Changed display

.github/workflows/publish-release.yml

@@ -0,0 +1,38 @@
+name: Publish release
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  publish-release:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout latest code
+        uses: actions/checkout@v2
+
+      - name: Set up JDK 16
+        uses: actions/setup-java@v2
+        with:
+          distribution: 'adopt'
+          java-version: 16
+
+      - name: Setup build cache
+        uses: actions/cache@v2.1.6
+        with:
+          path: ~/.gradle/caches
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle.kts') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+      - name: Publish artifact
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+        # The GITHUB_REF tag comes in the format 'refs/tags/xxx'.
+        # So if we split on '/' and take the 3rd value, we can get the release name.
+        run: |
+          NEW_VERSION=$(echo "${GITHUB_REF}" | cut -d "/" -f3)
+          echo "New version: ${NEW_VERSION}"
+          echo "Github username: ${GITHUB_ACTOR}"
+          ./gradlew -Pversion=${NEW_VERSION} publish

.gitignore

@@ -14,6 +14,7 @@ bin/
 # Gradle
 .gradle
 **/build/
+**/out/
 !eco-api/src/**/build/
 .gradletasknamecache
 !gradle-wrapper.jar

CONTRIBUTING.md

@@ -6,7 +6,7 @@
 - Every method and field must have a javadoc attached.
 
 2. Use lombok wherever possible.
-- @Getter, @Setter, @ToString, @EqualsAndHashCode, @UtilityClass are the most important.
+- @Getter, @Setter, @UtilityClass only.
 
 3. Use JetBrains annotations
 - Every parameter should be annotated with @NotNull or @Nullable
@@ -24,4 +24,4 @@
 
 ## Other
 - All drops **must** be sent through a DropQueue - calls to World#dropItem will get your PR rejected.
-- eco is built with java 8. Usage of J9+ will get your PR rejected.
+- eco is built with java 16.

README.md

@@ -1 +1,165 @@
-## eco - Library for spigot plugin development.
+<h1 align="center">
+  <br>
+  <img src="https://i.imgur.com/p5uR2Qp.png" alt="eco logo" width="256">
+  <br>
+</h1>
+
+<h4 align="center">eco - Simplify spigot development.</h4>
+
+### Plugin Information
+- Requires ProtocolLib to be installed: get the latest version [here](https://www.spigotmc.org/resources/protocollib.1997/)
+- Supports 1.16.5+
+
+### bStats
+<img src="https://bstats.org/signatures/bukkit/eco.svg" width="512">
+
+# Information for development
+
+## Javadoc
+The 6.0.0 Javadoc can be found [here](https://javadoc.jitpack.io/com/willfp/eco/6.0.0/javadoc/)
+
+## Plugin Information
+
+eco is a standalone plugin, so you will need to install it on any servers that have plugins which depend on it,
+and specify it as a dependency in your plugin.yml:
+
+```yaml
+depend:
+  - eco
+```
+
+eco is available from any of these places:
+
+- [GitHub](https://github.com/Auxilor/eco/releases)
+- [Spigot](https://www.spigotmc.org/resources/eco.87955/)
+- [Polymart](https://polymart.org/resource/eco.773)
+- [Build it locally](https://github.com/Auxilor/eco#build-locally).
+
+## Get from JitPack:
+
+Gradle:
+
+```groovy
+repositories {
+        maven { url 'https://jitpack.io' }
+}
+
+```
+
+```groovy
+dependencies {
+        compileOnly 'com.willfp:eco:Tag'
+}
+```
+
+Replace `Tag` with a release tag for eco, eg `6.0.0`.
+
+Maven:
+
+```xml
+<repository>
+        <id>jitpack.io</id>
+        <url>https://jitpack.io</url>
+</repository>
+```
+
+```xml
+<dependency>
+        <groupId>com.willfp</groupId>
+        <artifactId>eco</artifactId>
+        <version>Tag</version>
+        <scope>provided</scope>
+</dependency>
+```
+
+Replace `Tag` with a release tag for eco, eg `6.0.0`.
+
+## Build locally:
+
+Run the following commands in your terminal of choice.
+
+If you're on windows, you will need to have git bash installed.
+```
+git clone https://github.com/Auxilor/eco
+cd eco
+./gradlew build
+```
+
+# Features
+
+Here's a list of some (not all) of the features of eco:
+
+- Command system with subcommands
+- Reworked config system
+- JSON Config Support
+- Client-Side item display
+- World drop system
+- Event manager
+    - PlayerJumpEvent
+    - ArmorEquipEvent
+    - EntityDeathByEntityEvent
+    - NaturalExpGainEvent
+- Plugin extensions (com.willfp.eco.internal.Plugins for plugins)
+- GUI System
+- Integration system for external plugins
+    - Anticheat support
+        - AAC
+        - Matrix
+        - NCP
+        - Spartan
+        - Vulcan
+    - Antigrief/Combat support
+        - CombatLogX (V10 + V11)
+        - FactionsUUID
+        - GriefPrevention
+        - Kingdoms
+        - Lands
+        - Towny
+        - WorldGuard
+    - mcMMO support
+    - Custom Items support
+        - Oraxen
+    - PlaceholderAPI support
+- NMS Proxy / Wrapper system built in
+- Custom Items system
+- Crafting Recipe handler
+- Tuples
+- Support uploading to / downloading from hastebin
+- Packet System (via ProtocolLib)
+- Dependency Injection systems
+- Prerequisite system
+- API additions (via utility classes)
+    - Get bow from arrow
+    - Break a block as a player
+    - Get a vein of blocks
+    - Create 2D lists
+    - Create NamespacedKeys safely
+    - Random number, distribution, roman numerals
+    - Set skull texture
+    - Format all strings
+        - Hex Support
+        - Gradient Support
+        - Placeholder Support
+    - Get a scoreboard team from any color
+    - Telekinesis (Drops straight to inventory) system
+    - More vector options
+- Update checker
+- bStats integration
+- Reworked systems for:
+    - NamespacedKey
+    - MetadataValue
+    - Runnables / Scheduling
+
+... and a lot more!
+
+## License
+
+*Click here to read [the entire license](https://github.com/Auxilor/eco/blob/master/LICENSE.md).*
+
+<h1 align="center">
+  <br>
+    <a href="https://dedimc.promo/Auxilor" target="_blank">
+      <img src="https://i.imgur.com/zdDLhFA.png" alt="dedimc banner">
+    </a>
+  <br>
+</h1>

build.gradle

@@ -7,7 +7,11 @@ plugins {
 
 dependencies {
     implementation project(":eco-api")
-    implementation project(":eco-core").getSubprojects()
+    implementation project(":eco-core:core-plugin")
+    implementation project(":eco-core:core-proxy")
+    implementation project(":eco-core:core-backend")
+    implementation project(":eco-core:core-nms:v1_16_R3")
+    implementation project(path: ":eco-core:core-nms:v1_17_R1", configuration: 'mapped')
 }
 
 allprojects {
@@ -57,6 +61,10 @@ allprojects {
         annotationProcessor 'org.projectlombok:lombok:1.18.20'
         testCompileOnly 'org.projectlombok:lombok:1.18.20'
         testAnnotationProcessor 'org.projectlombok:lombok:1.18.20'
+
+        // Test
+        testImplementation 'org.junit.jupiter:junit-jupiter-api:5.3.1'
+        testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.3.1'
     }
 
     tasks.withType(JavaCompile) {
@@ -68,14 +76,14 @@ allprojects {
         exclude group: "org.codehaus.plexus", module: "plexus-utils"
         exclude group: "com.mojang", module: "brigadier"
         exclude group: "org.kitteh", module: "paste-gg-api"
+        exclude group: "org.kitteh", module: "pastegg"
         exclude group: "org.spongepowered", module: "configurate-hocon"
         exclude group: "com.darkblade12", module: "particleeffect"
         exclude group: "com.github.cryptomorin", module: "XSeries"
     }
 
     shadowJar {
-        relocate('org.bstats.bukkit', 'com.willfp.eco.shaded.bstats')
-        relocate('org.apache.maven', 'com.willfp.eco.shaded.maven')
+        relocate('org.bstats', 'com.willfp.eco.shaded.bstats')
     }
 
     jar {
@@ -89,6 +97,19 @@ allprojects {
     java {
         sourceCompatibility = JavaVersion.VERSION_16
         targetCompatibility = JavaVersion.VERSION_16
+        withSourcesJar()
+    }
+
+    test {
+        useJUnitPlatform()
+
+        // Always run tests, even when nothing changed.
+        dependsOn cleanTest
+
+        // Show test results.
+        testLogging {
+            events "passed", "skipped", "failed"
+        }
     }
 
     compileJava.options.encoding = 'UTF-8'

config/checkstyle/checkstyle.xml

@@ -45,7 +45,7 @@
     -->
     <property name="severity" value="error"/>
 
-    <property name="fileExtensions" value="java, properties, xml"/>
+    <property name="fileExtensions" value="java, properties, xml, kt"/>
 
     <!-- Excludes all 'module-info.java' files              -->
     <!-- See https://checkstyle.org/config_filefilters.html -->
@@ -66,6 +66,7 @@
     <module name="FileLength"/>
     <module name="LineLength">
         <property name="fileExtensions" value="java"/>
+        <property name="fileExtensions" value="kt"/>
         <property name="max" value="200"/>
     </module>
 

config/checkstyle/suppression.xml

@@ -10,6 +10,8 @@
     <suppress files="[\\/]internal[\\/]" checks="JavadocVariable"/>
     <suppress files="[\\/]eco[\\/]spigot[\\/]" checks="MissingJavadocMethod"/>
     <suppress files="[\\/]eco[\\/]spigot[\\/]" checks="JavadocVariable"/>
+    <suppress files="[\\/]eco[\\/]proxy[\\/]" checks="MissingJavadocMethod"/>
+    <suppress files="[\\/]eco[\\/]proxy[\\/]" checks="JavadocVariable"/>
 
     <!-- Modified version of library -->
     <suppress files="ArmorEquipEvent.java" checks="JavadocVariable"/>

eco-api/build.gradle

@@ -6,16 +6,18 @@ group 'com.willfp'
 version rootProject.version
 
 dependencies {
-    compileOnly 'org.spigotmc:spigot:1.17-R0.1-SNAPSHOT'
+    compileOnly 'org.spigotmc:spigot-api:1.17-R0.1-SNAPSHOT'
     compileOnly 'org.apache.maven:maven-artifact:3.0.3'
-    compileOnly 'org.bstats:bstats-bukkit:1.7'
     compileOnly 'com.comphenix.protocol:ProtocolLib:4.6.0-SNAPSHOT'
-    compileOnly 'me.clip:placeholderapi:2.10.9'
     compileOnly 'com.google.code.gson:gson:2.8.7'
+    compileOnly 'net.kyori:adventure-text-serializer-gson:4.8.1'
+    compileOnly 'net.kyori:adventure-text-serializer-legacy:4.8.1'
+}
+
+java {
+    withJavadocJar()
 }
 
-compileJava.options.encoding = 'UTF-8'
-compileJava.dependsOn clean
 
 build.dependsOn publishToMavenLocal
 
@@ -26,4 +28,15 @@ publishing {
             artifactId 'eco'
         }
     }
+
+    repositories {
+        maven {
+            name = "GitHubPackages"
+            url = uri("https://maven.pkg.github.com/Auxilor/eco")
+            credentials {
+                username = System.getenv("GITHUB_ACTOR")
+                password = System.getenv("GITHUB_TOKEN")
+            }
+        }
+    }
 }

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

@@ -12,6 +12,9 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.Collections;
 
+/**
+ * Wrapper class for ProtocolLib packets.
+ */
 public abstract class AbstractPacketAdapter extends PacketAdapter {
     /**
      * The packet type to listen for.
@@ -56,28 +59,6 @@ public abstract class AbstractPacketAdapter extends PacketAdapter {
         this(plugin, type, ListenerPriority.NORMAL, postLoad);
     }
 
-    /**
-     * The code that should be executed once the packet has been received.
-     *
-     * @param packet The packet.
-     * @param player The player.
-     */
-    public void onReceive(@NotNull final PacketContainer packet,
-                          @NotNull final Player player) {
-        // Empty rather than abstract as implementations don't need both
-    }
-
-    /**
-     * THe code that should be executed once the packet has been sent.
-     *
-     * @param packet The packet.
-     * @param player The player.
-     */
-    public void onSend(@NotNull final PacketContainer packet,
-                       @NotNull final Player player) {
-        // Empty rather than abstract as implementations don't need both
-    }
-
     /**
      * The code that should be executed once the packet has been received.
      *
@@ -119,7 +100,6 @@ public abstract class AbstractPacketAdapter extends PacketAdapter {
             return;
         }
 
-        onReceive(event.getPacket(), event.getPlayer());
         onReceive(event.getPacket(), event.getPlayer(), event);
     }
 
@@ -138,7 +118,6 @@ public abstract class AbstractPacketAdapter extends PacketAdapter {
             return;
         }
 
-        onSend(event.getPacket(), event.getPlayer());
         onSend(event.getPacket(), event.getPlayer(), event);
     }
 

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

@@ -0,0 +1,40 @@
+package com.willfp.eco.core;
+
+import lombok.Getter;
+import lombok.experimental.UtilityClass;
+import org.apache.commons.lang.Validate;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Base class to hold the handler.
+ *
+ * @see Handler
+ */
+@UtilityClass
+public class Eco {
+    /**
+     * Instance of eco handler.
+     * <p>
+     * The handler is, in essence, a way to interface between the eco-api
+     * frontend module, and the eco-backend implementations.
+     * <p>
+     * There shouldn't really be any reason to ever use the handler
+     * in your own plugins, but if you want to then you can - it's
+     * just a part of the API like any other.
+     */
+    @Getter
+    private Handler handler;
+
+    /**
+     * Set the handler.
+     *
+     * @param handler The handler.
+     */
+    @ApiStatus.Internal
+    public void setHandler(@NotNull final Handler handler) {
+        Validate.isTrue(Eco.handler == null, "Already initialized!");
+
+        Eco.handler = handler;
+    }
+}

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

@@ -1,10 +1,9 @@
 package com.willfp.eco.core;
 
-import com.willfp.eco.core.command.AbstractCommand;
 import com.willfp.eco.core.command.impl.PluginCommand;
-import com.willfp.eco.core.config.ConfigHandler;
 import com.willfp.eco.core.config.base.ConfigYml;
 import com.willfp.eco.core.config.base.LangYml;
+import com.willfp.eco.core.config.updating.ConfigHandler;
 import com.willfp.eco.core.display.Display;
 import com.willfp.eco.core.display.DisplayModule;
 import com.willfp.eco.core.events.EventManager;
@@ -14,23 +13,13 @@ import com.willfp.eco.core.factory.NamespacedKeyFactory;
 import com.willfp.eco.core.factory.RunnableFactory;
 import com.willfp.eco.core.integrations.IntegrationLoader;
 import com.willfp.eco.core.integrations.placeholder.PlaceholderManager;
+import com.willfp.eco.core.proxy.AbstractProxy;
+import com.willfp.eco.core.proxy.ProxyFactory;
 import com.willfp.eco.core.scheduling.Scheduler;
-import com.willfp.eco.internal.Internals;
-import com.willfp.eco.internal.UpdateChecker;
-import com.willfp.eco.internal.arrows.ArrowDataListener;
-import com.willfp.eco.internal.config.updating.EcoConfigHandler;
-import com.willfp.eco.internal.events.EcoEventManager;
-import com.willfp.eco.internal.extensions.EcoExtensionLoader;
-import com.willfp.eco.internal.factory.EcoMetadataValueFactory;
-import com.willfp.eco.internal.factory.EcoNamespacedKeyFactory;
-import com.willfp.eco.internal.factory.EcoRunnableFactory;
-import com.willfp.eco.internal.integrations.PlaceholderIntegrationPAPI;
-import com.willfp.eco.internal.logging.EcoLogger;
-import com.willfp.eco.internal.scheduling.EcoScheduler;
+import com.willfp.eco.core.web.UpdateChecker;
 import lombok.Getter;
 import org.apache.commons.lang.Validate;
 import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
-import org.bstats.bukkit.Metrics;
 import org.bukkit.Bukkit;
 import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.event.Listener;
@@ -47,22 +36,23 @@ import java.util.Set;
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 
-@SuppressWarnings({"deprecation", "DeprecatedIsStillUsed"})
+/**
+ * EcoPlugin is the base plugin class for eco-based plugins.
+ * <p>
+ * It functions as a replacement for {@link JavaPlugin}.
+ * <p>
+ * EcoPlugin is a lot more powerful than {@link JavaPlugin} and
+ * contains many methods to reduce boilerplate code and reduce
+ * plugin complexity.
+ * <p>
+ * It is recommended to view the source code for this class to
+ * gain a better understanding of how it works.
+ * <p>
+ * <b>IMPORTANT: When reloading a plugin, all runnables / tasks will
+ * be cancelled.</b>
+ */
+@SuppressWarnings("unused")
 public abstract class EcoPlugin extends JavaPlugin {
-    /**
-     * Loaded eco plugins.
-     */
-    public static final List<String> LOADED_ECO_PLUGINS = new ArrayList<>();
-
-    /**
-     * The name of the plugin.
-     *
-     * @deprecated Pointless, use getName instead.
-     */
-    @Getter
-    @Deprecated
-    private final String pluginName;
-
     /**
      * The spigot resource ID of the plugin.
      */
@@ -93,11 +83,6 @@ public abstract class EcoPlugin extends JavaPlugin {
     @Getter
     private final Set<String> loadedIntegrations = new HashSet<>();
 
-    /**
-     * Set of classes to be processed on config update.
-     */
-    private final List<Class<?>> updatableClasses = new ArrayList<>();
-
     /**
      * The internal plugin scheduler.
      */
@@ -177,6 +162,12 @@ public abstract class EcoPlugin extends JavaPlugin {
     @Getter
     private final boolean supportingExtensions;
 
+    /**
+     * The proxy factory.
+     */
+    @Getter
+    private final ProxyFactory proxyFactory;
+
     /**
      * Create a new plugin without a specified color, proxy support, spigot, or bStats.
      */
@@ -198,7 +189,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      * Create a new plugin unlinked to spigot and bStats.
      *
      * @param proxyPackage The package where proxy implementations are stored.
-     * @param color        The color of the plugin (used in messages, such as &a, &b)
+     * @param color        The color of the plugin (used in messages, using standard formatting)
      */
     protected EcoPlugin(@NotNull final String proxyPackage,
                         @NotNull final String color) {
@@ -210,7 +201,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      *
      * @param resourceId The spigot resource ID for the plugin.
      * @param bStatsId   The bStats resource ID for the plugin.
-     * @param color      The color of the plugin (used in messages, such as &a, &b)
+     * @param color      The color of the plugin (used in messages, using standard formatting)
      */
     protected EcoPlugin(final int resourceId,
                         final int bStatsId,
@@ -223,7 +214,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      *
      * @param resourceId           The spigot resource ID for the plugin.
      * @param bStatsId             The bStats resource ID for the plugin.
-     * @param color                The color of the plugin (used in messages, such as &a, &b)
+     * @param color                The color of the plugin (used in messages, using standard formatting)
      * @param supportingExtensions If the plugin supports extensions.
      */
     protected EcoPlugin(final int resourceId,
@@ -239,7 +230,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      * @param resourceId   The spigot resource ID for the plugin.
      * @param bStatsId     The bStats resource ID for the plugin.
      * @param proxyPackage The package where proxy implementations are stored.
-     * @param color        The color of the plugin (used in messages, such as &a, &b)
+     * @param color        The color of the plugin (used in messages, using standard formatting)
      */
     protected EcoPlugin(final int resourceId,
                         final int bStatsId,
@@ -254,7 +245,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      * @param resourceId           The spigot resource ID for the plugin.
      * @param bStatsId             The bStats resource ID for the plugin.
      * @param proxyPackage         The package where proxy implementations are stored.
-     * @param color                The color of the plugin (used in messages, such as &a, &b)
+     * @param color                The color of the plugin (used in messages, using standard formatting)
      * @param supportingExtensions If the plugin supports extensions.
      */
     protected EcoPlugin(final int resourceId,
@@ -262,68 +253,62 @@ public abstract class EcoPlugin extends JavaPlugin {
                         @NotNull final String proxyPackage,
                         @NotNull final String color,
                         final boolean supportingExtensions) {
-        this("", resourceId, bStatsId, proxyPackage, color, supportingExtensions);
-    }
+        /*
+        The handler must be initialized before any plugin's constructors
+        are called, as the constructors call Eco#getHandler().
 
