From f7b5bd6246e364d42b4aa65433a81b6b24a4394c Mon Sep 17 00:00:00 2001
From: Tofaa <82680183+Tofaa2@users.noreply.github.com>
Date: Wed, 1 May 2024 16:34:31 +0400
Subject: [PATCH] Add optional api getter to avoid NullPointer on metadata

---
 .idea/misc.xml                                |   2 +-
 .idea/workspace.xml                           |  58 ++++----
 .../java/me/tofaa/entitylib/EntityLib.java    |   8 +-
 .../entitylib/extras/MojangApiError.java      |  23 +++
 .../tofaa/entitylib/extras/skin/CSFBImpl.java |  37 +++++
 .../extras/skin/CachedSkinFetcherBuilder.java |  14 ++
 .../extras/skin/CachedSkinFetcherImpl.java    | 136 ++++++++++++++++++
 .../extras/skin/ErroredTextureProperties.java |  35 +++++
 .../tofaa/entitylib/extras/skin/SFBImpl.java  |  28 ++++
 .../tofaa/entitylib/extras/skin/SFUtils.java  |  71 +++++++++
 .../entitylib/extras/skin/SkinFetcher.java    |  28 ++++
 .../extras/skin/SkinFetcherBuilder.java       |  15 ++
 .../extras/skin/SkinFetcherImpl.java          |  59 ++++++++
 .../me/tofaa/entitylib/meta/Metadata.java     |   5 +-
 .../testentitylib/TestPlayerCommand.java      |  22 ++-
 15 files changed, 502 insertions(+), 39 deletions(-)
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/MojangApiError.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/CSFBImpl.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherBuilder.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherImpl.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/ErroredTextureProperties.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/SFBImpl.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/SFUtils.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcher.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherBuilder.java
 create mode 100644 api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherImpl.java

diff --git a/.idea/misc.xml b/.idea/misc.xml
index e3506b9..35a6479 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -4,5 +4,5 @@
   <component name="FrameworkDetectionExcludesConfiguration">
     <file type="web" url="file://$PROJECT_DIR$" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="corretto-17" project-jdk-type="JavaSDK" />
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="corretto-17" project-jdk-type="JavaSDK" />
 </project>
\ No newline at end of file
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 1e6af11..29f2b72 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -4,7 +4,22 @@
     <option name="autoReloadType" value="SELECTIVE" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="9d5d9b6f-43c8-41a4-bb42-a66ffc96c9b0" name="Changes" comment="" />
+    <list default="true" id="9d5d9b6f-43c8-41a4-bb42-a66ffc96c9b0" name="Changes" comment="">
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/MojangApiError.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/CSFBImpl.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherBuilder.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherImpl.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/ErroredTextureProperties.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/SFBImpl.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/SFUtils.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcher.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherBuilder.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherImpl.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/.idea/misc.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/misc.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/EntityLib.java" beforeDir="false" afterPath="$PROJECT_DIR$/api/src/main/java/me/tofaa/entitylib/EntityLib.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/test-plugin/src/main/java/me/tofaa/testentitylib/TestPlayerCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/test-plugin/src/main/java/me/tofaa/testentitylib/TestPlayerCommand.java" afterDir="false" />
+    </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
     <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
@@ -34,17 +49,6 @@
                 <item name="" type="6a2764b6:ExternalProjectsStructure$RootNode" />
