plugin/src/main/java/lol/pyr/znpcsplus/ZNpcsPlus.java

@@ -93,7 +93,7 @@ public class ZNpcsPlus {
         packetEvents.load();
 
         configManager = new ConfigManager(getDataFolder());
-        skinCache = new MojangSkinCache(configManager);
+        skinCache = new MojangSkinCache(configManager, new File(getDataFolder(), "skins"));
         propertyRegistry = new EntityPropertyRegistryImpl(skinCache, configManager);
 
         NpcPropertyRegistryProvider.register(propertyRegistry);

plugin/src/main/java/lol/pyr/znpcsplus/commands/SkinCommand.java

@@ -17,10 +17,14 @@ import lol.pyr.znpcsplus.skin.descriptor.PrefetchedDescriptor;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.format.NamedTextColor;
 
+import java.io.File;
+import java.io.FileNotFoundException;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 public class SkinCommand implements CommandHandler {
     private final MojangSkinCache skinCache;
@@ -90,6 +94,30 @@ public class SkinCommand implements CommandHandler {
                 context.send(Component.text("Invalid url!", NamedTextColor.RED));
             }
             return;
+        } else if (type.equalsIgnoreCase("file")) {
+            context.ensureArgsNotEmpty();
+            String path = context.dumpAllArgs();
+            context.send(Component.text("Fetching skin from file \"" + path + "\"...", NamedTextColor.GREEN));
+            PrefetchedDescriptor.fromFile(skinCache, path).exceptionally(e -> {
+                if (e instanceof FileNotFoundException || e.getCause() instanceof FileNotFoundException) {
+                    context.send(Component.text("A file at the specified path could not be found!", NamedTextColor.RED));
+                } else {
+                    context.send(Component.text("An error occurred while fetching the skin from file! Check the console for more details.", NamedTextColor.RED));
+                    //noinspection CallToPrintStackTrace
+                    e.printStackTrace();
+                }
+                return null;
+            }).thenAccept(skin -> {
+                if (skin == null) return;
+                if (skin.getSkin() == null) {
+                    context.send(Component.text("Failed to fetch skin, are you sure the file path is valid?", NamedTextColor.RED));
+                    return;
+                }
+                npc.setProperty(propertyRegistry.getByName("skin", SkinDescriptor.class), skin);
+                npc.respawn();
+                context.send(Component.text("The NPC's skin has been set.", NamedTextColor.GREEN));
+            });
+            return;
         }
         context.send(Component.text("Unknown skin type! Please use one of the following: mirror, static, dynamic, url"));
     }
@@ -97,11 +125,19 @@ public class SkinCommand implements CommandHandler {
     @Override
     public List<String> suggest(CommandContext context) throws CommandExecutionException {
         if (context.argSize() == 1) return context.suggestCollection(npcRegistry.getModifiableIds());
-        if (context.argSize() == 2) return context.suggestLiteral("mirror", "static", "dynamic", "url");
+        if (context.argSize() == 2) return context.suggestLiteral("mirror", "static", "dynamic", "url", "file");
         if (context.matchSuggestion("*", "static")) return context.suggestPlayers();
         if (context.argSize() == 3 && context.matchSuggestion("*", "url")) {
             return context.suggestLiteral("slim", "classic");
         }
+        if (context.argSize() == 3 && context.matchSuggestion("*", "file")) {
+            if (skinCache.getSkinsFolder().exists()) {
+                File[] files = skinCache.getSkinsFolder().listFiles();
+                if (files != null) {
+                    return Arrays.stream(files).map(File::getName).collect(Collectors.toList());
+                }
+            }
+        }
         return Collections.emptyList();
     }
 }

plugin/src/main/java/lol/pyr/znpcsplus/skin/cache/MojangSkinCache.java

@@ -15,6 +15,7 @@ import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
@@ -27,9 +28,12 @@ public class MojangSkinCache {
 
     private final Map<String, SkinImpl> cache = new ConcurrentHashMap<>();
     private final Map<String, CachedId> idCache = new ConcurrentHashMap<>();
+    private final File skinsFolder;
 