-    /**
-     * Create a new plugin.
-     *
-     * @param pluginName   The name of the plugin.
-     * @param resourceId   The spigot resource ID for the plugin.
-     * @param bStatsId     The bStats resource ID for the plugin.
-     * @param proxyPackage The package where proxy implementations are stored.
-     * @param color        The color of the plugin (used in messages, such as &a, &b)
-     * @deprecated pluginName is redundant.
-     */
-    @Deprecated
-    @SuppressWarnings("unused")
-    protected EcoPlugin(@NotNull final String pluginName,
-                        final int resourceId,
-                        final int bStatsId,
-                        @NotNull final String proxyPackage,
-                        @NotNull final String color) {
-        this(pluginName, resourceId, bStatsId, proxyPackage, color, false);
-    }
+        To fix this, EcoSpigotPlugin an abstract class and the 'actual'
+        plugin class is EcoHandler - that way I can create the handler
+        before any plugins are loaded while still having a separation between
+        the plugin class and the handler class (for code clarity).
+
+        I don't really like the fact that the handler class *is* the
+        spigot plugin, but it is what it is.
+
+        There is probably a better way of doing it - maybe with
+        some sort of HandlerCreator interface in order to still have
+        a standalone handler class, but then there would be an interface
+        left in the API that doesn't really help anything.
+
+        The other alternative would be do use reflection to get a 'createHandler'
+        method that only exists in EcoSpigotPlugin - but that feels really dirty
+        and I'd rather only use reflection where necessary.
+        */
+
+        if (Eco.getHandler() == null && this instanceof Handler) {
+            /*
+            This code is only ever called by EcoSpigotPlugin (EcoHandler)
+            as it's the first plugin to load and it is a handler.
+
+            Any other plugins will never call this code as the handler
+            will have already been initialized.
+             */
+
+            Eco.setHandler((Handler) this);
+        }
+
+        assert Eco.getHandler() != null;
 
-    /**
-     * Create a new plugin.
-     *
-     * @param pluginName           The name of the plugin.
-     * @param resourceId           The spigot resource ID for the plugin.
-     * @param bStatsId             The bStats resource ID for the plugin.
-     * @param proxyPackage         The package where proxy implementations are stored.
-     * @param color                The color of the plugin (used in messages, such as &a, &b)
-     * @param supportingExtensions If the plugin supports extensions.
-     * @deprecated pluginName is redundant.
-     */
-    @Deprecated
-    @SuppressWarnings("unused")
-    protected EcoPlugin(@NotNull final String pluginName,
-                        final int resourceId,
-                        final int bStatsId,
-                        @NotNull final String proxyPackage,
-                        @NotNull final String color,
-                        final boolean supportingExtensions) {
-        this.pluginName = this.getName();
         this.resourceId = resourceId;
         this.bStatsId = bStatsId;
         this.proxyPackage = proxyPackage;
         this.color = color;
         this.supportingExtensions = supportingExtensions;
 
-        this.scheduler = new EcoScheduler(this);
-        this.eventManager = new EcoEventManager(this);
-        this.namespacedKeyFactory = new EcoNamespacedKeyFactory(this);
-        this.metadataValueFactory = new EcoMetadataValueFactory(this);
-        this.runnableFactory = new EcoRunnableFactory(this);
-        this.extensionLoader = new EcoExtensionLoader(this);
-        this.configHandler = new EcoConfigHandler(this);
-        this.logger = new EcoLogger(this);
+        this.scheduler = Eco.getHandler().createScheduler(this);
+        this.eventManager = Eco.getHandler().createEventManager(this);
+        this.namespacedKeyFactory = Eco.getHandler().createNamespacedKeyFactory(this);
+        this.metadataValueFactory = Eco.getHandler().createMetadataValueFactory(this);
+        this.runnableFactory = Eco.getHandler().createRunnableFactory(this);
+        this.extensionLoader = Eco.getHandler().createExtensionLoader(this);
+        this.configHandler = Eco.getHandler().createConfigHandler(this);
+        this.logger = Eco.getHandler().createLogger(this);
+        this.proxyFactory = this.proxyPackage.equalsIgnoreCase("") ? null : Eco.getHandler().createProxyFactory(this);
 
         this.langYml = new LangYml(this);
         this.configYml = new ConfigYml(this);
 
-        LOADED_ECO_PLUGINS.add(this.getName().toLowerCase());
+        Eco.getHandler().addNewPlugin(this);
     }
 
     /**
@@ -336,8 +321,6 @@ public abstract class EcoPlugin extends JavaPlugin {
         this.getLogger().info("");
         this.getLogger().info("Loading " + this.getColor() + this.getName());
 
-        this.getEventManager().registerListener(new ArrowDataListener(this));
-
         if (this.getResourceId() != 0) {
             new UpdateChecker(this).getVersion(version -> {
                 DefaultArtifactVersion currentVersion = new DefaultArtifactVersion(this.getDescription().getVersion());
@@ -353,7 +336,7 @@ public abstract class EcoPlugin extends JavaPlugin {
             });
         }
 
-        DefaultArtifactVersion runningVersion = new DefaultArtifactVersion(Internals.getInstance().getPlugin().getDescription().getVersion());
+        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!");
@@ -364,17 +347,17 @@ public abstract class EcoPlugin extends JavaPlugin {
         }
 
         if (this.getBStatsId() != 0) {
-            new Metrics(this, this.getBStatsId());
+            Eco.getHandler().registerBStats(this);
         }
 
         Set<String> enabledPlugins = Arrays.stream(Bukkit.getPluginManager().getPlugins()).map(Plugin::getName).collect(Collectors.toSet());
 
         if (enabledPlugins.contains("PlaceholderAPI")) {
             this.loadedIntegrations.add("PlaceholderAPI");
-            PlaceholderManager.addIntegration(new PlaceholderIntegrationPAPI(this));
+            PlaceholderManager.addIntegration(Eco.getHandler().createPAPIIntegration(this));
         }
 
-        this.getIntegrationLoaders().forEach((integrationLoader -> {
+        this.loadIntegrationLoaders().forEach((integrationLoader -> {
             if (enabledPlugins.contains(integrationLoader.getPluginName())) {
                 this.loadedIntegrations.add(integrationLoader.getPluginName());
                 integrationLoader.load();
@@ -385,23 +368,18 @@ public abstract class EcoPlugin extends JavaPlugin {
 
         Prerequisite.update();
 
-        this.getPacketAdapters().forEach(abstractPacketAdapter -> {
+        this.loadPacketAdapters().forEach(abstractPacketAdapter -> {
             if (!abstractPacketAdapter.isPostLoad()) {
                 abstractPacketAdapter.register();
             }
         });
 
-        updatableClasses.addAll(this.getUpdatableClasses());
+        this.loadListeners().forEach(listener -> this.getEventManager().registerListener(listener));
 
-        this.getListeners().forEach(listener -> this.getEventManager().registerListener(listener));
-
-        this.getCommands().forEach(AbstractCommand::register);
-        this.getPluginCommands().forEach(PluginCommand::register);
+        this.loadPluginCommands().forEach(PluginCommand::register);
 
         this.getScheduler().runLater(this::afterLoad, 1);
 
-        this.updatableClasses.forEach(clazz -> this.getConfigHandler().registerUpdatableClass(clazz));
-
         if (this.isSupportingExtensions()) {
             this.getExtensionLoader().loadExtensions();
 
@@ -413,7 +391,7 @@ public abstract class EcoPlugin extends JavaPlugin {
             }
         }
 
-        this.enable();
+        this.handleEnable();
 
         this.getLogger().info("");
     }
@@ -427,13 +405,15 @@ public abstract class EcoPlugin extends JavaPlugin {
 
         this.getEventManager().unregisterAllListeners();
         this.getScheduler().cancelAll();
-        this.getConfigHandler().saveAllConfigs();
 
-        this.disable();
+        this.handleDisable();
 
         if (this.isSupportingExtensions()) {
             this.getExtensionLoader().unloadExtensions();
         }
+
+        this.getLogger().info("Cleaning up...");
+        Eco.getHandler().getCleaner().clean(this);
     }
 
     /**
@@ -443,7 +423,7 @@ public abstract class EcoPlugin extends JavaPlugin {
     public final void onLoad() {
         super.onLoad();
 
-        this.load();
+        this.handleLoad();
     }
 
     /**
@@ -456,7 +436,7 @@ public abstract class EcoPlugin extends JavaPlugin {
             Display.registerDisplayModule(this.getDisplayModule());
         }
 
-        this.getPacketAdapters().forEach(abstractPacketAdapter -> {
+        this.loadPacketAdapters().forEach(abstractPacketAdapter -> {
             if (abstractPacketAdapter.isPostLoad()) {
                 abstractPacketAdapter.register();
             }
@@ -475,15 +455,15 @@ public abstract class EcoPlugin extends JavaPlugin {
             this.getLogger().severe("");
         }
 
-        this.postLoad();
+        this.handleAfterLoad();
 
         this.reload();
 
-        this.getLogger().info("Loaded " + this.color + this.pluginName);
+        this.getLogger().info("Loaded " + this.color + this.getName());
     }
 
     /**
-     * Default code to be executed on plugin reload.
+     * Reload the plugin.
      */
     public final void reload() {
         this.getConfigHandler().updateConfigs();
@@ -492,7 +472,20 @@ public abstract class EcoPlugin extends JavaPlugin {
         this.getConfigHandler().callUpdate(); // Call twice to fix issues
         this.getScheduler().cancelAll();
 
-        this.onReload();
+        this.handleReload();
+    }
+
+    /**
+     * Reload the plugin and return the time taken to reload.
+     *
+     * @return The time.
+     */
+    public final long reloadWithTime() {
+        long startTime = System.currentTimeMillis();
+
+        this.reload();
+
+        return System.currentTimeMillis() - startTime;
     }
 
     /**
@@ -500,7 +493,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      * <p>
      * Override when needed.
      */
-    public void enable() {
+    protected void handleEnable() {
 
     }
 
@@ -509,7 +502,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      * <p>
      * Override when needed.
      */
-    public void disable() {
+    protected void handleDisable() {
 
     }
 
@@ -520,7 +513,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      * <p>
      * Override when needed.
      */
-    public void load() {
+    protected void handleLoad() {
 
     }
 
@@ -529,7 +522,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      * <p>
      * Override when needed.
      */
-    public void onReload() {
+    protected void handleReload() {
 
     }
 
@@ -538,7 +531,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      * <p>
      * Override when needed.
      */
-    public void postLoad() {
+    protected void handleAfterLoad() {
 
     }
 
@@ -547,18 +540,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      *
      * @return A list of integrations.
      */
-    public List<IntegrationLoader> getIntegrationLoaders() {
-        return new ArrayList<>();
-    }
-
-    /**
-     * The commands to be registered.
-     *
-     * @return A list of commands.
-     * @deprecated Use {@link this#getPluginCommands()} instead.
-     */
-    @Deprecated
-    public List<AbstractCommand> getCommands() {
+    protected List<IntegrationLoader> loadIntegrationLoaders() {
         return new ArrayList<>();
     }
 
@@ -567,7 +549,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      *
      * @return A list of commands.
      */
-    public List<PluginCommand> getPluginCommands() {
+    protected List<PluginCommand> loadPluginCommands() {
         return new ArrayList<>();
     }
 
@@ -578,7 +560,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      *
      * @return A list of packet adapters.
      */
-    public List<AbstractPacketAdapter> getPacketAdapters() {
+    protected List<AbstractPacketAdapter> loadPacketAdapters() {
         return new ArrayList<>();
     }
 
@@ -587,16 +569,7 @@ public abstract class EcoPlugin extends JavaPlugin {
      *
      * @return A list of all listeners.
      */
-    public abstract List<Listener> getListeners();
-
-    /**
-     * All updatable classes.
-     *
-     * @return A list of all updatable classes.
-     */
-    public List<Class<?>> getUpdatableClasses() {
-        return new ArrayList<>();
-    }
+    protected abstract List<Listener> loadListeners();
 
     /**
      * Create the display module for the plugin.
@@ -618,8 +591,8 @@ public abstract class EcoPlugin extends JavaPlugin {
      *
      * @return The version.
      */
-    protected String getMinimumEcoVersion() {
-        return "5.0.0";
+    public String getMinimumEcoVersion() {
+        return "6.0.0";
     }
 
     /**
@@ -633,12 +606,25 @@ public abstract class EcoPlugin extends JavaPlugin {
         return logger;
     }
 
+    /**
+     * Get a proxy.
+     *
+     * @param proxyClass The proxy class.
+     * @param <T>        The proxy type.
+     * @return The proxy.
+     */
+    public final <T extends AbstractProxy> T getProxy(@NotNull final Class<T> proxyClass) {
+        Validate.notNull(proxyFactory, "Plugin does not support proxy!");
+
+        return proxyFactory.getProxy(proxyClass);
+    }
+
     /**
      * Get unwrapped config.
      * Does not use eco config system, don't use.
      *
      * @return The bukkit config.
-     * @deprecated Use {@link EcoPlugin#getConfigYml()} instead.
+     * @deprecated Use getConfigYml() instead.
      */
     @NotNull
     @Override
@@ -646,7 +632,7 @@ public abstract class EcoPlugin extends JavaPlugin {
     public final FileConfiguration getConfig() {
         this.getLogger().warning("Call to default config method in eco plugin!");
 
-        return this.getConfigYml().getHandle();
+        return this.getConfigYml().getBukkitHandle();
     }
 
     /**
@@ -687,4 +673,23 @@ public abstract class EcoPlugin extends JavaPlugin {
 
         super.reloadConfig();
     }
+
+    /**
+     * Get an EcoPlugin by name.
+     *
+     * @param pluginName The name.
+     * @return The plugin.
+     */
+    public static EcoPlugin getPlugin(@NotNull final String pluginName) {
+        return Eco.getHandler().getPluginByName(pluginName);
+    }
+
+    /**
+     * Get all EcoPlugin names.
+     *
+     * @return The set of names.
+     */
+    public static Set<String> getPluginNames() {
+        return new HashSet<>(Eco.getHandler().getLoadedPlugins());
+    }
 }