                 <item name="EntityLib" type="f1a62948:ProjectNode" />
               </path>
-              <path>
-                <item name="" type="6a2764b6:ExternalProjectsStructure$RootNode" />
-                <item name="EntityLib" type="f1a62948:ProjectNode" />
-                <item name="Tasks" type="e4a08cd1:TasksNode" />
-              </path>
-              <path>
-                <item name="" type="6a2764b6:ExternalProjectsStructure$RootNode" />
-                <item name="EntityLib" type="f1a62948:ProjectNode" />
-                <item name="Tasks" type="e4a08cd1:TasksNode" />
-                <item name="publishing" type="c8890929:TasksNode$1" />
-              </path>
             </expand>
             <select />
           </tree_state>
@@ -64,16 +68,9 @@
     <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$" />
   </component>
   <component name="HighlightingSettingsPerFile">
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.github.retrooper.packetevents/api/2.2.1/5aea4193d2dadf2f99523ded56a910c4dd98d23f/api-2.2.1-default.jar!/com/github/retrooper/packetevents/protocol/entity/pose/EntityPose.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.github.retrooper.packetevents/api/2.2.1/5aea4193d2dadf2f99523ded56a910c4dd98d23f/api-2.2.1-default.jar!/com/github/retrooper/packetevents/wrapper/play/server/WrapperPlayServerEntityAnimation.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.github.retrooper.packetevents/api/2.2.1/5aea4193d2dadf2f99523ded56a910c4dd98d23f/api-2.2.1-default.jar!/com/github/retrooper/packetevents/wrapper/play/server/WrapperPlayServerSystemChatMessage.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.github.retrooper.packetevents/api/2.2.1/5aea4193d2dadf2f99523ded56a910c4dd98d23f/api-2.2.1-default.jar!/com/github/retrooper/packetevents/wrapper/play/server/WrapperPlayServerTeams.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.github.retrooper.packetevents/spigot/2.0.2/e1b5c8968213460b6bcf919597ea94de2157cb31/spigot-2.0.2.jar!/com/github/retrooper/packetevents/event/PacketListenerCommon.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.github.retrooper.packetevents/spigot/2.2.0/d8ce06232bdbdec3b31021c84545bd1aff957af0/spigot-2.2.0.jar!/com/github/retrooper/packetevents/wrapper/play/server/WrapperPlayServerTeams.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.spigotmc/spigot-api/1.20.1-R0.1-SNAPSHOT/23c0dae3633c3dd31d4503969fa7f9f3d36840fb/spigot-api-1.20.1-R0.1-SNAPSHOT.jar!/org/bukkit/plugin/EventExecutor.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.spigotmc/spigot-api/1.20.1-R0.1-SNAPSHOT/23c0dae3633c3dd31d4503969fa7f9f3d36840fb/spigot-api-1.20.1-R0.1-SNAPSHOT.jar!/org/bukkit/plugin/PluginManager.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.spigotmc/spigot-api/1.20.1-R0.1-SNAPSHOT/23c0dae3633c3dd31d4503969fa7f9f3d36840fb/spigot-api-1.20.1-R0.1-SNAPSHOT.jar!/org/bukkit/profile/PlayerProfile.class" root0="SKIP_INSPECTION" />
-    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.spigotmc/spigot-api/1.20.1-R0.1-SNAPSHOT/23c0dae3633c3dd31d4503969fa7f9f3d36840fb/spigot-api-1.20.1-R0.1-SNAPSHOT.jar!/org/bukkit/profile/PlayerTextures.class" root0="SKIP_INSPECTION" />
+    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.github.retrooper.packetevents/api/2.2.1/c70f2380ee7c60be444e22a10e679577ab9f8afa/api-2.2.1-default.jar!/com/github/retrooper/packetevents/protocol/player/TextureProperty.class" root0="SKIP_INSPECTION" />
+    <setting file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/com.google.code.gson/gson/2.8.0/c4ba5371a29ac9b2ad6129b1d39ea38750043eff/gson-2.8.0.jar!/com/google/gson/JsonArray.class" root0="SKIP_INSPECTION" />
+    <setting file="jar://$USER_HOME$/.jdks/corretto-17.0.10/lib/src.zip!/java.base/java/util/List.java" root0="SKIP_INSPECTION" />
   </component>
   <component name="MarkdownSettingsMigration">
     <option name="stateVersion" value="1" />
@@ -98,7 +95,7 @@
     &quot;Gradle.EntityLib [publish].executor&quot;: &quot;Run&quot;,
     &quot;Gradle.EntityLib:code-gen [:code-gen:Main.main()].executor&quot;: &quot;Run&quot;,
     &quot;Gradle.EntityLib:test-plugin [publish].executor&quot;: &quot;Run&quot;,
