Implement MVWorldDeleteEvent event

src/main/java/org/mvplugins/multiverse/core/event/MVWorldDeleteEvent.java

@@ -4,8 +4,8 @@ import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
 
+import org.jetbrains.annotations.NotNull;
 import org.mvplugins.multiverse.core.world.LoadedMultiverseWorld;
-import org.mvplugins.multiverse.core.world.MultiverseWorld;
 
 /**
  * Called when a world is about to be deleted by Multiverse.
@@ -14,14 +14,9 @@ public class MVWorldDeleteEvent extends Event implements Cancellable {
     private boolean cancelled = false;
 
     private final LoadedMultiverseWorld world;
-    private final boolean removeFromConfig;
 
-    public MVWorldDeleteEvent(LoadedMultiverseWorld world, boolean removeFromConfig) {
+    public MVWorldDeleteEvent(@NotNull LoadedMultiverseWorld world) {
-        if (world == null) {
-            throw new IllegalArgumentException("world can't be null!");
-        }
         this.world = world;
-        this.removeFromConfig = removeFromConfig;
     }
 
     private static final HandlerList HANDLERS = new HandlerList();
@@ -61,19 +56,9 @@ public class MVWorldDeleteEvent extends Event implements Cancellable {
     /**
      * Gets the world that's about to be deleted.
      *
-     * @return That {@link MultiverseWorld}.
+     * @return That {@link LoadedMultiverseWorld}.
      */
     public LoadedMultiverseWorld getWorld() {
         return world;
     }
-
-    /**
-     * Is the world about to be removed from the config?
-     *
-     * @return True if yes, false if no.
-     */
-    public boolean removeWorldFromConfig() {
-        return removeFromConfig;
-    }
-
 }

src/main/java/org/mvplugins/multiverse/core/world/WorldManager.java

@@ -20,13 +20,14 @@ import org.bukkit.Location;
 import org.bukkit.World;
 import org.bukkit.WorldCreator;
 import org.bukkit.WorldType;
-import org.bukkit.entity.Player;
+import org.bukkit.plugin.PluginManager;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jvnet.hk2.annotations.Service;
 
 import org.mvplugins.multiverse.core.api.BlockSafety;
 import org.mvplugins.multiverse.core.api.LocationManipulation;
+import org.mvplugins.multiverse.core.event.MVWorldDeleteEvent;
 import org.mvplugins.multiverse.core.utils.message.MessageReplacement;
 import org.mvplugins.multiverse.core.utils.result.Attempt;
 import org.mvplugins.multiverse.core.utils.result.FailureReason;
@@ -75,6 +76,7 @@ public class WorldManager {
     private final FilesManipulator filesManipulator;
     private final BlockSafety blockSafety;
     private final LocationManipulation locationManipulation;
+    private final PluginManager pluginManager;
 
     @Inject
     WorldManager(
@@ -84,7 +86,9 @@ public class WorldManager {
             @NotNull PlayerWorldTeleporter playerWorldActions,
             @NotNull FilesManipulator filesManipulator,
             @NotNull BlockSafety blockSafety,
-            @NotNull LocationManipulation locationManipulation) {
+            @NotNull LocationManipulation locationManipulation,
+            @NotNull PluginManager pluginManager) {
+        this.pluginManager = pluginManager;
         this.worldsMap = new HashMap<>();
         this.loadedWorldsMap = new HashMap<>();
         this.unloadTracker = new ArrayList<>();
@@ -476,6 +480,13 @@ public class WorldManager {
         AtomicReference<File> worldFolder = new AtomicReference<>();
         return validateWorldToDelete(world)
                 .peek(worldFolder::set)
+                .mapAttempt(() -> {
+                    MVWorldDeleteEvent event = new MVWorldDeleteEvent(world);
+                    pluginManager.callEvent(event);
+                    return event.isCancelled()
+                            ? Attempt.failure(DeleteFailureReason.EVENT_CANCELLED)
+                            : Attempt.success(null);
+                })
                 .mapAttempt(() -> removeWorld(world).transform(DeleteFailureReason.REMOVE_FAILED))
                 .mapAttempt(() -> filesManipulator.deleteFolder(worldFolder.get()).fold(
                         exception -> worldActionResult(DeleteFailureReason.FAILED_TO_DELETE_FOLDER,

src/main/java/org/mvplugins/multiverse/core/world/reasons/DeleteFailureReason.java

@@ -3,6 +3,7 @@ package org.mvplugins.multiverse.core.world.reasons;
 import co.aikar.locales.MessageKey;
 import co.aikar.locales.MessageKeyProvider;
 
+import org.mvplugins.multiverse.core.event.MVWorldDeleteEvent;
 import org.mvplugins.multiverse.core.utils.MVCorei18n;
 import org.mvplugins.multiverse.core.utils.result.FailureReason;
 
@@ -33,7 +34,12 @@ public enum DeleteFailureReason implements FailureReason {
     /**
      * The world folder could not be deleted.
      */
-    FAILED_TO_DELETE_FOLDER(MVCorei18n.DELETEWORLD_FAILEDTODELETEFOLDER);
+    FAILED_TO_DELETE_FOLDER(MVCorei18n.DELETEWORLD_FAILEDTODELETEFOLDER),
+
+    /**
+     * The {@link MVWorldDeleteEvent} was cancelled.
+     */
+    EVENT_CANCELLED(MVCorei18n.GENERIC_FAILURE); // todo: messaging
 
     private final MessageKeyProvider message;