Merge branch 'develop' into develop-sm-authentication-management

User Story #1953
User Story #1954

**Changes**
- Refactored Notification model to use SerializedNotification for shared memory persistence.
- Removed notification ownership from the User model and stored notifications separately in the DataStore.
- Added notification state tracking to support soft deletion.
- Updated notification creation, retrieval, and deletion flows to use DataStore-managed notifications.
- Refactored observer persistence for Service, Payment, and Inventory Management services to use shared memory mappings.
- Removed file-based observer loading and saving logic.
- Updated notification services to persist notifications directly through the DataStore.
- Added observer load/save support in DataStore.
- Removed legacy FileManager and file-based notification persistence utilities.
- Simplified observer interfaces and removed unused observer ID persistence methods.
- Updated application startup and shutdown flow to use DataStore initialization and cleanup.

Related work items: #1953, #1954

.gitignore

@@ -427,5 +427,5 @@ FodyWeavers.xsd
 *.msm
 *.msp
 
-# CSV Files
+# DAT Files
-*.csv
+*.dat

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem.vcxproj

@@ -140,7 +140,6 @@
     <ClCompile Include="models\User.cpp" />
     <ClCompile Include="services\AuthenticationManagementService.cpp" />
     <ClCompile Include="services\InventoryManagementService.cpp" />
-    <ClCompile Include="services\NotificationManagementService.cpp" />
     <ClCompile Include="services\PaymentManagementService.cpp" />
     <ClCompile Include="services\ServiceManagementService.cpp" />
     <ClCompile Include="services\UserManagementService.cpp" />
@@ -157,6 +156,7 @@
     <ClInclude Include="core\patterns\Observer.h" />
     <ClInclude Include="core\patterns\Subject.h" />
     <ClInclude Include="datastores\DataStore.h" />
+    <ClInclude Include="datastores\DataStoreLockGuard.h" />
     <ClInclude Include="datastores\sharedmemory\FileHeader.h" />
     <ClInclude Include="datastores\sharedmemory\MappingInfo.h" />
     <ClInclude Include="datastores\sharedmemory\RecordState.h" />
@@ -181,7 +181,6 @@
     <ClInclude Include="utilities\Config.h" />
     <ClInclude Include="utilities\Enums.h" />
     <ClInclude Include="utilities\FileHelper.h" />
-    <ClInclude Include="utilities\FileManager.h" />
     <ClInclude Include="utilities\InputHelper.h" />
     <ClInclude Include="utilities\Map.h" />
     <ClInclude Include="utilities\OutputHelper.h" />

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem.vcxproj.filters

@@ -114,9 +114,6 @@
     <ClCompile Include="datastores\DataStore.cpp">
       <Filter>Source Files\DataStores</Filter>
     </ClCompile>
-    <ClCompile Include="services\NotificationManagementService.cpp">
-      <Filter>Source Files\Services</Filter>
-    </ClCompile>
     <ClCompile Include="core\patterns\Observer.cpp">
       <Filter>Source Files\Core\Patterns</Filter>
     </ClCompile>
@@ -245,9 +242,6 @@
     <ClInclude Include="utilities\Config.h">
       <Filter>Header Files\Utilities</Filter>
     </ClInclude>
-    <ClInclude Include="utilities\FileManager.h">
-      <Filter>Header Files\Utilities</Filter>
-    </ClInclude>
     <ClInclude Include="utilities\StringHelper.h">
       <Filter>Header Files\Utilities</Filter>
     </ClInclude>
@@ -278,5 +272,8 @@
     <ClInclude Include="datastores\sharedmemory\SharedMemory.h">
       <Filter>Header Files\DataStores\SharedMemory</Filter>
     </ClInclude>
+    <ClInclude Include="datastores\DataStoreLockGuard.h">
+      <Filter>Header Files\DataStores</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.cpp

@@ -588,63 +588,37 @@ void Controller::configureNotifications(bool paymentNotifications, bool serviceN
 }
 
 /*
-Function: loadSystemData
+Function: initialize
-Description: Loads all system data from persistent storage into memory.
+Description: Initializes the system and run system checks to ensure critical configurations, such as verifying admin existence.
-             Invokes the respective management services to load users, inventory items, services,
-             combo packages, service bookings, job cards, invoices, and observers.
 Parameters:
     - None
 Returns:
-    - void
+    - bool
 */
-void Controller::loadSystemData()
+bool Controller::initialize()
 {
-    m_userManagementService.loadUsers();
+    auto& dataStore = DataStore::getInstance();
-    m_inventoryManagementService.loadInventoryItems();
-    m_serviceManagementService.loadServices();
-    m_serviceManagementService.loadComboPackages();
-    m_serviceManagementService.loadServiceBookings();
-    m_serviceManagementService.loadJobCards();
-    m_paymentManagementService.loadInvoices();
-    m_serviceManagementService.loadObservers();
-    m_paymentManagementService.loadObservers();
-    m_inventoryManagementService.loadObservers();
-}
 
-/*
+    if (!dataStore.initialize())
-Function: saveSystemData
+    {
-Description: Saves all system data from memory back to persistent storage.
+        return false;
-             Invokes the respective management services to save users, inventory items, services,
+    }
-             combo packages, service bookings, job cards, invoices, and observers.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void Controller::saveSystemData()
-{
-    m_userManagementService.saveUsers();
-    m_inventoryManagementService.saveInventoryItems();
-    m_serviceManagementService.saveServices();
-    m_serviceManagementService.saveComboPackages();
-    m_serviceManagementService.saveServiceBookings();
-    m_serviceManagementService.saveJobCards();
-    m_paymentManagementService.saveInvoices();
-    m_serviceManagementService.saveObservers();
-    m_paymentManagementService.saveObservers();
-    m_inventoryManagementService.saveObservers();
-}
-
-/*
-Function: runSystemChecks
-Description: Runs system checks to ensure critical configurations, such as verifying admin existence.
-Parameter: None
-Return type: void
-*/
-void Controller::runSystemChecks()
-{
     m_userManagementService.ensureAdminExists();
     m_inventoryManagementService.sendLowStockAlerts();
     m_paymentManagementService.sendPaymentReminders();
+    return true;
 }
 
+/*
+Function: shutdown
+Description: Shutdown the system, and do necessary cleanups
+Parameters:
+    - None
+Returns:
+    - void
+*/
+void Controller::shutdown()
+{
+    auto& dataStore = DataStore::getInstance();
+    dataStore.shutdown();
+}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.h

@@ -70,7 +70,6 @@ public:
     util::Vector<const Notification*> getNotifications();
     void deleteNotification(const std::string& notificationID);
     void configureNotifications(bool paymentNotifications, bool serviceNotifications);
-    void loadSystemData();
+    bool initialize();
-    void saveSystemData();
+    void shutdown();
-    void runSystemChecks();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/patterns/Observer.h

@@ -7,11 +7,8 @@ Date: 19-May-2026
 
 #pragma once
 
-class Notification;
-
 class Observer
 {
 public:
     virtual ~Observer() = default;
-    virtual void addNotification(Notification* notification) = 0;
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/DataStore.cpp

@@ -13,9 +13,42 @@ Date: 19-May-2026
 #include "SerializedRecords.h"
 #include "FileHelper.h"
 
+/*
+Function: DataStore
+Description: Constructs the DataStore singleton and initializes
+             internal handles to their default values.
+Parameters:
+    - None
+Returns:
+    - None
+*/
 DataStore::DataStore() :
     m_globalMutex(NULL) {}
 
+/*
+Function: ~DataStore
+Description: Destroys the DataStore singleton and releases all
+             cached application objects owned by the datastore.
+             This includes users, notifications, services,
+             combo packages, inventory items, service bookings,
+             job cards, and invoices.
+Parameters:
+    - None
+Returns:
+    - None
+*/
+DataStore::~DataStore()
+{
+    clearCache(m_userCache);
+    clearCache(m_notificationCache);
+    clearCache(m_serviceCache);
+    clearCache(m_comboPackageCache);
+    clearCache(m_inventoryItemCache);
+    clearCache(m_serviceBookingCache);
+    clearCache(m_jobCardCache);
+    clearCache(m_invoiceCache);
+}
+
 /*
 Function: initialize
 Description: Initializes the shared-memory datastore.
@@ -111,11 +144,6 @@ bool DataStore::initialize()
             success = false;
             break;
         }
-        if (!SharedMemory::createOrOpenMapping(m_payments))
-        {
-            success = false;
-            break;
-        }
         if (!SharedMemory::createOrOpenMapping(m_serviceManagementObservers))
         {
             success = false;
@@ -160,7 +188,6 @@ void DataStore::shutdown()
     SharedMemory::closeMapping(m_serviceBookings);
     SharedMemory::closeMapping(m_jobCards);
     SharedMemory::closeMapping(m_invoices);
-    SharedMemory::closeMapping(m_payments);
     SharedMemory::closeMapping(m_serviceManagementObservers);
     SharedMemory::closeMapping(m_paymentManagementObservers);
     SharedMemory::closeMapping(m_inventoryManagementObservers);
@@ -193,9 +220,11 @@ Parameters:
 Returns:
     - util::Map<std::string, TrackedRecord<User>>: Collection of user records
 */
-util::Map<std::string, TrackedRecord<User>> DataStore::getUsers()
+util::Map<std::string, TrackedRecord<User>>& DataStore::getUsers()
 {
-    return util::Map<std::string, TrackedRecord<User>>();
+    auto users = loadRecords<User, SerializedUser>(m_users);
+    refreshCache(m_userCache, users);
+    return m_userCache;
 }
 
