Change plugin manager logic

Merge pull request #1346 from Grasscutters/plugin-priority

build.gradle

@@ -43,7 +43,7 @@ sourceCompatibility = JavaVersion.VERSION_17
 targetCompatibility = JavaVersion.VERSION_17
 
 group = 'xyz.grasscutters'
-version = '1.2.1-dev'
+version = '1.2.2-dev'
 
 
 sourceCompatibility = 17

plugin-schema.json

@@ -9,7 +9,11 @@
             "pattern": "^[A-Za-z\\d_.-]+$"
         }
     },
-  "required": [ "name", "description", "mainClass" ],
+    "required": [
+        "name",
+        "description",
+        "mainClass"
+    ],
     "properties": {
         "name": {
             "description": "The unique name of plugin.",
@@ -22,7 +26,10 @@
         },
         "version": {
             "description": "A plugin revision identifier.",
-      "type": [ "string", "number" ]
+            "type": [
+                "string",
+                "number"
+            ]
         },
         "description": {
             "description": "Human readable plugin summary.",
@@ -44,6 +51,13 @@
             "description": "The URL to the plugin's site",
             "type": "string",
             "format": "uri"
+        },
+        "loadAfter": {
+            "description": "Plugins to load before this plugin.",
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
         }
     }
 }

src/main/java/emu/grasscutter/Grasscutter.java

@@ -1,25 +1,34 @@
 package emu.grasscutter;
 
-import java.io.*;
+import ch.qos.logback.classic.Logger;
-import java.util.Calendar;
+import com.google.gson.Gson;
-
+import com.google.gson.GsonBuilder;
 import emu.grasscutter.auth.AuthenticationSystem;
 import emu.grasscutter.auth.DefaultAuthentication;
 import emu.grasscutter.command.CommandMap;
 import emu.grasscutter.command.DefaultPermissionHandler;
 import emu.grasscutter.command.PermissionHandler;
 import emu.grasscutter.game.dungeons.challenge.DungeonChallenge;
+import emu.grasscutter.data.ResourceLoader;
+import emu.grasscutter.database.DatabaseManager;
 import emu.grasscutter.game.managers.energy.EnergyManager;
 import emu.grasscutter.game.managers.stamina.StaminaManager;
 import emu.grasscutter.plugin.PluginManager;
 import emu.grasscutter.plugin.api.ServerHook;
 import emu.grasscutter.scripts.ScriptLoader;
+import emu.grasscutter.server.game.GameServer;
 import emu.grasscutter.server.http.HttpServer;
 import emu.grasscutter.server.http.dispatch.DispatchHandler;
-import emu.grasscutter.server.http.handlers.*;
 import emu.grasscutter.server.http.dispatch.RegionHandler;
 import emu.grasscutter.server.http.documentation.DocumentationServerHandler;
+import emu.grasscutter.server.http.handlers.AnnouncementsHandler;
+import emu.grasscutter.server.http.handlers.GachaHandler;
+import emu.grasscutter.server.http.handlers.GenericHandler;
+import emu.grasscutter.server.http.handlers.LogHandler;
+import emu.grasscutter.tools.Tools;
 import emu.grasscutter.utils.ConfigContainer;
+import emu.grasscutter.utils.Crypto;
+import emu.grasscutter.utils.Language;
 import emu.grasscutter.utils.Utils;
 import org.jline.reader.EndOfFileException;
 import org.jline.reader.LineReader;
@@ -30,21 +39,13 @@ import org.jline.terminal.TerminalBuilder;
 import org.reflections.Reflections;
 import org.slf4j.LoggerFactory;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-
-import ch.qos.logback.classic.Logger;
-import emu.grasscutter.data.ResourceLoader;
-import emu.grasscutter.database.DatabaseManager;
-import emu.grasscutter.utils.Language;
-import emu.grasscutter.server.game.GameServer;
-import emu.grasscutter.tools.Tools;
-import emu.grasscutter.utils.Crypto;
-
 import javax.annotation.Nullable;
+import java.io.*;
+import java.util.Calendar;
 
