Added: signup screen, routing logic for login,signup

lib/main.dart

@@ -5,6 +5,7 @@ import 'screens/vehicles_screen.dart';
 import 'screens/history_screen.dart';
 import 'screens/user_settings.dart';
 import 'screens/login.dart';
+import 'screens/signup.dart';
 
 void main() {
   runApp(FuelStatsApp());
@@ -33,6 +34,7 @@ class MainNavigation extends StatefulWidget {
 class _MainNavigationState extends State<MainNavigation> {
   int _currentIndex = 0;
   bool loggedIn = false;
+  bool get isAuthScreen => _currentIndex == 5 || _currentIndex == 6;
 
   @override
   void initState() {
@@ -43,15 +45,6 @@ class _MainNavigationState extends State<MainNavigation> {
     }
   }
 
-  final List<Widget> _screens = [
-    HomeScreen(),
-    AddScreen(),
-    VehiclesScreen(),
-    HistoryScreen(),
-    UserSettingsScreen(),
-    LoginScreen()
-  ];
-
   final List<Widget> titles = [
     Text("Fuel Stats"),
     Text("Add record"),
@@ -59,12 +52,55 @@ class _MainNavigationState extends State<MainNavigation> {
     Text("History"),
   ];
 
+  Widget get currentTitle {
+  switch (_currentIndex) {
+    case 0:
+      return Text("Fuel Stats");
+    case 1:
+      return Text("Add record");
+    case 2:
+      return Text("Vehicles");
+    case 3:
+      return Text("History");
+    case 4:
+      return Text("Settings");
+    case 5:
+      return Text("Login");
+    case 6:
+      return Text("Sign up");
+    default:
+      return Text("Fuel Stats");
+  }
+}
+
   @override
   Widget build(BuildContext context) {
+    List<Widget> screens = [
+      HomeScreen(),
+      AddScreen(),
+      VehiclesScreen(),
+      HistoryScreen(),
+      UserSettingsScreen(),
+      LoginScreen(
+        onSwitchToSignup: () {
+          WidgetsBinding.instance.addPostFrameCallback((_) {
+            setState(() => _currentIndex = 6);
+          });
+        },
+      ),
+      SignupScreen(
+        onSwitchToLogin: () {
+          WidgetsBinding.instance.addPostFrameCallback((_) {
+            setState(() => _currentIndex = 5);
+          });
+        },
+      ),
+    ];
+
     return Scaffold(
       appBar: AppBar(
-        title: _currentIndex <= 3 ? titles[_currentIndex] : Text("Fuel Stats"),
+        title: currentTitle,
-        actions: [
+        actions: !isAuthScreen ? [
           IconButton(
             icon: const Icon(Icons.person),
             tooltip: "User settings",
@@ -75,10 +111,11 @@ class _MainNavigationState extends State<MainNavigation> {
               );
             },
           ),
-        ],
+        ] : null,
       ),
-      body: _screens[_currentIndex],
+      body: screens[_currentIndex],
-      bottomNavigationBar: BottomNavigationBar(
+      bottomNavigationBar: !isAuthScreen ?
+        BottomNavigationBar(
           currentIndex: _currentIndex <= 3 ? _currentIndex : 0,
           onTap: (index) => setState(() => _currentIndex = index),
           backgroundColor: Colors.grey[900],
@@ -93,7 +130,7 @@ class _MainNavigationState extends State<MainNavigation> {
             ),
             BottomNavigationBarItem(icon: Icon(Icons.history), label: 'History'),
           ],
-      ),
+        ) : null,
     );
   }
 }

lib/screens/login.dart

@@ -1,6 +1,10 @@
 import 'package:flutter/material.dart';
+import 'signup.dart';
 