 /*
@@ -206,9 +235,11 @@ Parameters:
 Returns:
     - util::Map<std::string, TrackedRecord<Notification>>: Collection of notification records
 */
-util::Map<std::string, TrackedRecord<Notification>> DataStore::getNotifications()
+util::Map<std::string, TrackedRecord<Notification>>& DataStore::getNotifications()
 {
-    return util::Map<std::string, TrackedRecord<Notification>>();
+    auto notifications = loadRecords<Notification, SerializedNotification>(m_notifications);
+    refreshCache(m_notificationCache, notifications);
+    return m_notificationCache;
 }
 
 /*
@@ -219,9 +250,9 @@ Parameters:
 Returns:
     - util::Map<std::string, TrackedRecord<Service>>: Collection of service records
 */
-util::Map<std::string, TrackedRecord<Service>> DataStore::getServices()
+util::Map<std::string, TrackedRecord<Service>>& DataStore::getServices()
 {
-    return util::Map<std::string, TrackedRecord<Service>>();
+    return m_serviceCache;
 }
 
 /*
@@ -232,9 +263,9 @@ Parameters:
 Returns:
     - util::Map<std::string, TrackedRecord<ComboPackage>>: Collection of combo package records
 */
-util::Map<std::string, TrackedRecord<ComboPackage>> DataStore::getComboPackages()
+util::Map<std::string, TrackedRecord<ComboPackage>>& DataStore::getComboPackages()
 {
-    return util::Map<std::string, TrackedRecord<ComboPackage>>();
+    return m_comboPackageCache;
 }
 
 /*
@@ -245,9 +276,9 @@ Parameters:
 Returns:
     - util::Map<std::string, TrackedRecord<InventoryItem>>: Collection of inventory item records
 */
-util::Map<std::string, TrackedRecord<InventoryItem>> DataStore::getInventoryItems()
+util::Map<std::string, TrackedRecord<InventoryItem>>& DataStore::getInventoryItems()
 {
-    return util::Map<std::string, TrackedRecord<InventoryItem>>();
+    return m_inventoryItemCache;
 }
 
 /*
@@ -258,9 +289,9 @@ Parameters:
 Returns:
     - util::Map<std::string, TrackedRecord<ServiceBooking>>: Collection of service booking records
 */
-util::Map<std::string, TrackedRecord<ServiceBooking>> DataStore::getServiceBookings()
+util::Map<std::string, TrackedRecord<ServiceBooking>>& DataStore::getServiceBookings()
 {
-    return util::Map<std::string, TrackedRecord<ServiceBooking>>();
+    return m_serviceBookingCache;
 }
 
 /*
@@ -271,9 +302,9 @@ Parameters:
 Returns:
     - util::Map<std::string, TrackedRecord<JobCard>>: Collection of job card records
 */
-util::Map<std::string, TrackedRecord<JobCard>> DataStore::getJobCards()
+util::Map<std::string, TrackedRecord<JobCard>>& DataStore::getJobCards()
 {
-    return util::Map<std::string, TrackedRecord<JobCard>>();
+    return m_jobCardCache;
 }
 
 /*
@@ -284,22 +315,40 @@ Parameters:
 Returns:
     - util::Map<std::string, TrackedRecord<Invoice>>: Collection of invoice records
 */
-util::Map<std::string, TrackedRecord<Invoice>> DataStore::getInvoices()
+util::Map<std::string, TrackedRecord<Invoice>>& DataStore::getInvoices()
 {
-    return util::Map<std::string, TrackedRecord<Invoice>>();
+    return m_invoiceCache;
 }
 
 /*
-Function: getPayments
+Function: getObservers
-Description: Retrieves all payment records from the datastore.
+Description: Retrieves observer records from the specified observer mapping
+             and resolves them to User objects.
 Parameters:
-    - None
+    - mapping: Observer mapping to read from
 Returns:
-    - util::Map<std::string, TrackedRecord<Payment>>: Collection of payment records
+    - util::Map<std::string, User*>: Collection of observer records
+Throws:
+    - std::runtime_error if an observer references an invalid user ID
 */
-util::Map<std::string, TrackedRecord<Payment>> DataStore::getPayments()
+util::Map<std::string, User*> DataStore::getObservers(MappingInfo& mapping)
 {
-    return util::Map<std::string, TrackedRecord<Payment>>();
+    auto& users = getUsers();
+    util::Map<std::string, User*> observers;
+    SharedMemory::ensureLatestMapping(mapping);
+    size_t recordCount = SharedMemory::getRecordCount(mapping);
+    for (size_t index = 0; index < recordCount; index++)
+    {
+        const SerializedObserver* observer = static_cast<SerializedObserver*>(SharedMemory::getRecordAddress(mapping, index));
+        int userIndex = users.find(observer->id);
+        if (userIndex == -1)
+        {
+            throw std::runtime_error("Invalid observer user ID");
+        }
+        User* user = users.getValueAt(userIndex).data;
+        observers.insert(user->getId(), user);
+    }
+    return observers;
 }
 
 /*
@@ -308,11 +357,11 @@ Description: Retrieves all service management observer records from the datastor
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<std::string>>: Collection of observer records
+    - util::Map<std::string, User*>: Collection of observer records
 */
-util::Map<std::string, TrackedRecord<std::string>> DataStore::getServiceManagementObservers()
+util::Map<std::string, User*> DataStore::getServiceManagementObservers()
 {
-    return util::Map<std::string, TrackedRecord<std::string>>();
+    return getObservers(m_serviceManagementObservers);
 }
 
 /*
@@ -321,11 +370,11 @@ Description: Retrieves all payment management observer records from the datastor
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<std::string>>: Collection of observer records
+    - util::Map<std::string, User*>: Collection of observer records
 */
-util::Map<std::string, TrackedRecord<std::string>> DataStore::getPaymentManagementObservers()
+util::Map<std::string, User*> DataStore::getPaymentManagementObservers()
 {
-    return util::Map<std::string, TrackedRecord<std::string>>();
+    return getObservers(m_paymentManagementObservers);
 }
 
 /*
@@ -334,46 +383,48 @@ Description: Retrieves all inventory management observer records from the datast
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<std::string>>: Collection of observer records
+    - util::Map<std::string, User*>: Collection of observer records
 */
-util::Map<std::string, TrackedRecord<std::string>> DataStore::getInventoryManagementObservers()
+util::Map<std::string, User*> DataStore::getInventoryManagementObservers()
 {
-    return util::Map<std::string, TrackedRecord<std::string>>();
+    return getObservers(m_inventoryManagementObservers);
 }
 
 /*
 Function: saveUsers
 Description: Persists all user records to the datastore.
 Parameters:
-    - users: util::Map<std::string, TrackedRecord<User>>&, collection of user records
+    - None
 Returns:
     - None
 */
-void DataStore::saveUsers(util::Map<std::string, TrackedRecord<User>>& users)
+void DataStore::saveUsers()
 {
+    saveRecords<User, SerializedUser>(m_users, m_userCache);
 }
 
 /*
 Function: saveNotifications
 Description: Persists all notification records to the datastore.
 Parameters:
-    - notifications: util::Map<std::string, TrackedRecord<Notification>>&, collection of notification records
+    - None
 Returns:
     - None
 */
-void DataStore::saveNotifications(util::Map<std::string, TrackedRecord<Notification>>& notifications)
+void DataStore::saveNotifications()
 {
+    saveRecords<Notification, SerializedNotification>(m_notifications, m_notificationCache);
 }
 
 /*
 Function: saveServices
 Description: Persists all service records to the datastore.
 Parameters:
-    - services: util::Map<std::string, TrackedRecord<Service>>&, collection of service records
+    - None
 Returns:
     - None
 */
-void DataStore::saveServices(util::Map<std::string, TrackedRecord<Service>>& services)
+void DataStore::saveServices()
 {
 }
 
@@ -381,11 +432,11 @@ void DataStore::saveServices(util::Map<std::string, TrackedRecord<Service>>& ser
 Function: saveComboPackages
 Description: Persists all combo package records to the datastore.
 Parameters:
-    - comboPackages: util::Map<std::string, TrackedRecord<ComboPackage>>&, collection of combo package records
+    - None
 Returns:
     - None
 */
-void DataStore::saveComboPackages(util::Map<std::string, TrackedRecord<ComboPackage>>& comboPackages)
+void DataStore::saveComboPackages()
 {
 }
 
