ugly login page and dbhelper

lib/services/db_helper.dart

@@ -0,0 +1,27 @@
+import 'package:shared_preferences/shared_preferences.dart';
+
+class DbHelper {
+  static Future<SharedPreferences> get _prefs async =>
+      SharedPreferences.getInstance();
+
+  static void login(String username) async {
+    final prefs = await _prefs;
+    final String? savedUsername = prefs.getString('username');
+
+    if (savedUsername == null) {
+      await prefs.setString('username', username);
+      // TODO create new account
+    } else if (savedUsername == username) {
+      // TODO log into database
+    } else {
+      // TODO wrong username
+    }
+  }
+
+  static void logout() async {
+    final prefs = await _prefs;
+    bool success = await prefs.remove('username');
+
+    //TODO log out on database
+  }
+}