feat: add hero target

Client/Domain/Service/HeroHandler.cs

@@ -10,12 +10,13 @@ using System.Threading.Tasks;
 
 namespace Client.Domain.Service
 {
-    public class HeroHandler : EntityHandler<Hero>
+    public class HeroHandler : EntityHandler<Hero>, EventHandlerInterface<TargetChangedEvent>
     {
         public override void OnCreate(Hero entity)
         {
             entity.ExperienceInfo.ExpToLevel = experienceHelper.GetExperienceToLevel(entity.ExperienceInfo.Level + 1);
             entity.ExperienceInfo.ExpToPrevLevel = experienceHelper.GetExperienceToLevel(entity.ExperienceInfo.Level);
+            entity.PropertyChanged += Hero_PropertyChanged;
             eventBus.Publish(new HeroCreatedEvent(entity));
         }
 
@@ -39,6 +40,31 @@ namespace Client.Domain.Service
             this.experienceHelper = experienceHelper;
         }
 
+        private void Hero_PropertyChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
+        {
+            if (sender == null)
+            {
+                return;
+            }
+
+            var hero = (Hero)sender;
+            if (e.PropertyName == "TargetId")
+            {
+                hero.Target = null;
+                eventBus.Publish(new TargetChangedEvent(hero));
+            }
+        }
+
+        public void Handle(TargetChangedEvent @event)
+        {
+            var target = GetEntity(@event.Hero.TargetId);
+            if (target == null)
+            {
+                return;
+            }
+            @event.Hero.Target = target;
+        }
+
         private readonly EventBusInterface eventBus;
         private readonly ExperienceHelperInterface experienceHelper;
     }