Merged PR 1202: Vehicle Service System v1.2.0.0

## New Features

### Shared Memory DataStore

* Replaced the existing in-memory DataStore with a shared-memory implementation using Windows File Mapping.
* Added support for sharing application data between multiple running instances.
* Created separate mappings for users, notifications, services, bookings, invoices, payments, and other entities.

### Binary Data Storage

* Added binary serialization for all major entities.
* Introduced record tracking to handle new, modified, and deleted records.
* Added automatic growth and shrinking of mappings when required.

## Refactoring

### DataStore Changes

* Refactored DataStore to use shared memory instead of local process memory.
* Added generic helper functions for loading and saving records.
* Updated application startup and shutdown to initialize and clean up shared-memory resources.

### Synchronization

* Added a global mutex to synchronize datastore operations across processes.
* Added remapping logic to detect mapping size changes made by other instances.

## Bug Fixes

* Fixed issues with data not being shared correctly between multiple application instances.
* Improved reliability of record updates and deletions.
* Fixed stale mapping issues when mappings were resized by another process.

Related work items: #1925, #1926, #1927, #1928, #1929, #1930, #1949, #1950, #1951, #1952, #1953, #1954, #1955, #1956, #1957, #1958, #1959, #1960, #2061, #2074, #2075, #2076, #2077, #2078, #2079, #2080, #2081, #2082, #2100, #2105, #2114, #2115, #2116

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/ServiceManagementService.cpp

@@ -629,6 +629,7 @@ void ServiceManagementService::createJobCard(const std::string& bookingID, const
     DataStoreLockGuard lock(m_dataStore);
 	UserManagementService m_userManagementService;
 	ServiceBooking* currentBooking = getServiceBooking(bookingID);
+    std::string title, message;
     if (currentBooking == nullptr)
     {
         throw std::runtime_error("Service Booking not available");
@@ -684,18 +685,30 @@ void ServiceManagementService::createJobCard(const std::string& bookingID, const
             trackedCurrentInventoryItem.state = RecordState::MODIFIED;
 		}
 	}
-	currentBooking->setAssignedTechnician(selectedTechnician);
-	currentBooking->setAssignedTechnicianId(selectedTechnician->getId());
+    const User* currentAssignedTechnician = currentBooking->getAssignedTechnician();
+    const std::string& currentAssignedTechnicianId = currentBooking->getAssignedTechnicianId();
+    if (!currentAssignedTechnician && currentAssignedTechnicianId.empty())
+    {
+        currentBooking->setAssignedTechnician(selectedTechnician);
+        currentBooking->setAssignedTechnicianId(selectedTechnician->getId());
+        title = "Technician assigned";
+        message = "A technician has been assigned to your Service Booking with ID " + bookingID;
+        sendNotification(currentBooking->getCustomer(), title, message);
+    }
+
     if (currentBooking->getStatus() == util::ServiceJobStatus::PENDING)
     {
         currentBooking->setStatus(util::ServiceJobStatus::STARTED);
     }
     currentTrackedServiceBooking.state = RecordState::MODIFIED;
-	std::string title = "Job card created";
-	std::string message = "Job card created for the service and you are assigned for that.";
 	JobCard* jobCard = Factory::getObject<JobCard>(bookingID, currentBooking, currentService, serviceID, technicianID, selectedTechnician, util::Timestamp(), util::ServiceJobStatus::STARTED, util::Timestamp());
 	if (jobCard)
 	{
+        title = "Job Card Assigned";
+        message = "A new Job Card (ID: " + jobCard->getId() +
+            ") has been created for Service " + serviceID +
+            " in Booking " + bookingID +
+            ". You have been assigned to this job.";
 		currentTrackedJobCards.insert(jobCard->getId(), util::createNewRecord(jobCard));
 		sendNotification(selectedTechnician, title, message);
 	}
@@ -703,9 +716,6 @@ void ServiceManagementService::createJobCard(const std::string& bookingID, const
 	{
 		throw std::runtime_error("Failed to create job card.");
 	}
-    title = "Technician assigned";
-    message = "A technician has been assigned to your Service Booking with ID " + bookingID;
-    sendNotification(currentBooking->getCustomer(), title, message);
     m_dataStore.saveJobCards();
     m_dataStore.saveServiceBookings();
     m_dataStore.saveInventoryItems();
@@ -852,8 +862,8 @@ void ServiceManagementService::removeServiceBooking(const std::string& bookingID
         {
             if (currentServiceBooking->getStatus() == util::ServiceJobStatus::PENDING)
             {
-                const std::string title = "Service Booking cancelled.";
-                const std::string message = "Service Booking of id " + bookingID + " successfully cancelled.";
+                const std::string title = "Service Booking Cancelled";
+                const std::string message = "Service Booking (ID: " + bookingID + ") has been successfully cancelled";
                 currentServiceBooking->setStatus(util::ServiceJobStatus::CANCELLED);
                 currentTrackedServiceBooking.state = RecordState::MODIFIED;
                 serviceBookingRemoved = true;
@@ -1025,8 +1035,8 @@ void ServiceManagementService::updateJobStatus(const std::string& jobID)
                 currentJob->getBooking()->setStatus(util::ServiceJobStatus::COMPLETED);
                 trackedServiceBookings.getValueAt(trackedServiceBookings.find(bookingId)).state = RecordState::MODIFIED;
                 paymentManagementService.generateInvoice(currentJob->getBooking());
-                std::string title = "Service Booking completed. Invoice Generated.";
-                std::string message = "Services completed for the booking and invoice generated.";
+                std::string title = "Service Booking Completed";
+                std::string message = "Service Booking (ID: " + bookingId + ") has been completed successfully. An invoice has been generated.";
                 sendNotification(currentJob->getBooking()->getCustomer(), title, message);
             }
         }

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

@@ -1471,3 +1471,45 @@ 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;
+}