-    &quot;Gradle.EntityLib:test-plugin [runServer].executor&quot;: &quot;Debug&quot;,
+    &quot;Gradle.EntityLib:test-plugin [runServer].executor&quot;: &quot;Run&quot;,
     &quot;Gradle.EntityLib:test-plugin [shadowJar].executor&quot;: &quot;Run&quot;,
     &quot;Repository.Attach.Annotations&quot;: &quot;false&quot;,
     &quot;Repository.Attach.JavaDocs&quot;: &quot;false&quot;,
@@ -110,7 +107,7 @@
     &quot;ignore.virus.scanning.warn.message&quot;: &quot;true&quot;,
     &quot;jdk.selected.JAVA_MODULE&quot;: &quot;corretto-17&quot;,
     &quot;kotlin-language-version-configured&quot;: &quot;true&quot;,
-    &quot;last_opened_file_path&quot;: &quot;D:/Github/EntityLib/api/src/main/java/me/tofaa/entitylib/extras&quot;,
+    &quot;last_opened_file_path&quot;: &quot;/mnt/sda2/Github/EntityLib&quot;,
     &quot;node.js.detected.package.eslint&quot;: &quot;true&quot;,
     &quot;node.js.detected.package.tslint&quot;: &quot;true&quot;,
     &quot;node.js.selected.package.eslint&quot;: &quot;(autodetect)&quot;,
@@ -121,6 +118,11 @@
     &quot;project.structure.side.proportion&quot;: &quot;0.2&quot;,
     &quot;settings.editor.selected.configurable&quot;: &quot;preferences.pluginManager&quot;,
     &quot;vue.rearranger.settings.migration&quot;: &quot;true&quot;
+  },
+  &quot;keyToStringList&quot;: {
+    &quot;kotlin-gradle-user-dirs&quot;: [
+      &quot;/home/tofaa/.gradle&quot;
+    ]
   }
 }</component>
   <component name="RecentsManager">
@@ -245,9 +247,8 @@
   <component name="SharedIndexes">
     <attachedChunks>
       <set>
-        <option value="jdk-1.8.0_402-temurin-1.8.0_402-4caba194b151-d4a4326d" />
-        <option value="jdk-17.0.10-temurin-17.0.10-4caba194b151-b3785831" />
-        <option value="jdk-21.0.2-openjdk-21.0.2-4caba194b151-4f524021" />
+        <option value="bundled-jdk-9f38398b9061-18abd8497189-intellij.indexing.shared.core-IU-241.14494.240" />
+        <option value="bundled-js-predefined-1d06a55b98c1-74d2a5396914-JavaScript-IU-241.14494.240" />
       </set>
     </attachedChunks>
   </component>
@@ -322,6 +323,7 @@
       <workItem from="1709074092924" duration="24000" />
       <workItem from="1709139306864" duration="1813000" />
       <workItem from="1709142473633" duration="2565000" />
+      <workItem from="1714477887801" duration="3618000" />
     </task>
     <servers />
   </component>
@@ -347,7 +349,7 @@
         </line-breakpoint>
         <line-breakpoint enabled="true" type="java-line">
           <url>file://$PROJECT_DIR$/test-plugin/src/main/java/me/tofaa/testentitylib/TestPlayerCommand.java</url>
-          <line>69</line>
+          <line>77</line>
           <option name="timeStamp" value="4" />
         </line-breakpoint>
         <line-breakpoint enabled="true" type="java-method">
diff --git a/api/src/main/java/me/tofaa/entitylib/EntityLib.java b/api/src/main/java/me/tofaa/entitylib/EntityLib.java
index 1870081..92ab436 100644
--- a/api/src/main/java/me/tofaa/entitylib/EntityLib.java
+++ b/api/src/main/java/me/tofaa/entitylib/EntityLib.java
@@ -1,6 +1,7 @@
 package me.tofaa.entitylib;
 
 import java.io.IOException;
+import java.util.Optional;
 import java.util.logging.Level;
 
 public final class EntityLib {
@@ -23,13 +24,16 @@ public final class EntityLib {
                     platform.getLogger().log(Level.WARNING, "You are using an outdated version of EntityLib. Please take a look at the Github releases page.");
                 }
 
-            }
-            catch (IOException e) {
+            } catch (IOException e) {
                 platform.getLogger().log(Level.WARNING, e, () -> "EntityLib failed to check for updates.");
             }
         }
     }
 
+    public static Optional<EntityLibAPI<?>> getOptionalApi() {
+        return Optional.ofNullable(api);
+    }
+
     public static <T> EntityLibAPI<T> getApi() {
         return api;
     }
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/MojangApiError.java b/api/src/main/java/me/tofaa/entitylib/extras/MojangApiError.java
new file mode 100644
index 0000000..507abc1
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/MojangApiError.java
@@ -0,0 +1,23 @@
+package me.tofaa.entitylib.extras;
+