@@ -393,11 +444,11 @@ void DataStore::saveComboPackages(util::Map<std::string, TrackedRecord<ComboPack
 Function: saveInventoryItems
 Description: Persists all inventory item records to the datastore.
 Parameters:
-    - inventoryItems: util::Map<std::string, TrackedRecord<InventoryItem>>&, collection of inventory item records
+    - None
 Returns:
     - None
 */
-void DataStore::saveInventoryItems(util::Map<std::string, TrackedRecord<InventoryItem>>& inventoryItems)
+void DataStore::saveInventoryItems()
 {
 }
 
@@ -405,11 +456,11 @@ void DataStore::saveInventoryItems(util::Map<std::string, TrackedRecord<Inventor
 Function: saveServiceBookings
 Description: Persists all service booking records to the datastore.
 Parameters:
-    - bookings: util::Map<std::string, TrackedRecord<ServiceBooking>>&, collection of service booking records
+    - None
 Returns:
     - None
 */
-void DataStore::saveServiceBookings(util::Map<std::string, TrackedRecord<ServiceBooking>>& bookings)
+void DataStore::saveServiceBookings()
 {
 }
 
@@ -417,11 +468,11 @@ void DataStore::saveServiceBookings(util::Map<std::string, TrackedRecord<Service
 Function: saveJobCards
 Description: Persists all job card records to the datastore.
 Parameters:
-    - jobCards: util::Map<std::string, TrackedRecord<JobCard>>&, collection of job card records
+    - None
 Returns:
     - None
 */
-void DataStore::saveJobCards(util::Map<std::string, TrackedRecord<JobCard>>& jobCards)
+void DataStore::saveJobCards()
 {
 }
 
@@ -429,86 +480,83 @@ void DataStore::saveJobCards(util::Map<std::string, TrackedRecord<JobCard>>& job
 Function: saveInvoices
 Description: Persists all invoice records to the datastore.
 Parameters:
-    - invoices: util::Map<std::string, TrackedRecord<Invoice>>&, collection of invoice records
+    - None
 Returns:
     - None
 */
-void DataStore::saveInvoices(util::Map<std::string, TrackedRecord<Invoice>>& invoices)
+void DataStore::saveInvoices()
 {
 }
 
 /*
-Function: savePayments
+Function: saveObservers
-Description: Persists all payment records to the datastore.
+Description: Persists observer records to the specified observer mapping.
 Parameters:
-    - payments: util::Map<std::string, TrackedRecord<Payment>>&, collection of payment records
+    - mapping: MappingInfo&, observer mapping to save to
+    - observers: util::Map<std::string, User*>&, collection of observer records
 Returns:
     - None
 */
-void DataStore::savePayments(util::Map<std::string, TrackedRecord<Payment>>& payments)
+void DataStore::saveObservers(MappingInfo& mapping, util::Map<std::string, User*>& observers)
 {
+    size_t observerCount = static_cast<size_t>(observers.getSize());
+    size_t capacity = config::file::INITIAL_CAPACITY;
+    while (capacity < observerCount)
+    {
+        capacity *= config::file::GROWTH_FACTOR;
+    }
+    if (!SharedMemory::resizeMapping(mapping, capacity))
+    {
+        throw std::runtime_error("Failed to resize observer mapping");
+    }
+    SharedMemory::setRecordCount(mapping, observerCount);
+    for (size_t index = 0; index < observerCount; index++)
+    {
+        SerializedObserver serializedObserver;
+        User* user = observers.getValueAt(static_cast<int>(index));
+        strcpy_s(serializedObserver.id, sizeof(serializedObserver.id), user->getId().c_str());
+        SerializedObserver* destination = static_cast<SerializedObserver*>(SharedMemory::getRecordAddress(mapping, index));
+        *destination = serializedObserver;
+    }
 }
 
 /*
 Function: saveServiceManagementObservers
 Description: Persists all service management observer records to the datastore.
 Parameters:
-    - observers: util::Map<std::string, TrackedRecord<std::string>>&, collection of observer records
+    - observers: util::Map<std::string, User*>&, collection of observer records
 Returns:
     - None
 */
-void DataStore::saveServiceManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers)
+void DataStore::saveServiceManagementObservers(util::Map<std::string, User*>& observers)
 {
+    saveObservers(m_serviceManagementObservers, observers);
 }
 
 /*
 Function: savePaymentManagementObservers
 Description: Persists all payment management observer records to the datastore.
 Parameters:
-    - observers: util::Map<std::string, TrackedRecord<std::string>>&, collection of observer records
+    - observers: util::Map<std::string, User*>&, collection of observer records
 Returns:
     - None
 */
-void DataStore::savePaymentManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers)
+void DataStore::savePaymentManagementObservers(util::Map<std::string, User*>& observers)
 {
+    saveObservers(m_paymentManagementObservers, observers);
 }
 
 /*
 Function: saveInventoryManagementObservers
 Description: Persists all inventory management observer records to the datastore.
 Parameters:
-    - observers: util::Map<std::string, TrackedRecord<std::string>>&, collection of observer records
+    - observers: util::Map<std::string, User*>&, collection of observer records
 Returns:
     - None
 */
-void DataStore::saveInventoryManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers)
+void DataStore::saveInventoryManagementObservers(util::Map<std::string, User*>& observers)
 {
-}
+    saveObservers(m_inventoryManagementObservers, observers);
-
-/*
-Function: lockDataStore
-Description: Acquires exclusive access to the datastore.
-Parameters:
-    - None
-Returns:
-    - bool: True if the datastore was successfully locked, otherwise false
-*/
-bool DataStore::lockDataStore()
-{
-    return false;
-}
-
-/*
-Function: unlockDataStore
-Description: Releases exclusive access to the datastore.
-Parameters:
-    - None
-Returns:
-    - bool: True if the datastore was successfully unlocked, otherwise false
-*/
-bool DataStore::unlockDataStore()
-{
-    return false;
 }
 
 /*
@@ -553,4 +601,5 @@ bool DataStore::unlockDataStore()
         return false;
     }
     return ReleaseMutex(m_globalMutex) != 0;
-}
+}
+

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/DataStore.h

@@ -12,20 +12,20 @@ Date: 19-May-2026
 #include "MappingInfo.h"
 #include "TrackedRecord.h"
 #include "SharedMemory.h"
-class User;
+#include "User.h"
-class Notification;
+#include "Notification.h"
-class Service;
+#include "Service.h"
-class ComboPackage;
+#include "ComboPackage.h"
-class InventoryItem;
+#include "InventoryItem.h"
-class ServiceBooking;
+#include "ServiceBooking.h"
-class JobCard;
+#include "JobCard.h"
-class Invoice;
+#include "Invoice.h"
-class Payment;
 
