implement logging of arena states

src/balancing/ArenaWidget.h

@@ -14,16 +14,27 @@ class ArenaWidget : public QFrame
     Q_OBJECT
 
 public:
+    enum class State
+    {
+        NotStarted,
+        Running,
+        Ended
+    };
+
     ArenaWidget(int arenaIndex, const std::string& arenaName, QWidget* parent = nullptr);
 
     void updateStatus(const ArenaStatus& status);
     void startSimulation();
     void resetToGrey();
 
+    const ArenaStatus& getLastStatus() const { return m_lastStatus; }
+    State getState() const;
+
 private:
     void buildLayout(const std::string& arenaName);
 
     int m_arenaIndex;
+    ArenaStatus m_lastStatus;
     QLabel* m_titleLabel;
     QLabel* m_team1Header;
     QLabel* m_team2Header;