move a buncho stuff from Save.hx to SaveSystem.hx

to rebase

source/funkin/save/SaveSystem.hx

@@ -0,0 +1,81 @@
+package funkin.save;
+
+import funkin.save.migrator.RawSaveData_v1_0_0;
+import funkin.save.migrator.SaveDataMigrator;
+import flixel.util.FlxSave;
+
+/**
+ * A bit more of the backend and nitty gritty of FNF's save system
+ */
+class SaveSystem
+{
+  public function new():Void {}
+
+  /**
+   * Call this to make sure the save data is written to disk.
+   */
+  public function flush():Void
+  {
+    FlxG.save.flush();
+  }
+
+  public function clearSlot(slot:Int):Save
+  {
+    FlxG.save.bind(Constants.SAVE_NAME + slot, Constants.SAVE_PATH);
+
+    if (FlxG.save.status == EMPTY) return new Save();
+
+    // Archive the save data just in case.
+    // Not reliable but better than nothing.
+    var backupSlot:Int = Save.system.archiveBadSaveData(FlxG.save.data);
+
+    FlxG.save.erase();
+    return new Save();
+  }
+
+  public function fetchLegacySaveData():Option<RawSaveData_v1_0_0>
+  {
+    trace("[SAVE] Checking for legacy save data...");
+    var legacySave:FlxSave = new FlxSave();
+    legacySave.bind(Constants.SAVE_NAME_LEGACY, Constants.SAVE_PATH_LEGACY);
+
+    if (legacySave.isEmpty())
+    {
+      trace("[SAVE] No legacy save data found.");
+      return None;
+    }
+    else
+    {
+      trace("[SAVE] Legacy save data found.");
+      return Some(cast legacySave.data);
+    }
+  }
+
+  public function archiveBadSaveData(data:Dynamic):Int
+  {
+    // We want to save this somewhere so we can try to recover it for the user in the future!
+    final RECOVERY_SLOT_START = 1000;
+    return writeToAvailableSlot(RECOVERY_SLOT_START, data);
+  }
+
+  function writeToAvailableSlot(slot:Int, data:Dynamic):Int
+  {
+    trace('[SAVE] Finding slot to write data to (starting with ${slot})...');
+
+    var targetSaveData:FlxSave = new FlxSave();
+    targetSaveData.bind(Constants.SAVE_NAME + slot, Constants.SAVE_PATH);
+    while (!targetSaveData.isEmpty())
+    {
+      // Keep trying to bind to slots until we find an empty slot.
+      trace('[SAVE] Slot ${slot} is taken, continuing...');
+      slot++;
+      targetSaveData.bind(Constants.SAVE_NAME + slot, Constants.SAVE_PATH);
+    }
+
+    trace('[SAVE] Writing data to slot ${slot}...');
+    targetSaveData.mergeData(data, true);
+
+    trace('[SAVE] Data written to slot ${slot}!');
+    return slot;
+  }
+}