+import static emu.grasscutter.Configuration.DATA;
+import static emu.grasscutter.Configuration.SERVER;
 import static emu.grasscutter.utils.Language.translate;
-import static emu.grasscutter.Configuration.*;
 
 public final class Grasscutter {
     private static final Logger log = (Logger) LoggerFactory.getLogger(Grasscutter.class);
@@ -90,13 +91,16 @@ public final class Grasscutter {
         for (String arg : args) {
             switch (arg.toLowerCase()) {
                 case "-handbook" -> {
-					Tools.createGmHandbook(); exitEarly = true;
+                    Tools.createGmHandbook();
+                    exitEarly = true;
                 }
                 case "-gachamap" -> {
-					Tools.createGachaMapping(DATA("gacha_mappings.js")); exitEarly = true;
+                    Tools.createGachaMapping(DATA("gacha_mappings.js"));
+                    exitEarly = true;
                 }
                 case "-version" -> {
-					System.out.println("Grasscutter version: " + BuildConfig.VERSION + "-" + BuildConfig.GIT_HASH); exitEarly = true;
+                    System.out.println("Grasscutter version: " + BuildConfig.VERSION + "-" + BuildConfig.GIT_HASH);
+                    exitEarly = true;
                 }
             }
         }
@@ -113,8 +117,6 @@ public final class Grasscutter {
         Grasscutter.updateDayOfWeek();
         ResourceLoader.loadAll();
         ScriptLoader.init();
-		EnergyManager.initialize();
-		DungeonChallenge.initialize();
 
         // Initialize database.
         DatabaseManager.initialize();
@@ -142,9 +144,6 @@ public final class Grasscutter {
         httpServer.addRouter(GachaHandler.class);
         httpServer.addRouter(DocumentationServerHandler.class);
 
-		// TODO: find a better place?
-		StaminaManager.initialize();
-	
         // Start servers.
         var runMode = SERVER.runMode;
         if (runMode == ServerRunMode.HYBRID) {
@@ -176,6 +175,7 @@ public final class Grasscutter {
      */
     private static void onShutdown() {
         // Disable all plugins.
+        if(pluginManager != null)
             pluginManager.disablePlugins();
     }
 
@@ -215,6 +215,7 @@ public final class Grasscutter {
 
     /**
      * Saves the provided server configuration.
+     *
      * @param config The configuration to save, or null for a new one.
      */
     public static void saveConfig(@Nullable ConfigContainer config) {
@@ -350,6 +351,7 @@ public final class Grasscutter {
 
     /**
      * Sets the authentication system for the server.
+     *
      * @param authenticationSystem The authentication system to use.
      */
     public static void setAuthenticationSystem(AuthenticationSystem authenticationSystem) {
@@ -358,6 +360,7 @@ public final class Grasscutter {
 
     /**
      * Sets the permission handler for the server.
+     *
      * @param permissionHandler The permission handler to use.
      */
     public static void setPermissionHandler(PermissionHandler permissionHandler) {

src/main/java/emu/grasscutter/command/CommandMap.java

@@ -1,9 +1,7 @@
 package emu.grasscutter.command;
 
 import emu.grasscutter.Grasscutter;
-import emu.grasscutter.game.Account;
 import emu.grasscutter.game.player.Player;
-
 import org.reflections.Reflections;
 
 import java.util.*;
@@ -11,6 +9,7 @@ import java.util.*;
 @SuppressWarnings({"UnusedReturnValue", "unused"})
 public final class CommandMap {
     private final Map<String, CommandHandler> commands = new HashMap<>();
+    private final Map<String, CommandHandler> aliases = new HashMap<>();
     private final Map<String, Command> annotations = new HashMap<>();
     private final Map<String, Integer> targetPlayerIds = new HashMap<>();
     private static final String consoleId = "console";
@@ -45,7 +44,7 @@ public final class CommandMap {
         // Register aliases.
         if (annotation.aliases().length > 0) {
             for (String alias : annotation.aliases()) {
-                this.commands.put(alias, command);
+                this.aliases.put(alias, command);
                 this.annotations.put(alias, annotation);
             }
         }
@@ -60,6 +59,7 @@ public final class CommandMap {
      */
     public CommandMap unregisterCommand(String label) {
         Grasscutter.getLogger().debug("Unregistered command: " + label);
+
         CommandHandler handler = this.commands.get(label);
         if (handler == null) return this;
 
