFactoryProxy
 import com.willfp.eco.spigot.integrations.bstats.MetricHandler
 import org.bukkit.inventory.ItemStack
-import com.willfp.eco.proxy.FastItemStackFactoryProxy
 import java.util.logging.Logger
 
 @Suppress("UNUSED")
@@ -105,7 +105,7 @@ class EcoHandler : EcoSpigotPlugin(), Handler {
     }
 
     override fun getLoadedPlugins(): List<String> {
-        return ArrayList(Plugins.LOADED_ECO_PLUGINS.keys)
+        return Plugins.LOADED_ECO_PLUGINS.keys.toMutableList()
     }
 
     override fun getPluginByName(name: String): EcoPlugin? {

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/EcoSpigotPlugin.kt

@@ -8,6 +8,10 @@ import com.willfp.eco.core.integrations.anticheat.AnticheatManager
 import com.willfp.eco.core.integrations.antigrief.AntigriefManager
 import com.willfp.eco.core.integrations.customitems.CustomItemsManager
 import com.willfp.eco.core.integrations.mcmmo.McmmoManager
+import com.willfp.eco.core.integrations.shop.ShopManager
+import com.willfp.eco.core.items.Items
+import com.willfp.eco.core.items.args.EnchantmentArgParser
+import com.willfp.eco.core.items.args.TextureArgParser
 import com.willfp.eco.internal.drops.DropManager
 import com.willfp.eco.proxy.BlockBreakProxy
 import com.willfp.eco.proxy.FastItemStackFactoryProxy
@@ -19,8 +23,11 @@ import com.willfp.eco.spigot.eventlisteners.*
 import com.willfp.eco.spigot.gui.GUIListener
 import com.willfp.eco.spigot.integrations.anticheat.*
 import com.willfp.eco.spigot.integrations.antigrief.*
+import com.willfp.eco.spigot.integrations.customitems.CustomItemsHeadDatabase
+import com.willfp.eco.spigot.integrations.customitems.CustomItemsItemsAdder
 import com.willfp.eco.spigot.integrations.customitems.CustomItemsOraxen
 import com.willfp.eco.spigot.integrations.mcmmo.McmmoIntegrationImpl
+import com.willfp.eco.spigot.integrations.shop.ShopShopGuiPlus
 import com.willfp.eco.spigot.recipes.ShapedRecipeListener
 import com.willfp.eco.util.BlockUtils
 import com.willfp.eco.util.SkullUtils
@@ -41,8 +48,14 @@ abstract class EcoSpigotPlugin : EcoPlugin(
     init {
         Display.setFinalizeKey(namespacedKeyFactory.create("finalized"))
 
+        Items.registerArgParser(EnchantmentArgParser())
+        Items.registerArgParser(TextureArgParser())
+
         val skullProxy = getProxy(SkullProxy::class.java)
-        SkullUtils.initialize { meta: SkullMeta, base64: String -> skullProxy.setSkullTexture(meta, base64) }
+        SkullUtils.initialize(
+            { meta: SkullMeta, base64: String -> skullProxy.setSkullTexture(meta, base64) },
+            { meta: SkullMeta -> skullProxy.getSkullTexture(meta) }
+        )
 
         val blockBreakProxy = getProxy(BlockBreakProxy::class.java)
         BlockUtils.initialize { player: Player, block: Block -> blockBreakProxy.breakBlock(player, block) }
@@ -109,6 +122,11 @@ abstract class EcoSpigotPlugin : EcoPlugin(
 
             // Custom Items
             IntegrationLoader("Oraxen") { CustomItemsManager.register(CustomItemsOraxen()) },
+            IntegrationLoader("ItemsAdder") { CustomItemsManager.register(CustomItemsItemsAdder(this)) },
+            IntegrationLoader("HeadDatabase") { CustomItemsManager.register(CustomItemsHeadDatabase()) },
+
+            // Shop
+            IntegrationLoader("ShopGuiPlus") { ShopManager.register(ShopShopGuiPlus()) },
 