+public class MojangApiError extends RuntimeException {
+
+    public MojangApiError() {
+    }
+
+    public MojangApiError(String message) {
+        super(message);
+    }
+
+    public MojangApiError(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public MojangApiError(Throwable cause) {
+        super(cause);
+    }
+
+    public MojangApiError(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+        super(message, cause, enableSuppression, writableStackTrace);
+    }
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/CSFBImpl.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/CSFBImpl.java
new file mode 100644
index 0000000..e5b0394
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/CSFBImpl.java
@@ -0,0 +1,37 @@
+package me.tofaa.entitylib.extras.skin;
+
+import me.tofaa.entitylib.extras.MojangApiError;
+
+import java.util.function.Consumer;
+
+final class CSFBImpl implements CachedSkinFetcherBuilder{
+
+    private Consumer<MojangApiError> onErr;
+    private long cacheDuration = -1;
+
+    CSFBImpl(Consumer<MojangApiError> onErr) {
+        this.onErr = onErr;
+    }
+
+    @Override
+    public CachedSkinFetcherBuilder cacheDuration(long duration) {
+        this.cacheDuration = duration;
+        return this;
+    }
+
+    @Override
+    public CachedSkinFetcherBuilder cached() {
+        return this;
+    }
+
+    @Override
+    public CachedSkinFetcherBuilder onErr(Consumer<MojangApiError> onErr) {
+        this.onErr = onErr;
+        return this;
+    }
+
+    @Override
+    public SkinFetcher build() {
+        return new CachedSkinFetcherImpl(onErr, cacheDuration);
+    }
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherBuilder.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherBuilder.java
new file mode 100644
index 0000000..cb56ba4
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherBuilder.java
@@ -0,0 +1,14 @@
+package me.tofaa.entitylib.extras.skin;
+
+import me.tofaa.entitylib.extras.MojangApiError;
+
+import java.util.function.Consumer;
+
+public interface CachedSkinFetcherBuilder extends SkinFetcherBuilder {
+
+    CachedSkinFetcherBuilder cacheDuration(long duration);
+
+    @Override
+    CachedSkinFetcherBuilder onErr(Consumer<MojangApiError> onErr);
+
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherImpl.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherImpl.java
new file mode 100644
index 0000000..904bf14
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/CachedSkinFetcherImpl.java
@@ -0,0 +1,136 @@
+package me.tofaa.entitylib.extras.skin;
+
+import com.github.retrooper.packetevents.protocol.player.TextureProperty;
+import me.tofaa.entitylib.extras.MojangApiError;
+
+import java.util.*;
+import java.util.function.Consumer;
+
+final class CachedSkinFetcherImpl implements SkinFetcher {
+
+    private final long cacheDuration;
+    private final Consumer<MojangApiError> onErr;
+    private final Map<String, CachedData> cache = new HashMap<>();
+    private final Map<UUID, CachedData> cacheUUID = new HashMap<>();
+
+    CachedSkinFetcherImpl(Consumer<MojangApiError> onErr, long cacheDuration) {
+        this.onErr = onErr;
+        this.cacheDuration = cacheDuration;
+    }
+
+
+    @Override
+    public List<TextureProperty> getSkin(String playerName) {
+        if (cache.containsKey(playerName)) {
+            CachedData data = cache.get(playerName);
+            if (data.expiration > System.currentTimeMillis()) {
+                return data.skin;
+            }
+            else {
+                cache.remove(playerName);
+            }
+        }
+        return putAndReturn(playerName);
+    }
+
+    @Override
+    public List<TextureProperty> getSkin(UUID uuid) {
+        if (cacheUUID.containsKey(uuid)) {
+            CachedData data = cacheUUID.get(uuid);
+            if (data.expiration > System.currentTimeMillis()) {
+                return data.skin;
+            }
+            else {
+                cacheUUID.remove(uuid);
+            }
+        }
+        return putAndReturn(uuid);
+    }
+
+    @Override
+    public List<TextureProperty> getSkinOrDefault(String playerName, List<TextureProperty> defaults) {