@@ -70,7 +70,7 @@ public final class CommandMap {
         // Unregister aliases.
         if (annotation.aliases().length > 0) {
             for (String alias : annotation.aliases()) {
-                this.commands.remove(alias);
+                this.aliases.remove(alias);
                 this.annotations.remove(alias);
             }
         }
@@ -78,7 +78,9 @@ public final class CommandMap {
         return this;
     }
 
-    public List<Command> getAnnotationsAsList() { return new LinkedList<>(this.annotations.values()); }
+    public List<Command> getAnnotationsAsList() {
+        return new LinkedList<>(this.annotations.values());
+    }
 
     public HashMap<String, Command> getAnnotations() {
         return new LinkedHashMap<>(this.annotations);
@@ -142,7 +144,7 @@ public final class CommandMap {
         }
         if (targetUidStr != null) {
             if (targetUidStr.equals("")) { // Clears the default targetPlayer.
-                targetPlayerIds.remove(playerId);
+                this.targetPlayerIds.remove(playerId);
                 CommandHandler.sendTranslatedMessage(player, "commands.execution.clear_target");
             } else { // Sets default targetPlayer to the UID provided.
                 try {
@@ -151,7 +153,7 @@ public final class CommandMap {
                     if (targetPlayer == null) {
                         CommandHandler.sendTranslatedMessage(player, "commands.execution.player_exist_error");
                     } else {
-                        targetPlayerIds.put(playerId, uid);
+                        this.targetPlayerIds.put(playerId, uid);
                         CommandHandler.sendTranslatedMessage(player, "commands.execution.set_target", targetUidStr);
                         CommandHandler.sendTranslatedMessage(player, targetPlayer.isOnline() ? "commands.execution.set_target_online" : "commands.execution.set_target_offline", targetUidStr);
                     }
@@ -164,11 +166,19 @@ public final class CommandMap {
 
         // Get command handler.
         CommandHandler handler = this.commands.get(label);
+        if(handler == null)
+            // Try to get the handler by alias.
+            handler = this.aliases.get(label);
+
+        // Check if the handler is still null.
         if (handler == null) {
             CommandHandler.sendTranslatedMessage(player, "commands.generic.unknown_command", label);
             return;
         }
 
+        // Get the command's annotation.
+        Command annotation = this.annotations.get(label);
+
         // If any @UID argument is present, override targetPlayer with it.
         for (int i = 0; i < args.size(); i++) {
             String arg = args.get(i);
@@ -191,8 +201,8 @@ public final class CommandMap {
 
         // If there's still no targetPlayer at this point, use previously-set target
         if (targetPlayer == null) {
-            if (targetPlayerIds.containsKey(playerId)) {
+            if (this.targetPlayerIds.containsKey(playerId)) {
-                targetPlayer = Grasscutter.getGameServer().getPlayerByUid(targetPlayerIds.get(playerId), true);  // We check every time in case the target is deleted after being targeted
+                targetPlayer = Grasscutter.getGameServer().getPlayerByUid(this.targetPlayerIds.get(playerId), true);  // We check every time in case the target is deleted after being targeted
                 if (targetPlayer == null) {
                     CommandHandler.sendTranslatedMessage(player, "commands.execution.player_exist_error");
                     return;
@@ -204,32 +214,36 @@ public final class CommandMap {
         }
 
         // Check for permissions.
-        if (!Grasscutter.getPermissionHandler().checkPermission(player, targetPlayer, this.annotations.get(label).permission(), this.annotations.get(label).permissionTargeted())) {
+        if (!Grasscutter.getPermissionHandler().checkPermission(player, targetPlayer, annotation.permission(), this.annotations.get(label).permissionTargeted())) {
             return;
         }
 
         // Check if command has unfulfilled constraints on targetPlayer
-        Command.TargetRequirement targetRequirement = this.annotations.get(label).targetRequirement();
+        Command.TargetRequirement targetRequirement = annotation.targetRequirement();
         if (targetRequirement != Command.TargetRequirement.NONE) {
             if (targetPlayer == null) {
-                CommandHandler.sendTranslatedMessage(player, "commands.execution.need_target");
+                CommandHandler.sendTranslatedMessage(null, "commands.execution.need_target");
                 return;
             }
+
             if ((targetRequirement == Command.TargetRequirement.ONLINE) && !targetPlayer.isOnline()) {
                 CommandHandler.sendTranslatedMessage(player, "commands.execution.need_target_online");
                 return;
             }
+
             if ((targetRequirement == Command.TargetRequirement.OFFLINE) && targetPlayer.isOnline()) {
                 CommandHandler.sendTranslatedMessage(player, "commands.execution.need_target_offline");
                 return;
             }
         }
 