             // Misc
             IntegrationLoader("mcMMO") { McmmoManager.register(McmmoIntegrationImpl()) }
@@ -116,19 +134,14 @@ abstract class EcoSpigotPlugin : EcoPlugin(
     }
 
     override fun loadPacketAdapters(): List<AbstractPacketAdapter> {
-        val adapters = mutableListOf(
+        return listOf(
             PacketAutoRecipe(this),
             PacketChat(this),
             PacketSetCreativeSlot(this),
             PacketSetSlot(this),
-            PacketWindowItems(this)
+            PacketWindowItems(this),
+            PacketOpenWindowMerchant(this)
         )
-
-        if (!configYml.getBool("disable-display-on-villagers")) {
-            adapters.add(PacketOpenWindowMerchant(this))
-        }
-
-        return adapters
     }
 
     override fun loadListeners(): List<Listener> {

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/arrows/ArrowDataListener.kt

@@ -1,7 +1,6 @@
 package com.willfp.eco.spigot.arrows
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import org.bukkit.Material
 import org.bukkit.entity.Arrow
 import org.bukkit.entity.LivingEntity
@@ -11,8 +10,8 @@ import org.bukkit.event.Listener
 import org.bukkit.event.entity.ProjectileLaunchEvent
 
 class ArrowDataListener(
-    plugin: EcoPlugin
+    private val plugin: EcoPlugin
-) : PluginDependent<EcoPlugin>(plugin), Listener {
+) : Listener {
 
     @EventHandler(priority = EventPriority.LOWEST)
     fun onLaunch(event:ProjectileLaunchEvent) {

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/display/PacketOpenWindowMerchant.kt

@@ -19,7 +19,7 @@ class PacketOpenWindowMerchant(plugin: EcoPlugin) :
         player: Player,
         event: PacketEvent
     ) {
-        val recipes: MutableList<MerchantRecipe> = ArrayList()
+        val recipes = mutableListOf<MerchantRecipe>()
 
 
         /*

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/eventlisteners/EntityDeathByEntityListeners.kt

@@ -1,7 +1,6 @@
 package com.willfp.eco.spigot.eventlisteners
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import org.bukkit.entity.LivingEntity
 import org.bukkit.event.EventHandler
 import org.bukkit.event.EventPriority
@@ -11,8 +10,8 @@ import org.bukkit.event.entity.EntityDeathEvent
 import java.util.concurrent.atomic.AtomicReference
 
 class EntityDeathByEntityListeners(
-    plugin: EcoPlugin
+    private val plugin: EcoPlugin
-) : PluginDependent<EcoPlugin>(plugin), Listener {
+) : Listener {
     private val events = HashSet<EntityDeathByEntityBuilder>()
 
     @EventHandler(priority = EventPriority.HIGH)

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/gui/GUIListener.kt

@@ -1,7 +1,6 @@
 package com.willfp.eco.spigot.gui
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.drops.DropQueue
 import com.willfp.eco.internal.gui.menu.EcoMenu
 import com.willfp.eco.internal.gui.menu.MenuHandler
@@ -16,7 +15,7 @@ import org.bukkit.event.inventory.ClickType
 import org.bukkit.event.inventory.InventoryClickEvent
 import org.bukkit.event.inventory.InventoryCloseEvent
 
-class GUIListener(plugin: EcoPlugin) : PluginDependent<EcoPlugin>(plugin), Listener {
+class GUIListener(private val plugin: EcoPlugin) : Listener {
     @EventHandler
     fun handleSlotClick(event: InventoryClickEvent) {
         val player = event.whoClicked
@@ -39,7 +38,7 @@ class GUIListener(plugin: EcoPlugin) : PluginDependent<EcoPlugin>(plugin), Liste
 
         val extendedInventory = MenuHandler.getExtendedInventory(event.clickedInventory!!) ?: return
 
