Завершить инженерный кандидат Stage 5

app/src/main/java/com/projectsacrifice/game/ProgressStore.java

@@ -5,10 +5,12 @@ import android.content.SharedPreferences;
 
 public final class ProgressStore {
     private static final String FILE = "project_sacrifice_progress_v1";
+    public static final int CURRENT_SAVE_VERSION = 2;
     private final SharedPreferences preferences;
 
     public ProgressStore(Context context) {
         preferences = context.getSharedPreferences(FILE, Context.MODE_PRIVATE);
+        migrateIfSupported();
     }
 
     public int unlockedCount() {
@@ -36,6 +38,17 @@ public final class ProgressStore {
         editor.apply();
     }
 
+    public int saveVersion() {
+        return preferences.getInt("save_version", 1);
+    }
+
+    private void migrateIfSupported() {
+        int version = preferences.getInt("save_version", 1);
+        if (version >= 1 && version < CURRENT_SAVE_VERSION) {
+            preferences.edit().putInt("save_version", CURRENT_SAVE_VERSION).apply();
+        }
+    }
+
     private static String key(int levelNumber, String suffix) {
         return "level_" + levelNumber + "_" + suffix;
     }