 class DataStore
 {
 private:
     DataStore();
+    ~DataStore();
     DataStore(const DataStore&) = delete;
     DataStore& operator=(const DataStore&) = delete;
     DataStore(DataStore&&) = delete;
@@ -39,38 +39,43 @@ private:
     MappingInfo m_serviceBookings;
     MappingInfo m_jobCards;
     MappingInfo m_invoices;
-    MappingInfo m_payments;
     MappingInfo m_serviceManagementObservers;
     MappingInfo m_paymentManagementObservers;
     MappingInfo m_inventoryManagementObservers;
+    util::Map<std::string, TrackedRecord<User>> m_userCache;
+    util::Map<std::string, TrackedRecord<Notification>> m_notificationCache;
+    util::Map<std::string, TrackedRecord<Service>> m_serviceCache;
+    util::Map<std::string, TrackedRecord<ComboPackage>> m_comboPackageCache;
+    util::Map<std::string, TrackedRecord<InventoryItem>> m_inventoryItemCache;
+    util::Map<std::string, TrackedRecord<ServiceBooking>> m_serviceBookingCache;
+    util::Map<std::string, TrackedRecord<JobCard>> m_jobCardCache;
+    util::Map<std::string, TrackedRecord<Invoice>> m_invoiceCache;
 public:
     static DataStore& getInstance();
     bool initialize();
     void shutdown();
-    util::Map<std::string, TrackedRecord<User>> getUsers();
+    util::Map<std::string, TrackedRecord<User>>& getUsers();
-    util::Map<std::string, TrackedRecord<Notification>> getNotifications();
+    util::Map<std::string, TrackedRecord<Notification>>& getNotifications();
-    util::Map<std::string, TrackedRecord<Service>> getServices();
+    util::Map<std::string, TrackedRecord<Service>>& getServices();
-    util::Map<std::string, TrackedRecord<ComboPackage>> getComboPackages();
+    util::Map<std::string, TrackedRecord<ComboPackage>>& getComboPackages();
-    util::Map<std::string, TrackedRecord<InventoryItem>> getInventoryItems();
+    util::Map<std::string, TrackedRecord<InventoryItem>>& getInventoryItems();
-    util::Map<std::string, TrackedRecord<ServiceBooking>> getServiceBookings();
+    util::Map<std::string, TrackedRecord<ServiceBooking>>& getServiceBookings();
-    util::Map<std::string, TrackedRecord<JobCard>> getJobCards();
+    util::Map<std::string, TrackedRecord<JobCard>>& getJobCards();
-    util::Map<std::string, TrackedRecord<Invoice>> getInvoices();
+    util::Map<std::string, TrackedRecord<Invoice>>& getInvoices();
-    util::Map<std::string, TrackedRecord<Payment>> getPayments();
+    util::Map<std::string, User*> getServiceManagementObservers();
-    util::Map<std::string, TrackedRecord<std::string>> getServiceManagementObservers();
+    util::Map<std::string, User*> getPaymentManagementObservers();
-    util::Map<std::string, TrackedRecord<std::string>> getPaymentManagementObservers();
+    util::Map<std::string, User*> getInventoryManagementObservers();
-    util::Map<std::string, TrackedRecord<std::string>> getInventoryManagementObservers();
+    void saveUsers();
-    void saveUsers(util::Map<std::string, TrackedRecord<User>>& users);
+    void saveNotifications();
-    void saveNotifications(util::Map<std::string, TrackedRecord<Notification>>& notifications);
+    void saveServices();
-    void saveServices(util::Map<std::string, TrackedRecord<Service>>& services);
+    void saveComboPackages();
-    void saveComboPackages(util::Map<std::string, TrackedRecord<ComboPackage>>& comboPackages);
+    void saveInventoryItems();
-    void saveInventoryItems(util::Map<std::string, TrackedRecord<InventoryItem>>& inventoryItems);
+    void saveServiceBookings();
-    void saveServiceBookings(util::Map<std::string, TrackedRecord<ServiceBooking>>& bookings);
+    void saveJobCards();
-    void saveJobCards(util::Map<std::string, TrackedRecord<JobCard>>& jobCards);
+    void saveInvoices();
-    void saveInvoices(util::Map<std::string, TrackedRecord<Invoice>>& invoices);
+    void saveServiceManagementObservers(util::Map<std::string, User*>& observers);
-    void savePayments(util::Map<std::string, TrackedRecord<Payment>>& payments);
+    void savePaymentManagementObservers(util::Map<std::string, User*>& observers);
-    void saveServiceManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers);
+    void saveInventoryManagementObservers(util::Map<std::string, User*>& observers);
-    void savePaymentManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers);
-    void saveInventoryManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers);
     bool lockDataStore();
     bool unlockDataStore();
 private:
@@ -78,6 +83,10 @@ private:
     util::Map<std::string, TrackedRecord<TObject>> loadRecords(MappingInfo& mapping);
     template<typename TObject, typename TSerialized>
     void saveRecords(MappingInfo& mapping, util::Map<std::string, TrackedRecord<TObject>>& records);
+    template<typename TObject> void clearCache(util::Map<std::string, TrackedRecord<TObject>>&cache);
+    template<typename TObject> void refreshCache(util::Map<std::string, TrackedRecord<TObject>>&cache, util::Map<std::string, TrackedRecord<TObject>>&refreshedCache);
+    util::Map<std::string, User*> getObservers(MappingInfo& mapping);
+    void saveObservers(MappingInfo& mapping, util::Map<std::string, User*>& observers);
 };
 
 /*
@@ -123,9 +132,7 @@ Description: Persists all modified and newly added records
              shared-memory mapping. Modified records overwrite
              their existing slots, while new records are
              appended to the end of the mapping. Records marked
-             as CLEAN are ignored. After persistence, all
+             as CLEAN are ignored.
-             temporary objects owned by the tracked records are
-             destroyed to release memory.
 Parameter:
     - mapping: Reference to the mapping where records are
                stored.
@@ -158,14 +165,82 @@ template<typename TObject, typename TSerialized> void DataStore::saveRecords(Map
                 continue;
             }
             size_t recordCount = SharedMemory::getRecordCount(mapping);
-            TSerialized* destination = static_cast<TSerialized*>(SharedMemory::getRecordAddress(mapping, recordCount));
+            TSerialized* destination = static_cast<TSerialized*>(SharedMemory::getRecordAddress(mapping,recordCount));
             *destination = serialized;
             SharedMemory::setRecordCount(mapping, recordCount + 1);
+            record.slotIndex = recordCount;
+        }
+        record.state = RecordState::CLEAN;
+    }
+}
+
+/*
+Function: clearCache
+Description: Releases all objects owned by the cache and
+             clears the cache contents.
+Parameters:
+    - cache: Cache to be cleared.
+Returns:
+    - None
+*/
+template<typename TObject>
+void DataStore::clearCache(util::Map<std::string, TrackedRecord<TObject>>&cache)
+{
+    for (int index = 0; index < cache.getSize(); ++index)
+    {
+        delete cache.getValueAt(index).data;
+        cache.getValueAt(index).data = nullptr;
+    }
+    cache.clear();
+}
+
+/*
+Function: refreshCache
+Description: Refreshes the cache while preserving object addresses
+             for records that already exist. Existing objects are
+             updated in-place so that pointers held elsewhere remain
+             valid after the refresh.
+Parameters:
+    - cache: Existing cache to refresh.
+    - refreshedCache: Newly loaded cache contents.
+Returns:
+    - None
+*/
+template<typename TObject>
+void DataStore::refreshCache(util::Map<std::string, TrackedRecord<TObject>>& cache, util::Map<std::string, TrackedRecord<TObject>>& refreshedCache)
+{
+    util::Map<std::string, TrackedRecord<TObject>> oldCache = cache;
+    cache.clear();
+    for (int index = 0; index < refreshedCache.getSize(); ++index)
+    {
+        const std::string& id = refreshedCache.getKeyAt(index);
+        TrackedRecord<TObject>& refreshedRecord = refreshedCache.getValueAt(index);
+        int oldIndex = oldCache.find(id);
+        if (oldIndex != -1)
+        {
+            TrackedRecord<TObject>& oldRecord = oldCache.getValueAt(oldIndex);
+            *oldRecord.data = *refreshedRecord.data;
+            oldRecord.slotIndex = refreshedRecord.slotIndex;
+            oldRecord.state = refreshedRecord.state;
+            delete refreshedRecord.data;
+            refreshedRecord.data = oldRecord.data;
+        }
+        cache.insert(id, refreshedRecord);
+    }
+    for (int index = 0; index < oldCache.getSize(); ++index)
+    {
+        const std::string& id = oldCache.getKeyAt(index);
+        const TrackedRecord<TObject>& localTrackedRecord = oldCache.getValueAt(index);
+        if (cache.find(id) == -1)
+        {
+            if (localTrackedRecord.state == RecordState::NEW_RECORD)
+            {
+                cache.insert(id, localTrackedRecord);
+            }
+            else
+            {
+                delete localTrackedRecord.data;
+            }
         }
     }
-    for (int index = 0; index < records.getSize(); ++index)
-    {
-        delete records.getValueAt(index).data;
-        records.getValueAt(index).data = nullptr;
-    }
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/DataStoreLockGuard.h

@@ -0,0 +1,28 @@
+/*
+File: DataStoreLockGuard.h
+Description: Defines the DataStoreLockGuard class used to manage DataStore
+             locking and unlocking automatically within a scope.
+Author: Trenser
+Date: 12-June-2026
+*/
+
+#pragma once
+#include "DataStore.h"
+
+class DataStoreLockGuard
+{
+public:
+    explicit DataStoreLockGuard(DataStore& dataStore)
+        : m_dataStore(dataStore)
+    {
+        m_dataStore.lockDataStore();
+    }
+    ~DataStoreLockGuard()
+    {
+        m_dataStore.unlockDataStore();
+    }
+    DataStoreLockGuard(const DataStoreLockGuard&) = delete;
+    DataStoreLockGuard& operator=(const DataStoreLockGuard&) = delete;
+private:
+    DataStore& m_dataStore;
+};

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/sharedmemory/SharedMemory.cpp

@@ -10,6 +10,7 @@ Created: 11-June-2026
 */
 
 #include "SharedMemory.h"
+#include "Windows.h"
 #include "Config.h"
 
 /*
@@ -319,7 +320,7 @@ bool SharedMemory::ensureCapacityForInsert(MappingInfo& mapping)
     {
         return true;
     }
-    return resizeMapping(mapping, capacity * 2);
+    return resizeMapping(mapping, capacity * config::file::GROWTH_FACTOR);
 }
 
 /*

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/ComboPackage.cpp

@@ -9,7 +9,6 @@ Date: 19-May-2026
 
 #include <sstream>
 #include <stdexcept>
-#include "SerializedRecords.h"
 #include "ComboPackage.h"
 #include "Service.h"
 #include "Factory.h"
@@ -271,38 +270,72 @@ static util::Vector<std::string> getServiceIDsAsVector(const std::string& servic
 