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

@@ -0,0 +1,178 @@
+package com.willfp.eco.core;
+
+import com.willfp.eco.core.config.updating.ConfigHandler;
+import com.willfp.eco.core.config.wrapper.ConfigFactory;
+import com.willfp.eco.core.drops.DropQueueFactory;
+import com.willfp.eco.core.events.EventManager;
+import com.willfp.eco.core.extensions.ExtensionLoader;
+import com.willfp.eco.core.factory.MetadataValueFactory;
+import com.willfp.eco.core.factory.NamespacedKeyFactory;
+import com.willfp.eco.core.factory.RunnableFactory;
+import com.willfp.eco.core.fast.FastItemStack;
+import com.willfp.eco.core.gui.GUIFactory;
+import com.willfp.eco.core.integrations.placeholder.PlaceholderIntegration;
+import com.willfp.eco.core.proxy.Cleaner;
+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 java.util.List;
+import java.util.logging.Logger;
+
+/**
+ * @see Eco
+ */
+public interface Handler {
+    /**
+     * Create a scheduler.
+     *
+     * @param plugin The plugin.
+     * @return The scheduler.
+     */
+    Scheduler createScheduler(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create an event manager.
+     *
+     * @param plugin The plugin.
+     * @return The event manager.
+     */
+    EventManager createEventManager(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create a NamespacedKey factory.
+     *
+     * @param plugin The plugin.
+     * @return The factory.
+     */
+    NamespacedKeyFactory createNamespacedKeyFactory(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create a MetadataValue factory.
+     *
+     * @param plugin The plugin.
+     * @return The factory.
+     */
+    MetadataValueFactory createMetadataValueFactory(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create a Runnable factory.
+     *
+     * @param plugin The plugin.
+     * @return The factory.
+     */
+    RunnableFactory createRunnableFactory(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create an ExtensionLoader.
+     *
+     * @param plugin The plugin.
+     * @return The factory.
+     */
+    ExtensionLoader createExtensionLoader(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create a config handler.
+     *
+     * @param plugin The plugin.
+     * @return The handler.
+     */
+    ConfigHandler createConfigHandler(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create a logger.
+     *
+     * @param plugin The plugin.
+     * @return The logger.
+     */
+    Logger createLogger(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create a PAPI integration.
+     *
+     * @param plugin The plugin.
+     * @return The integration.
+     */
+    PlaceholderIntegration createPAPIIntegration(@NotNull EcoPlugin plugin);
+
+    /**
+     * Create a proxy factory.
+     *
+     * @param plugin The plugin.
+     * @return The factory.
+     */
+    ProxyFactory createProxyFactory(@NotNull EcoPlugin plugin);
+
+    /**
+     * Get eco Spigot plugin.
+     *
+     * @return The plugin.
+     */
+    EcoPlugin getEcoPlugin();
+
+    /**
+     * Get config factory.
+     *
+     * @return The factory.
+     */
+    ConfigFactory getConfigFactory();
+
+    /**
+     * Get drop queue factory.
+     *
+     * @return The factory.
+     */
+    DropQueueFactory getDropQueueFactory();
+
+    /**
+     * Get GUI factory.
+     *
+     * @return The factory.
+     */
+    GUIFactory getGUIFactory();
+
+    /**
+     * Get cleaner.
+     *
+     * @return The cleaner.
+     */
+    Cleaner getCleaner();
+
+    /**
+     * Add new plugin.
+     *
+     * @param plugin The plugin.
+     */
+    void addNewPlugin(@NotNull EcoPlugin plugin);
+
+    /**
+     * Get plugin by name.
+     *
+     * @param name The name.
+     * @return The plugin.
+     */
+    EcoPlugin getPluginByName(@NotNull String name);
+
+    /**
+     * Get all loaded eco plugins.
+     *
+     * @return A list of plugin names in lowercase.
+     */
+    List<String> getLoadedPlugins();
+
+    /**
+     * Create a FastItemStack.
+     *
+     * @param itemStack The base ItemStack.
+     * @return The FastItemStack.
+     */
+    FastItemStack createFastItemStack(@NotNull ItemStack itemStack);
+
+    /**
+     * Register bStats metrics.
+     *
+     * @param plugin The plugin.
+     */
+    void registerBStats(@NotNull EcoPlugin plugin);
+}

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

@@ -4,6 +4,11 @@ import lombok.AccessLevel;
 import lombok.Getter;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Quick DI class to manage passing eco plugins.
+ *
+ * @param <T> The eco plugin type.
+ */
 public abstract class PluginDependent<T extends EcoPlugin> {
     /**
      * The {@link EcoPlugin} that is stored.

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

@@ -10,6 +10,12 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.function.Supplier;
 
+/**
+ * A prerequisite is a requirement for something.
+ * <p>
+ * For example, you can require the server to have paper or be a specific version,
+ * or have some other dependency.
+ */
 public class Prerequisite {
     /**
      * All existing prerequisites are registered on creation.
@@ -25,12 +31,11 @@ public class Prerequisite {
     );
 
     /**
-     * Requires the server to be running 1.17.
+     * Requires the server to be running an implementation of paper.
      */
-    @Deprecated
-    public static final Prerequisite v1_17 = new Prerequisite(
-            () -> ProxyConstants.NMS_VERSION.contains("17"),
-            "Requires server to be running 1.17+"
+    public static final Prerequisite HAS_VAULT = new Prerequisite(
+            () -> ClassUtils.exists("net.milkbowl.vault.economy.Economy"),
+            "Requires server to have vault"
     );
 
     /**

eco-api/src/main/java/com/willfp/eco/core/command/AbstractCommand.java

@@ -1,156 +0,0 @@
-package com.willfp.eco.core.command;
-
-import com.willfp.eco.core.PluginDependent;
-import com.willfp.eco.core.EcoPlugin;
-import org.bukkit.Bukkit;
-import org.bukkit.command.Command;
-import org.bukkit.command.CommandExecutor;
-import org.bukkit.command.CommandSender;
-import org.bukkit.command.PluginCommand;
-import org.bukkit.entity.Player;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.Arrays;
-import java.util.List;
-
-@Deprecated
-@SuppressWarnings("DeprecatedIsStillUsed")
-public abstract class AbstractCommand extends PluginDependent<EcoPlugin> implements CommandExecutor {
-    /**
-     * The name of the command
-     * <p>
-     * i.e. the name used on execution, for example /enchantinfo would have the name enchantinfo.
-     */
-    private final String name;
-
-    /**
-     * The permission required to execute the command.
-     * <p>
-     * Written out as a string for flexibility with subclasses.
-     */
-    private final String permission;
-
-    /**
-     * Should the command only be allowed to be executed by players?
-     * <p>
-     * In other worlds, only allowed to be executed by console.
-     */
-    private final boolean playersOnly;
-
-    /**
-     * Create a new command.
-     * <p>
-     * The command will not be registered until {@link this#register()} is called.
-     * <p>
-     * The name cannot be the same as an existing command as this will conflict.
-     *
-     * @param plugin      The owning {@link EcoPlugin}.
-     * @param name        The name used in execution.
-     * @param permission  The permission required to execute the command.
-     * @param playersOnly If only players should be able to execute this command.
-     */
-    protected AbstractCommand(@NotNull final EcoPlugin plugin,
-                              @NotNull final String name,
-                              @NotNull final String permission,
-                              final boolean playersOnly) {
-        super(plugin);
-        this.name = name;
-        this.permission = permission;
-        this.playersOnly = playersOnly;
-    }
-
-    /**
-     * Get the {@link AbstractTabCompleter} associated with this command.
-     * <p>
-     * Implementations of {@link AbstractCommand} do not have to override this method:
-     * null represents no associated tab-completer.
-     *
-     * @return The associated {@link AbstractTabCompleter}, or null if none associated.
-     */
-    public @Nullable AbstractTabCompleter getTab() {
-        return null;
-    }
-
-    /**
-     * Get the name of the permission required to execute this command.
-     *
-     * @return The name of the permission.
-     */
-    public String getPermission() {
-        return this.permission;
-    }
-
-    /**
-     * Get the name of the command used in execution.
-     *
-     * @return The command name.
-     */
-    public String getName() {
-        return this.name;
-    }
-
-    /**
-     * Internal implementation used to clean up boilerplate.
-     * Used for parity with {@link CommandExecutor#onCommand(CommandSender, Command, String, String[])}.
-     * <p>
-     * Calls {@link this#onExecute(CommandSender, List)}.
-     *
-     * @param sender  The executor of the command.
-     * @param command The bukkit command.
-     * @param label   The name of the executed command.
-     * @param args    The arguments of the command (anything after the physical command name)
-     * @return If the command was processed by the linked {@link EcoPlugin}
-     */
-    @Override
-    public final boolean onCommand(@NotNull final CommandSender sender,
-                                   @NotNull final Command command,
-                                   @NotNull final String label,
-                                   @NotNull final String[] args) {
-        if (!command.getName().equalsIgnoreCase(name)) {
-            return false;
-        }
-
-        if (playersOnly && !(sender instanceof Player)) {
-            sender.sendMessage(this.getPlugin().getLangYml().getMessage("not-player"));
-            return true;
-        }
-
-        if (!sender.hasPermission(permission) && sender instanceof Player) {
-            sender.sendMessage(this.getPlugin().getLangYml().getNoPermission());
-            return true;
-        }
-
-        onExecute(sender, Arrays.asList(args));
-
-        return true;
-    }
-
-    /**
-     * Registers the command with the server,
-     * <p>
-     * Requires the command name to exist, defined in plugin.yml.
-     */
-    public final void register() {
-        PluginCommand command = Bukkit.getPluginCommand(name);
-        assert command != null;
-        command.setExecutor(this);
-
-        AbstractTabCompleter tabCompleter = this.getTab();
-        if (tabCompleter != null) {
-            command.setTabCompleter(tabCompleter);
-        }
-    }
-
-    /**
-     * The code for the execution of the command (The actual functionality).
-     * <p>
-     * Unlike {@link this#onCommand(CommandSender, Command, String, String[])},
-     * this does not return a value as the command <b>will</b> have been processed.
-     *
-     * @param sender The sender of the command
-     * @param args   The arguments of the command
-     */
-    protected abstract void onExecute(CommandSender sender,
-                                      List<String> args);
-}

eco-api/src/main/java/com/willfp/eco/core/command/AbstractTabCompleter.java

@@ -1,66 +0,0 @@
-package com.willfp.eco.core.command;
-
-import org.bukkit.command.Command;
-import org.bukkit.command.CommandSender;
-import org.bukkit.command.TabCompleter;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.Arrays;
-import java.util.List;
-
-@Deprecated
-public abstract class AbstractTabCompleter implements TabCompleter {
-    /**
-     * The {@link AbstractCommand} that is tab-completed.
-     */
-    private final AbstractCommand command;
-
-    /**
-     * Create a tab-completer for a specified {@link AbstractCommand}.
-     *
-     * @param command The command to tab-complete.
-     */
-    protected AbstractTabCompleter(@NotNull final AbstractCommand command) {
-        this.command = command;
-    }
-
-    /**
-     * Internal implementation used to clean up boilerplate.
-     * Used for parity with {@link TabCompleter#onTabComplete(CommandSender, Command, String, String[])}.
-     * <p>
-     * Calls {@link this#onTab(CommandSender, List)}.
-     *
-     * @param sender  The executor of the command.
-     * @param command The bukkit command.
-     * @param label   The name of the executed command.
-     * @param args    The arguments of the command (anything after the physical command name).
-     * @return The list of tab-completions.
-     */
-    @Override
-    public @Nullable List<String> onTabComplete(@NotNull final CommandSender sender,
-                                                @NotNull final Command command,
-                                                @NotNull final String label,
-                                                @NotNull final String[] args) {
-        if (!command.getName().equalsIgnoreCase(this.command.getName())) {
-            return null;
-        }
-
-        if (!sender.hasPermission(this.command.getPermission())) {
-            return null;
-        }
-
-        return onTab(sender, Arrays.asList(args));
-    }
-
-    /**
-     * The code for the tab-completion of the command (The actual functionality).
-     * <p>
-     *
-     * @param sender The sender of the command.
-     * @param args   The arguments of the command.
-     * @return The list of tab-completions.
-     */
-    public abstract List<String> onTab(@NotNull CommandSender sender,
-                                       @NotNull List<String> args);
-}

eco-api/src/main/java/com/willfp/eco/core/command/CommandBase.java

@@ -2,6 +2,9 @@ package com.willfp.eco.core.command;
 
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Interface for all command implementations.
+ */
 public interface CommandBase {
     /**
      * Get command name.
@@ -39,10 +42,24 @@ public interface CommandBase {
      */
     CommandHandler getHandler();
 
+    /**
+     * Set the handler.
+     *
+     * @param handler The handler.
+     */
+    void setHandler(@NotNull CommandHandler handler);
+
     /**
      * Get the tab completer.
      *
      * @return The tab completer.
      */
     TabCompleteHandler getTabCompleter();
+
+    /**
+     * Set the tab completer.
+     *
+     * @param handler The handler.
+     */
+    void setTabCompleter(@NotNull TabCompleteHandler handler);
 }

eco-api/src/main/java/com/willfp/eco/core/command/CommandHandler.java

@@ -1,10 +1,17 @@
 package com.willfp.eco.core.command;
 
+import org.bukkit.command.Command;
 import org.bukkit.command.CommandSender;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.List;
 
+/**
+ * A command handler handles the actual code for a command.
+ * <p>
+ * The replacement for {@link org.bukkit.command.CommandExecutor#onCommand(CommandSender, Command, String, String[])}
+ * @see CommandBase
+ */
 @FunctionalInterface
 public interface CommandHandler {
     /**

eco-api/src/main/java/com/willfp/eco/core/command/TabCompleteHandler.java

@@ -1,10 +1,17 @@
 package com.willfp.eco.core.command;
 
+import org.bukkit.command.Command;
 import org.bukkit.command.CommandSender;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.List;
 
+/**
+ * A Tab Complete handler handles the actual tab-completion code.
+ * <p>
+ * The replacement for {@link org.bukkit.command.TabCompleter#onTabComplete(CommandSender, Command, String, String[])}
+ * @see CommandBase
+ */
 @FunctionalInterface
 public interface TabCompleteHandler {
     /**

eco-api/src/main/java/com/willfp/eco/core/command/impl/HandledCommand.java

@@ -1,14 +1,15 @@
-package com.willfp.eco.internal.commands;
+package com.willfp.eco.core.command.impl;
 
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.PluginDependent;
 import com.willfp.eco.core.command.CommandBase;
 import com.willfp.eco.core.command.CommandHandler;
 import com.willfp.eco.core.command.TabCompleteHandler;
-import com.willfp.eco.internal.commands.util.CommandUtils;
 import lombok.AccessLevel;
 import lombok.Getter;
+import lombok.Setter;
 import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
 import org.bukkit.util.StringUtil;
 import org.jetbrains.annotations.NotNull;
 
@@ -18,7 +19,14 @@ import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
-public abstract class HandledCommand extends PluginDependent<EcoPlugin> implements CommandBase {
+/**
+ * Abstract class for commands that can be handled.
+ * <p>
+ * Handled commands have a method to pass in raw input from bukkit commands
+ * in order to execute the command-specific code. It's essentially an internal
+ * layer, hence why it's a package-private class.
+ */
+abstract class HandledCommand extends PluginDependent<EcoPlugin> implements CommandBase {
     /**
      * The name of the command.
      */
@@ -41,6 +49,20 @@ public abstract class HandledCommand extends PluginDependent<EcoPlugin> implemen
     @Getter
     private final boolean playersOnly;
 
+    /**
+     * The actual code to be executed in the command.
+     */
+    @Getter
+    @Setter
+    private CommandHandler handler = (sender, args) -> { };
+
+    /**
+     * The tab completion code to be executed in the command.
+     */
+    @Getter
+    @Setter
+    private TabCompleteHandler tabCompleter = (sender, args) -> new ArrayList<>();
+
     /**
      * All subcommands for the command.
      */
@@ -57,10 +79,10 @@ public abstract class HandledCommand extends PluginDependent<EcoPlugin> implemen
      * @param permission  The permission required to execute the command.
      * @param playersOnly If only players should be able to execute this command.
      */
-    protected HandledCommand(@NotNull final EcoPlugin plugin,
-                             @NotNull final String name,
-                             @NotNull final String permission,
-                             final boolean playersOnly) {
+    HandledCommand(@NotNull final EcoPlugin plugin,
+                   @NotNull final String name,
+                   @NotNull final String permission,
+                   final boolean playersOnly) {
         super(plugin);
         this.name = name;
         this.permission = permission;
@@ -89,14 +111,14 @@ public abstract class HandledCommand extends PluginDependent<EcoPlugin> implemen
      */
     protected final void handle(@NotNull final CommandSender sender,
                                 @NotNull final String[] args) {
-        if (!CommandUtils.canExecute(sender, this, this.getPlugin())) {
+        if (!canExecute(sender, this, this.getPlugin())) {
             return;
         }
 
         if (args.length > 0) {
             for (CommandBase subcommand : this.getSubcommands()) {
                 if (subcommand.getName().equalsIgnoreCase(args[0])) {
-                    if (!CommandUtils.canExecute(sender, subcommand, this.getPlugin())) {
+                    if (!canExecute(sender, subcommand, this.getPlugin())) {
                         return;
                     }
 
@@ -115,6 +137,7 @@ public abstract class HandledCommand extends PluginDependent<EcoPlugin> implemen
      *
      * @param sender The sender.
      * @param args   The arguments.
+     * @return The tab completion results.
      */
     protected final List<String> handleTabCompletion(@NotNull final CommandSender sender,
                                                      @NotNull final String[] args) {
@@ -156,11 +179,27 @@ public abstract class HandledCommand extends PluginDependent<EcoPlugin> implemen
         return this.getTabCompleter().tabComplete(sender, Arrays.asList(args));
     }
 
-    @Override
-    public abstract CommandHandler getHandler();
+    /**
+     * If a sender can execute the command.
+     *
+     * @param sender  The sender.
+     * @param command The command.
+     * @param plugin  The plugin.
+     * @return If the sender can execute.
+     */
+    public static boolean canExecute(@NotNull final CommandSender sender,
+                                     @NotNull final CommandBase command,
+                                     @NotNull final EcoPlugin plugin) {
+        if (command.isPlayersOnly() && !(sender instanceof Player)) {
+            sender.sendMessage(plugin.getLangYml().getMessage("not-player"));
+            return false;
+        }
 
-    @Override
-    public TabCompleteHandler getTabCompleter() {
-        return (sender, args) -> new ArrayList<>();
+        if (!sender.hasPermission(command.getPermission()) && sender instanceof Player) {
+            sender.sendMessage(plugin.getLangYml().getNoPermission());
+            return false;
+        }
+
+        return true;
     }
 }

eco-api/src/main/java/com/willfp/eco/core/command/impl/PluginCommand.java

@@ -1,7 +1,6 @@
 package com.willfp.eco.core.command.impl;
 
 import com.willfp.eco.core.EcoPlugin;
-import com.willfp.eco.internal.commands.HandledCommand;
 import org.bukkit.Bukkit;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
@@ -12,13 +11,16 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 
+/**
+ * PluginCommands are the class to be used instead of CommandExecutor.
+ * <p>
+ * The command will not be registered until register() is called.
+ * <p>
+ * The name cannot be the same as an existing command as this will conflict.
+ */
 public abstract class PluginCommand extends HandledCommand implements CommandExecutor, TabCompleter {
     /**
      * Create a new command.
-     * <p>
-     * The command will not be registered until {@link this#register()} is called.
-     * <p>
-     * The name cannot be the same as an existing command as this will conflict.
      *
      * @param plugin      The plugin.
      * @param name        The name used in execution.