+        if (cache.containsKey(playerName)) {
+            CachedData data = cache.get(playerName);
+            if (data.expiration > System.currentTimeMillis()) {
+                return data.skin;
+            }
+            else {
+                cache.remove(playerName);
+            }
+        }
+        List<TextureProperty> skin = putAndReturn(playerName);
+        if (skin.isEmpty()) {
+            cache.remove(playerName);
+            return defaults;
+        }
+        return skin;
+    }
+
+    @Override
+    public List<TextureProperty> getSkinOrDefault(UUID uuid, List<TextureProperty> defaults) {
+        if (cacheUUID.containsKey(uuid)) {
+            CachedData data = cacheUUID.get(uuid);
+            if (data.expiration > System.currentTimeMillis()) {
+                return data.skin;
+            }
+            else {
+                cacheUUID.remove(uuid);
+            }
+        }
+        List<TextureProperty> skin = putAndReturn(uuid);
+        if (skin.isEmpty()) {
+            cacheUUID.remove(uuid);
+            return defaults;
+        }
+        return skin;
+    }
+
+    private List<TextureProperty> putAndReturn(String playerName) {
+        ErroredTextureProperties p = SFUtils.getTextures(playerName);
+        if (p.didError()) {
+            if (onErr != null) {
+                onErr.accept(new MojangApiError(p.getError()));
+            }
+            return Collections.emptyList();
+        }
+        List<TextureProperty> skin = p.getTextureProperties();
+        CachedData data;
+        if (cacheDuration == -1) {
+            data = new CachedData(skin, Long.MAX_VALUE);
+        }
+        else {
+            data = new CachedData(skin, System.currentTimeMillis() + cacheDuration);
+        }
+        cache.put(playerName, data);
+        if (p.uuid != null) {
+            cacheUUID.put(p.uuid, data);
+        }
+        return skin;
+    }
+
+    private List<TextureProperty> putAndReturn(UUID uuid) {
+        ErroredTextureProperties p = SFUtils.getTextures(uuid);
+        if (p.didError()) {
+            if (onErr != null) {
+                onErr.accept(new MojangApiError(p.getError()));
+            }
+            return Collections.emptyList();
+        }
+        List<TextureProperty> skin = p.getTextureProperties();
+        if (cacheDuration != -1) {
+            cacheUUID.put(uuid, new CachedData(skin, System.currentTimeMillis() + cacheDuration));
+        }
+        else {
+            cacheUUID.put(uuid, new CachedData(skin, Long.MAX_VALUE));
+        }
+        return skin;
+    }
+    static class CachedData {
+        private final List<TextureProperty> skin;
+        private final long expiration;
+        CachedData(List<TextureProperty> skin, long expiration) {
+            this.skin = skin;
+            this.expiration = expiration;
+        }
+    }
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/ErroredTextureProperties.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/ErroredTextureProperties.java
new file mode 100644
index 0000000..ccd8820
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/ErroredTextureProperties.java
@@ -0,0 +1,35 @@
+package me.tofaa.entitylib.extras.skin;
+
+import com.github.retrooper.packetevents.protocol.player.TextureProperty;
+import me.tofaa.entitylib.extras.MojangApiError;
+
+import java.util.List;
+import java.util.UUID;
+
+final class ErroredTextureProperties {
+
+    UUID uuid;
+    private MojangApiError error;
+    private List<TextureProperty> textureProperties;
+
+    ErroredTextureProperties(MojangApiError error) {
+        this.error = error;
+    }
+
+    ErroredTextureProperties(List<TextureProperty> textureProperties) {
+        this.textureProperties = textureProperties;
+    }
+
+    boolean didError() {
+        return error != null;
+    }
+
+    MojangApiError getError() {
+        return error;
+    }
+
+    List<TextureProperty> getTextureProperties() {
+        return textureProperties;
+    }
+
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/SFBImpl.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/SFBImpl.java
new file mode 100644
index 0000000..2278970
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/SFBImpl.java