 /*
 Function: serialize
-Description: Serializes the ComboPackage object into a SerializedComboPackage record.
+Description: Serializes the combo package into a CSV-formatted string.
 Parameters:
     - None
 Returns:
-    - SerializedComboPackage: Serialized representation of the combo package
+    - std::string: Serialized combo package record
 */
-SerializedComboPackage ComboPackage::serialize() const
+std::string ComboPackage::serialize() const
 {
-    SerializedComboPackage serialized = {};
+    std::ostringstream serializedComboPackage;
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    serializedComboPackage << m_id << ','
-    strcpy_s(serialized.packageName, sizeof(serialized.packageName), m_packageName.c_str());
+        << m_packageName << ','
-    strcpy_s(serialized.serviceIDs, sizeof(serialized.serviceIDs), getServiceIDsAsString(m_serviceIDs).c_str());
+        << m_discountPercentage << ','
-    serialized.discountPercentage = m_discountPercentage;
+        << getServiceIDsAsString(m_serviceIDs) << ','
-    serialized.status = m_status;
+        << util::getStateString(m_status);
-    return serialized;
+    return serializedComboPackage.str();
 }
 
 /*
 Function: deserialize
-Description: Deserializes a SerializedComboPackage record into a ComboPackage object.
+Description: Deserializes a CSV-formatted string into a ComboPackage object.
 Parameters:
-    - serializedComboPackage: const SerializedComboPackage&, serialized combo package record
+    - record: const std::string&, serialized combo package record
 Returns:
     - ComboPackage*: Pointer to the deserialized ComboPackage object
+Throws:
+    - std::runtime_error if data is invalid
 */
-ComboPackage* ComboPackage::deserialize(const SerializedComboPackage& serializedComboPackage)
+ComboPackage* ComboPackage::deserialize(const std::string& record)
 {
-    util::Vector<std::string> serviceIDs = getServiceIDsAsVector(serializedComboPackage.serviceIDs);
+    std::string id, packageName;
+    std::string discountPercentageString, serviceIDsString, statusString;
+    double discountPercentage;
+    std::istringstream serializedComboPackage(record);
+    getline(serializedComboPackage, id, ',');
+    getline(serializedComboPackage, packageName, ',');
+    getline(serializedComboPackage, discountPercentageString, ',');
+    getline(serializedComboPackage, serviceIDsString, ',');
+    getline(serializedComboPackage, statusString, ',');
+    try
+    {
+        discountPercentage = std::stod(discountPercentageString);
+    }
+    catch (...)
+    {
+        throw std::runtime_error("Invalid combo package data");
+    }
+    util::Vector<std::string> serviceIDs = getServiceIDsAsVector(serviceIDsString);
+    util::State status = util::getState(statusString);
     return Factory::getObject<ComboPackage>(
-        serializedComboPackage.id,
+        id,
-        serializedComboPackage.packageName,
+        packageName,
-        serializedComboPackage.discountPercentage,
+        discountPercentage,
         serviceIDs,
-        serializedComboPackage.status);
+        status
-}
+    );
+}
+
+/*
+Function: getHeaders
+Description: Retrieves the CSV headers for combo package serialization.
+Parameters:
+    - None
+Returns:
+    - std::string: Header string ("ID,PackageName,DiscountPercentage,ServiceIDs,Status")
+*/
+std::string ComboPackage::getHeaders()
+{
+    return "ID,PackageName,DiscountPercentage,ServiceIDs,Status";
+}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/ComboPackage.h

@@ -12,7 +12,7 @@ Date: 19-May-2026
 #include "Enums.h"
 
 class Service;
-class SerializedComboPackage;
+struct SerializedComboPackage;
 
 class ComboPackage
 {
@@ -39,6 +39,7 @@ public:
     void setDiscountPercentage(double discountPercentage);
     void setServices(const util::Map<std::string, Service*>& services);
     void setState(util::State status);
-    SerializedComboPackage serialize() const;
+    std::string serialize() const;
-    static ComboPackage* deserialize(const SerializedComboPackage&);
+    static ComboPackage* deserialize(const std::string&);
+    static std::string getHeaders();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/InventoryItem.cpp

@@ -8,7 +8,6 @@ Date: 19-May-2026
 
 #include <sstream>
 #include <stdexcept>
-#include "SerializedRecords.h"
 #include "Factory.h"
 #include "StringHelper.h"
 #include "InventoryItem.h"
@@ -207,37 +206,73 @@ void InventoryItem::setState(util::State status)
 
 /*
 Function: serialize
-Description: Serializes the InventoryItem object into a SerializedInventoryItem record.
+Description: Serializes the inventory item into a CSV-formatted string.
 Parameters:
     - None
 Returns:
-    - SerializedInventoryItem: Serialized representation of the inventory item
+    - std::string: Serialized inventory item record
 */
-SerializedInventoryItem InventoryItem::serialize() const
+std::string InventoryItem::serialize() const
 {
-    SerializedInventoryItem serialized = {};
+    std::ostringstream serializedInventoryItem;
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    serializedInventoryItem << m_id << ','
-    strcpy_s(serialized.partName, sizeof(serialized.partName), m_partName.c_str());
+        << m_partName << ','
-    serialized.quantity = m_quantity;
+        << m_quantity << ','
-    serialized.price = m_price;
+        << m_price << ','
-    serialized.status = m_status;
+        << util::getStateString(m_status);
-    return serialized;
+    return serializedInventoryItem.str();
 }
 
 /*
 Function: deserialize
-Description: Deserializes a SerializedInventoryItem record into an InventoryItem object.
+Description: Deserializes a CSV-formatted string into an InventoryItem object.
 Parameters:
-    - serializedInventoryItem: const SerializedInventoryItem&, serialized inventory item record
+    - record: const std::string&, serialized inventory item record
 Returns:
     - InventoryItem*: Pointer to the deserialized InventoryItem object
+Throws:
+    - std::runtime_error if data is invalid
 */
-InventoryItem* InventoryItem::deserialize(const SerializedInventoryItem& serializedInventoryItem)
+InventoryItem* InventoryItem::deserialize(const std::string& record)
 {
+    std::string id, partName;
+    std::string quantityString, priceString, statusString;
+    int quantity;
+    double price;
+    std::istringstream serializedInventoryItem(record);
+    getline(serializedInventoryItem, id, ',');
+    getline(serializedInventoryItem, partName, ',');
+    getline(serializedInventoryItem, quantityString, ',');
+    getline(serializedInventoryItem, priceString, ',');
+    getline(serializedInventoryItem, statusString, ',');
+    try
+    {
+        quantity = std::stoi(quantityString);
+        price = std::stod(priceString);
+    }
+    catch (...)
+    {
+        throw std::runtime_error("Invalid inventory item data");
+    }
+    util::State status = util::getState(statusString);
     return Factory::getObject<InventoryItem>(
-        serializedInventoryItem.id,
+        id,
-        serializedInventoryItem.partName,
+        partName,
-        serializedInventoryItem.quantity,
+        quantity,
-        serializedInventoryItem.price,
+        price,
-        serializedInventoryItem.status);
+        status
+    );
+}
+
+/*
+Function: getHeaders
+Description: Retrieves the CSV headers for inventory item serialization.
+Parameters:
+    - None
+Returns:
+    - std::string: Header string ("ID,PartName,Quantity,Price,Status")
+*/
+std::string InventoryItem::getHeaders()
+{
+    return "ID,PartName,Quantity,Price,Status";
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/InventoryItem.h

@@ -6,12 +6,11 @@ Author: Trenser
 Date: 19-May-2026
 */
 
+
 #pragma once
 #include <string>
 #include "Enums.h"
 
-struct SerializedInventoryItem;
-
 class InventoryItem
 {
 private:
@@ -35,6 +34,7 @@ public:
     void setQuantity(int quantity);
     void setPrice(double price);
     void setState(util::State status);
-    SerializedInventoryItem serialize() const;
+    std::string serialize() const;
-    static InventoryItem* deserialize(const SerializedInventoryItem&);
+    static InventoryItem* deserialize(const std::string&);
+    static std::string getHeaders();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/Invoice.cpp

@@ -9,7 +9,6 @@ Date: 19-May-2026
 
 #include <sstream>
 #include <stdexcept>
-#include "SerializedRecords.h"
 #include "Invoice.h"
 #include "Factory.h"
 #include "InventoryItem.h"
@@ -474,50 +473,100 @@ static util::Vector<std::string> getPartIDsAsVector(const std::string& partIDsSt
 
