ugly login page and dbhelper

lib/main.dart

@@ -1,11 +1,13 @@
 import 'package:flutter/material.dart';
 
+import 'pages/login_page.dart';
+
 void main() {
-  runApp(const MyApp());
+  runApp(const Application());
 }
 
-class MyApp extends StatelessWidget {
-  const MyApp({super.key});
+class Application extends StatelessWidget {
+  const Application({super.key});
 
   @override
   Widget build(BuildContext context) {
@@ -15,6 +17,7 @@ class MyApp extends StatelessWidget {
         colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
         useMaterial3: true,
       ),
+      home: const LoginPage(),
     );
   }
 }

lib/pages/login_page.dart

@@ -0,0 +1,34 @@
+import 'package:flutter/material.dart';
+
+import '../services/db_helper.dart';
+
+class LoginPage extends StatelessWidget {
+  const LoginPage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    TextEditingController username = TextEditingController();
+    return Scaffold(
+      body: Center(
+        child: Column(
+          children: [
+            TextField(
+              controller: username,
+              decoration: const InputDecoration(
+                label: Text('Username'),
+              ),
+            ),
+            TextButton(
+              onPressed: () => DbHelper.login(username.text),
+              child: const Text('Login'),
+            ),
+            TextButton(
+              onPressed: () => DbHelper.logout(),
+              child: const Text('Logout'),
+            )
+          ],
+        ),
+      ),
+    );
+  }
+}

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
+  }
+}