-    public MojangSkinCache(ConfigManager configManager) {
+    public MojangSkinCache(ConfigManager configManager, File skinsFolder) {
         this.configManager = configManager;
+        this.skinsFolder = skinsFolder;
+        if (!skinsFolder.exists()) skinsFolder.mkdirs();
     }
 
     public void cleanCache() {
@@ -143,6 +147,58 @@ public class MojangSkinCache {
         });
     }
 
+    public CompletableFuture<SkinImpl> fetchFromFile(String path) throws FileNotFoundException {
+        File file = new File(skinsFolder, path);
+        if (!file.exists()) throw new FileNotFoundException("File not found: " + path);
+        return CompletableFuture.supplyAsync(() -> {
+            URL apiUrl = parseUrl("https://api.mineskin.org/generate/upload");
+            HttpURLConnection connection = null;
+            try {
+                String boundary = "*****";
+                String CRLF = "\r\n";
+
+                connection = (HttpURLConnection) apiUrl.openConnection();
+                connection.setRequestMethod("POST");
+                connection.setReadTimeout(10000);
+                connection.setConnectTimeout(15000);
+                connection.setUseCaches(false);
+                connection.setRequestProperty("Cache-Control", "no-cache");
+                connection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
+                connection.setDoInput(true);
+                connection.setDoOutput(true);
+                OutputStream outputStream = connection.getOutputStream();
+                DataOutputStream out = new DataOutputStream(outputStream);
+                out.writeBytes("--" + boundary + CRLF);
+                out.writeBytes("Content-Disposition: form-data; name=\"file\"; filename=\"" + file.getName() + "\"" + CRLF);
+                out.writeBytes("Content-Type: image/png" + CRLF);
+                out.writeBytes(CRLF);
+                out.write(Files.readAllBytes(file.toPath()));
+                out.writeBytes(CRLF);
+                out.writeBytes("--" + boundary + "--" + CRLF);
+                out.flush();
+                out.close();
+                outputStream.close();
+
+                try (Reader reader = new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8)) {
+                    JsonObject obj = JsonParser.parseReader(reader).getAsJsonObject();
+                    if (obj.has("error")) return null;
+                    if (!obj.has("data")) return null;
+                    JsonObject texture = obj.get("data").getAsJsonObject().get("texture").getAsJsonObject();
+                    return new SkinImpl(texture.get("value").getAsString(), texture.get("signature").getAsString());
+                }
+
+            } catch (IOException exception) {
+                if (!configManager.getConfig().disableSkinFetcherWarnings()) {
+                    logger.warning("Failed to get skin from file:");
+                    exception.printStackTrace();
+                }
+            } finally {
+                if (connection != null) connection.disconnect();
+            }
+            return null;
+        });
+    }
+
     public boolean isNameFullyCached(String s) {
         String name = s.toLowerCase();
         if (!idCache.containsKey(name)) return false;
@@ -214,4 +270,8 @@ public class MojangSkinCache {
             throw new RuntimeException(exception);
         }
     }
+
+    public File getSkinsFolder() {
+        return skinsFolder;
+    }
 }

plugin/src/main/java/lol/pyr/znpcsplus/skin/descriptor/PrefetchedDescriptor.java

@@ -8,6 +8,7 @@ import lol.pyr.znpcsplus.skin.cache.MojangSkinCache;
 import lol.pyr.znpcsplus.util.FutureUtil;
 import org.bukkit.entity.Player;
 
+import java.io.FileNotFoundException;
 import java.net.URL;
 import java.util.concurrent.CompletableFuture;
 
@@ -26,6 +27,16 @@ public class PrefetchedDescriptor implements BaseSkinDescriptor, SkinDescriptor
         return FutureUtil.exceptionPrintingSupplyAsync(() -> new PrefetchedDescriptor(cache.fetchByUrl(url, variant).join()));
     }
 
+    public static CompletableFuture<PrefetchedDescriptor> fromFile(MojangSkinCache cache, String path) {
+        return CompletableFuture.supplyAsync(() -> {
+            try {
+                return new PrefetchedDescriptor(cache.fetchFromFile(path).join());
+            } catch (FileNotFoundException e) {
+                throw new RuntimeException(e);
+            }
+        });
+    }
+
     @Override
     public CompletableFuture<SkinImpl> fetch(Player player) {
         return CompletableFuture.completedFuture(skin);