-        plugin.scheduler.run{ extendedInventory.refresh(player) }
+        plugin.scheduler.run { extendedInventory.refresh(player) }
     }
 
     @EventHandler
@@ -52,7 +51,7 @@ class GUIListener(plugin: EcoPlugin) : PluginDependent<EcoPlugin>(plugin), Liste
         MenuHandler.getMenu(player.openInventory.topInventory) ?: return
         MenuHandler.getExtendedInventory(player.openInventory.topInventory) ?: return
 
-        plugin.scheduler.run{ MenuHandler.getExtendedInventory(player.openInventory.topInventory)?.refresh(player) }
+        plugin.scheduler.run { MenuHandler.getExtendedInventory(player.openInventory.topInventory)?.refresh(player) }
     }
 
     @EventHandler

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/integrations/antigrief/AntigriefLands.kt

@@ -1,7 +1,6 @@
 package com.willfp.eco.spigot.integrations.antigrief
 
 import com.willfp.eco.core.EcoPlugin
-import com.willfp.eco.core.PluginDependent
 import com.willfp.eco.core.integrations.antigrief.AntigriefWrapper
 import me.angeschossen.lands.api.integration.LandsIntegration
 import me.angeschossen.lands.api.role.enums.RoleSetting
@@ -10,8 +9,8 @@ import org.bukkit.block.Block
 import org.bukkit.entity.LivingEntity
 import org.bukkit.entity.Player
 
-class AntigriefLands(plugin: EcoPlugin) : PluginDependent<EcoPlugin?>(plugin), AntigriefWrapper {
+class AntigriefLands(private val plugin: EcoPlugin) : AntigriefWrapper {
-    private val landsIntegration = LandsIntegration(this.plugin!!)
+    private val landsIntegration = LandsIntegration(this.plugin)
     override fun canBreakBlock(
         player: Player,
         block: Block

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/integrations/customitems/CustomItemsHeadDatabase.kt

@@ -0,0 +1,34 @@
+package com.willfp.eco.spigot.integrations.customitems
+
+import com.willfp.eco.core.integrations.customitems.CustomItemsWrapper
+import com.willfp.eco.core.items.CustomItem
+import com.willfp.eco.util.NamespacedKeyUtils
+import me.arcaniax.hdb.api.HeadDatabaseAPI
+import me.arcaniax.hdb.enums.CategoryEnum
+import java.util.function.Predicate
+
+class CustomItemsHeadDatabase : CustomItemsWrapper {
+    private val api = HeadDatabaseAPI()
+
+    override fun registerAllItems() {
+        for (categoryEnum in CategoryEnum.values()) {
+            for (head in api.getHeads(categoryEnum).toList()) {
+                val stack = head.head
+                val id = head.id
+                val key = NamespacedKeyUtils.create("headdb", id.lowercase());
+                CustomItem(
+                    key,
+                    Predicate { test ->
+                        val headId = api.getItemID(test) ?: return@Predicate false
+                        headId.equals(id, ignoreCase = true)
+                    },
+                    stack
+                ).register()
+            }
+        }
+    }
+
+    override fun getPluginName(): String {
+        return "HeadDatabase"
+    }
+}

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/integrations/customitems/CustomItemsItemsAdder.kt