-        // Invoke execute method for handler.
+        // Copy player and handler to final properties.
-        boolean threading  = this.annotations.get(label).threading();
         final Player targetPlayerF = targetPlayer; // Is there a better way to do this?
-        Runnable runnable = () -> handler.execute(player, targetPlayerF, args);
+        final CommandHandler handlerF = handler; // Is there a better way to do this?
-        if(threading) {
+
+        // Invoke execute method for handler.
+        Runnable runnable = () -> handlerF.execute(player, targetPlayerF, args);
+        if (annotation.threading()) {
             new Thread(runnable).start();
         } else {
             runnable.run();
@@ -242,10 +256,11 @@ public final class CommandMap {
     private void scan() {
         Reflections reflector = Grasscutter.reflector;
         Set<Class<?>> classes = reflector.getTypesAnnotatedWith(Command.class);
+
         classes.forEach(annotated -> {
             try {
                 Command cmdData = annotated.getAnnotation(Command.class);
-                Object object = annotated.newInstance();
+                Object object = annotated.getDeclaredConstructor().newInstance();
                 if (object instanceof CommandHandler)
                     this.registerCommand(cmdData.label(), (CommandHandler) object);
                 else Grasscutter.getLogger().error("Class " + annotated.getName() + " is not a CommandHandler!");

src/main/java/emu/grasscutter/data/DataLoader.java

@@ -6,11 +6,11 @@ import emu.grasscutter.tools.Tools;
 import emu.grasscutter.utils.FileUtils;
 import emu.grasscutter.utils.Utils;
 
-import java.io.*;
+import java.io.FileInputStream;
-import java.nio.file.FileSystems;
+import java.io.FileNotFoundException;
+import java.io.InputStream;
 import java.nio.file.Path;
 import java.util.List;
-import java.util.regex.Pattern;
 
 import static emu.grasscutter.Configuration.DATA;
 
@@ -18,10 +18,11 @@ public class DataLoader {
 
     /**
      * Load a data file by its name. If the file isn't found within the /data directory then it will fallback to the default within the jar resources
-     * @see #load(String, boolean)
+     *
      * @param resourcePath The path to the data file to be loaded.
      * @return InputStream of the data file.
      * @throws FileNotFoundException
+     * @see #load(String, boolean)
      */
     public static InputStream load(String resourcePath) throws FileNotFoundException {
         return load(resourcePath, true);
@@ -29,6 +30,7 @@ public class DataLoader {
 
     /**
      * Load a data file by its name.
+     *
      * @param resourcePath The path to the data file to be loaded.
      * @param useFallback  If the file does not exist in the /data directory, should it use the default file in the jar?
      * @return InputStream of the data file.
@@ -53,9 +55,7 @@ public class DataLoader {
 
             if (filenames == null) {
                 Grasscutter.getLogger().error("We were unable to locate your default data files.");
-            }
+            } else for (Path file : filenames) {
-
-            for (Path file : filenames) {
                 String relativePath = String.valueOf(file).split("defaults[\\\\\\/]data[\\\\\\/]")[1];
 
                 CheckAndCopyData(relativePath);

src/main/java/emu/grasscutter/game/player/Player.java

@@ -990,7 +990,7 @@ public class Player {
 	}
 
 
-	public void interactWith(int gadgetEntityId, GadgetInteractReq req) {
+	public void interactWith(int gadgetEntityId, GadgetInteractReq opType) {
 		GameEntity entity = getScene().getEntityById(gadgetEntityId);
 		if (entity == null) {
 			return;
@@ -1023,7 +1023,7 @@ public class Player {
 				return;
 			}
 
