add dragon phase change event, fixes #1923

plugin/src/main/java/net/aufdemrand/denizen/events/ScriptEventRegistry.java

@@ -25,6 +25,7 @@ public static void registermainEvents() {
 
         // Entity events
         ScriptEvent.registerScriptEvent(new CreeperPoweredScriptEvent());
+        ScriptEvent.registerScriptEvent(new DragonPhaseChangeScriptEvent());
         ScriptEvent.registerScriptEvent(new EntityAirLevelChangeScriptEvent());
         ScriptEvent.registerScriptEvent(new EntityBreaksHangingScriptEvent());
         ScriptEvent.registerScriptEvent(new EntityBreedScriptEvent());

plugin/src/main/java/net/aufdemrand/denizen/events/entity/DragonPhaseChangeScriptEvent.java

@@ -0,0 +1,113 @@
+package net.aufdemrand.denizen.events.entity;
+
+import net.aufdemrand.denizen.BukkitScriptEntryData;
+import net.aufdemrand.denizen.events.BukkitScriptEvent;
+import net.aufdemrand.denizen.objects.dEntity;
+import net.aufdemrand.denizencore.objects.Element;
+import net.aufdemrand.denizencore.objects.dObject;
+import net.aufdemrand.denizencore.scripts.ScriptEntryData;
+import net.aufdemrand.denizencore.scripts.containers.ScriptContainer;
+import net.aufdemrand.denizencore.utilities.CoreUtilities;
+import org.bukkit.entity.EnderDragon;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EnderDragonChangePhaseEvent;
+
+public class DragonPhaseChangeScriptEvent extends BukkitScriptEvent implements Listener {
+
+    // <--[event]
+    // @Events
+    // dragon changes phase
+    // <entity> changes phase
+    //
+    // @Regex ^on [^\s]+ changes phase$
+    // @Switch in <area>
+    // @Switch from <phase>
+    // @Switch to <phase>
+    //
+    // @Cancellable true
+    //
+    // @Triggers when a dragon's combat phase changes.
+    //
+    // @Context
+    // <context.entity> returns the dEntity of the dragon.
+    // <context.new_phase> returns an Element of the dragon's new phase. Phases: <@see link https://hub.spigotmc.org/javadocs/spigot/org/bukkit/event/entity/EnderDragonChangePhaseEvent.html>
+    // <context.old_phase> returns an Element of the dragon's old phase. Can be any phase or 'null' in some cases.
+    //
+    // @Determine
+    // Element to change the dragon's new phase.
+    //
+    // -->
+
+    public DragonPhaseChangeScriptEvent() {
+        instance = this;
+    }
+
+    public static DragonPhaseChangeScriptEvent instance;
+    public dEntity entity;
+    public EnderDragonChangePhaseEvent event;
+
+    @Override
+    public boolean couldMatch(ScriptContainer scriptContainer, String s) {
+        return (CoreUtilities.toLowerCase(s).contains("changes phase"));
+    }
+
+    @Override
+    public boolean matches(ScriptPath path) {
+        String target = path.eventArgLowerAt(0);
+
+        if (!tryEntity(entity, target)) {
+            return false;
+        }
+
+        if (!runInCheck(path, entity.getLocation())) {
+            return false;
+        }
+
+        path.checkSwitch("from", event.getCurrentPhase() == null ? "null" : event.getCurrentPhase().name());
+        path.checkSwitch("to", event.getNewPhase().name());
+
+        return true;
+    }
+
+    @Override
+    public String getName() {
+        return "AirLevelChanged";
+    }
+
+    @Override
+    public boolean applyDetermination(ScriptContainer container, String determination) {
+        if (!isDefaultDetermination(determination)) {
+            EnderDragon.Phase phase = EnderDragon.Phase.valueOf(determination.toUpperCase());
+            event.setNewPhase(phase);
+            return true;
+        }
+        return super.applyDetermination(container, determination);
+    }
+
+    @Override
+    public ScriptEntryData getScriptEntryData() {
+        return new BukkitScriptEntryData(null, null);
+    }
+
+    @Override
+    public dObject getContext(String name) {
+        if (name.equals("entity")) {
+            return entity.getDenizenObject();
+        }
+        else if (name.equals("old_phase")) {
+            return new Element(event.getCurrentPhase() == null ? "null" : event.getCurrentPhase().name());
+        }
+        else if (name.equals("new_phase")) {
+            return new Element(event.getNewPhase().name());
+        }
+        return super.getContext(name);
+    }
+
+    @EventHandler
+    public void onEnderDragonChangePhase(EnderDragonChangePhaseEvent event) {
+        entity = new dEntity(event.getEntity());
+        this.event = event;
+        fire(event);
+    }
+}