eco-api/src/main/java/com/willfp/eco/core/command/impl/Subcommand.java

@@ -2,9 +2,11 @@ package com.willfp.eco.core.command.impl;
 
 import com.willfp.eco.core.EcoPlugin;
 import com.willfp.eco.core.command.CommandBase;
-import com.willfp.eco.internal.commands.HandledCommand;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Subcommands can be added to PluginCommands or to other Subcommands.
+ */
 public abstract class Subcommand extends HandledCommand {
     /**
      * Create subcommand.
@@ -24,7 +26,7 @@ public abstract class Subcommand extends HandledCommand {
     /**
      * Create subcommand.
      *
-     * @param plugin      The plugin.
+     * @param plugin The plugin.
      * @param name   The name of the subcommand.
      * @param parent The parent command.
      */

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

@@ -1,40 +0,0 @@
-package com.willfp.eco.core.config;
-
-import com.willfp.eco.internal.config.yaml.UpdatableYamlConfig;
-import com.willfp.eco.core.EcoPlugin;
-import org.jetbrains.annotations.NotNull;
-
-public abstract class BaseConfig extends UpdatableYamlConfig {
-
-    /**
-     * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
-     * <p>
-     * Automatically updates.
-     *
-     * @param configName      The name of the config
-     * @param removeUnused    Whether keys not present in the default config should be removed on update.
-     * @param plugin          The plugin.
-     * @param updateBlacklist Substring of keys to not add/remove keys for.
-     */
-    protected BaseConfig(@NotNull final String configName,
-                         final boolean removeUnused,
-                         @NotNull final EcoPlugin plugin,
-                         @NotNull final String... updateBlacklist) {
-        super(configName, plugin, "", plugin.getClass(), removeUnused, updateBlacklist);
-    }
-
-    /**
-     * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
-     * <p>
-     * Automatically updates.
-     *
-     * @param configName      The name of the config
-     * @param removeUnused    Whether keys not present in the default config should be removed on update.
-     * @param plugin          The plugin.
-     */
-    protected BaseConfig(@NotNull final String configName,
-                         final boolean removeUnused,
-                         @NotNull final EcoPlugin plugin) {
-        super(configName, plugin, "", plugin.getClass(), removeUnused, "");
-    }
-}

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

@@ -1,11 +0,0 @@
-package com.willfp.eco.core.config;
-
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
-
-@Retention(RetentionPolicy.RUNTIME)
-@Target(ElementType.METHOD)
-public @interface ConfigUpdater {
-}

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

@@ -1,28 +0,0 @@
-package com.willfp.eco.core.config;
-
-import com.willfp.eco.internal.config.yaml.UpdatableYamlConfig;
-import com.willfp.eco.core.EcoPlugin;
-import org.jetbrains.annotations.NotNull;
-
-public abstract class ExtendableConfig extends UpdatableYamlConfig {
-    /**
-     * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
-     * <p>
-     * Automatically updates.
-     *
-     * @param configName       The name of the config
-     * @param removeUnused     Whether keys not present in the default config should be removed on update.
-     * @param plugin           The plugin.
-     * @param updateBlacklist  Substring of keys to not add/remove keys for.
-     * @param subDirectoryPath The subdirectory path.
-     * @param source           The class that owns the resource.
-     */
-    protected ExtendableConfig(@NotNull final String configName,
-                               final boolean removeUnused,
-                               @NotNull final EcoPlugin plugin,
-                               @NotNull final Class<?> source,
-                               @NotNull final String subDirectoryPath,
-                               @NotNull final String... updateBlacklist) {
-        super(configName, plugin, subDirectoryPath, source, removeUnused, updateBlacklist);
-    }
-}

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

@@ -1,20 +0,0 @@
-package com.willfp.eco.core.config;
-
-import com.willfp.eco.core.EcoPlugin;
-import com.willfp.eco.internal.config.json.LoadableJsonConfig;
-import org.jetbrains.annotations.NotNull;
-
-public abstract class JsonStaticBaseConfig extends LoadableJsonConfig {
-    /**
-     * Config implementation for configs present in the plugin's base directory (eg config.json, lang.json).
-     * <p>
-     * Does not automatically update.
-     *
-     * @param configName The name of the config
-     * @param plugin     The plugin.
-     */
-    protected JsonStaticBaseConfig(@NotNull final String configName,
-                                   @NotNull final EcoPlugin plugin) {
-        super(configName, plugin, "", plugin.getClass());
-    }
-}

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

@@ -1,20 +0,0 @@
-package com.willfp.eco.core.config;
-
-import com.willfp.eco.internal.config.yaml.LoadableYamlConfig;
-import com.willfp.eco.core.EcoPlugin;
-import org.jetbrains.annotations.NotNull;
-
-public abstract class StaticBaseConfig extends LoadableYamlConfig {
-    /**
-     * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
-     * <p>
-     * Does not automatically update.
-     *
-     * @param configName The name of the config
-     * @param plugin     The plugin.
-     */
-    protected StaticBaseConfig(@NotNull final String configName,
-                               @NotNull final EcoPlugin plugin) {
-        super(configName, plugin, "", plugin.getClass());
-    }
-}

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

@@ -1,18 +0,0 @@
-package com.willfp.eco.core.config;
-
-import com.willfp.eco.internal.config.yaml.YamlConfigWrapper;
-import org.bukkit.configuration.file.YamlConfiguration;
-import org.jetbrains.annotations.NotNull;
-
-public abstract class YamlConfig extends YamlConfigWrapper<YamlConfiguration> {
-    /**
-     * Config implementation for passing YamlConfigurations.
-     * <p>
-     * Does not automatically update.
-     *
-     * @param config     The YamlConfiguration handle.
-     */
-    public YamlConfig(@NotNull final YamlConfiguration config) {
-        init(config);
-    }
-}

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

@@ -1,11 +1,13 @@
 package com.willfp.eco.core.config.base;
 
-import com.willfp.eco.core.config.BaseConfig;
 import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.config.yaml.YamlBaseConfig;
 import org.jetbrains.annotations.NotNull;
 
-
-public class ConfigYml extends BaseConfig {
+/**
+ * Default plugin config.yml.
+ */
+public class ConfigYml extends YamlBaseConfig {
     /**
      * Config.yml.
      *

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

@@ -1,10 +1,13 @@
 package com.willfp.eco.core.config.base;
 
-import com.willfp.eco.core.config.BaseConfig;
 import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.config.yaml.YamlBaseConfig;
 import org.jetbrains.annotations.NotNull;
 
-public class LangYml extends BaseConfig {
+/**
+ * Default plugin lang.yml.
+ */
+public class LangYml extends YamlBaseConfig {
     /**
      * Lang.yml.
      *

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

@@ -1,11 +1,16 @@
-package com.willfp.eco.core.config;
+package com.willfp.eco.core.config.interfaces;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 
-public interface Config {
+/**
+ * All canfigs implement this interface.
+ * <p>
+ * Contains all methods that must exist in yaml and json configurations.
+ */
+public interface Config extends Cloneable {
     /**
      * Clears cache.
      */
@@ -162,6 +167,17 @@ public interface Config {
     @NotNull
     String getString(@NotNull String path);
 
+    /**
+     * Get a string from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param format If the string should be formatted.
+     * @return The found value, or an empty string if not found.
+     */
+    @NotNull
+    String getString(@NotNull String path,
+                     boolean format);
+
     /**
      * Get a string from config.
      *
@@ -171,6 +187,17 @@ public interface Config {
     @Nullable
     String getStringOrNull(@NotNull String path);
 
+    /**
+     * Get a string from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param format If the string should be formatted.
+     * @return The found value, or null if not found.
+     */
+    @Nullable
+    String getStringOrNull(@NotNull String path,
+                           boolean format);
+
     /**
      * Get a list of strings from config.
      * <p>
@@ -185,7 +212,7 @@ public interface Config {
     /**
      * Get a list of strings from config.
      *
-     * @param path The key to fetch the value from.
+     * @param path   The key to fetch the value from.
      * @param format If the strings should be formatted.
      * @return The found value, or a blank {@link java.util.ArrayList} if not found.
      */
@@ -202,6 +229,17 @@ public interface Config {
     @Nullable
     List<String> getStringsOrNull(@NotNull String path);
 
+    /**
+     * Get a list of strings from config.
+     *
+     * @param path   The key to fetch the value from.
+     * @param format If the strings should be formatted.
+     * @return The found value, or null if not found.
+     */
+    @Nullable
+    List<String> getStringsOrNull(@NotNull String path,
+                                  boolean format);
+
     /**
      * Get a decimal from config.
      *
@@ -236,4 +274,11 @@ public interface Config {
      */
     @Nullable
     List<Double> getDoublesOrNull(@NotNull String path);
+
+    /**
+     * Clone the config.
+     *
+     * @return The clone.
+     */
+    Config clone();
 }

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

@@ -1,10 +1,15 @@
-package com.willfp.eco.core.config;
+package com.willfp.eco.core.config.interfaces;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 
+/**
+ * JSON configs have extra methods compared to yaml configs.
+ * <p>
+ * If you need to use them, then use JSONConfig instead.
+ */
 public interface JSONConfig extends Config {
     /**
      * Get a list of subsections from config.
@@ -23,4 +28,28 @@ public interface JSONConfig extends Config {
      */
     @Nullable
     List<JSONConfig> getSubsectionsOrNull(@NotNull String path);
+
+
+    /**
+     * Get subsection from config.
+     *
+     * @param path The key to check.
+     * @return The subsection. Throws NPE if not found.
+     */
+    @Override
+    @NotNull
+    JSONConfig getSubsection(@NotNull String path);
+
+    /**
+     * Get subsection from config.
+     *
+     * @param path The key to check.
+     * @return The subsection, or null if not found.
+     */
+    @Override
+    @Nullable
+    JSONConfig getSubsectionOrNull(@NotNull String path);
+
+    @Override
+    JSONConfig clone();
 }

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

@@ -1,8 +1,11 @@
-package com.willfp.eco.internal.config;
+package com.willfp.eco.core.config.interfaces;
 
 import java.io.File;
 import java.io.IOException;
 
+/**
+ * Interface for configs that physically exist as files in plugins.
+ */
 public interface LoadableConfig {
     /**
      * Create the file.

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

@@ -0,0 +1,17 @@
+package com.willfp.eco.core.config.interfaces;
+
+import org.bukkit.configuration.file.YamlConfiguration;
+
+/**
+ * Interface for configs that wrap an {@link YamlConfiguration}.
+ *
+ * @see com.willfp.eco.core.config.yaml.wrapper.YamlConfigWrapper
+ */
+public interface WrappedYamlConfiguration {
+    /**
+     * Get the ConfigurationSection handle.
+     *
+     * @return The handle.
+     */
+    YamlConfiguration getBukkitHandle();
+}

eco-api/src/main/java/com/willfp/eco/core/config/json/JSONStaticBaseConfig.java

@@ -0,0 +1,24 @@
+package com.willfp.eco.core.config.json;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.config.json.wrapper.LoadableJSONConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Non-updatable JSON config that exists within a plugin jar.
+ */
+public abstract class JSONStaticBaseConfig extends LoadableJSONConfigWrapper {
+    /**
+     * Config implementation for configs present in the plugin's base directory (eg config.json, lang.json).
+     * <p>
+     * Does not automatically update.
+     *
+     * @param configName The name of the config
+     * @param plugin     The plugin.
+     */
+    protected JSONStaticBaseConfig(@NotNull final String configName,
+                                   @NotNull final EcoPlugin plugin) {
+        super(Eco.getHandler().getConfigFactory().createLoadableJSONConfig(configName, plugin, "", plugin.getClass()));
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/config/json/JSONTransientConfig.java

@@ -0,0 +1,23 @@
+package com.willfp.eco.core.config.json;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.config.json.wrapper.JSONConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Map;
+
+/**
+ * Raw JSON config with a map of values at its core.
+ */
+public class JSONTransientConfig extends JSONConfigWrapper {
+    /**
+     * Config implementation for passing maps.
+     * <p>
+     * Does not automatically update.
+     *
+     * @param values The map of values.
+     */
+    public JSONTransientConfig(@NotNull final Map<String, Object> values) {
+        super(Eco.getHandler().getConfigFactory().createJSONConfig(values));
+    }
+}

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

@@ -0,0 +1,48 @@
+package com.willfp.eco.core.config.json.wrapper;
+
+import com.willfp.eco.core.config.interfaces.JSONConfig;
+import com.willfp.eco.core.config.wrapper.ConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+
+/**
+ * Wrapper to handle the backend JSON config implementations.
+ */
+public abstract class JSONConfigWrapper extends ConfigWrapper<JSONConfig> implements JSONConfig {
+    /**
+     * Create a config wrapper.
+     *
+     * @param handle The handle.
+     */
+    protected JSONConfigWrapper(@NotNull final JSONConfig handle) {
+        super(handle);
+    }
+
+
+    @Override
+    public @NotNull List<JSONConfig> getSubsections(@NotNull final String path) {
+        return this.getHandle().getSubsections(path);
+    }
+
+    @Override
+    public @Nullable List<JSONConfig> getSubsectionsOrNull(@NotNull final String path) {
+        return this.getHandle().getSubsectionsOrNull(path);
+    }
+
+    @Override
+    public @NotNull JSONConfig getSubsection(@NotNull final String path) {
+        return this.getHandle().getSubsection(path);
+    }
+
+    @Override
+    public @Nullable JSONConfig getSubsectionOrNull(@NotNull final String path) {
+        return this.getHandle().getSubsectionOrNull(path);
+    }
+
+    @Override
+    public JSONConfig clone() {
+        return this.getHandle().clone();
+    }
+}

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

@@ -0,0 +1,51 @@
+package com.willfp.eco.core.config.json.wrapper;
+
+import com.willfp.eco.core.config.interfaces.JSONConfig;
+import com.willfp.eco.core.config.interfaces.LoadableConfig;
+import org.apache.commons.lang.Validate;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Wrapper to handle the backend loadable JSON config implementations.
+ */
+public abstract class LoadableJSONConfigWrapper extends JSONConfigWrapper implements LoadableConfig {
+    /**
+     * Create a config wrapper.
+     *
+     * @param handle The handle.
+     */
+    protected LoadableJSONConfigWrapper(@NotNull final JSONConfig handle) {
+        super(handle);
+
+        Validate.isTrue(handle instanceof LoadableConfig, "Wrapped config must be loadable!");
+    }
+
+
+    @Override
+    public void createFile() {
+        ((LoadableConfig) this.getHandle()).createFile();
+    }
+
+    @Override
+    public String getResourcePath() {
+        return ((LoadableConfig) this.getHandle()).getResourcePath();
+    }
+
+    @Override
+    public void save() throws IOException {
+        ((LoadableConfig) this.getHandle()).save();
+    }
+
+    @Override
+    public File getConfigFile() {
+        return ((LoadableConfig) this.getHandle()).getConfigFile();
+    }
+
+    @Override
+    public String getName() {
+        return ((LoadableConfig) this.getHandle()).getName();
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/config/updating/ConfigHandler.java

@@ -1,21 +1,19 @@
-package com.willfp.eco.core.config;
+package com.willfp.eco.core.config.updating;
 
-import com.willfp.eco.internal.config.LoadableConfig;
+import com.willfp.eco.core.config.interfaces.LoadableConfig;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Every {@link com.willfp.eco.core.EcoPlugin} has a config handler.
+ * <p>
+ * Handles updating and saving configs.
+ */
 public interface ConfigHandler {
     /**
      * Invoke all update methods.
      */
     void callUpdate();
 
-    /**
-     * Register an updatable class.
-     *
-     * @param updatableClass The class with an update method.
-     */
-    void registerUpdatableClass(@NotNull Class<?> updatableClass);
-
     /**
      * Save all configs.
      */

eco-api/src/main/java/com/willfp/eco/core/config/updating/ConfigUpdater.java

@@ -0,0 +1,39 @@
+package com.willfp.eco.core.config.updating;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Annotation to put on update methods.
+ * <p>
+ * All update methods must be public and static,
+ * and can accept an EcoPlugin as a parameter.
+ * <p>
+ * As such, there are only 2 valid update methods:
+ * <p>
+ * The first:
+ * <pre>{@code
+ * @ConfigUpdater
+ * public static void update() {
+ *     // Update code
+ * }
+ * }</pre>
+ * <p>
+ * The second:
+ * <pre>{@code
+ * public static void update(EcoPlugin plugin) {}
+ *     // Update code
+ * }</pre>
+ * <p>
+ * Config update methods in all classes in a plugin jar will be called
+ * on reload.
+ * <p>
+ * By having a plugin as a parameter, you shouldn't really need getInstance()
+ * calls in your code.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface ConfigUpdater {
+}