-			boolean shouldDelete = gadget.getContent().onInteract(this, req);
+			boolean shouldDelete = gadget.getContent().onInteract(this, opType);
 
 			if (shouldDelete) {
 				entity.getScene().removeEntity(entity);

src/main/java/emu/grasscutter/plugin/PluginConfig.java

@@ -7,11 +7,13 @@ public final class PluginConfig {
     public String name, description, version;
     public String mainClass;
     public String[] authors;
+    public String[] loadAfter;
 
     /**
      * Attempts to validate this config instance.
      * @return True if the config is valid, false otherwise.
      */
+    @SuppressWarnings("BooleanMethodIsAlwaysInverted")
     public boolean validate() {
         return name != null && description != null && mainClass != null;
     }

src/main/java/emu/grasscutter/plugin/PluginManager.java

@@ -1,35 +1,41 @@
 package emu.grasscutter.plugin;
 
 import emu.grasscutter.Grasscutter;
-import emu.grasscutter.server.event.Event;
+import emu.grasscutter.server.event.*;
-import emu.grasscutter.server.event.EventHandler;
-import emu.grasscutter.server.event.HandlerPriority;
 import emu.grasscutter.utils.Utils;
+import lombok.*;
 
-import java.io.File;
+import javax.annotation.Nullable;
-import java.io.FileNotFoundException;
+import java.io.*;
-import java.io.InputStreamReader;
 import java.lang.reflect.Method;
-import java.net.MalformedURLException;
+import java.net.*;
-import java.net.URL;
-import java.net.URLClassLoader;
 import java.util.*;
-import java.util.jar.JarEntry;
+import java.util.jar.*;
-import java.util.jar.JarFile;
 
-import static emu.grasscutter.Configuration.*;
+import static emu.grasscutter.Configuration.PLUGIN;
 
 /**
  * Manages the server's plugins and the event system.
  */
 public final class PluginManager {
-    private final Map<String, Plugin> plugins = new HashMap<>();
+    /* All loaded plugins. */
-    private final List<EventHandler<? extends Event>> listeners = new LinkedList<>();
+    private final Map<String, Plugin> plugins = new LinkedHashMap<>();
+    /* All currently registered listeners per plugin. */
+    private final Map<Plugin, List<EventHandler<? extends Event>>> listeners = new LinkedHashMap<>();
 
     public PluginManager() {
         this.loadPlugins(); // Load all plugins from the plugins directory.
     }
 
+    /* Data about an unloaded plugin. */
+    @AllArgsConstructor @Getter
+    static class PluginData {
+        private Plugin plugin;
+        private PluginIdentifier identifier;
+        private URLClassLoader classLoader;
+        private String[] dependencies;
+    }
+
     /**
      * Loads plugins from the config-specified directory.
      */
@@ -59,36 +65,59 @@ public final class PluginManager {
             }
         });
 
+        // Create a class loader for the plugins.
         URLClassLoader classLoader = new URLClassLoader(pluginNames);
+        // Create a list of plugins that require dependencies.
+        List<PluginData> dependencies = new ArrayList<>();
 
-        plugins.forEach(plugin -> {
+        // Initialize all plugins.
+        for(var plugin : plugins) {
             try {
                 URL url = plugin.toURI().toURL();
                 try (URLClassLoader loader = new URLClassLoader(new URL[]{url})) {
-                    URL configFile = loader.findResource("plugin.json"); // Find the plugin.json file for each plugin.
+                    // Find the plugin.json file for each plugin.
+                    URL configFile = loader.findResource("plugin.json");
+                    // Open the config file for reading.
                     InputStreamReader fileReader = new InputStreamReader(configFile.openStream());
 
+                    // Create a plugin config instance from the config file.
                     PluginConfig pluginConfig = Grasscutter.getGsonFactory().fromJson(fileReader, PluginConfig.class);
+                    // Check if the plugin config is valid.
                     if (!pluginConfig.validate()) {
                         Utils.logObject(pluginConfig);
                         Grasscutter.getLogger().warn("Plugin " + plugin.getName() + " has an invalid config file.");
                         return;
                     }
 