 class LoginScreen extends StatefulWidget {
+  final VoidCallback onSwitchToSignup;
+  const LoginScreen({required this.onSwitchToSignup, super.key});
+
   @override
   State<LoginScreen> createState() => _LoginScreenState();
 }
@@ -25,7 +29,7 @@ class _LoginScreenState extends State<LoginScreen> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      appBar: AppBar(title: Text('User Login')),
+      //appBar: AppBar(title: Text('User Login')),
       body: Padding(
         padding: const EdgeInsets.all(24.0),
         child: Form(
@@ -87,6 +91,11 @@ class _LoginScreenState extends State<LoginScreen> {
                       padding: EdgeInsets.symmetric(horizontal: 32, vertical: 12),
                     ),
                   ),
+                  const SizedBox(height: 12),
+                  TextButton(
+                    onPressed: widget.onSwitchToSignup,
+                    child: Text("Don't have an account? Sign up"),
+                  ),
                 ],
               ),
             ),

lib/screens/signup.dart

@@ -0,0 +1,119 @@
+import 'package:flutter/material.dart';
+
+class SignupScreen extends StatefulWidget {
+  final VoidCallback onSwitchToLogin;
+  const SignupScreen({required this.onSwitchToLogin, super.key});
+
+  @override
+  State<SignupScreen> createState() => _SignupScreenState();
+}
+
+class _SignupScreenState extends State<SignupScreen> {
+  final _formKey = GlobalKey<FormState>();
+  final _usernameController = TextEditingController();
+  final _emailController = TextEditingController();
+  final _passwordController = TextEditingController();
+
+  void _signup() {
+    if (_formKey.currentState!.validate()) {
+      final username = _usernameController.text;
+      final email = _emailController.text;
+      final password = _passwordController.text;
+      // TODO: Replace with actual signup logic
+      print('Signing up with $username, $email, $password');
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      //appBar: AppBar(title: Text('Sign Up')),
+      body: Padding(
+        padding: const EdgeInsets.all(24.0),
+        child: Form(
+          key: _formKey,
+          child: Center(
+            child: SingleChildScrollView(
+              child: Column(
+                children: [
+                  Text(
+                    'Create your Fuel Stats account',
+                    style: TextStyle(
+                      fontSize: 24,
+                      fontWeight: FontWeight.bold,
+                    ),
+                  ),
+                  const SizedBox(height: 32),
+                  TextFormField(
+                    controller: _usernameController,
+                    decoration: InputDecoration(
+                      labelText: 'Username',
+                      prefixIcon: Icon(Icons.person),
+                      border: OutlineInputBorder(),
+                    ),
+                    validator: (value) {
+                      if (value == null || value.isEmpty)
+                        return 'Please enter a username';
+                      return null;
+                    },
+                  ),
+                  const SizedBox(height: 16),
+                  TextFormField(
+                    controller: _emailController,
+                    decoration: InputDecoration(
+                      labelText: 'Email',
+                      prefixIcon: Icon(Icons.email),
+                      border: OutlineInputBorder(),
+                    ),
+                    keyboardType: TextInputType.emailAddress,
+                    validator: (value) {
+                      if (value == null || value.isEmpty)
+                        return 'Please enter an email';
+                      if (!RegExp(r'^[^@]+@[^@]+\.[^@]+').hasMatch(value))
+                        return 'Enter a valid email';
+                      return null;
+                    },
+                  ),
+                  const SizedBox(height: 16),
+                  TextFormField(
+                    controller: _passwordController,
+                    decoration: InputDecoration(
+                      labelText: 'Password',
+                      prefixIcon: Icon(Icons.lock),
+                      border: OutlineInputBorder(),
+                    ),
+                    obscureText: true,
+                    validator: (value) {
+                      if (value == null || value.isEmpty)
+                        return 'Please enter a password';
+                      if (value.length < 6)
+                        return 'Password must be at least 6 characters';
+                      return null;
+                    },
+                  ),
+                  const SizedBox(height: 24),
+                  ElevatedButton.icon(
+                    onPressed: _signup,
+                    icon: Icon(Icons.person_add),
+                    label: Text('Sign Up'),
+                    style: ElevatedButton.styleFrom(
+                      backgroundColor: Colors.blue,
+                      foregroundColor: Colors.white,
+                      padding: EdgeInsets.symmetric(horizontal: 32, vertical: 12),
+                    ),
+                  ),
+                  const SizedBox(height: 12),
+                  TextButton(
+                    onPressed: widget.onSwitchToLogin,
+                    child: Text("Already have an account? Log in"),
+                  ),
+                ],
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+