 /*
 Function: serialize
-Description: Serializes the Invoice object into a SerializedInvoice record.
+Description: Serializes the invoice into a CSV-formatted string.
 Parameters:
     - None
 Returns:
-    - SerializedInvoice: Serialized representation of the invoice
+    - std::string: Serialized invoice record
 */
-SerializedInvoice Invoice::serialize() const
+std::string Invoice::serialize() const
 {
-    SerializedInvoice serialized = {};
+    std::ostringstream serializedInvoice;
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    serializedInvoice << m_id << ','
-    strcpy_s(serialized.bookingId, sizeof(serialized.bookingId), m_bookingId.c_str());
+        << m_bookingId << ','
-    strcpy_s(serialized.partIDs, sizeof(serialized.partIDs), getPartIDsAsString(m_partIDs).c_str());
+        << m_invoiceDate.toString() << ','
-    serialized.invoiceDate = m_invoiceDate;
+        << m_laborCost << ','
-    serialized.laborCost = m_laborCost;
+        << getPartIDsAsString(m_partIDs) << ','
-    serialized.partsCost = m_partsCost;
+        << m_partsCost << ','
-    serialized.discountPercentage = m_discountPercentage;
+        << m_discountPercentage << ','
-    serialized.totalAmount = m_totalAmount;
+        << m_totalAmount << ','
-    serialized.paymentDate = m_paymentDate;
+        << m_paymentDate.toString() << ','
-    serialized.paymentMethod = m_paymentMethod;
+        << util::getPaymentModeString(m_paymentMethod) << ','
-    serialized.status = m_status;
+        << util::getPaymentStatusString(m_status);
-    return serialized;
+    return serializedInvoice.str();
 }
 
 /*
 Function: deserialize
-Description: Deserializes a SerializedInvoice record into an Invoice object.
+Description: Deserializes a CSV-formatted string into an Invoice object.
 Parameters:
-    - serializedInvoice: const SerializedInvoice&, serialized invoice record
+    - record: const std::string&, serialized invoice record
 Returns:
     - Invoice*: Pointer to the deserialized Invoice object
+Throws:
+    - std::runtime_error if data is invalid
 */
-Invoice* Invoice::deserialize(const SerializedInvoice& serializedInvoice)
+Invoice* Invoice::deserialize(const std::string& record)
 {
-    util::Vector<std::string> partIDs = getPartIDsAsVector(serializedInvoice.partIDs);
+    std::string id, bookingId;
+    std::string invoiceDateString, laborCostString, partIDsString;
+    std::string partsCostString, discountPercentageString, totalAmountString;
+    std::string paymentDateString, paymentMethodString, statusString;
+    double laborCost, partsCost, discountPercentage, totalAmount;
+    std::istringstream serializedInvoice(record);
+    getline(serializedInvoice, id, ',');
+    getline(serializedInvoice, bookingId, ',');
+    getline(serializedInvoice, invoiceDateString, ',');
+    getline(serializedInvoice, laborCostString, ',');
+    getline(serializedInvoice, partIDsString, ',');
+    getline(serializedInvoice, partsCostString, ',');
+    getline(serializedInvoice, discountPercentageString, ',');
+    getline(serializedInvoice, totalAmountString, ',');
+    getline(serializedInvoice, paymentDateString, ',');
+    getline(serializedInvoice, paymentMethodString, ',');
+    getline(serializedInvoice, statusString, ',');
+    util::Timestamp invoiceDate;
+    util::Timestamp paymentDate;
+    try
+    {
+        invoiceDate = util::Timestamp::fromString(invoiceDateString);
+        paymentDate = util::Timestamp::fromString(paymentDateString);
+        laborCost = std::stod(laborCostString);
+        partsCost = std::stod(partsCostString);
+        discountPercentage = std::stod(discountPercentageString);
+        totalAmount = std::stod(totalAmountString);
+    }
+    catch (...)
+    {
+        throw std::runtime_error("Invalid invoice data");
+    }
+    util::Vector<std::string> partIDs = getPartIDsAsVector(partIDsString);
+    util::PaymentMode paymentMethod = util::getPaymentMode(paymentMethodString);
+    util::PaymentStatus status = util::getPaymentStatus(statusString);
     return Factory::getObject<Invoice>(
-        serializedInvoice.id,
+        id,
-        serializedInvoice.bookingId,
+        bookingId,
-        serializedInvoice.invoiceDate,
+        invoiceDate,
         partIDs,
-        serializedInvoice.laborCost,
+        laborCost,
-        serializedInvoice.partsCost,
+        partsCost,
-        serializedInvoice.discountPercentage,
+        discountPercentage,
-        serializedInvoice.totalAmount,
+        totalAmount,
-        serializedInvoice.paymentDate,
+        paymentDate,
-        serializedInvoice.paymentMethod,
+        paymentMethod,
-        serializedInvoice.status);
+        status
+    );
+}
+
+/*
+Function: getHeaders
+Description: Retrieves the CSV headers for invoice serialization.
+Parameters:
+    - None
+Returns:
+    - std::string: Header string ("ID,BookingID,InvoiceDate,LaborCost,PartIDs,PartsCost,DiscountPercentage,TotalAmount,PaymentDate,PaymentMethod,Status")
+*/
+std::string Invoice::getHeaders()
+{
+    return "ID,BookingID,InvoiceDate,LaborCost,PartIDs,PartsCost,DiscountPercentage,TotalAmount,PaymentDate,PaymentMethod,Status";
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/Invoice.h

@@ -16,7 +16,6 @@ Date: 19-May-2026
 
 class ServiceBooking;
 class InventoryItem;
-struct SerializedInvoice;
 
 class Invoice
 {
@@ -88,6 +87,7 @@ public:
     void setPaymentDate(const util::Timestamp& paymentDate);
     void setPaymentMethod(util::PaymentMode paymentMethod);
     void setStatus(util::PaymentStatus status);
-    SerializedInvoice serialize() const;
+    std::string serialize() const;
-    static Invoice* deserialize(const SerializedInvoice&);
+    static Invoice* deserialize(const std::string&);
+    static std::string getHeaders();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/JobCard.cpp

@@ -9,7 +9,6 @@ Date:19-May-2026
 
 #include <sstream>
 #include <stdexcept>
-#include "SerializedRecords.h"
 #include "JobCard.h"
 #include "Factory.h"
 #include "StringHelper.h"
@@ -352,41 +351,79 @@ void JobCard::setCompletionDate(const util::Timestamp& completionDate)
 
 /*
 Function: serialize
-Description: Serializes the JobCard object into a SerializedJobCard record.
+Description: Serializes the job card into a CSV-formatted string.
 Parameters:
     - None
 Returns:
-    - SerializedJobCard: Serialized representation of the job card
+    - std::string: Serialized job card record
 */
-SerializedJobCard JobCard::serialize() const
+std::string JobCard::serialize() const
 {
-    SerializedJobCard serialized = {};
+    std::ostringstream serializedJobCard;
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    serializedJobCard << m_id << ','
-    strcpy_s(serialized.bookingId, sizeof(serialized.bookingId), m_bookingId.c_str());
+        << m_bookingId << ','
-    strcpy_s(serialized.serviceId, sizeof(serialized.serviceId), m_serviceId.c_str());
+        << m_serviceId << ','
-    strcpy_s(serialized.technicianId, sizeof(serialized.technicianId), m_technicianId.c_str());
+        << m_technicianId << ','
-    serialized.assignedDate = m_assignedDate;
+        << m_assignedDate.toString() << ','
-    serialized.status = m_status;
+        << util::getServiceJobStatusString(m_status) << ','
-    serialized.completionDate = m_completionDate;
+        << m_completionDate.toString();
-    return serialized;
+    return serializedJobCard.str();
 }
 
 /*
 Function: deserialize
-Description: Deserializes a SerializedJobCard record into a JobCard object.
+Description: Deserializes a CSV-formatted string into a JobCard object.
 Parameters:
-    - serializedJobCard: const SerializedJobCard&, serialized job card record
+    - record: const std::string&, serialized job card record
 Returns:
     - JobCard*: Pointer to the deserialized JobCard object
+Throws:
+    - std::runtime_error if timestamp parsing fails
 */
-JobCard* JobCard::deserialize(const SerializedJobCard& serializedJobCard)
+JobCard* JobCard::deserialize(const std::string& record)
 {
+    std::string id, bookingId, serviceId, technicianId;
+    std::string assignedDateString, statusString, completionDateString;
+    std::istringstream serializedJobCard(record);
+    getline(serializedJobCard, id, ',');
+    getline(serializedJobCard, bookingId, ',');
+    getline(serializedJobCard, serviceId, ',');
+    getline(serializedJobCard, technicianId, ',');
+    getline(serializedJobCard, assignedDateString, ',');
+    getline(serializedJobCard, statusString, ',');
+    getline(serializedJobCard, completionDateString, ',');
+    util::Timestamp assignedDate;
+    util::Timestamp completionDate;
+    try
+    {
+        assignedDate = util::Timestamp::fromString(assignedDateString);
+        completionDate = util::Timestamp::fromString(completionDateString);
+    }
+    catch (...)
+    {
+        throw std::runtime_error("Invalid timestamp");
+    }
+    util::ServiceJobStatus status = util::getServiceJobStatus(statusString);
     return Factory::getObject<JobCard>(
-        serializedJobCard.id,
+        id,
-        serializedJobCard.bookingId,
+        bookingId,
-        serializedJobCard.serviceId,
+        serviceId,
-        serializedJobCard.technicianId,
+        technicianId,
-        serializedJobCard.assignedDate,
+        assignedDate,
-        serializedJobCard.status,
+        status,
-        serializedJobCard.completionDate);
+        completionDate
+    );
+}
+
+/*
+Function: getHeaders
+Description: Retrieves the CSV headers for job card serialization.
+Parameters:
+    - None
+Returns:
+    - std::string: Header string ("ID,BookingID,ServiceID,TechnicianID,AssignedDate,Status,CompletionDate")
+*/
+std::string JobCard::getHeaders()
+{
+    return "ID,BookingID,ServiceID,TechnicianID,AssignedDate,Status,CompletionDate";
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/JobCard.h

