user balance logic

mobile/lib/pages/cart_page.dart

@@ -5,6 +5,7 @@ import 'package:flutter/material.dart';
 import 'package:mobile/pages/finish_shopping_page.dart';
 import 'package:mobile/repos/cart.dart';
 import 'package:mobile/repos/product.dart';
+import 'package:mobile/repos/user.dart';
 import 'package:mobile/results.dart';
 import 'package:mobile/widgets/primary_button.dart';
 import 'package:mobile/widgets/sized_card.dart';
@@ -141,7 +142,8 @@ class CartItemView extends StatelessWidget {
 }
 
 class CartPage extends StatelessWidget {
-  const CartPage({super.key});
+  final User user;
+  const CartPage({super.key, required this.user});
 
   @override
   Widget build(BuildContext context) {
@@ -318,7 +320,7 @@ class CartPage extends StatelessWidget {
                                   context,
                                   MaterialPageRoute(
                                       builder: (context) =>
-                                          const FinishShoppingPage()));
+                                          FinishShoppingPage(user: user)));
                             },
                             child: const Text("Afslut indkøb")),
                       ),

mobile/lib/pages/dashboard.dart

@@ -19,7 +19,7 @@ class Dashboard extends StatelessWidget {
         user: user,
       ),
       const AllProductsPage(),
-      const CartPage(),
+      CartPage(user: user),
       const AllReceiptsPage(),
     ]);
   }

mobile/lib/pages/finish_shopping_page.dart

@@ -2,12 +2,16 @@ import 'package:flutter/material.dart';
 import 'package:mobile/repos/cart.dart';
 import 'package:mobile/repos/paying_state.dart';
 import 'package:mobile/repos/receipt.dart';
+import 'package:mobile/repos/user.dart';
+import 'package:mobile/results.dart';
 import 'package:mobile/widgets/primary_button.dart';
 import 'package:mobile/widgets/receipt_item.dart';
 import 'package:provider/provider.dart';
 
 class FinishShoppingPage extends StatelessWidget {
-  const FinishShoppingPage({super.key});
+  final User user;
+
+  const FinishShoppingPage({super.key, required this.user});
 
   @override
   Widget build(BuildContext context) {
@@ -53,8 +57,28 @@ class FinishShoppingPage extends StatelessWidget {
                     child: PrimaryButton(
                         onPressed: () async {
                           payingStateRepo.next();
-                          receiptRepo.createReceipt(cart);
                           await Future.delayed(const Duration(seconds: 1));
+                          if (user.pay(cartRepo.totalPrice()) is Err) {
+                            if (context.mounted) {
+                              showDialog<String>(
+                                context: context,
+                                builder: (BuildContext context) => AlertDialog(
+                                  content: const Text(
+                                      'Du har desværre ikke råd til at købe dette'),
+                                  actions: <Widget>[
+                                    TextButton(
+                                      onPressed: () =>
+                                          Navigator.pop(context, 'OK'),
+                                      child: const Text('OK'),
+                                    ),
+                                  ],
+                                ),
+                              );
+                            }
+                            payingStateRepo.reset();
+                            return;
+                          }
+                          receiptRepo.createReceipt(cart);
                           payingStateRepo.next();
                           await Future.delayed(const Duration(seconds: 1));
                           cartRepo.clearCart();

mobile/lib/repos/product.dart

@@ -83,7 +83,7 @@ class ProductRepo extends ChangeNotifier {
       Product(
           id: _nextId++,
           name: "Jägermeister 750 ml",
-          price: 60,
+          price: 120,
           description: ""),
       Product(
           id: _nextId++,

mobile/lib/repos/user.dart

@@ -32,7 +32,8 @@ class UsersRepo extends ChangeNotifier {
       return Err("User with mail $mail already exists");
     }
 
-    final user = User(id: nextId++, name: name, mail: mail, password: password);
+    final user = User(
+        id: nextId++, name: name, mail: mail, password: password, balance: 0);
     users.add(user);
 
     return Ok(user);
@@ -51,11 +52,24 @@ class UsersRepo extends ChangeNotifier {
     return Err("User with mail $mail doesn't exist");
   }
 
+  Result<int, String> pay(int userId, int amount) {
+    final user = getUserById(userId);
+    if (user is Ok) {
+      return (user as User).pay(amount);
+    }
+    return Err("User with id $userId doesn't exist");
+  }
+
   void addTestUsers() {
     users
       ..add(User(
-          id: nextId++, mail: "test@test.com", name: "test", password: "test"))
-      ..add(User(id: nextId++, mail: "", name: "", password: ""));
+          id: nextId++,
+          mail: "test@test.com",
+          name: "test",
+          password: "test",
+          balance: 1000))
+      ..add(
+          User(id: nextId++, mail: "", name: "", password: "", balance: 10000));
   }
 }
 
@@ -64,10 +78,20 @@ class User {
   final String mail;
   final String name;
   final String password;
+  int balance;
 
   User(
       {required this.id,
       required this.mail,
       required this.name,
-      required this.password});
+      required this.password,
+      required this.balance});
+
+  Result<int, String> pay(int amount) {
+    if (balance < amount) {
+      return Err("User can not afford paying amount $amount");
+    }
+    balance -= amount;
+    return Ok(balance);
+  }
 }