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

@@ -0,0 +1,76 @@
+package com.willfp.eco.core.config.wrapper;
+
+import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.config.interfaces.Config;
+import com.willfp.eco.core.config.interfaces.JSONConfig;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Map;
+
+/**
+ * Internal component to create backend config implementations.
+ */
+public interface ConfigFactory {
+    /**
+     * Updatable config.
+     *
+     * @param configName       The name of the config
+     * @param plugin           The plugin.
+     * @param subDirectoryPath The subdirectory path.
+     * @param source           The class that owns the resource.
+     * @param removeUnused     Whether keys not present in the default config should be removed on update.
+     * @param updateBlacklist  Substring of keys to not add/remove keys for.
+     * @return The config implementation.
+     */
+    Config createUpdatableYamlConfig(@NotNull String configName,
+                                     @NotNull EcoPlugin plugin,
+                                     @NotNull String subDirectoryPath,
+                                     @NotNull Class<?> source,
+                                     boolean removeUnused,
+                                     @NotNull String... updateBlacklist);
+
+    /**
+     * JSON loadable config.
+     *
+     * @param configName       The name of the config
+     * @param plugin           The plugin.
+     * @param subDirectoryPath The subdirectory path.
+     * @param source           The class that owns the resource.
+     * @return The config implementation.
+     */
+    JSONConfig createLoadableJSONConfig(@NotNull String configName,
+                                        @NotNull EcoPlugin plugin,
+                                        @NotNull String subDirectoryPath,
+                                        @NotNull Class<?> source);
+
+    /**
+     * Yaml loadable config.
+     *
+     * @param configName       The name of the config
+     * @param plugin           The plugin.
+     * @param subDirectoryPath The subdirectory path.
+     * @param source           The class that owns the resource.
+     * @return The config implementation.
+     */
+    Config createLoadableYamlConfig(@NotNull String configName,
+                                    @NotNull EcoPlugin plugin,
+                                    @NotNull String subDirectoryPath,
+                                    @NotNull Class<?> source);
+
+    /**
+     * Yaml config.
+     *
+     * @param config The handle.
+     * @return The config implementation.
+     */
+    Config createYamlConfig(@NotNull YamlConfiguration config);
+
+    /**
+     * JSON config.
+     *
+     * @param values The values.
+     * @return The config implementation.
+     */
+    JSONConfig createJSONConfig(@NotNull Map<String, Object> values);
+}

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

@@ -0,0 +1,196 @@
+package com.willfp.eco.core.config.wrapper;
+
+import com.willfp.eco.core.config.interfaces.Config;
+import lombok.Getter;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+
+/**
+ * Configs from eco have an internal implementation,
+ * which is the handle.
+ * <p>
+ * This class handles them.
+ *
+ * @param <T> The type of the handle.
+ */
+public abstract class ConfigWrapper<T extends Config> implements Config {
+    /**
+     * Configs from eco have an internal implementation,
+     * which is the handle.
+     * <p>
+     * The handle should only ever be used if you want to
+     * do something <i>interesting</i> config-wise with some
+     * internals.
+     * <p>
+     * In general use, though, the handle isn't necessary.
+     */
+    @Getter
+    private final T handle;
+
+    /**
+     * Create a config wrapper.
+     *
+     * @param handle The config that is being wrapped.
+     */
+    protected ConfigWrapper(@NotNull final T handle) {
+        this.handle = handle;
+    }
+
+    @Override
+    public void clearCache() {
+        handle.clearCache();
+    }
+
+    @Override
+    public String toPlaintext() {
+        return handle.toPlaintext();
+    }
+
+    @Override
+    public boolean has(@NotNull final String path) {
+        return handle.has(path);
+    }
+
+    @Override
+    public @NotNull List<String> getKeys(final boolean deep) {
+        return handle.getKeys(deep);
+    }
+
+    @Override
+    public @Nullable Object get(@NotNull final String path) {
+        return handle.get(path);
+    }
+
+    @Override
+    public void set(@NotNull final String path,
+                    @Nullable final Object object) {
+        handle.set(path, object);
+    }
+
+    @Override
+    public @NotNull Config getSubsection(@NotNull final String path) {
+        return handle.getSubsection(path);
+    }
+
+    @Override
+    public @Nullable Config getSubsectionOrNull(@NotNull final String path) {
+        return handle.getSubsectionOrNull(path);
+    }
+
+    @Override
+    public int getInt(@NotNull final String path) {
+        return handle.getInt(path);
+    }
+
+    @Override
+    public @Nullable Integer getIntOrNull(@NotNull final String path) {
+        return handle.getIntOrNull(path);
+    }
+
+    @Override
+    public int getInt(@NotNull final String path,
+                      final int def) {
+        return handle.getInt(path, def);
+    }
+
+    @Override
+    public @NotNull List<Integer> getInts(@NotNull final String path) {
+        return handle.getInts(path);
+    }
+
+    @Override
+    public @Nullable List<Integer> getIntsOrNull(@NotNull final String path) {
+        return handle.getIntsOrNull(path);
+    }
+
+    @Override
+    public boolean getBool(@NotNull final String path) {
+        return handle.getBool(path);
+    }
+
+    @Override
+    public @Nullable Boolean getBoolOrNull(@NotNull final String path) {
+        return handle.getBoolOrNull(path);
+    }
+
+    @Override
+    public @NotNull List<Boolean> getBools(@NotNull final String path) {
+        return handle.getBools(path);
+    }
+
+    @Override
+    public @Nullable List<Boolean> getBoolsOrNull(@NotNull final String path) {
+        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) {
+        return handle.getString(path, format);
+    }
+
+    @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) {
+        return handle.getStringOrNull(path, format);
+    }
+
+    @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) {
+        return handle.getStrings(path, format);
+    }
+
+    @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) {
+        return handle.getStringsOrNull(path, format);
+    }
+
+    @Override
+    public double getDouble(@NotNull final String path) {
+        return handle.getDouble(path);
+    }
+
+    @Override
+    public @Nullable Double getDoubleOrNull(@NotNull final String path) {
+        return handle.getDoubleOrNull(path);
+    }
+
+    @Override
+    public @NotNull List<Double> getDoubles(@NotNull final String path) {
+        return handle.getDoubles(path);
+    }
+
+    @Override
+    public @Nullable List<Double> getDoublesOrNull(@NotNull final String path) {
+        return handle.getDoublesOrNull(path);
+    }
+
+    @Override
+    public Config clone() {
+        return handle.clone();
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/config/yaml/YamlBaseConfig.java

@@ -0,0 +1,53 @@
+package com.willfp.eco.core.config.yaml;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.config.yaml.wrapper.LoadableYamlConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
+ * <p>
+ * Automatically updates.
+ */
+public abstract class YamlBaseConfig extends LoadableYamlConfigWrapper {
+    /**
+     * @param configName      The name of the config
+     * @param removeUnused    Whether keys not present in the default config should be removed on update.
+     * @param plugin          The plugin.
+     * @param updateBlacklist Substring of keys to not add/remove keys for.
+     */
+    protected YamlBaseConfig(@NotNull final String configName,
+                             final boolean removeUnused,
+                             @NotNull final EcoPlugin plugin,
+                             @NotNull final String... updateBlacklist) {
+        super(
+                Eco.getHandler().getConfigFactory().createUpdatableYamlConfig(
+                        configName,
+                        plugin,
+                        "",
+                        plugin.getClass(),
+                        removeUnused, updateBlacklist
+                )
+        );
+    }
+
+    /**
+     * @param configName   The name of the config
+     * @param removeUnused Whether keys not present in the default config should be removed on update.
+     * @param plugin       The plugin.
+     */
+    protected YamlBaseConfig(@NotNull final String configName,
+                             final boolean removeUnused,
+                             @NotNull final EcoPlugin plugin) {
+        super(
+                Eco.getHandler().getConfigFactory().createUpdatableYamlConfig(
+                        configName,
+                        plugin,
+                        "",
+                        plugin.getClass(),
+                        removeUnused
+                )
+        );
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/config/yaml/YamlExtendableConfig.java

@@ -0,0 +1,43 @@
+package com.willfp.eco.core.config.yaml;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.config.yaml.wrapper.LoadableYamlConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Config implementation for configs present in one of two places:
+ * <ul>
+ *     <li>Plugin base directory (eg config.yml, lang.yml)</li>
+ *     <li>Other extension's configs</li>
+ * </ul>
+ * <p>
+ * Automatically updates.
+ */
+public abstract class YamlExtendableConfig extends LoadableYamlConfigWrapper {
+    /**
+     * @param configName       The name of the config
+     * @param removeUnused     Whether keys not present in the default config should be removed on update.
+     * @param plugin           The plugin.
+     * @param updateBlacklist  Substring of keys to not add/remove keys for.
+     * @param subDirectoryPath The subdirectory path.
+     * @param source           The class that owns the resource.
+     */
+    protected YamlExtendableConfig(@NotNull final String configName,
+                                   final boolean removeUnused,
+                                   @NotNull final EcoPlugin plugin,
+                                   @NotNull final Class<?> source,
+                                   @NotNull final String subDirectoryPath,
+                                   @NotNull final String... updateBlacklist) {
+        super(
+                Eco.getHandler().getConfigFactory().createUpdatableYamlConfig(
+                        configName,
+                        plugin,
+                        subDirectoryPath,
+                        source,
+                        removeUnused,
+                        updateBlacklist
+                )
+        );
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/config/yaml/YamlStaticBaseConfig.java

@@ -0,0 +1,24 @@
+package com.willfp.eco.core.config.yaml;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.config.yaml.wrapper.LoadableYamlConfigWrapper;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Non-updatable yaml config that exists within a plugin jar.
+ */
+public abstract class YamlStaticBaseConfig extends LoadableYamlConfigWrapper {
+    /**
+     * Config implementation for configs present in the plugin's base directory (eg config.yml, lang.yml).
+     * <p>
+     * Does not automatically update.
+     *
+     * @param configName The name of the config
+     * @param plugin     The plugin.
+     */
+    protected YamlStaticBaseConfig(@NotNull final String configName,
+                                   @NotNull final EcoPlugin plugin) {
+        super(Eco.getHandler().getConfigFactory().createLoadableYamlConfig(configName, plugin, "", plugin.getClass()));
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/config/yaml/YamlTransientConfig.java

@@ -0,0 +1,29 @@
+package com.willfp.eco.core.config.yaml;
+
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.config.yaml.wrapper.YamlConfigWrapper;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.StringReader;
+
+/**
+ * Config implementation for passing YamlConfigurations.
+ * <p>
+ * Does not automatically update.
+ */
+public class YamlTransientConfig extends YamlConfigWrapper {
+    /**
+     * @param config     The YamlConfiguration handle.
+     */
+    public YamlTransientConfig(@NotNull final YamlConfiguration config) {
+        super(Eco.getHandler().getConfigFactory().createYamlConfig(config));
+    }
+
+    /**
+     * @param contents     The contents of the config.
+     */
+    public YamlTransientConfig(@NotNull final String contents) {
+        super(Eco.getHandler().getConfigFactory().createYamlConfig(YamlConfiguration.loadConfiguration(new StringReader(contents))));
+    }
+}

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

@@ -0,0 +1,51 @@
+package com.willfp.eco.core.config.yaml.wrapper;
+
+import com.willfp.eco.core.config.interfaces.Config;
+import com.willfp.eco.core.config.interfaces.LoadableConfig;
+import org.apache.commons.lang.Validate;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Wrapper to handle the backend loadable yaml config implementations.
+ */
+public abstract class LoadableYamlConfigWrapper extends YamlConfigWrapper implements LoadableConfig {
+    /**
+     * Create a config wrapper.
+     *
+     * @param handle The handle.
+     */
+    protected LoadableYamlConfigWrapper(@NotNull final Config handle) {
+        super(handle);
+
+        Validate.isTrue(handle instanceof LoadableConfig, "Wrapped config must be loadable!");
+    }
+
+
+    @Override
+    public void createFile() {
+        ((LoadableConfig) this.getHandle()).createFile();
+    }
+
+    @Override
+    public String getResourcePath() {
+        return ((LoadableConfig) this.getHandle()).getResourcePath();
+    }
+
+    @Override
+    public void save() throws IOException {
+        ((LoadableConfig) this.getHandle()).save();
+    }
+
+    @Override
+    public File getConfigFile() {
+        return ((LoadableConfig) this.getHandle()).getConfigFile();
+    }
+
+    @Override
+    public String getName() {
+        return ((LoadableConfig) this.getHandle()).getName();
+    }
+}

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

@@ -0,0 +1,27 @@
+package com.willfp.eco.core.config.yaml.wrapper;
+
+import com.willfp.eco.core.config.interfaces.Config;
+import com.willfp.eco.core.config.interfaces.WrappedYamlConfiguration;
+import com.willfp.eco.core.config.wrapper.ConfigWrapper;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Wrapper to handle the backend yaml config implementations.
+ */
+public abstract class YamlConfigWrapper extends ConfigWrapper<Config> implements WrappedYamlConfiguration {
+    /**
+     * Create a config wrapper.
+     *
+     * @param handle The handle.
+     */
+    protected YamlConfigWrapper(@NotNull final Config handle) {
+        super(handle);
+    }
+
+
+    @Override
+    public YamlConfiguration getBukkitHandle() {
+        return ((WrappedYamlConfiguration) this.getHandle()).getBukkitHandle();
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/data/Data.java

@@ -1,85 +0,0 @@
-package com.willfp.eco.core.data;
-
-import com.willfp.eco.core.EcoPlugin;
-import com.willfp.eco.core.config.Config;
-import com.willfp.eco.core.config.JSONConfig;
-import com.willfp.eco.core.config.JsonStaticBaseConfig;
-import com.willfp.eco.internal.config.LoadableConfig;
-import com.willfp.eco.internal.config.json.JsonConfigSection;
-import lombok.experimental.UtilityClass;
-import org.bukkit.OfflinePlayer;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
-
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.UUID;
-
-@UtilityClass
-public class Data {
-    /**
-     * Instance of eco data.yml.
-     */
-    private static JSONConfig datafile = null;
-
-    /**
-     * All cached player data.
-     */
-    private static final Map<UUID, Map<EcoPlugin, JSONConfig>> PLAYER_DATA = new HashMap<>();
-
-    /**
-     * Initialize the player data with an instance of data.json.
-     *
-     * @param config data.json.
-     */
-    @ApiStatus.Internal
-    public void init(@NotNull final JsonStaticBaseConfig config) {
-        datafile = config;
-    }
-
-    /**
-     * Save to data.yml.
-     *
-     * @param config Instance of data.yml.
-     * @throws IOException Error during saving.
-     */
-    @ApiStatus.Internal
-    public void save(@NotNull final Config config) throws IOException {
-        for (Map.Entry<UUID, Map<EcoPlugin, JSONConfig>> entry : PLAYER_DATA.entrySet()) {
-            entry.getValue().forEach((plugin, jsonConfig) -> {
-                for (String key : jsonConfig.getKeys(false)) {
-                    config.set("player-data." + plugin.getName().toLowerCase() + "." + entry.getKey().toString() + "." + key, jsonConfig);
-                }
-            });
-        }
-        ((LoadableConfig) config).save();
-    }
-
-    /**
-     * Get the data for a player.
-     *
-     * @param player The player.
-     * @param plugin The plugin.
-     * @return The data.
-     */
-    public JSONConfig getData(@NotNull final OfflinePlayer player,
-                              @NotNull final EcoPlugin plugin) {
-        if (!PLAYER_DATA.containsKey(player.getUniqueId())) {
-            PLAYER_DATA.put(player.getUniqueId(), new HashMap<>());
-        }
-
-        JSONConfig config = PLAYER_DATA.get(player.getUniqueId()).get(plugin);
-
-        if (config == null) {
-            config = (JSONConfig) datafile.getSubsectionOrNull("player-data." + plugin.getName().toLowerCase() + "." + player.getUniqueId());
-            if (config == null) {
-                config = new JsonConfigSection(new HashMap<>());
-            }
-            PLAYER_DATA.get(player.getUniqueId()).put(plugin, config);
-            return getData(player, plugin);
-        }
-
-        return config;
-    }
-}

eco-api/src/main/java/com/willfp/eco/core/display/Display.java

@@ -3,22 +3,27 @@ package com.willfp.eco.core.display;
 import lombok.experimental.UtilityClass;
 import org.apache.commons.lang.Validate;
 import org.bukkit.NamespacedKey;
+import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
 import org.bukkit.persistence.PersistentDataContainer;
 import org.bukkit.persistence.PersistentDataType;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+/**
+ * Utility class to manage client-side item display.
+ */
 @UtilityClass
 public class Display {
     /**
-     * The prefix for lore lines.
+     * The prefix for client-side lore lines.
      */
     public static final String PREFIX = "§z";
 
@@ -51,13 +56,21 @@ public class Display {
      * Display on ItemStacks.
      *
      * @param itemStack The item.
-     * @return The itemstack.
+     * @return The ItemStack.
      */
     public ItemStack display(@NotNull final ItemStack itemStack) {
-        if (!itemStack.hasItemMeta()) {
-            return itemStack; // return early if there's no customization of the item
-        }
+        return display(itemStack, null);
+    }
 
+    /**
+     * Display on ItemStacks.
+     *
+     * @param itemStack The item.
+     * @param player    The player.
+     * @return The ItemStack.
+     */
+    public ItemStack display(@NotNull final ItemStack itemStack,
+                             @Nullable final Player player) {
         Map<String, Object[]> pluginVarArgs = new HashMap<>();
 
         for (DisplayPriority priority : DisplayPriority.values()) {
@@ -80,6 +93,9 @@ public class Display {
             for (DisplayModule module : modules) {
                 Object[] varargs = pluginVarArgs.get(module.getPluginName());
                 module.display(itemStack, varargs);
+                if (player != null) {
+                    module.display(itemStack, player, varargs);
+                }
             }
         }
 
@@ -90,27 +106,35 @@ public class Display {
      * Display on ItemStacks and then finalize.
      *
      * @param itemStack The item.
-     * @return The itemstack.
+     * @return The ItemStack.
      */
     public ItemStack displayAndFinalize(@NotNull final ItemStack itemStack) {
-        return finalize(display(itemStack));
+        return finalize(display(itemStack, null));
+    }
+
+    /**
+     * Display on ItemStacks and then finalize.
+     *
+     * @param itemStack The item.
+     * @param player    The player.
+     * @return The ItemStack.
+     */
+    public ItemStack displayAndFinalize(@NotNull final ItemStack itemStack,
+                                        @Nullable final Player player) {
+        return finalize(display(itemStack, player));
     }
 
