Wave of item effects and implementation

Zennysoft.Game.Ma/src/Components/ExperiencePointsComponent.cs

@@ -1,4 +1,5 @@
 using Chickensoft.Collections;
+using Godot;
 using System;
 using Zennysoft.Ma.Adapter;
 
@@ -24,6 +25,8 @@ public class ExperiencePointsComponent : IExperiencePointsComponent
 
   public event Action PlayerLevelUp;
 
+  public event Action PlayerLevelDown;
+
   public ExperiencePointsComponent()
   {
     var firstLevelExpRequirement = ExpToNextLevelCalculation(1);
@@ -73,6 +76,21 @@ public class ExperiencePointsComponent : IExperiencePointsComponent
     PlayerLevelUp?.Invoke();
   }
 
+  public void LevelDown()
+  {
+    SfxDatabase.Instance.Play(SoundEffect.DecreaseStat);
+    _currentExp.OnNext(0);
+
+    if (_level.Value == 1)
+      return;
+
+    var newLevel = Mathf.Max(_level.Value - 1, 1);
+    _level.OnNext(newLevel);
+    var expToNextLevel = ExpToNextLevelCalculation(newLevel);
+    _expToNextLevel.OnNext(expToNextLevel);
+    PlayerLevelDown.Invoke();
+  }
+
   private int ExpToNextLevelCalculation(int nextLevel)
   {
     return (int)(6.5 * nextLevel + 4.5 * Math.Pow(nextLevel, 2) + Math.Pow(nextLevel, 3));