+                    // Create a JAR file instance from the plugin's URL.
                     JarFile jarFile = new JarFile(plugin);
+                    // Load all class files from the JAR file.
                     Enumeration<JarEntry> entries = jarFile.entries();
                     while (entries.hasMoreElements()) {
                         JarEntry entry = entries.nextElement();
-                        if(entry.isDirectory() || !entry.getName().endsWith(".class") || entry.getName().contains("module-info")) continue;
+                        if (entry.isDirectory() || !entry.getName().endsWith(".class") || entry.getName().contains("module-info"))
+                            continue;
                         String className = entry.getName().replace(".class", "").replace("/", ".");
                         classLoader.loadClass(className); // Use the same class loader for ALL plugins.
                     }
 
+                    // Create a plugin instance.
                     Class<?> pluginClass = classLoader.loadClass(pluginConfig.mainClass);
                     Plugin pluginInstance = (Plugin) pluginClass.getDeclaredConstructor().newInstance();
-                    this.loadPlugin(pluginInstance, PluginIdentifier.fromPluginConfig(pluginConfig), loader);
+                    // Close the file reader.
+                    fileReader.close();
 
-                    fileReader.close(); // Close the file reader.
+                    // Check if the plugin has alternate dependencies.
+                    if(pluginConfig.loadAfter != null && pluginConfig.loadAfter.length > 0) {
+                        // Add the plugin to a "load later" list.
+                        dependencies.add(new PluginData(
+                            pluginInstance, PluginIdentifier.fromPluginConfig(pluginConfig),
+                            loader, pluginConfig.loadAfter));
+                        continue;
+                    }
+
+                    // Load the plugin.
+                    this.loadPlugin(pluginInstance, PluginIdentifier.fromPluginConfig(pluginConfig), loader);
                 } catch (ClassNotFoundException ignored) {
                     Grasscutter.getLogger().warn("Plugin " + plugin.getName() + " has an invalid main class.");
                 } catch (FileNotFoundException ignored) {
@@ -97,11 +126,41 @@ public final class PluginManager {
             } catch (Exception exception) {
                 Grasscutter.getLogger().error("Failed to load plugin: " + plugin.getName(), exception);
             }
-        });
+        }
+
+        // Load plugins with dependencies.
+        int depth = 0; final int maxDepth = 30;
+        while(!dependencies.isEmpty()) {
+            // Check if the depth is too high.
+            if(depth >= maxDepth) {
+                Grasscutter.getLogger().error("Failed to load plugins with dependencies.");
+                break;
+            }
+
+            try {
+                // Get the next plugin to load.
+                var pluginData = dependencies.get(0);
+
+                // Check if the plugin's dependencies are loaded.
+                if(!this.plugins.keySet().containsAll(List.of(pluginData.getDependencies()))) {
+                    depth++; // Increase depth counter.
+                    continue; // Continue to next plugin.
+                }
+
+                // Remove the plugin from the list of dependencies.
+                dependencies.remove(pluginData);
+
+                // Load the plugin.
+                this.loadPlugin(pluginData.getPlugin(), pluginData.getIdentifier(), pluginData.getClassLoader());
+            } catch (Exception exception) {
+                Grasscutter.getLogger().error("Failed to load a plugin.", exception); depth++;
+            }
+        }
     }
 
     /**
      * Load the specified plugin.
+     *
      * @param plugin The plugin instance.
      */
     private void loadPlugin(Plugin plugin, PluginIdentifier identifier, URLClassLoader classLoader) {
@@ -111,15 +170,24 @@ public final class PluginManager {
         try {
             Class<Plugin> pluginClass = Plugin.class;
             Method method = pluginClass.getDeclaredMethod("initializePlugin", PluginIdentifier.class, URLClassLoader.class);
-            method.setAccessible(true); method.invoke(plugin, identifier, classLoader); method.setAccessible(false);
+            method.setAccessible(true);
+            method.invoke(plugin, identifier, classLoader);
+            method.setAccessible(false);
         } catch (Exception ignored) {
             Grasscutter.getLogger().warn("Failed to add plugin identifier: " + identifier.name);
         }
 
         // Add the plugin to the list of loaded plugins.
         this.plugins.put(identifier.name, plugin);
+        // Create a collection for the plugin's listeners.
+        this.listeners.put(plugin, new LinkedList<>());
+
         // Call the plugin's onLoad method.
+        try {
             plugin.onLoad();
+        } catch (Throwable exception) {
+            Grasscutter.getLogger().error("Failed to load plugin: " + identifier.name, exception);
+        }
     }
 
