add a cauldron level change event, fixes #1922

plugin/src/main/java/com/denizenscript/denizen/events/ScriptEventRegistry.java

@@ -23,6 +23,7 @@ public static void registermainEvents() {
         ScriptEvent.registerScriptEvent(new BlockIgnitesScriptEvent());
         ScriptEvent.registerScriptEvent(new BlockPhysicsScriptEvent());
         ScriptEvent.registerScriptEvent(new BlockSpreadsScriptEvent());
+        ScriptEvent.registerScriptEvent(new CauldronLevelChangeScriptEvent());
 
         // Entity events
         ScriptEvent.registerScriptEvent(new CreeperPoweredScriptEvent());

plugin/src/main/java/com/denizenscript/denizen/events/block/CauldronLevelChangeScriptEvent.java

@@ -0,0 +1,124 @@
+package com.denizenscript.denizen.events.block;
+
+import com.denizenscript.denizen.events.BukkitScriptEvent;
+import com.denizenscript.denizen.objects.EntityTag;
+import com.denizenscript.denizen.objects.LocationTag;
+import com.denizenscript.denizencore.objects.ArgumentHelper;
+import com.denizenscript.denizencore.objects.ObjectTag;
+import com.denizenscript.denizencore.objects.core.ElementTag;
+import com.denizenscript.denizencore.scripts.containers.ScriptContainer;
+import com.denizenscript.denizencore.utilities.CoreUtilities;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.CauldronLevelChangeEvent;
+
+public class CauldronLevelChangeScriptEvent extends BukkitScriptEvent implements Listener {
+
+    // <--[event]
+    // @Events
+    // cauldron level changes
+    // cauldron level raises
+    // cauldron level lowers
+    //
+    // @Regex ^on cauldron level (changes|raises|lowers)$
+    //
+    // @Switch in <area>
+    // @Switch cause <cause>
+    //
+    // @Cancellable true
+    //
+    // @Triggers when a cauldron's level changes.
+    //
+    // @Context
+    // <context.location> returns the LocationTag of the cauldron that changed.
+    // <context.entity> returns the LocationTag of the enteity that caused the cauldron level to change (if any).
+    // <context.cause> returns the reason that the cauldron level changed, from <@link url https://hub.spigotmc.org/javadocs/spigot/org/bukkit/event/block/CauldronLevelChangeEvent.ChangeReason.html>
+    // <context.old_level> returns the previous cauldron level.
+    // <context.new_level> returns the new cauldron level.
+    //
+    // @Determine
+    // Element(Number) to set the new level.
+    //
+    // -->
+
+    public CauldronLevelChangeScriptEvent() {
+        instance = this;
+    }
+
+    public static CauldronLevelChangeScriptEvent instance;
+    public LocationTag location;
+    public CauldronLevelChangeEvent event;
+
+    @Override
+    public boolean couldMatch(ScriptContainer scriptContainer, String s) {
+        String lower = CoreUtilities.toLowerCase(s);
+        return lower.startsWith("cauldron level ");
+    }
+
+    @Override
+    public boolean matches(ScriptPath path) {
+        if (!runInCheck(path, location)) {
+            return false;
+        }
+        if (!runGenericSwitchCheck(path, "cause", event.getReason().name())) {
+            return false;
+        }
+        String changeType = path.eventArgLowerAt(2);
+        if (changeType.equals("raises")) {
+            if (event.getNewLevel() <= event.getOldLevel()) {
+                return false;
+            }
+        }
+        if (changeType.equals("lowers")) {
+            if (event.getNewLevel() >= event.getOldLevel()) {
+                return false;
+            }
+        }
+        else if (!changeType.equals("changes")) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public String getName() {
+        return "CauldronLevelChange";
+    }
+
+    @Override
+    public boolean applyDetermination(ScriptContainer container, String determination) {
+        if (!isDefaultDetermination(determination)) {
+            if (ArgumentHelper.matchesInteger(determination)) {
+                event.setNewLevel(ArgumentHelper.getIntegerFrom(determination));
+            }
+        }
+        return super.applyDetermination(container, determination);
+    }
+
+    @Override
+    public ObjectTag getContext(String name) {
+        if (name.equals("location")) {
+            return location;
+        }
+        else if (name.equals("cause")) {
+            return new ElementTag(event.getReason().name());
+        }
+        else if (name.equals("old_level")) {
+            return new ElementTag(event.getOldLevel());
+        }
+        else if (name.equals("new_level")) {
+            return new ElementTag(event.getNewLevel());
+        }
+        else if (name.equals("entity") && event.getEntity() != null) {
+            return new EntityTag(event.getEntity());
+        }
+        return super.getContext(name);
+    }
+
+    @EventHandler
+    public void onCauldronLevelChange(CauldronLevelChangeEvent event) {
+        location = new LocationTag(event.getBlock().getLocation());
+        this.event = event;
+        fire(event);
+    }
+}