@@ -0,0 +1,28 @@
+package me.tofaa.entitylib.extras.skin;
+
+import me.tofaa.entitylib.extras.MojangApiError;
+
+import java.util.function.Consumer;
+
+class SFBImpl implements SkinFetcherBuilder {
+
+    private Consumer<MojangApiError> rateLimitErrorConsumer;
+
+    @Override
+    public CachedSkinFetcherBuilder cached() {
+        return new CSFBImpl(rateLimitErrorConsumer);
+    }
+
+    @Override
+    public SkinFetcherBuilder onErr(Consumer<MojangApiError> onErr) {
+        this.rateLimitErrorConsumer = onErr;
+        return this;
+    }
+
+    @Override
+    public SkinFetcher build() {
+        return new SkinFetcherImpl(rateLimitErrorConsumer);
+    }
+
+
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/SFUtils.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/SFUtils.java
new file mode 100644
index 0000000..838f969
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/SFUtils.java
@@ -0,0 +1,71 @@
+package me.tofaa.entitylib.extras.skin;
+
+import com.github.retrooper.packetevents.protocol.player.TextureProperty;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import me.tofaa.entitylib.extras.MojangApiError;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+final class SFUtils {
+
+    public static ErroredTextureProperties getTextures(String username) {
+        try {
+            URL url = new URL("https://api.mojang.com/users/profiles/minecraft/" + username);
+            InputStream stream = url.openStream();
+            InputStreamReader isr = new InputStreamReader(stream);
+            JsonObject root = parse(isr);
+            UUID uuid = UUID.fromString(root.get("id").getAsString());
+            isr.close();
+            stream.close();
+            return getTextures(uuid);
+        }
+        catch (IOException e) {
+            return new ErroredTextureProperties(new MojangApiError(e));
+        }
+    }
+
+    public static ErroredTextureProperties getTextures(UUID uuid) {
+        try {
+            URL url = new URL("https://sessionserver.mojang.com/session/minecraft/profile/" + uuid.toString().replace("-", "") + "?unsigned=false");
+            InputStream stream = url.openStream();
+            InputStreamReader isr = new InputStreamReader(stream);
+            JsonObject root = parse(isr);
+            JsonArray textures = getTexturesObject(root);
+            List<TextureProperty> properties = new ArrayList<>(textures.size());
+            for (int i = 0; i < textures.size(); i++) {
+                JsonObject texture = textures.get(i).getAsJsonObject();
+                String name = texture.get("name").getAsString();
+                String value = texture.get("value").getAsString();
+                String signature = texture.has("signature") ? texture.get("signature").getAsString() : null;
+                properties.add(new TextureProperty(name, value, signature));
+            }
+            isr.close();
+            stream.close();
+            ErroredTextureProperties prop = new ErroredTextureProperties(properties);
+            prop.uuid = uuid;
+            return prop;
+        }
+        catch (IOException e) {
+            return new ErroredTextureProperties(new MojangApiError(e));
+        }
+    }
+
+    private SFUtils() {}
+
+    static JsonArray getTexturesObject(JsonObject root) {
+        return root.getAsJsonArray("properties");
+    }
+
+    static JsonObject parse(InputStreamReader isr) {
+        return new JsonParser().parse(isr).getAsJsonObject();
+    }
+
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcher.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcher.java
new file mode 100644
index 0000000..1f32edb
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcher.java
@@ -0,0 +1,28 @@
+package me.tofaa.entitylib.extras.skin;
+
+import com.github.retrooper.packetevents.protocol.player.TextureProperty;
+
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * Represents a interface that fetches the skin of a player.
+ * This class is non static, you should create and store an instance of it.
+ * Creating one should be done using the builder. SkinFetcher is synchronous. You must handle that yourself.
