Add thunder changes event (#2317)

* Added ThunderChangesScriptEvent

Adds an event that allows a user to detect when thunder changes in a world

* Added newline to last end bracket

Simple update to adhere better to denizen formatting

* firstst attempt at corrections for thunderchangeevent pr

Remove `thunder` and `world` fields, replaced the if statements in `getContext` with a switch statement, and added the `in <world>` match that i originally forgot

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

@@ -249,6 +249,7 @@ public static void registerMainEvents() {
         ScriptEvent.registerScriptEvent(PotionSplashScriptEvent.class);
         ScriptEvent.registerScriptEvent(SpawnChangeScriptEvent.class);
         ScriptEvent.registerScriptEvent(StructureGrowsScriptEvent.class);
+        ScriptEvent.registerScriptEvent(ThunderChangesScriptEvent.class);
         ScriptEvent.registerScriptEvent(TimeChangeScriptEvent.class);
         ScriptEvent.registerScriptEvent(WeatherChangesScriptEvent.class);
         ScriptEvent.registerScriptEvent(WorldInitsScriptEvent.class);

plugin/src/main/java/com/denizenscript/denizen/events/world/ThunderChangesScriptEvent.java

@@ -0,0 +1,80 @@
+package com.denizenscript.denizen.events.world;
+
+import com.denizenscript.denizen.objects.WorldTag;
+import com.denizenscript.denizen.events.BukkitScriptEvent;
+import com.denizenscript.denizencore.objects.core.ElementTag;
+import com.denizenscript.denizencore.objects.ObjectTag;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.weather.ThunderChangeEvent;
+
+public class ThunderChangesScriptEvent extends BukkitScriptEvent implements Listener {
+
+    // <--[event]
+    // @Events
+    // thunder changes|begins|clears (in <world>)
+    //
+    // @Group World
+    //
+    // @Cancellable true
+    //
+    // @Triggers when thunder changes in a world.
+    //
+    // @Context
+    // <context.world> returns the WorldTag the thunder changed in.
+    // <context.thunder> returns an ElementTag(Boolean) with the new state of thunder.
+    //
+    // -->
+
+    public ThunderChangesScriptEvent() {
+        instance = this;
+        registerCouldMatcher("thunder changes|begins|clears (in <world>)");
+    }
+
+    public static ThunderChangesScriptEvent instance;
+    public ThunderChangeEvent event;
+
+    @Override
+    public boolean matches(ScriptPath path) {
+        String changeType = path.eventArgLowerAt(1);
+        if (changeType.equals("clears")) {
+            if (event.toThunderState()) {
+                return false;
+            }
+        }
+        else if (changeType.equals("begins")) {
+            if (!event.toThunderState()) {
+                return false;
+            }
+        }
+        else if (!changeType.equals("changes")) {
+            return false;
+        }
+        if (path.eventArgLowerAt(2).equals("in") && !tryWorld(new WorldTag(event.getWorld()), path.eventArgLowerAt(3))) {
+            return false;
+        }
+        return super.matches(path);
+    }
+
+    @Override
+    public String getName() {
+        return "ThunderChanges";
+    }
+
+    @Override
+    public ObjectTag getContext(String name) {
+        switch(name) {
+            case "world":
+                return new WorldTag(event.getWorld());
+            case "thunder":
+                return new ElementTag(event.toThunderState());
+        }
+        return super.getContext(name);
+    }
+
+    @EventHandler
+    public void onThunderChanges(ThunderChangeEvent event) {
+        this.event = event;
+        fire(event);
+    }
+}