@@ -15,7 +15,6 @@ Date:19-May-2026
 class ServiceBooking;
 class Service;
 class User;
-struct SerializedJobCard;
 
 class JobCard
 {
@@ -71,6 +70,7 @@ public:
     void setAssignedDate(const util::Timestamp& assignedDate);
     void setStatus(util::ServiceJobStatus status);
     void setCompletionDate(const util::Timestamp& completionDate);
-    SerializedJobCard serialize() const;
+    std::string serialize() const;
-    static JobCard* deserialize(const SerializedJobCard&);
+    static JobCard* deserialize(const std::string&);
+    static std::string getHeaders();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/Notification.cpp

@@ -1,7 +1,7 @@
 /*
 File: Notification.cpp
 Description: Implements the Notification class which represents system notifications in the Vehicle Service Management System.
-             Provides constructors, accessors, and mutators for notification details such as ID, recipient, title, message, and timestamp.
+             Provides constructors, accessors, and mutators for notification details such as ID, recipientID, title, message, and timestamp.
 Author: Trenser
 Date: 19-May-2026
 */
@@ -23,8 +23,8 @@ Returns:
     - A new Notification object.
 */
 Notification::Notification()
-    : m_id("NOT" + std::to_string(++m_uid)),
+    : m_id("NOT" + std::to_string(++m_uid)), 
-    m_recipient(nullptr), m_state(util::State::ACTIVE) {}
+    m_state(util::State::ACTIVE) {}
 
 /*
 Function: Notification
@@ -38,14 +38,14 @@ Parameters:
 Returns:
     - A new Notification object.
 */
-Notification::Notification(const std::string& recipientUserId, User* recipient, const std::string& title, const std::string& message, const util::Timestamp& createdAt)
+Notification::Notification(const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt)
     : m_id("NOT" + std::to_string(++m_uid)),
     m_recipientUserId(recipientUserId),
-    m_recipient(recipient),
     m_title(title),
     m_message(message),
     m_state(util::State::ACTIVE),
-    m_createdAt(createdAt){}
+    m_createdAt(createdAt) {
+}
 
 /*
 Function: Notification (parameterized constructor with ID)
@@ -63,7 +63,6 @@ Returns:
 Notification::Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt, const util::State& state)
     : m_id(id),
     m_recipientUserId(recipientUserId),
-    m_recipient(nullptr),
     m_title(title),
     m_message(message),
     m_createdAt(createdAt),
@@ -82,7 +81,7 @@ Description: Retrieves the unique ID of the notification.
 Returns:
     - const std::string& representing the notification ID.
 */
-const std::string& Notification::getId() const 
+const std::string& Notification::getId() const
 {
     return m_id;
 }
@@ -98,17 +97,6 @@ const std::string& Notification::getRecipientUserId() const
     return m_recipientUserId;
 }
 
-/*
-Function: getRecipient
-Description: Retrieves the pointer to the recipient user.
-Returns:
-    - User* representing the recipient.
-*/
-User* Notification::getRecipient() const
-{
-    return m_recipient;
-}
-
 /*
 Function: getTitle
 Description: Retrieves the title of the notification.
@@ -142,6 +130,17 @@ const util::Timestamp& Notification::getCreatedAt() const
     return m_createdAt;
 }
 
+/*
+Function: getState
+Description: Retrieves the Notification state
+Returns:
+    - const util::Timestamp& representing the creation timestamp.
+*/
+util::State Notification::getState() const
+{
+    return m_state;
+}
+
 /*
 Function: setId
 Description: Sets the unique ID of the notification.
@@ -168,19 +167,6 @@ void Notification::setRecipientUserId(const std::string& recipientUserId)
     m_recipientUserId = recipientUserId;
 }
 
-/*
-Function: setRecipient
-Description: Sets the recipient user pointer for the notification.
-Parameters:
-    - recipient: Pointer to the User object.
-Returns:
-    - void
-*/
-void Notification::setRecipient(User* recipient)
-{
-    m_recipient = recipient;
-}
-
 /*
 Function: setTitle
 Description: Sets the title of the notification.
@@ -220,6 +206,19 @@ void Notification::setCreatedAt(const util::Timestamp& createdAt)
     m_createdAt = createdAt;
 }
 
+/*
+Function: setState
+Description: Sets the Notification state.
+Parameters:
+    - state: Notification state value.
+Returns:
+    - void
+*/
+void Notification::setState(util::State state)
+{
+    m_state = state;
+}
+
 /*
 Function: serialize
 Description: Serializes the Notification object into a SerializedNotification record.

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/Notification.h

@@ -20,28 +20,25 @@ private:
     static int m_uid;
     std::string m_id;
     std::string m_recipientUserId;
-    User* m_recipient;
     std::string m_title;
     std::string m_message;
     util::Timestamp m_createdAt;
     util::State m_state;
 public:
     Notification();
-    Notification(const std::string& recipientUserId, User* recipient, const std::string& title, const std::string& message, const util::Timestamp& createdAt);
+    Notification(const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt);
     Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt, const util::State& state);
     const std::string& getId() const;
     const std::string& getRecipientUserId() const;
-    User* getRecipient() const;
     const std::string& getTitle() const;
     const std::string& getMessage() const;
     const util::Timestamp& getCreatedAt() const;
     void setId(const std::string& id);
     void setRecipientUserId(const std::string& recipientUserId);
-    void setRecipient(User* recipient);
     void setTitle(const std::string& title);
     void setMessage(const std::string& message);
     void setCreatedAt(const util::Timestamp& createdAt);
-    util::State getState();
+    util::State getState() const;
     void setState(util::State state);
     SerializedNotification serialize() const;
     static Notification* deserialize(const SerializedNotification&);

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/Service.cpp

@@ -8,7 +8,6 @@ Date: 19-May-2026
 */
 
 #include <sstream>
-#include "SerializedRecords.h"
 #include "Service.h"
 #include "InventoryItem.h"
 #include "StringHelper.h"
@@ -267,38 +266,72 @@ static util::Vector<std::string> getInventoryItemIDsAsVector(const std::string&
 
 /*
 Function: serialize
-Description: Serializes the Service object into a SerializedService record.
+Description: Serializes the service into a CSV-formatted string.
 Parameters:
     - None
 Returns:
-    - SerializedService: Serialized representation of the service
+    - std::string: Serialized service record
 */
-SerializedService Service::serialize() const
+std::string Service::serialize() const
 {
-    SerializedService serialized = {};
+    std::ostringstream serializedService;
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    serializedService << m_id << ','
-    strcpy_s(serialized.name, sizeof(serialized.name), m_name.c_str());
+        << m_name << ','
-    strcpy_s(serialized.inventoryItemIDs, sizeof(serialized.inventoryItemIDs), getInventoryItemIDsAsString(m_requiredInventoryItemIDs).c_str());
+        << getInventoryItemIDsAsString(m_requiredInventoryItemIDs) << ','
-    serialized.laborCost = m_laborCost;
+        << m_laborCost << ','
-    serialized.status = m_status;
+        << util::getStateString(m_status);
-    return serialized;
+    return serializedService.str();
 }
 