+ */
+public interface SkinFetcher {
+
+    static SkinFetcherBuilder builder() {
+        return new SFBImpl();
+    }
+
+
+    List<TextureProperty> getSkin(String playerName);
+
+    List<TextureProperty> getSkin(UUID uuid);
+
+    List<TextureProperty> getSkinOrDefault(String playerName, List<TextureProperty> defaults);
+
+    List<TextureProperty> getSkinOrDefault(UUID uuid, List<TextureProperty> defaults);
+
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherBuilder.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherBuilder.java
new file mode 100644
index 0000000..ad3d2b5
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherBuilder.java
@@ -0,0 +1,15 @@
+package me.tofaa.entitylib.extras.skin;
+
+import me.tofaa.entitylib.extras.MojangApiError;
+
+import java.util.function.Consumer;
+
+public interface SkinFetcherBuilder {
+
+    CachedSkinFetcherBuilder cached();
+
+    SkinFetcherBuilder onErr(Consumer<MojangApiError> onErr);
+
+    SkinFetcher build();
+
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherImpl.java b/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherImpl.java
new file mode 100644
index 0000000..0e510d1
--- /dev/null
+++ b/api/src/main/java/me/tofaa/entitylib/extras/skin/SkinFetcherImpl.java
@@ -0,0 +1,59 @@
+package me.tofaa.entitylib.extras.skin;
+
+import com.github.retrooper.packetevents.protocol.player.TextureProperty;
+import me.tofaa.entitylib.extras.MojangApiError;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.UUID;
+import java.util.function.Consumer;
+
+final class SkinFetcherImpl implements SkinFetcher {
+
+    private final Consumer<MojangApiError> rateLimitErrorConsumer;
+
+    public SkinFetcherImpl(Consumer<MojangApiError> rateLimitErrorConsumer) {
+        this.rateLimitErrorConsumer = rateLimitErrorConsumer;
+    }
+
+    @Override
+    public List<TextureProperty> getSkin(String playerName) {
+        ErroredTextureProperties p = SFUtils.getTextures(playerName);
+        if (p.didError()) {
+            rateLimitErrorConsumer.accept(p.getError());
+            return Collections.emptyList();
+        }
+        return p.getTextureProperties();
+    }
+
+    @Override
+    public List<TextureProperty> getSkin(UUID uuid) {
+        ErroredTextureProperties p = SFUtils.getTextures(uuid);
+        if (p.didError()) {
+            rateLimitErrorConsumer.accept(p.getError());
+            return Collections.emptyList();
+        }
+        return p.getTextureProperties();
+    }
+
+    @Override
+    public List<TextureProperty> getSkinOrDefault(String playerName, List<TextureProperty> defaults) {
+        ErroredTextureProperties p = SFUtils.getTextures(playerName);
+        if (p.didError()) {
+            rateLimitErrorConsumer.accept(p.getError());
+            return defaults;
+        }
+        return p.getTextureProperties();
+    }
+
+    @Override
+    public List<TextureProperty> getSkinOrDefault(UUID uuid, List<TextureProperty> defaults) {
+        ErroredTextureProperties p = SFUtils.getTextures(uuid);
+        if (p.didError()) {
+            rateLimitErrorConsumer.accept(p.getError());
+            return defaults;
+        }
+        return p.getTextureProperties();
+    }
+
+}
diff --git a/api/src/main/java/me/tofaa/entitylib/meta/Metadata.java b/api/src/main/java/me/tofaa/entitylib/meta/Metadata.java
index 18d8c06..79dffc4 100644
--- a/api/src/main/java/me/tofaa/entitylib/meta/Metadata.java
+++ b/api/src/main/java/me/tofaa/entitylib/meta/Metadata.java
@@ -4,6 +4,7 @@ import com.github.retrooper.packetevents.protocol.entity.data.EntityData;
 import com.github.retrooper.packetevents.protocol.entity.data.EntityDataType;
 import com.github.retrooper.packetevents.wrapper.play.server.WrapperPlayServerEntityMetadata;
 import me.tofaa.entitylib.EntityLib;
+import me.tofaa.entitylib.EntityLibAPI;
 import me.tofaa.entitylib.wrapper.WrapperEntity;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -34,7 +35,9 @@ public class Metadata {
         final EntityData entry = new EntityData(index, dataType, value);
         this.metadataMap.put(index, entry);
 
-        final WrapperEntity entity = EntityLib.getApi().getEntity(entityId);
+        final Optional<EntityLibAPI<?>> optionalApi = EntityLib.getOptionalApi();
+        if (!optionalApi.isPresent()) return;
+        final WrapperEntity entity = optionalApi.get().getEntity(entityId);
         if (entity == null || !entity.isSpawned()) return; // Not EntityLib entity then, the user must send the packet manually. OR not spawned.
