Energy works

Assets/Battle/BattleController.cs

@@ -6,7 +6,8 @@ public class BattleController : MonoBehaviour
 {
     public HeroId[] heroIds;
     public MonsterId[] monsterIds;
-
+    public int maxEnergy = 6;
+    
     public HeroInfoUI heroUIPrefab;
     public GameObject uiCanvas;
     public BattlePlayerControls battlePlayerControls;
@@ -19,6 +20,12 @@ public class BattleController : MonoBehaviour
     private GameObject[] monsterSprites;
     private HeroInfoUI[] monsterUIs;
 
+    private int energy;
+
+    void Awake() {
+        this.energy = this.maxEnergy;
+    }
+
     // Start is called before the first frame update
     void Start()
     {
@@ -74,11 +81,36 @@ public class BattleController : MonoBehaviour
     }
 
     public void OnCardUsed(BaseCard card) {
-        Debug.Log("OnCardClicked " + card);
-        StartCoroutine(card.Use(battlePlayerControls));
+        Debug.Log("OnCardUsed " + card);
+        if (!CanUseCard(card)) {
+            throw new System.InvalidOperationException("Cannot use card " + card.GetDisplayName());
+        }
+        StartCoroutine(UseCard(card));
+    }
+
+    public IEnumerator UseCard(BaseCard card) {
+        yield return card.Use(battlePlayerControls);
+        PayCardCost(card);
     }
 
     public void OnTurnPassed() {
         Debug.Log("OnTurnPassed");
+        this.energy = this.maxEnergy;
+    }
+
+    public bool CanUseCard(BaseCard card) {
+        return this.energy >= card.GetCost();
+    }
+
+    private void PayCardCost(BaseCard card) {
+        this.energy -= card.GetCost();
+    }
+
+    public int GetEnergy() {
+        return this.energy;
+    }
+
+    public int GetMaxEnergy() {
+        return this.maxEnergy;
     }
 }