@@ -0,0 +1,36 @@
+package com.willfp.eco.spigot.integrations.customitems
+
+import com.willfp.eco.core.EcoPlugin
+import com.willfp.eco.core.integrations.customitems.CustomItemsWrapper
+import com.willfp.eco.core.items.CustomItem
+import com.willfp.eco.util.NamespacedKeyUtils
+import dev.lone.itemsadder.api.CustomStack
+import dev.lone.itemsadder.api.ItemsAdder
+import org.bukkit.inventory.ItemStack
+import java.util.function.Predicate
+
+class CustomItemsItemsAdder(
+    private val plugin: EcoPlugin
+) : CustomItemsWrapper {
+    override fun registerAllItems() {
+        plugin.scheduler.runLater({
+            for (item in ItemsAdder.getAllItems()) {
+                val stack = item.itemStack
+                val id = item.id
+                val key = NamespacedKeyUtils.create("itemsadder", id.lowercase())
+                CustomItem(
+                    key,
+                    Predicate { test: ItemStack ->
+                        val customStack = CustomStack.byItemStack(test) ?: return@Predicate false
+                        customStack.id.equals(id, ignoreCase = true)
+                    },
+                    stack
+                ).register()
+            }
+        }, 2)
+    }
+
+    override fun getPluginName(): String {
+        return "ItemsAdder"
+    }
+}

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/integrations/customitems/CustomItemsOraxen.kt

@@ -23,4 +23,8 @@ class CustomItemsOraxen : CustomItemsWrapper {
             ).register()
         }
     }
+
+    override fun getPluginName(): String {
+        return "Oraxen"
+    }
 }

eco-core/core-plugin/src/main/kotlin/com/willfp/eco/spigot/integrations/shop/ShopShopGuiPlus.kt

@@ -0,0 +1,31 @@
+package com.willfp.eco.spigot.integrations.shop
+
+import com.willfp.eco.core.integrations.shop.ShopWrapper
+import com.willfp.eco.core.items.Items
+import net.brcdev.shopgui.ShopGuiPlusApi
+import net.brcdev.shopgui.provider.item.ItemProvider
+import org.bukkit.configuration.ConfigurationSection
+import org.bukkit.inventory.ItemStack
+
+class ShopShopGuiPlus : ShopWrapper {
+    override fun registerEcoProvider() {
+        ShopGuiPlusApi.registerItemProvider(EcoShopGuiPlusProvider())
+    }
+
+    class EcoShopGuiPlusProvider : ItemProvider("eco") {
+        override fun isValidItem(itemStack: ItemStack?): Boolean {
+            itemStack ?: return false
+
+            return Items.isCustomItem(itemStack)
+        }
+
+        override fun loadItem(configurationSection: ConfigurationSection): ItemStack? {
+            val id = configurationSection.getString("eco")
+            return if (id == null) null else Items.lookup(id)?.item
+        }
+
+        override fun compare(itemStack1: ItemStack, itemStack2: ItemStack): Boolean {
+            return Items.getCustomItem(itemStack1)?.key == Items.getCustomItem(itemStack2)?.key
+        }
+    }
+}

eco-core/core-plugin/src/main/resources/config.yml

@@ -5,7 +5,6 @@
 
 
 # Options to fix villager bugs left behind from old (buggy) versions.
-disable-display-on-villagers: false
 villager-display-fix: false
 
 # DropQueue by default uses a faster collated queue system where all drops

eco-core/core-plugin/src/main/resources/plugin.yml

@@ -4,6 +4,7 @@ main: com.willfp.eco.spigot.EcoHandler
 api-version: 1.16
 authors: [Auxilor]
 website: willfp.com
+load: STARTUP
 depend:
   - ProtocolLib
 softdepend:
@@ -20,6 +21,10 @@ softdepend:
   - PlaceholderAPI
   - mcMMO
   - CombatLogX
+  - ShopGuiPlus
+  - ItemsAdder
+  - Oraxen
+  - HeadDatabase
 libraries:
   - org.reflections:reflections:0.9.12
   - org.apache.maven:maven-artifact:3.0.3

eco-core/core-proxy/src/main/kotlin/com/willfp/eco/proxy/SkullProxy.kt

@@ -8,4 +8,8 @@ interface SkullProxy : AbstractProxy {
         meta: SkullMeta,
         base64: String
     )
+
+    fun getSkullTexture(
+        meta: SkullMeta
+    ): String?
 }

gradle.properties

@@ -1,2 +1,2 @@
-version = 6.4.2
+version = 6.7.1
 plugin-name = eco