     /**
      * Revert on ItemStacks.
      *
      * @param itemStack The item.
-     * @return The itemstack.
+     * @return The ItemStack.
      */
     public ItemStack revert(@NotNull final ItemStack itemStack) {
         if (Display.isFinalized(itemStack)) {
             unfinalize(itemStack);
         }
 
-        if (!itemStack.hasItemMeta()) {
-            return itemStack;
-        }
-
         ItemMeta meta = itemStack.getItemMeta();
 
         if (meta == null) {
@@ -138,7 +162,7 @@ public class Display {
      * Finalize an ItemStacks.
      *
      * @param itemStack The item.
-     * @return The itemstack.
+     * @return The ItemStack.
      */
     public ItemStack finalize(@NotNull final ItemStack itemStack) {
         Validate.notNull(finalizeKey, "Key cannot be null!");
@@ -162,7 +186,7 @@ public class Display {
      * Unfinalize an ItemStacks.
      *
      * @param itemStack The item.
-     * @return The itemstack.
+     * @return The ItemStack.
      */
     public ItemStack unfinalize(@NotNull final ItemStack itemStack) {
         Validate.notNull(finalizeKey, "Key cannot be null!");

eco-api/src/main/java/com/willfp/eco/core/display/DisplayModule.java

@@ -1,11 +1,16 @@
 package com.willfp.eco.core.display;
 
-import com.willfp.eco.core.PluginDependent;
 import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.PluginDependent;
 import lombok.Getter;
+import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
+/**
+ * Class for all plugin-specific client-side item display modules.
+ */
 public abstract class DisplayModule extends PluginDependent<EcoPlugin> {
     /**
      * The priority of the module.
@@ -36,6 +41,19 @@ public abstract class DisplayModule extends PluginDependent<EcoPlugin> {
         // Technically optional.
     }
 
+    /**
+     * Display an item.
+     *
+     * @param itemStack The item.
+     * @param player    The player.
+     * @param args      Optional args for display.
+     */
+    protected void display(@NotNull final ItemStack itemStack,
+                           @Nullable final Player player,
+                           @NotNull final Object... args) {
+        // Technically optional.
+    }
+
     /**
      * Revert an item.
      *
@@ -46,7 +64,7 @@ public abstract class DisplayModule extends PluginDependent<EcoPlugin> {
     }
 
     /**
-     * Create varargs to pass back to itemstack after reverting, but before display.
+     * Create varargs to pass back to ItemStack after reverting, but before display.
      *
      * @param itemStack The itemStack.
      * @return The plugin-specific varargs.
@@ -60,7 +78,7 @@ public abstract class DisplayModule extends PluginDependent<EcoPlugin> {
      *
      * @return The plugin name.
      */
-    final String getPluginName() {
+    public final String getPluginName() {
         return super.getPlugin().getName();
     }
 }

eco-api/src/main/java/com/willfp/eco/core/display/DisplayPriority.java

@@ -1,5 +1,8 @@
 package com.willfp.eco.core.display;
 
+/**
+ * The priority (order) of display modules.
+ */
 public enum DisplayPriority {
     /**
      * Ran first.

eco-api/src/main/java/com/willfp/eco/core/drops/DropQueue.java

@@ -1,10 +1,6 @@
 package com.willfp.eco.core.drops;
 
-import com.willfp.eco.internal.drops.AbstractDropQueue;
-import com.willfp.eco.internal.drops.DropManager;
-import com.willfp.eco.internal.drops.DropQueueType;
-import com.willfp.eco.internal.drops.impl.FastCollatedDropQueue;
-import com.willfp.eco.internal.drops.impl.InternalDropQueue;
+import com.willfp.eco.core.Eco;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
@@ -12,21 +8,26 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.Collection;
 
+/**
+ * A {@link DropQueue} is a set of drops linked to player.
+ * <p>
+ * All drops should be passed through a drop queue for telekinesis integration.
+ * <p>
+ * It functions essentially as a builder class, and runs very quickly.
+ *
+ * @see com.willfp.eco.util.TelekinesisUtils
+ */
 public class DropQueue {
     /**
-     * The internally used {@link AbstractDropQueue}.
+     * The internally used {@link DropQueue}.
      */
-    private final AbstractDropQueue handle;
+    private final InternalDropQueue handle;
 
     /**
-     * Create {@link DropQueue} linked to player.
-     * <p>
-     * All drops should be passed through a drop queue for telekinesis integration.
-     *
      * @param player The player.
      */
     public DropQueue(@NotNull final Player player) {
-        handle = DropManager.getType() == DropQueueType.COLLATED ? new FastCollatedDropQueue(player) : new InternalDropQueue(player);
+        handle = Eco.getHandler().getDropQueueFactory().create(player);
     }
 
     /**

eco-api/src/main/java/com/willfp/eco/core/drops/DropQueueFactory.java

@@ -0,0 +1,17 @@
+package com.willfp.eco.core.drops;
+
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Internal component to create backend DropQueue implementations.
+ */
+public interface DropQueueFactory {
+    /**
+     * Create a DropQueue.
+     *
+     * @param player The player.
+     * @return The Queue.
+     */
+    InternalDropQueue create(@NotNull Player player);
+}

eco-api/src/main/java/com/willfp/eco/core/drops/InternalDropQueue.java

@@ -1,4 +1,4 @@
-package com.willfp.eco.internal.drops;
+package com.willfp.eco.core.drops;
 
 import org.bukkit.Location;
 import org.bukkit.inventory.ItemStack;
@@ -6,14 +6,17 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.Collection;
 
-public interface AbstractDropQueue {
+/**
+ * Internal interface for backend DropQueue implementations.
+ */
+public interface InternalDropQueue {
     /**
      * Add item to queue.
      *
      * @param item The item to add.
      * @return The DropQueue.
      */
-    AbstractDropQueue addItem(@NotNull ItemStack item);
+    InternalDropQueue addItem(@NotNull ItemStack item);
 
     /**
      * Add multiple items to queue.
@@ -21,7 +24,7 @@ public interface AbstractDropQueue {
      * @param itemStacks The items to add.
      * @return The DropQueue.
      */
-    AbstractDropQueue addItems(@NotNull Collection<ItemStack> itemStacks);
+    InternalDropQueue addItems(@NotNull Collection<ItemStack> itemStacks);
 
     /**
      * Add xp to queue.
@@ -29,7 +32,7 @@ public interface AbstractDropQueue {
      * @param amount The amount to add.
      * @return The DropQueue.
      */
-    AbstractDropQueue addXP(int amount);
+    InternalDropQueue addXP(int amount);
 
     /**
      * Set location of the origin of the drops.
@@ -37,14 +40,14 @@ public interface AbstractDropQueue {
      * @param location The location.
      * @return The DropQueue.
      */
-    AbstractDropQueue setLocation(@NotNull Location location);
+    InternalDropQueue setLocation(@NotNull Location location);
 
     /**
      * Force the queue to act as if player is telekinetic.
      *
      * @return The DropQueue.
      */
-    AbstractDropQueue forceTelekinesis();
+    InternalDropQueue forceTelekinesis();
 
     /**
      * Push the queue.

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

@@ -0,0 +1,70 @@
+package com.willfp.eco.core.events;
+
+import lombok.Getter;
+import org.bukkit.entity.Player;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.player.PlayerEvent;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+/**
+ * The armor change event <b>does</b> contain information about the event.
+ * <p>
+ * Unlike {@link ArmorEquipEvent}, it is called the next tick and contains previous and current armor contents.
+ */
+public class ArmorChangeEvent extends PlayerEvent {
+    /**
+     * Bukkit parity.
+     */
+    private static final HandlerList HANDLERS = new HandlerList();
+
+    /**
+     * The armor contents before. 0 is helmet, 3 is boots.
+     */
+    @Getter
+    private final List<ItemStack> before;
+
+    /**
+     * The armor contents after. 0 is helmet, 3 is boots.
+     */
+    @Getter
+    private final List<ItemStack> after;
+
+    /**
+     * Create a new ArmorChangeEvent.
+     *
+     * @param player The player.
+     * @param before The armor contents before.
+     * @param after The armor contents after.
+     */
+    public ArmorChangeEvent(@NotNull final Player player,
+                            @NotNull final List<ItemStack> before,
+                            @NotNull final List<ItemStack> after) {
+        super(player);
+        this.before = before;
+        this.after = after;
+    }
+
+    /**
+     * Gets a list of handlers handling this event.
+     *
+     * @return A list of handlers handling this event.
+     */
+
+    @Override
+    @NotNull
+    public HandlerList getHandlers() {
+        return HANDLERS;
+    }
+
+    /**
+     * Bukkit parity.
+     *
+     * @return The handler list.
+     */
+    public static HandlerList getHandlerList() {
+        return HANDLERS;
+    }
+}

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

@@ -5,10 +5,29 @@ import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
 import org.jetbrains.annotations.NotNull;
 
-
+/**
+ * The armor equip event <b>does not contain information about the event.</b>
+ * <p>
+ * It is purely a trigger called whenever a player changes armor, you have to run
+ * your own checks.
+ * <p>
+ * The event is called before the player's inventory actually updates,
+ * so you can check a tick later to see the new contents.
+ *
+ * @see ArmorChangeEvent
+ */
+@Deprecated
 public class ArmorEquipEvent extends PlayerEvent {
+    /**
+     * Bukkit parity.
+     */
     private static final HandlerList HANDLERS = new HandlerList();
 
+    /**
+     * Create a new ArmorEquipEvent.
+     *
+     * @param player The player.
+     */
     public ArmorEquipEvent(@NotNull final Player player) {
         super(player);
     }
@@ -25,6 +44,11 @@ public class ArmorEquipEvent extends PlayerEvent {
         return HANDLERS;
     }
 
+    /**
+     * Bukkit parity.
+     *
+     * @return The handler list.
+     */
     public static HandlerList getHandlerList() {
         return HANDLERS;
     }

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

@@ -12,7 +12,9 @@ import org.jetbrains.annotations.NotNull;
 import java.util.List;
 
 /**
- * Event triggered when entity is killed by entity.
+ * Event called when an entity is killed by another entity.
+ * <p>
+ * Not sure why spigot doesn't have this event normally.
  */
 public class EntityDeathByEntityEvent extends Event {
     /**

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

@@ -2,6 +2,9 @@ package com.willfp.eco.core.events;
 
 import org.bukkit.event.Listener;
 
+/**
+ * Manages listeners for a plugin.
+ */
 public interface EventManager {
     /**
      * Register a listener with bukkit.

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

@@ -6,6 +6,10 @@ import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerExpChangeEvent;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Event similar to {@link PlayerExpChangeEvent}, except it
+ * isn't called if the exp is from a bottle.
+ */
 public class NaturalExpGainEvent extends Event {
     /**
      * Internal bukkit.

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

@@ -1,15 +1,25 @@
 package com.willfp.eco.core.events;
 
+import org.bukkit.Location;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerMoveEvent;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
+/**
+ * Event called when a player jumps.
+ */
 public class PlayerJumpEvent extends PlayerMoveEvent {
     /**
      * Internal bukkit.
      */
     private static final HandlerList HANDLERS = new HandlerList();
 
+    /**
+     * The handled event.
+     */
+    private final PlayerMoveEvent handle;
+
     /**
      * Create a new PlayerJumpEvent.
      *
@@ -17,6 +27,8 @@ public class PlayerJumpEvent extends PlayerMoveEvent {
      */
     public PlayerJumpEvent(@NotNull final PlayerMoveEvent event) {
         super(event.getPlayer(), event.getFrom(), event.getTo());
+
+        this.handle = event;
     }
 
     /**
@@ -37,4 +49,36 @@ public class PlayerJumpEvent extends PlayerMoveEvent {
     public static @NotNull HandlerList getHandlerList() {
         return HANDLERS;
     }
+
+    @Override
+    public boolean isCancelled() {
+        return handle.isCancelled();
+    }
+
+    @Override
+    public void setCancelled(final boolean cancel) {
+        handle.setCancelled(cancel);
+    }
+
+    @NotNull
+    @Override
+    public Location getFrom() {
+        return handle.getFrom();
+    }
+
+    @Override
+    public void setFrom(@NotNull final Location from) {
+        handle.setFrom(from);
+    }
+
+    @Nullable
+    @Override
+    public Location getTo() {
+        return handle.getTo();
+    }
+
+    @Override
+    public void setTo(@NotNull final Location to) {
+        handle.setTo(to);
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/extensions/Extension.java

@@ -1,12 +1,22 @@
 package com.willfp.eco.core.extensions;
 
-import com.willfp.eco.internal.extensions.ExtensionMetadata;
 import com.willfp.eco.core.EcoPlugin;
 import lombok.AccessLevel;
 import lombok.Getter;
 import org.apache.commons.lang.Validate;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * An extension is a separate jar file that hooks into the base plugin jar.
+ * <p>
+ * If you take PlaceholderAPI as an example, the PAPI expansions are identical to
+ * extensions.
+ * <p>
+ * Syntactically, extensions are very similar to plugins in their own right, except that
+ * they are loaded by another plugin.
+ *
+ * @see <a href="https://ecoenchants.polymart.org">EcoEnchants extension examples.</a>
+ */
 public abstract class Extension {
     /**
      * The {@link EcoPlugin} that this extension is for.
@@ -74,6 +84,16 @@ public abstract class Extension {
         return this.metadata.name();
     }
 
+    /**
+     * Get the author of the extension.
+     *
+     * @return The author of the metadata attached to the extension.
+     */
+    public final String getAuthor() {
+        Validate.notNull(metadata, "Metadata cannot be null!");
+        return this.metadata.author();
+    }
+
     /**
      * Get the version of the extension.
      *

eco-api/src/main/java/com/willfp/eco/core/extensions/ExtensionLoader.java

@@ -3,11 +3,9 @@ package com.willfp.eco.core.extensions;
 import java.util.Set;
 
 /**
- * Interface for extension loader.
- * Some external plugins may modify extension loading for internal server purposes.
+ * Internal component to manage loading and unloading extensions.
  */
 public interface ExtensionLoader {
-
     /**
      * Load all extensions.
      */

eco-api/src/main/java/com/willfp/eco/core/extensions/ExtensionMetadata.java

@@ -0,0 +1,18 @@
+package com.willfp.eco.core.extensions;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * The extension's metadata.
+ * <p>
+ * Stored as a record internally.
+ *
+ * @param version The extension version.
+ * @param name    The extension name.
+ * @param author  The extension's author.
+ */
+public record ExtensionMetadata(@NotNull String version,
+                                @NotNull String name,
+                                @NotNull String author) {
+
+}

eco-api/src/main/java/com/willfp/eco/core/extensions/MalformedExtensionException.java

@@ -3,16 +3,13 @@ package com.willfp.eco.core.extensions;
 import org.jetbrains.annotations.NotNull;
 
 /**
- * Called when the extension is made incorrectly.
+ * Potential causes include:
+ * Missing or invalid extension.yml.
+ * Invalid filetype.
  */
 public class MalformedExtensionException extends RuntimeException {
-
     /**
      * Create a new MalformedExtensionException.
-     * <p>
-     * Potential causes include:
-     * Missing or invalid extension.yml.
-     * Invalid filetype.
      *
      * @param errorMessage The error message to show.
      */

eco-api/src/main/java/com/willfp/eco/core/factory/MetadataValueFactory.java

@@ -3,6 +3,9 @@ package com.willfp.eco.core.factory;
 import org.bukkit.metadata.FixedMetadataValue;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Factory to create metadata values for a specific plugin.
+ */
 public interface MetadataValueFactory {
     /**
      * Create a metadata value for a given plugin and object.

eco-api/src/main/java/com/willfp/eco/core/factory/NamespacedKeyFactory.java

@@ -3,6 +3,9 @@ package com.willfp.eco.core.factory;
 import org.bukkit.NamespacedKey;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Factory to create {@link NamespacedKey}s for a plugin.
+ */
 public interface NamespacedKeyFactory {
     /**
      * Create an {@link NamespacedKey} associated with an {@link com.willfp.eco.core.EcoPlugin}.

eco-api/src/main/java/com/willfp/eco/core/factory/RunnableFactory.java

@@ -5,6 +5,10 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.function.Consumer;
 
+/**
+ * Factory to create runnables. Much cleaner syntax than instantiating
+ * {@link org.bukkit.scheduler.BukkitRunnable}s.
+ */
 public interface RunnableFactory {
     /**
      * Create a {@link RunnableTask}.