         if (!this.notifyAboutChanges) {
             synchronized (this.notNotifiedChanges) {
diff --git a/test-plugin/src/main/java/me/tofaa/testentitylib/TestPlayerCommand.java b/test-plugin/src/main/java/me/tofaa/testentitylib/TestPlayerCommand.java
index a3adc94..79ffc4e 100644
--- a/test-plugin/src/main/java/me/tofaa/testentitylib/TestPlayerCommand.java
+++ b/test-plugin/src/main/java/me/tofaa/testentitylib/TestPlayerCommand.java
@@ -1,21 +1,16 @@
 package me.tofaa.testentitylib;
 
-import com.github.retrooper.packetevents.PacketEvents;
 import com.github.retrooper.packetevents.protocol.entity.type.EntityTypes;
 import com.github.retrooper.packetevents.protocol.item.ItemStack;
 import com.github.retrooper.packetevents.protocol.item.type.ItemTypes;
 import com.github.retrooper.packetevents.protocol.player.GameMode;
-import com.github.retrooper.packetevents.protocol.player.TextureProperty;
 import com.github.retrooper.packetevents.protocol.player.UserProfile;
-import com.github.retrooper.packetevents.wrapper.PacketWrapper;
-import com.github.retrooper.packetevents.wrapper.play.server.WrapperPlayServerPlayerInfo;
-import com.github.retrooper.packetevents.wrapper.play.server.WrapperPlayServerPlayerInfoUpdate;
 import io.github.retrooper.packetevents.util.SpigotConversionUtil;
 import me.tofaa.entitylib.EntityLib;
+import me.tofaa.entitylib.extras.skin.SkinFetcher;
 import me.tofaa.entitylib.spigot.ExtraConversionUtil;
 import me.tofaa.entitylib.wrapper.WrapperPlayer;
 import net.kyori.adventure.text.Component;
-import org.bukkit.Bukkit;
 import org.bukkit.command.CommandSender;
 import org.bukkit.command.defaults.BukkitCommand;
 import org.bukkit.entity.Player;
@@ -26,6 +21,7 @@ import java.util.*;
 public class TestPlayerCommand extends BukkitCommand {
 
     private WrapperPlayer p;
+    private SkinFetcher sf;
     public TestPlayerCommand() {
         super("testplayer");
     }
@@ -33,12 +29,24 @@ public class TestPlayerCommand extends BukkitCommand {
     @Override
     public boolean execute(@NotNull CommandSender commandSender, @NotNull String s, @NotNull String[] strings) {
         Player player = (Player) commandSender;
-        if (strings.length != 1) {
+        if (strings.length < 1) {
             player.sendMessage("Usage: /testplayer <spawn|hello|ping|gamemode|displayname|tablist|remove>");
             return false;
         }
         String arg = strings[0].toLowerCase();
         switch (arg) {
+            case "skin":
+                String input = strings[1];
+                if (p == null) {
+                    player.sendMessage("Spawn an entity first");
+                    return false;
+                }
+                if (sf == null) {
+                    sf = SkinFetcher.builder()
+                            .cached()
+                            .build();
+                }
+                p.setTextureProperties(sf.getSkin(input));
             case "spawn":
                 UserProfile profile = new UserProfile(UUID.randomUUID(), "randomname", new ArrayList<>());
                 p = new WrapperPlayer(profile, EntityLib.getPlatform().getEntityIdProvider().provide(profile.getUUID(), EntityTypes.PLAYER));