Implement review fixes

- Added verifyAllPaymentsCompleted() helper in MenuHelper.h to check if the authenticated customer has completed all invoices.

- Integrated payment verification into CustomerMenu::selectService() to block new service bookings when pending payments exist.

- Integrated payment verification into CustomerMenu::selectComboPackage() to block new combo package bookings when invoices are incomplete.

- Implemented iteration over customer invoices to ensure only users with all payments marked as COMPLETED can proceed with new bookings.

- Added user-facing messages to inform customers when bookings are denied due to outstanding payments.

Fixes #2116

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/CustomerMenu.cpp

@@ -220,6 +220,13 @@ void CustomerMenu::selectService()
         util::pressEnter();
         return;
     }
+    if (!verifyAllPaymentsCompleted(m_controller))
+    {
+        std::cout << "Your booking cannot be processed because you have pending payments for previous services. Please complete all outstanding invoices before booking a new service."
+             << std::endl;
+        util::pressEnter();
+        return;
+    }
     util::Vector<std::string> selectedServices;
     const Service* selectedService = selectServiceFromServices(services);
     if (selectedService == nullptr)
@@ -262,6 +269,13 @@ void CustomerMenu::selectComboPackage()
         util::pressEnter();
         return;
     }
+    if (!verifyAllPaymentsCompleted(m_controller))
+    {
+        std::cout << "Your booking cannot be processed because you have pending payments for previous services. Please complete all outstanding invoices before booking a new combo package."
+            << std::endl;
+        util::pressEnter();
+        return;
+    }
     const ComboPackage* selectedComboPackage = selectComboPackageFromPackages(activeComboPackages);
     if (selectedComboPackage == nullptr)
     {

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/MenuHelper.h

@@ -1467,3 +1467,45 @@ inline void displayNewNotification(util::Vector<const Notification*> notificatio
             MB_ICONINFORMATION);
     }
 }
+
+/*
+Function: verifyAllPaymentsCompleted
+Description: Checks whether the authenticated customer has completed
+             all payments for their invoices. Iterates through all
+             invoices belonging to the customer and verifies that
+             each invoice has a payment status of COMPLETED.
+Parameters: Controller& m_controller -
+            reference to the Controller object used to access
+            authenticated user and invoice data
+Return type: bool
+             true if all invoices for the authenticated customer
+             are completed, false if any invoice is pending or not completed
+Throws: std::runtime_error if no authenticated user is found
+*/
+inline bool verifyAllPaymentsCompleted(Controller& m_controller)
+{
+    const User* authenticatedUser = m_controller.getAuthenticatedUser();
+    if (!authenticatedUser)
+    {
+        throw std::runtime_error("No authenticated user found.");
+    }
+    const std::string& authenticatedUserId = authenticatedUser->getId();
+    util::Map<std::string, const Invoice*> listOfInvoices = m_controller.getAllInvoices();
+    for (int invoiceIndex = 0; invoiceIndex < listOfInvoices.getSize(); ++invoiceIndex)
+    {
+        const Invoice* invoice = listOfInvoices.getValueAt(invoiceIndex);
+        if (!invoice)
+        {
+            continue;
+        }
+        const std::string& customerId = invoice->getBooking()->getCustomerId();
+        if (customerId == authenticatedUserId)
+        {
+            if (invoice->getStatus() != util::PaymentStatus::COMPLETED)
+            {
+                return false;
+            }
+        }
+    }
+    return true;
+}