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

@@ -0,0 +1,81 @@
+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.ItemStack;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * FastItemStack contains methods to modify and read items faster than in default bukkit.
+ */
+public interface FastItemStack {
+    /**
+     * Get all enchantments on an item.
+     *
+     * @param checkStored If stored NBT should also be checked.
+     * @return A map of all enchantments.
+     */
+    Map<Enchantment, Integer> getEnchantmentsOnItem(boolean checkStored);
+
+    /**
+     * Get the level of an enchantment on an item.
+     *
+     * @param enchantment The enchantment.
+     * @param checkStored If the stored NBT should also be checked.
+     * @return The enchantment level, or 0 if not found.
+     */
+    int getLevelOnItem(@NotNull Enchantment enchantment,
+                       boolean checkStored);
+
+    /**
+     * Set the item lore.
+     *
+     * @param lore The lore.
+     */
+    void setLore(@Nullable List<String> lore);
+
+    /**
+     * Get the item lore.
+     *
+     * @return The lore.
+     */
+    List<String> getLore();
+
+
+    /**
+     * Set the rework penalty.
+     *
+     * @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();
+
+    /**
+     * Get the Bukkit ItemStack again.
+     *
+     * @return The ItemStack.
+     */
+    ItemStack unwrap();
+
+    /**
+     * Wrap an ItemStack to create a FastItemStack.
+     *
+     * @param itemStack The ItemStack.
+     * @return The FastItemStack.
+     */
+    static FastItemStack wrap(final ItemStack itemStack) {
+        return Eco.getHandler().createFastItemStack(Objects.requireNonNullElseGet(itemStack, () -> new ItemStack(Material.AIR)));
+    }
+}

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

@@ -0,0 +1,29 @@
+package com.willfp.eco.core.gui;
+
+import com.willfp.eco.core.gui.menu.MenuBuilder;
+import com.willfp.eco.core.gui.slot.SlotBuilder;
+import com.willfp.eco.core.gui.slot.functional.SlotProvider;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Internal component used by {@link com.willfp.eco.core.gui.menu.Menu#builder(int)}
+ * and {@link com.willfp.eco.core.gui.slot.Slot#builder(ItemStack)}.
+ */
+public interface GUIFactory {
+    /**
+     * Create slot builder.
+     *
+     * @param provider The provider.
+     * @return The builder.
+     */
+    SlotBuilder createSlotBuilder(@NotNull SlotProvider provider);
+
+    /**
+     * Create menu builder.
+     *
+     * @param rows The amount of rows.
+     * @return The builder.
+     */
+    MenuBuilder createMenuBuilder(int rows);
+}

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

@@ -0,0 +1,19 @@
+package com.willfp.eco.core.gui.menu;
+
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Interface to run on menu close.
+ */
+@FunctionalInterface
+public interface CloseHandler {
+    /**
+     * Performs this operation on the given arguments.
+     *
+     * @param event The close event.
+     * @param menu  The menu.
+     */
+    void handle(@NotNull InventoryCloseEvent event,
+                @NotNull Menu menu);
+}

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

@@ -1,60 +0,0 @@
-package com.willfp.eco.core.gui.menu;
-
-import com.willfp.eco.core.gui.slot.Slot;
-import com.willfp.eco.core.items.builder.ItemStackBuilder;
-import com.willfp.eco.internal.gui.FillerSlot;
-import com.willfp.eco.util.ListUtils;
-import lombok.Getter;
-import org.bukkit.Material;
-import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.List;
-
-public class FillerMask {
-    /**
-     * Mask.
-     */
-    @Getter
-    private final List<List<Slot>> mask;
-
-    /**
-     * Create a new filler mask.
-     *
-     * @param material The mask material.
-     * @param pattern  The pattern.
-     */
-    public FillerMask(@NotNull final Material material,
-                      @NotNull final String... pattern) {
-        if (material == Material.AIR) {
-            throw new IllegalArgumentException("Material cannot be air!");
-        }
-
-        mask = ListUtils.create2DList(6, 9);
-
-        ItemStack itemStack = new ItemStackBuilder(material)
-                .setDisplayName("&r")
-                .build();
-
-        int row = 0;
-
-        for (String patternRow : pattern) {
-            int column = 0;
-            if (patternRow.length() != 9) {
-                throw new IllegalArgumentException("Invalid amount of columns in pattern!");
-            }
-            for (char c : patternRow.toCharArray()) {
-                if (c == '0') {
-                    mask.get(row).set(column, null);
-                } else if (c == '1') {
-                    mask.get(row).set(column, new FillerSlot(itemStack));
-                } else {
-                    throw new IllegalArgumentException("Invalid character in pattern! (Must only be 0 and 1)");
-                }
-
-                column++;
-            }
-            row++;
-        }
-    }
-}

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

@@ -1,20 +1,19 @@
 package com.willfp.eco.core.gui.menu;
 
+import com.willfp.eco.core.Eco;
 import com.willfp.eco.core.gui.slot.Slot;
-import com.willfp.eco.internal.gui.EcoMenu;
-import com.willfp.eco.internal.gui.FillerSlot;
-import com.willfp.eco.util.ListUtils;
-import com.willfp.eco.util.StringUtils;
-import org.bukkit.Material;
 import org.bukkit.entity.Player;
-import org.bukkit.event.inventory.InventoryCloseEvent;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.List;
-import java.util.function.Consumer;
 
+/**
+ * GUI version of {@link Inventory}.
+ * <p>
+ * A menu contains slots and is 1-indexed. (Top row has index 1, bottom row has index 6).
+ */
 public interface Menu {
     /**
      * Get the amount of rows.
@@ -48,99 +47,21 @@ public interface Menu {
      */
     Inventory open(@NotNull Player player);
 
+    /**
+     * Get captive items.
+     *
+     * @param player The player.
+     * @return The items.
+     */
+    List<ItemStack> getCaptiveItems(@NotNull Player player);
+
     /**
      * Create a builder with a given amount of rows.
      *
      * @param rows The rows.
      * @return The builder.
      */
-    static Builder builder(final int rows) {
-        return new Builder(rows);
-    }
-
-    class Builder {
-        /**
-         * The amount of rows.
-         */
-        private final int rows;
-
-        /**
-         * The title.
-         */
-        private String title = "Menu";
-
-        /**
-         * The mask slots.
-         */
-        private List<List<Slot>> maskSlots;
-
-        /**
-         * The slots.
-         */
-        private final List<List<Slot>> slots;
-
-        /**
-         * The close event handler.
-         */
-        private Consumer<InventoryCloseEvent> onClose = (event) -> {
-        };
-
-        Builder(final int rows) {
-            this.rows = rows;
-            this.slots = ListUtils.create2DList(rows, 9);
-            this.maskSlots = ListUtils.create2DList(rows, 9);
-        }
-
-        public Builder setTitle(@NotNull final String title) {
-            this.title = StringUtils.translate(title);
-            return this;
-        }
-
-        public Builder setSlot(final int row,
-                               final int column,
-                               @NotNull final Slot slot) {
-            if (row < 1 || row > this.rows) {
-                throw new IllegalArgumentException("Invalid row number!");
-            }
-
-            if (column < 1 || column > 9) {
-                throw new IllegalArgumentException("Invalid column number!");
-            }
-
-            slots.get(row - 1).set(column - 1, slot);
-            return this;
-        }
-
-        public Builder setMask(@NotNull final FillerMask mask) {
-            this.maskSlots = mask.getMask();
-            return this;
-        }
-
-        public Builder onClose(@NotNull final Consumer<InventoryCloseEvent> action) {
-            this.onClose = action;
-            return this;
-        }
-
-        public Menu build() {
-            List<List<Slot>> finalSlots = maskSlots;
-            for (int i = 0; i < slots.size(); i++) {
-                for (int j = 0; j < slots.get(i).size(); j++) {
-                    Slot slot = slots.get(i).get(j);
-                    if (slot != null) {
-                        finalSlots.get(i).set(j, slot);
-                    }
-                }
-            }
-
-            for (List<Slot> finalSlot : finalSlots) {
-                for (int j = 0; j < finalSlot.size(); j++) {
-                    if (finalSlot.get(j) == null) {
-                        finalSlot.set(j, new FillerSlot(new ItemStack(Material.AIR)));
-                    }
-                }
-            }
-
-            return new EcoMenu(rows, finalSlots, title, onClose);
-        }
+    static MenuBuilder builder(final int rows) {
+        return Eco.getHandler().getGUIFactory().createMenuBuilder(rows);
     }
 }

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

@@ -0,0 +1,75 @@
+package com.willfp.eco.core.gui.menu;
+
+import com.willfp.eco.core.gui.slot.FillerMask;
+import com.willfp.eco.core.gui.slot.Slot;
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.function.Consumer;
+
+/**
+ * Builder to create menus.
+ */
+public interface MenuBuilder {
+    /**
+     * Set the menu title.
+     *
+     * @param title The title.
+     * @return The builder.
+     */
+    MenuBuilder setTitle(@NotNull String title);
+
+    /**
+     * Set a slot.
+     *
+     * @param row    The row.
+     * @param column The column.
+     * @param slot   The slot.
+     * @return The builder.
+     */
+    MenuBuilder setSlot(int row,
+                        int column,
+                        @NotNull Slot slot);
+
+    /**
+     * Run function to modify the builder.
+     *
+     * @param modifier The modifier.
+     * @return The builder.
+     */
+    MenuBuilder modfiy(@NotNull Consumer<MenuBuilder> modifier);
+
+    /**
+     * Set the menu mask.
+     *
+     * @param mask The mask.
+     * @return The builder.
+     */
+    MenuBuilder setMask(@NotNull FillerMask mask);
+
+    /**
+     * Set the menu close handler.
+     *
+     * @param action The handler.
+     * @return The builder.
+     */
+    default MenuBuilder onClose(@NotNull Consumer<InventoryCloseEvent> action) {
+        onClose((event, menu) -> action.accept(event));
+        return this;
+    }
+
+    /**
+     * Set the menu close handler.
+     *
+     * @param action The handler.
+     * @return The builder.
+     */
+    MenuBuilder onClose(@NotNull CloseHandler action);
+
+    /**
+     * Build the menu.
+     *
+     * @return The menu.
+     */
+    Menu build();
+}

eco-api/src/main/java/com/willfp/eco/core/gui/slot/FillerMask.java

@@ -0,0 +1,85 @@
+package com.willfp.eco.core.gui.slot;
+
+import com.willfp.eco.core.items.builder.ItemStackBuilder;
+import com.willfp.eco.util.ListUtils;
+import lombok.Getter;
+import org.bukkit.Material;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Mask of filler slots.
+ * <p>
+ * A pattern consists of 1s and 0s, where a 1 is a filler slot,
+ * and a 0 isn't.
+ * <p>
+ * For example, creating a filler mask for a single-chest sized menu would look like this:
+ * <p>
+ * new FillerMask(
+ * material,
+ * "11111111"
+ * "10000001"
+ * "11111111"
+ * );
+ */
+public class FillerMask {
+    /**
+     * Mask.
+     */
+    @Getter
+    private final List<List<Slot>> mask;
+
+    /**
+     * Create a new filler mask.
+     *
+     * @param material The mask material.
+     * @param pattern  The pattern.
+     */
+    public FillerMask(@NotNull final Material material,
+                      @NotNull final String... pattern) {
+        this(new MaskMaterials(material), pattern);
+    }
+
+    /**
+     * Create a new filler mask.
+     *
+     * @param materials The mask materials.
+     * @param pattern  The pattern.
+     */
+    public FillerMask(@NotNull final MaskMaterials materials,
+                      @NotNull final String... pattern) {
+        if (Arrays.stream(materials.materials()).anyMatch(material -> material == Material.AIR)) {
+            throw new IllegalArgumentException("Materials cannot be air!");
+        }
+
+        mask = ListUtils.create2DList(6, 9);
+
+        for (int i = 0; i < materials.materials().length; i++) {
+            ItemStack itemStack = new ItemStackBuilder(materials.materials()[i])
+                    .setDisplayName("&r")
+                    .build();
+
+            int row = 0;
+
+            for (String patternRow : pattern) {
+                int column = 0;
+                if (patternRow.length() != 9) {
+                    throw new IllegalArgumentException("Invalid amount of columns in pattern!");
+                }
+                for (char c : patternRow.toCharArray()) {
+                    if (c == '0') {
+                        mask.get(row).set(column, null);
+                    } else if (c == Character.forDigit(i + 1, 10)) {
+                        mask.get(row).set(column, new FillerSlot(itemStack));
+                    }
+
+                    column++;
+                }
+                row++;
+            }
+        }
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/gui/slot/FillerSlot.java

@@ -0,0 +1,38 @@
+package com.willfp.eco.core.gui.slot;
+
+import lombok.Getter;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * A filler slot is a slot that does nothing when clicked.
+ * <p>
+ * Useful for backgrounds.
+ */
+public class FillerSlot implements Slot {
+    /**
+     * The ItemStack.
+     */
+    @Getter
+    private final ItemStack itemStack;
+
+    /**
+     * Create new filler slot.
+     *
+     * @param itemStack The ItemStack.
+     */
+    public FillerSlot(@NotNull final ItemStack itemStack) {
+        this.itemStack = itemStack;
+    }
+
+    @Override
+    public ItemStack getItemStack(@NotNull final Player player) {
+        return itemStack;
+    }
+
+    @Override
+    public boolean isCaptive() {
+        return false;
+    }
+}

eco-api/src/main/java/com/willfp/eco/core/gui/slot/MaskMaterials.java

@@ -0,0 +1,14 @@
+package com.willfp.eco.core.gui.slot;
+
+import org.bukkit.Material;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Mask materials store a set of materials which can be accessed by
+ * a filler mask.
+ *
+ * @param materials The materials.
+ */
+public record MaskMaterials(@NotNull Material... materials) {
+
+}

eco-api/src/main/java/com/willfp/eco/core/gui/slot/Slot.java

@@ -1,14 +1,17 @@
 package com.willfp.eco.core.gui.slot;
 
-import com.willfp.eco.internal.gui.EcoSlot;
+import com.willfp.eco.core.Eco;
+import com.willfp.eco.core.gui.slot.functional.SlotProvider;
+import org.bukkit.Material;
 import org.bukkit.entity.Player;
-import org.bukkit.event.inventory.InventoryClickEvent;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.function.BiConsumer;
 import java.util.function.Function;
 
+/**
+ * A slot is an item in a GUI that can handle clicks.
+ */
 public interface Slot {
     /**
      * Get the ItemStack that would be shown to a player.
@@ -18,14 +21,30 @@ public interface Slot {
      */
     ItemStack getItemStack(@NotNull Player player);
 
+    /**
+     * If the slot is captive. (Can items be placed in it).
+     *
+     * @return If captive.
+     */
+    boolean isCaptive();
+
+    /**
+     * Create a builder for an ItemStack.
+     *
+     * @return The builder.
+     */
+    static SlotBuilder builder() {
+        return Eco.getHandler().getGUIFactory().createSlotBuilder((player, menu) -> new ItemStack(Material.AIR));
+    }
+
     /**
      * Create a builder for an ItemStack.
      *
      * @param itemStack The ItemStack.
      * @return The builder.
      */
-    static Builder builder(@NotNull final ItemStack itemStack) {
-        return new Builder((player) -> itemStack);
+    static SlotBuilder builder(@NotNull final ItemStack itemStack) {
+        return Eco.getHandler().getGUIFactory().createSlotBuilder((player, menu) -> itemStack);
     }
 
     /**
@@ -34,72 +53,17 @@ public interface Slot {
      * @param provider The provider.
      * @return The builder.
      */
-    static Builder builder(@NotNull final Function<Player, ItemStack> provider) {
-        return new Builder(provider);
+    static SlotBuilder builder(@NotNull final Function<Player, ItemStack> provider) {
+        return Eco.getHandler().getGUIFactory().createSlotBuilder((player, menu) -> provider.apply(player));
     }
 
-    class Builder {
-        /**
-         * Provider.
-         */
-        private final Function<Player, ItemStack> provider;
-
-        /**
-         * Left click handler.
-         */
-        private BiConsumer<InventoryClickEvent, Slot> onLeftClick = null;
-
-        /**
-         * Right click handler.
-         */
-        private BiConsumer<InventoryClickEvent, Slot> onRightClick = null;
-
-        /**
-         * Shift-Left-Click handler.
-         */
-        private BiConsumer<InventoryClickEvent, Slot> onShiftLeftClick = null;
-
-        /**
-         * Shift-Right-Click handler.
-         */
-        private BiConsumer<InventoryClickEvent, Slot> onShiftRightClick = null;
-
-        /**
-         * Middle click handler.
-         */
-        private BiConsumer<InventoryClickEvent, Slot> onMiddleClick = null;
-
-        Builder(@NotNull final Function<Player, ItemStack> provider) {
-            this.provider = provider;
-        }
-
-        public Builder onLeftClick(@NotNull final BiConsumer<InventoryClickEvent, Slot> action) {
-            this.onLeftClick = action;
-            return this;
-        }
-
-        public Builder onRightClick(@NotNull final BiConsumer<InventoryClickEvent, Slot> action) {
-            this.onRightClick = action;
-            return this;
-        }
-
-        public Builder onShiftLeftClick(@NotNull final BiConsumer<InventoryClickEvent, Slot> action) {
-            this.onShiftLeftClick = action;
-            return this;
-        }
-
-        public Builder onShiftRightClick(@NotNull final BiConsumer<InventoryClickEvent, Slot> action) {
-            this.onShiftRightClick = action;
-            return this;
-        }
-
-        public Builder onMiddleClick(@NotNull final BiConsumer<InventoryClickEvent, Slot> action) {
-            this.onMiddleClick = action;
-            return this;
-        }
-
-        public Slot build() {
-            return new EcoSlot(provider, onLeftClick, onRightClick, onShiftLeftClick, onShiftRightClick, onMiddleClick);
-        }
+    /**
+     * Create a builder for a player-specific ItemStack.
+     *
+     * @param provider The provider.
+     * @return The builder.
+     */
+    static SlotBuilder builder(@NotNull final SlotProvider provider) {
+        return Eco.getHandler().getGUIFactory().createSlotBuilder(provider);
     }
 }

