Implement emotions

Assets/Battle/BattleState.cs

@@ -8,6 +8,7 @@ public class BattleState
 //     public delegate void BattleStateChangedAction();
 //     public event BattleStateChangedAction OnBattleStateChanged;
     private bool heroTurn;
+    private bool playedEmotion;
 
     public bool IsTeamsTurn(TeamChoice team) {
         if (team == TeamChoice.Heroes) {
@@ -17,5 +18,24 @@ public class BattleState
         }
     }
 
-    public bool HeroTurn {get => this.heroTurn; set => this.heroTurn = value;}
+    public bool CanPlayEmotion(TeamChoice team) {
+        return !this.playedEmotion && IsTeamsTurn(team);
+    }
+
+    public void NotifyPlayedEmotion(TeamChoice team) {
+        if (!this.CanPlayEmotion(team)) {
+            throw new System.InvalidOperationException("BattleState received NotifyPlayedEmotion but "
+                + "cannot play emotion");
+        }
+
+        this.playedEmotion = true;
+    }
+
+    public bool HeroTurn {
+        get => this.heroTurn;
+        set {
+            this.heroTurn = value;
+            this.playedEmotion = false;
+        }
+    }
 }