     /**
@@ -128,7 +196,11 @@ public final class PluginManager {
     public void enablePlugins() {
         this.plugins.forEach((name, plugin) -> {
             Grasscutter.getLogger().info("Enabling plugin: " + name);
+            try {
                 plugin.onEnable();
+            } catch (Throwable exception) {
+                Grasscutter.getLogger().error("Failed to enable plugin: " + name, exception);
+            }
         });
     }
 
@@ -138,20 +210,27 @@ public final class PluginManager {
     public void disablePlugins() {
         this.plugins.forEach((name, plugin) -> {
             Grasscutter.getLogger().info("Disabling plugin: " + name);
+            try {
                 plugin.onDisable();
+            } catch (Throwable exception) {
+                Grasscutter.getLogger().error("Failed to disable plugin: " + name, exception);
+            }
         });
     }
 
     /**
      * Registers a plugin's event listener.
+     *
+     * @param plugin The plugin registering the listener.
      * @param listener The event listener.
      */
-    public void registerListener(EventHandler<? extends Event> listener) {
+    public void registerListener(Plugin plugin, EventHandler<? extends Event> listener) {
-        this.listeners.add(listener);
+        this.listeners.get(plugin).add(listener);
     }
 
     /**
      * Invoke the provided event on all registered event listeners.
+     *
      * @param event The event to invoke.
      */
     public void invokeEvent(Event event) {
@@ -161,27 +240,70 @@ public final class PluginManager {
 
     /**
      * Check an event to handlers for the priority.
+     *
      * @param event    The event being called.
      * @param priority The priority to call for.
      */
     private void checkAndFilter(Event event, HandlerPriority priority) {
-        this.listeners.stream()
+        // Create a collection of listeners.
+        List<EventHandler<? extends Event>> listeners = new LinkedList<>();
+
+        // Add all listeners from every plugin.
+        this.listeners.values().forEach(listeners::addAll);
+
+        listeners.stream()
+            // Filter the listeners by priority.
             .filter(handler -> handler.handles().isInstance(event))
             .filter(handler -> handler.getPriority() == priority)
+            // Invoke the event.
             .toList().forEach(handler -> this.invokeHandler(event, handler));
     }
 
     /**
      * Gets a plugin's instance by its name.
+     *
      * @param name The name of the plugin.
      * @return Either null, or the plugin's instance.
      */
+    @Nullable
     public Plugin getPlugin(String name) {
         return this.plugins.get(name);
     }
 
+    /**
+     * Enables a plugin.
+     *
+     * @param plugin The plugin to enable.
+     */
+    public void enablePlugin(Plugin plugin) {
+        try {
+            // Call the plugin's onEnable method.
+            plugin.onEnable();
+        } catch (Exception exception) {
+            Grasscutter.getLogger().error("Failed to enable plugin: " + plugin.getName(), exception);
+        }
+    }
+
+    /**
+     * Disables a plugin.
+     *
+     * @param plugin The plugin to disable.
+     */
+    public void disablePlugin(Plugin plugin) {
+        try {
+            // Call the plugin's onDisable method.
+            plugin.onDisable();
+        } catch (Exception exception) {
+            Grasscutter.getLogger().error("Failed to disable plugin: " + plugin.getName(), exception);
+        }
+
+        // Un-register all listeners.
+        this.listeners.remove(plugin);
+    }
+
     /**
      * Performs logic checks then invokes the provided event handler.
+     *
      * @param event   The event passed through to the handler.
      * @param handler The handler to invoke.
      */

src/main/java/emu/grasscutter/server/event/EventHandler.java

@@ -1,6 +1,7 @@
 package emu.grasscutter.server.event;
 
 import emu.grasscutter.Grasscutter;
+import emu.grasscutter.plugin.Plugin;
 import emu.grasscutter.utils.EventConsumer;
 
 public final class EventHandler<T extends Event> {
@@ -75,7 +76,7 @@ public final class EventHandler<T extends Event> {
     /**
      * Registers the handler into the PluginManager.
      */
-    public void register() {
+    public void register(Plugin plugin) {
-        Grasscutter.getPluginManager().registerListener(this);
+        Grasscutter.getPluginManager().registerListener(plugin, this);
     }
 }