eco-api/src/main/java/com/willfp/eco/core/gui/slot/SlotBuilder.java

@@ -0,0 +1,125 @@
+package com.willfp.eco.core.gui.slot;
+
+import com.willfp.eco.core.gui.slot.functional.SlotHandler;
+import com.willfp.eco.core.gui.slot.functional.SlotModifier;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.function.BiConsumer;
+
+/**
+ * Builder to create slots.
+ */
+public interface SlotBuilder {
+    /**
+     * Set click handler.
+     *
+     * @param action The handler.
+     * @return The builder.
+     */
+    default SlotBuilder onLeftClick(@NotNull BiConsumer<InventoryClickEvent, Slot> action) {
+        return onLeftClick((event, slot, menu) -> action.accept(event, slot));
+    }
+
+    /**
+     * Set click handler.
+     *
+     * @param handler The handler.
+     * @return The builder.
+     */
+    SlotBuilder onLeftClick(@NotNull SlotHandler handler);
+
+    /**
+     * Set click handler.
+     *
+     * @param action The handler.
+     * @return The builder.
+     */
+    default SlotBuilder onRightClick(@NotNull BiConsumer<InventoryClickEvent, Slot> action) {
+        return onRightClick((event, slot, menu) -> action.accept(event, slot));
+    }
+
+    /**
+     * Set click handler.
+     *
+     * @param handler The handler.
+     * @return The builder.
+     */
+    SlotBuilder onRightClick(@NotNull SlotHandler handler);
+
+    /**
+     * Set click handler.
+     *
+     * @param action The handler.
+     * @return The builder.
+     */
+    default SlotBuilder onShiftLeftClick(@NotNull BiConsumer<InventoryClickEvent, Slot> action) {
+        return onShiftLeftClick((event, slot, menu) -> action.accept(event, slot));
+    }
+
+    /**
+     * Set click handler.
+     *
+     * @param handler The handler.
+     * @return The builder.
+     */
+    SlotBuilder onShiftLeftClick(@NotNull SlotHandler handler);
+
+    /**
+     * Set click handler.
+     *
+     * @param action The handler.
+     * @return The builder.
+     */
+    default SlotBuilder onShiftRightClick(@NotNull BiConsumer<InventoryClickEvent, Slot> action) {
+        return onShiftRightClick((event, slot, menu) -> action.accept(event, slot));
+    }
+
+    /**
+     * Set click handler.
+     *
+     * @param handler The handler.
+     * @return The builder.
+     */
+    SlotBuilder onShiftRightClick(@NotNull SlotHandler handler);
+
+    /**
+     * Set click handler.
+     *
+     * @param action The handler.
+     * @return The builder.
+     */
+    default SlotBuilder onMiddleClick(@NotNull BiConsumer<InventoryClickEvent, Slot> action) {
+        return onMiddleClick((event, slot, menu) -> action.accept(event, slot));
+    }
+
+    /**
+     * Set click handler.
+     *
+     * @param handler The handler.
+     * @return The builder.
+     */
+    SlotBuilder onMiddleClick(@NotNull SlotHandler handler);
+
+    /**
+     * Modify the ItemStack.
+     *
+     * @param modifier The modifier.
+     * @return The builder.
+     */
+    SlotBuilder setModifier(@NotNull SlotModifier modifier);
+
+    /**
+     * Set slot to be a captive slot.
+     *
+     * @return The builder.
+     */
+    SlotBuilder setCaptive();
+
+    /**
+     * Build the slot.
+     *
+     * @return The slot.
+     */
+    Slot build();
+}

eco-api/src/main/java/com/willfp/eco/core/gui/slot/functional/SlotHandler.java

@@ -0,0 +1,23 @@
+package com.willfp.eco.core.gui.slot.functional;
+
+import com.willfp.eco.core.gui.menu.Menu;
+import com.willfp.eco.core.gui.slot.Slot;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Interface to run on slot click.
+ */
+@FunctionalInterface
+public interface SlotHandler {
+    /**
+     * Performs this operation on the given arguments.
+     *
+     * @param event The click event.
+     * @param slot  The slot
+     * @param menu  The menu.
+     */
+    void handle(@NotNull InventoryClickEvent event,
+                @NotNull Slot slot,
+                @NotNull Menu menu);
+}

eco-api/src/main/java/com/willfp/eco/core/gui/slot/functional/SlotModifier.java

@@ -0,0 +1,23 @@
+package com.willfp.eco.core.gui.slot.functional;
+
+import com.willfp.eco.core.gui.menu.Menu;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Interface to run on slot modify.
+ */
+@FunctionalInterface
+public interface SlotModifier {
+    /**
+     * Performs this operation on the given arguments.
+     *
+     * @param player   The player.
+     * @param menu     The menu.
+     * @param previous The previous ItemStack.
+     */
+    void modify(@NotNull Player player,
+                @NotNull Menu menu,
+                @NotNull ItemStack previous);
+}

eco-api/src/main/java/com/willfp/eco/core/gui/slot/functional/SlotProvider.java

@@ -0,0 +1,22 @@
+package com.willfp.eco.core.gui.slot.functional;
+
+import com.willfp.eco.core.gui.menu.Menu;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Interface to run on slot display.
+ */
+@FunctionalInterface
+public interface SlotProvider {
+    /**
+     * Performs this operation on the given arguments.
+     *
+     * @param player The player.
+     * @param menu   The menu.
+     * @return The ItemStack.
+     */
+    ItemStack provide(@NotNull Player player,
+                      @NotNull Menu menu);
+}

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

@@ -1,8 +1,12 @@
 package com.willfp.eco.core.integrations;
 
+/**
+ * Abstract class for integrations.
+ */
 public interface Integration {
     /**
      * Get the name of integration.
+     *
      * @return The name.
      */
     String getPluginName();

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

@@ -3,6 +3,11 @@ package com.willfp.eco.core.integrations;
 import lombok.Getter;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * An integration loader runs a runnable only if a specific plugin is present on the server.
+ * <p>
+ * Used by {@link com.willfp.eco.core.EcoPlugin} to load integrations.
+ */
 public class IntegrationLoader {
     /**
      * The lambda to be ran if the plugin is present.

eco-api/src/main/java/com/willfp/eco/core/integrations/anticheat/AnticheatManager.java

@@ -9,6 +9,9 @@ import org.jetbrains.annotations.NotNull;
 import java.util.HashSet;
 import java.util.Set;
 
+/**
+ * Class to handle anticheat integrations.
+ */
 @UtilityClass
 public class AnticheatManager {
     /**

eco-api/src/main/java/com/willfp/eco/core/integrations/anticheat/AnticheatWrapper.java

@@ -4,6 +4,9 @@ import com.willfp.eco.core.integrations.Integration;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Wrapper class for anticheat integrations.
+ */
 public interface AnticheatWrapper extends Integration {
     /**
      * Exempt a player from checks.

eco-api/src/main/java/com/willfp/eco/core/integrations/antigrief/AntigriefManager.java

@@ -10,6 +10,9 @@ import org.jetbrains.annotations.NotNull;
 import java.util.HashSet;
 import java.util.Set;
 
+/**
+ * Class to handle antigrief integrations.
+ */
 @UtilityClass
 public class AntigriefManager {
     /**

eco-api/src/main/java/com/willfp/eco/core/integrations/antigrief/AntigriefWrapper.java

@@ -6,6 +6,9 @@ import org.bukkit.block.Block;
 import org.bukkit.entity.LivingEntity;
 import org.bukkit.entity.Player;
 
+/**
+ * Wrapper class for antigrief integrations.
+ */
 public interface AntigriefWrapper extends Integration {
     /**
      * Can player break block.

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

@@ -0,0 +1,38 @@
+package com.willfp.eco.core.integrations.customitems;
+
+import lombok.experimental.UtilityClass;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Class to handle custom item integrations.
+ */
+@UtilityClass
+public class CustomItemsManager {
+    /**
+     * A set of all registered integrations.
+     */
+    private final Set<CustomItemsWrapper> registered = new HashSet<>();
+
+    /**
+     * Register a new integration.
+     *
+     * @param integration The integration to register.
+     */
+    public void register(@NotNull final CustomItemsWrapper integration) {
+        registered.add(integration);
+    }
+
+    /**
+     * Register all the custom items for a specific plugin into eco.
+     *
+     * @see com.willfp.eco.core.items.Items
+     */
+    public void registerAllItems() {
+        for (CustomItemsWrapper customItemsWrapper : registered) {
+            customItemsWrapper.registerAllItems();
+        }
+    }
+}

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

@@ -0,0 +1,13 @@
+package com.willfp.eco.core.integrations.customitems;
+
+/**
+ * Wrapper class for custom item integrations.
+ */
+public interface CustomItemsWrapper {
+    /**
+     * Register all the custom items for a specific plugin into eco.
+     *
+     * @see com.willfp.eco.core.items.Items
+     */
+    void registerAllItems();
+}

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

@@ -8,6 +8,9 @@ import org.jetbrains.annotations.NotNull;
 import java.util.HashSet;
 import java.util.Set;
 
+/**
+ * Class to handle mcmmo integrations.
+ */
 @UtilityClass
 public class McmmoManager {
     /**

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

@@ -4,6 +4,9 @@ import org.bukkit.block.Block;
 import org.bukkit.event.Event;
 import org.jetbrains.annotations.NotNull;
 
+/**
+ * Wrapper class for mcmmo integrations.
+ */
 public interface McmmoWrapper {
     /**
      * Get bonus drop count of block.

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

@@ -8,6 +8,11 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.function.Function;
 
+/**
+ * A {@link PlaceholderEntry} is a placeholder in and of itself.
+ * <p>
+ * It should be fairly straightforward.
+ */
 public class PlaceholderEntry {
     /**
      * The name of the placeholder, used in lookups.
@@ -72,4 +77,11 @@ public class PlaceholderEntry {
     public boolean requiresPlayer() {
         return requiresPlayer;
     }
+
+    /**
+     * Register the placeholder.
+     */
+    public void register() {
+        PlaceholderManager.registerPlaceholder(this);
+    }
 }

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

@@ -5,6 +5,9 @@ import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+/**
+ * Wrapper class for placeholder integrations.
+ */
 public interface PlaceholderIntegration extends Integration {
     /**
      * Register the integration with the specified plugin.

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

@@ -10,6 +10,9 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicReference;
 
+/**
+ * Class to handle placeholder integrations.
+ */
 @UtilityClass
 public class PlaceholderManager {
     /**

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

@@ -8,6 +8,15 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.function.Predicate;
 
+/**
+ * A custom item has 3 components:
+ *
+ * <ul>
+ *     <li>The key to identify it</li>
+ *     <li>The test to check if any item is this custom item</li>
+ *     <li>The actual custom item {@link ItemStack}</li>
+ * </ul>
+ */
 public class CustomItem implements TestableItem {
     /**
      * The key.
@@ -18,7 +27,7 @@ public class CustomItem implements TestableItem {
     /**
      * The test for ItemStacks to pass.
      */
-    private final Predicate<ItemStack> test;
+    private final Predicate<@NotNull ItemStack> test;
 
     /**
      * Example Item: what the user should see.
@@ -33,7 +42,7 @@ public class CustomItem implements TestableItem {
      * @param item The example ItemStacks.
      */
     public CustomItem(@NotNull final NamespacedKey key,
-                      @NotNull final Predicate<ItemStack> test,
+                      @NotNull final Predicate<@NotNull ItemStack> test,
                       @NotNull final ItemStack item) {
         this.key = key;
         this.test = test;
@@ -42,6 +51,10 @@ public class CustomItem implements TestableItem {
 
     @Override
     public boolean matches(@Nullable final ItemStack itemStack) {
+        if (itemStack == null) {
+            return false;
+        }
+
         return test.test(itemStack);
     }
 

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

@@ -1,19 +1,30 @@
 package com.willfp.eco.core.items;
 
+import com.willfp.eco.core.items.builder.ItemBuilder;
+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;
 import com.willfp.eco.core.recipe.parts.TestableStack;
+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 java.util.Arrays;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
+import java.util.Set;
 
+/**
+ * Class to manage all custom and vanilla items.
+ */
 @UtilityClass
-@SuppressWarnings("deprecation")
 public final class Items {
     /**
      * All recipe parts.
@@ -31,6 +42,15 @@ public final class Items {
         REGISTRY.put(key, part);
     }
 
+    /**
+     * Remove an item.
+     *
+     * @param key The key of the recipe part.
+     */
+    public void removeCustomItem(@NotNull final NamespacedKey key) {
+        REGISTRY.remove(key);
+    }
+
     /**
      * Lookup item from string.
      * <p>
@@ -40,36 +60,103 @@ public final class Items {
      * @return The found testable item, or an empty item if not found.
      */
     public TestableItem lookup(@NotNull final String key) {
-        String[] split = key.toLowerCase().split(":");
+        if (key.contains("?")) {
+            String[] options = key.split("\\?");
+            for (String option : options) {
+                TestableItem lookup = lookup(option);
+                if (!(lookup instanceof EmptyTestableItem)) {
+                    return lookup;
+                }
+            }
+
+            return new EmptyTestableItem();
+        }
+
+        String[] args = key.split(" ");
+        if (args.length == 0) {
+            return new EmptyTestableItem();
+        }
+
+        TestableItem item = null;
+
+        String[] split = args[0].toLowerCase().split(":");
 
         if (split.length == 1) {
-            Material material = Material.getMaterial(key.toUpperCase());
+            Material material = Material.getMaterial(args[0].toUpperCase());
             if (material == null || material == Material.AIR) {
                 return new EmptyTestableItem();
             }
-            return new MaterialTestableItem(material);
+            item = new MaterialTestableItem(material);
         }
 
         if (split.length == 2) {
-            CustomItem part = REGISTRY.get(new NamespacedKey(split[0], split[1]));
+            CustomItem part = REGISTRY.get(NamespacedKeyUtils.create(split[0], split[1]));
 
             if (part == null) {
                 Material material = Material.getMaterial(split[0].toUpperCase());
                 if (material == null || material == Material.AIR) {
                     return new EmptyTestableItem();
                 }
-                return new TestableStack(new MaterialTestableItem(material), Integer.parseInt(split[1]));
+                item = new TestableStack(new MaterialTestableItem(material), Integer.parseInt(split[1]));
             } else {
-                return part;
+                item = part;
             }
         }
 
         if (split.length == 3) {
-            CustomItem part = REGISTRY.get(new NamespacedKey(split[0], split[1]));
-            return part == null ? new EmptyTestableItem() : new TestableStack(part, Integer.parseInt(split[2]));
+            CustomItem part = REGISTRY.get(NamespacedKeyUtils.create(split[0], split[1]));
+            item = part == null ? new EmptyTestableItem() : new TestableStack(part, Integer.parseInt(split[2]));
         }
 
-        return new EmptyTestableItem();
+        if (item == null || item instanceof EmptyTestableItem) {
+            return new EmptyTestableItem();
+        }
+
+        String[] enchantArgs = Arrays.copyOfRange(args, 1, args.length);
+
+        Map<Enchantment, Integer> requiredEnchantments = new HashMap<>();
+
+        for (String enchantArg : enchantArgs) {
+            String[] enchantArgSplit = enchantArg.split(":");
+
+            Enchantment enchantment = Enchantment.getByKey(NamespacedKey.minecraft(enchantArgSplit[0].toLowerCase()));
+            int level = Integer.parseInt(enchantArgSplit[1]);
+
+            requiredEnchantments.put(enchantment, level);
+        }
+
+        if (requiredEnchantments.isEmpty()) {
+            return item;
+        }
+
+        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
+        );
     }
 
     /**
@@ -86,4 +173,13 @@ public final class Items {
         }
         return false;
     }
+
+    /**
+     * Get all registered custom items.
+     *
+     * @return A set of all items.
+     */
+    public Set<CustomItem> getCustomItems() {
+        return new HashSet<>(REGISTRY.values());
+    }
 }

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

@@ -3,6 +3,9 @@ package com.willfp.eco.core.items;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.Nullable;
 
+/**
+ * An item with a test to see if any item is that item.
+ */
 public interface TestableItem {
     /**
      * If an ItemStack matches the recipe part.

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

@@ -1,6 +1,5 @@
-package com.willfp.eco.internal.items;
+package com.willfp.eco.core.items.builder;
 
-import com.willfp.eco.core.items.builder.ItemBuilder;
 import com.willfp.eco.util.StringUtils;
 import lombok.AccessLevel;
 import lombok.Getter;
@@ -19,6 +18,12 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Supplier;
 
+/**
+ * Abstract item builder class to build items.
+ *
+ * @param <T> The meta type.
+ * @param <U> Itself.
+ */
 @SuppressWarnings("unchecked")
 public abstract class AbstractItemStackBuilder<T extends ItemMeta, U extends AbstractItemStackBuilder<T, U>> implements ItemBuilder {
     /**
@@ -80,7 +85,7 @@ public abstract class AbstractItemStackBuilder<T extends ItemMeta, U extends Abs
 
     @Override
     public U setDisplayName(@NotNull final String name) {
-        meta.setDisplayName(StringUtils.translate(name));
+        meta.setDisplayName(StringUtils.format(name));
         return (U) this;
     }
 
@@ -95,7 +100,7 @@ public abstract class AbstractItemStackBuilder<T extends ItemMeta, U extends Abs
     public U addLoreLine(@NotNull final String line) {
         List<String> lore = meta.hasLore() ? meta.getLore() : new ArrayList<>();
         assert lore != null;
-        lore.add(StringUtils.translate(line));
+        lore.add(StringUtils.format(line));
         meta.setLore(lore);
 
         return (U) this;
@@ -113,7 +118,7 @@ public abstract class AbstractItemStackBuilder<T extends ItemMeta, U extends Abs
         List<String> lore = meta.hasLore() ? meta.getLore() : new ArrayList<>();
         assert lore != null;
         for (String line : lines) {
-            lore.add(StringUtils.translate(line));
+            lore.add(StringUtils.format(line));
         }
         meta.setLore(lore);
 

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

@@ -1,11 +1,15 @@
 package com.willfp.eco.core.items.builder;
 
-import com.willfp.eco.internal.items.AbstractItemStackBuilder;
 import org.bukkit.Material;
 import org.bukkit.enchantments.Enchantment;
 import org.bukkit.inventory.meta.EnchantmentStorageMeta;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.function.Supplier;
+
+/**
+ * Class to build enchanted books.
+ */
 public class EnchantedBookBuilder extends AbstractItemStackBuilder<EnchantmentStorageMeta, EnchantedBookBuilder> {
     /**
      * Create a new EnchantedBookBuilder.
@@ -26,4 +30,16 @@ public class EnchantedBookBuilder extends AbstractItemStackBuilder<EnchantmentSt
         this.getMeta().addStoredEnchant(enchantment, level, true);
         return this;
     }
+
+    /**
+     * Add an enchantment to the item.
+     *
+     * @param enchantment The enchantment.
+     * @param level       The level.
+     * @return The builder.
+     */
+    public EnchantedBookBuilder addStoredEnchantment(@NotNull final Supplier<Enchantment> enchantment,
+                                                     final Supplier<Integer> level) {
+        return this.addStoredEnchantment(enchantment.get(), level.get());
+    }
 }