Added event handler for cauldron water level modification to prevent untrusted players interacting with a plot (#3035)

* Added check for burning players using non-trusted plots cauldrons to extinguish themselves, causing the cauldron level to decrease

* Cancelling burning of players without downscaling water instead of ignoring their burn status

* Using Java 14 JEP 305 enhanced instanceOf

Co-authored-by: NotMyFault <mc.cache@web.de>

* Players without permissions may not wash banners or armor now either. Rain modification is now permitted.

* Extinguishing is now explicitly handled so that event handling for other plugins has the actual information of the new cauldron water level

* Un-nestified the if-condition :)

* Properly cancelled the event (since it is semantically cancelled)

* (Actually) properly cancelled the event (since it is semantically cancelled)

Co-authored-by: NotMyFault <mc.cache@web.de>

Bukkit/src/main/java/com/plotsquared/bukkit/listener/BlockEventListener.java

@@ -98,6 +98,7 @@ import org.bukkit.event.block.BlockPistonRetractEvent;
 import org.bukkit.event.block.BlockPlaceEvent;
 import org.bukkit.event.block.BlockRedstoneEvent;
 import org.bukkit.event.block.BlockSpreadEvent;
+import org.bukkit.event.block.CauldronLevelChangeEvent;
 import org.bukkit.event.block.EntityBlockFormEvent;
 import org.bukkit.event.block.LeavesDecayEvent;
 import org.bukkit.event.world.StructureGrowEvent;
@@ -471,6 +472,58 @@ public class BlockEventListener implements Listener {
         }
     }
 
+    @EventHandler(priority = EventPriority.HIGHEST)
+    public void onCauldronEmpty(CauldronLevelChangeEvent event) {
+        Entity entity = event.getEntity();
+        Location location = BukkitUtil.adapt(event.getBlock().getLocation());
+        PlotArea area = location.getPlotArea();
+        if (area == null) {
+            return;
+        }
+        Plot plot = area.getPlot(location);
+        // TODO Add flags for specific control over cauldron changes (rain, dripstone...)
+        switch (event.getReason()) {
+            case BANNER_WASH, ARMOR_WASH, EXTINGUISH -> {
+                if (entity instanceof Player player) {
+                    BukkitPlayer plotPlayer = BukkitUtil.adapt(player);
+                    if (plot != null) {
+                        if (!plot.hasOwner()) {
+                            if (Permissions.hasPermission(plotPlayer, Permission.PERMISSION_ADMIN_INTERACT_UNOWNED)) {
+                                return;
+                            }
+                        } else if (!plot.isAdded(plotPlayer.getUUID())) {
+                            if (Permissions.hasPermission(plotPlayer, Permission.PERMISSION_ADMIN_INTERACT_OTHER)) {
+                                return;
+                            }
+                        } else {
+                            return;
+                        }
+                    } else {
+                        if (Permissions.hasPermission(plotPlayer, Permission.PERMISSION_ADMIN_INTERACT_ROAD)) {
+                            return;
+                        }
+                        if (this.worldEdit != null && plotPlayer.getAttribute("worldedit")) {
+                            if (player.getInventory().getItemInMainHand().getType() == Material
+                                    .getMaterial(this.worldEdit.getConfiguration().wandItem)) {
+                                return;
+                            }
+                        }
+                    }
+                }
+                if (event.getReason() == CauldronLevelChangeEvent.ChangeReason.EXTINGUISH && event.getEntity() != null) {
+                    event.getEntity().setFireTicks(0);
+                }
+                // Though the players fire ticks are modified,
+                // the cauldron water level change is cancelled and the event should represent that.
+                event.setCancelled(true);
+            }
+            default -> {
+                // Bucket empty, Bucket fill, Bottle empty, Bottle fill are already handled in PlayerInteract event
+                // Evaporation or Unknown reasons do not need to be cancelled as they are considered natural causes
+            }
+        }
+    }
+
     @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
     public void onBlockForm(BlockFormEvent event) {
         if (event instanceof EntityBlockFormEvent) {