 /*
 Function: deserialize
-Description: Deserializes a SerializedService record into a Service object.
+Description: Deserializes a CSV-formatted string into a Service object.
 Parameters:
-    - serializedService: const SerializedService&, serialized service record
+    - record: const std::string&, serialized service record
 Returns:
     - Service*: Pointer to the deserialized Service object
+Throws:
+    - std::runtime_error if labor cost parsing fails
 */
-Service* Service::deserialize(const SerializedService& serializedService)
+Service* Service::deserialize(const std::string& record)
 {
-    util::Vector<std::string> inventoryItemIDs = getInventoryItemIDsAsVector(serializedService.inventoryItemIDs);
+    std::string id, name;
+    std::string inventoryItemIDsString, laborCostString, statusString;
+    double laborCost;
+    std::istringstream serializedService(record);
+    getline(serializedService, id, ',');
+    getline(serializedService, name, ',');
+    getline(serializedService, inventoryItemIDsString, ',');
+    getline(serializedService, laborCostString, ',');
+    getline(serializedService, statusString, ',');
+    util::Vector<std::string> inventoryItemIDs = getInventoryItemIDsAsVector(inventoryItemIDsString);
+    try
+    {
+        laborCost = std::stod(laborCostString);
+    }
+    catch (...)
+    {
+        throw std::runtime_error("Invalid labor cost");
+    }
+    util::State status = util::getState(statusString);
     return Factory::getObject<Service>(
-        serializedService.id,
+        id,
-        serializedService.name,
+        name,
         inventoryItemIDs,
-        serializedService.laborCost,
+        laborCost,
-        serializedService.status);
+        status
+    );
+}
+
+/*
+Function: getHeaders
+Description: Retrieves the CSV headers for service serialization.
+Parameters:
+    - None
+Returns:
+    - std::string: Header string ("ID,Name,InventoryIDs,LaborCost,Status")
+*/
+std::string Service::getHeaders()
+{
+    return "ID,Name,InventoryIDs,LaborCost,Status";
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/Service.h

@@ -6,6 +6,7 @@ Author: Trenser
 Date: 19-May-2026
 */
 
+
 #pragma once
 #include <string>
 #include "Map.h"
@@ -13,7 +14,6 @@ Date: 19-May-2026
 #include "Enums.h"
 
 class InventoryItem;
-struct SerializedService;
 
 class Service
 {
@@ -40,6 +40,7 @@ public:
     void setRequiredInventoryItems(const util::Map<std::string, InventoryItem*>& requiredInventoryItems);
     void setLaborCost(double laborCost);
     void setState(util::State status);
-    SerializedService serialize() const;
+    std::string serialize() const;
-    static Service* deserialize(const SerializedService&);
+    static Service* deserialize(const std::string&);
+    static std::string getHeaders();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/ServiceBooking.cpp

@@ -6,10 +6,8 @@ Description: Implementation file containing the method definitions of the
 Author: Trenser
 Date:19-May-2026
 */
-
 #include <stdexcept>
 #include <sstream>
-#include "SerializedRecords.h"
 #include "ServiceBooking.h"
 #include "Service.h"
 #include "Enums.h"
@@ -439,46 +437,84 @@ static util::Vector<std::string> getServiceIDsAsVector(const std::string& servic
 
 /*
 Function: serialize
-Description: Serializes the ServiceBooking object into a SerializedServiceBooking record.
+Description: Serializes the service booking into a CSV-formatted string.
 Parameters:
     - None
 Returns:
-    - SerializedServiceBooking: Serialized representation of the service booking
+    - std::string: Serialized booking record
 */
-SerializedServiceBooking ServiceBooking::serialize() const
+std::string ServiceBooking::serialize() const
 {
-    SerializedServiceBooking serialized = {};
+    std::ostringstream serializedBooking;
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    serializedBooking << m_id << ','
-    strcpy_s(serialized.serviceIDs, sizeof(serialized.serviceIDs), getServiceIDsAsString(m_serviceIDs).c_str());
+        << util::getServiceJobStatusString(m_status) << ','
-    strcpy_s(serialized.customerId, sizeof(serialized.customerId), m_customerId.c_str());
+        << getServiceIDsAsString(m_serviceIDs) << ','
-    strcpy_s(serialized.vehicleNumber, sizeof(serialized.vehicleNumber), m_vehicleNumber.c_str());
+        << m_customerId << ','
-    strcpy_s(serialized.vehicleBrand, sizeof(serialized.vehicleBrand), m_vehicleBrand.c_str());
+        << m_vehicleNumber << ','
-    strcpy_s(serialized.vehicleModel, sizeof(serialized.vehicleModel), m_vehicleModel.c_str());
+        << m_vehicleBrand << ','
-    strcpy_s(serialized.assignedTechnicianId, sizeof(serialized.assignedTechnicianId), m_assignedTechnicianId.c_str());
+        << m_vehicleModel << ','
-    serialized.status = m_status;
+        << m_assignedTechnicianId << ','
-    serialized.discountPercentage = m_discountPercentage;
+        << m_discountPercentage << ',';
-    return serialized;
+    return serializedBooking.str();
 }
 
 /*
 Function: deserialize
-Description: Deserializes a SerializedServiceBooking record into a ServiceBooking object.
+Description: Deserializes a CSV-formatted string into a ServiceBooking object.
 Parameters:
-    - serializedServiceBooking: const SerializedServiceBooking&, serialized service booking record
+    - record: const std::string&, serialized booking record
 Returns:
     - ServiceBooking*: Pointer to the deserialized ServiceBooking object
+Throws:
+    - std::runtime_error if discount percentage parsing fails
 */
-ServiceBooking* ServiceBooking::deserialize(const SerializedServiceBooking& serializedServiceBooking)
+ServiceBooking* ServiceBooking::deserialize(const std::string& record)
 {
-    util::Vector<std::string> serviceIDs = getServiceIDsAsVector(serializedServiceBooking.serviceIDs);
+    std::string id, customerId, vehicleNumber, vehicleBrand, vehicleModel, assignedTechnicianId;
+    std::string serviceJobStatusString, serviceIDsString, discountPercentageString;
+    double discountPercentage;
+    std::istringstream serializedBooking(record);
+    getline(serializedBooking, id, ',');
+    getline(serializedBooking, serviceJobStatusString, ',');
+    getline(serializedBooking, serviceIDsString, ',');
+    getline(serializedBooking, customerId, ',');
+    getline(serializedBooking, vehicleNumber, ',');
+    getline(serializedBooking, vehicleBrand, ',');
+    getline(serializedBooking, vehicleModel, ',');
+    getline(serializedBooking, assignedTechnicianId, ',');
+    getline(serializedBooking, discountPercentageString, ',');
+    util::Vector<std::string> serviceIDs = getServiceIDsAsVector(serviceIDsString);
+    try
+    {
+        discountPercentage = std::stod(discountPercentageString);
+    }
+    catch (...)
+    {
+        throw std::runtime_error("Invalid discount percentage");
+    }
+    util::ServiceJobStatus status = util::getServiceJobStatus(serviceJobStatusString);
     return Factory::getObject<ServiceBooking>(
-        serializedServiceBooking.id,
+        id,
-        serializedServiceBooking.status,
+        status,
         serviceIDs,
-        serializedServiceBooking.customerId,
+        customerId,
-        serializedServiceBooking.vehicleNumber,
+        vehicleNumber,
-        serializedServiceBooking.vehicleBrand,
+        vehicleBrand,
-        serializedServiceBooking.vehicleModel,
+        vehicleModel,
-        serializedServiceBooking.assignedTechnicianId,
+        assignedTechnicianId,
-        serializedServiceBooking.discountPercentage);
+        discountPercentage
+    );
+}
+
+/*
+Function: getHeaders
+Description: Retrieves the CSV headers for service booking serialization.
+Parameters:
+    - None
+Returns:
+    - std::string: Header string ("ID,Status,ServiceIDs,CustomerID,VehicleNumber,VehicleBrand,VehicleModel,AssignedTechnicianID,DiscountPercentage")
+*/
+std::string ServiceBooking::getHeaders()
+{
+    return "ID,Status,ServiceIDs,CustomerID,VehicleNumber,VehicleBrand,VehicleModel,AssignedTechnicianID,DiscountPercentage";
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/ServiceBooking.h

@@ -6,7 +6,6 @@ Description: Header file declaring the ServiceBooking class, which represents
 Author: Trenser
 Date:19-May-2026
 */
-
 #pragma once
 #include <string>
 #include "Map.h"
@@ -15,7 +14,6 @@ Date:19-May-2026
 
 class Service;
 class User;
-struct SerializedServiceBooking;
 
 class ServiceBooking
 {
@@ -80,6 +78,7 @@ public:
     void setAssignedTechnicianId(const std::string& assignedTechnicianId);
     void setAssignedTechnician(User* assignedTechnician);
     void setDiscountPercentage(double discountPercentage);
-    SerializedServiceBooking serialize() const;
+    std::string serialize() const;
-    static ServiceBooking* deserialize(const SerializedServiceBooking&);
+    static ServiceBooking* deserialize(const std::string&);
+    static std::string getHeaders();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/User.cpp

@@ -29,7 +29,8 @@ Returns:
 User::User()
     : m_id("USR" + std::to_string(++m_uid)),
     m_type(util::UserType::CUSTOMER),
-    m_status(util::State::ACTIVE) {}
+    m_status(util::State::ACTIVE) {
+}
 
 /*
 Function: User
@@ -52,7 +53,8 @@ User::User(const std::string& userName, const std::string& password, const std::
     m_phone(phone),
     m_email(email),
     m_type(role),
-    m_status(util::State::ACTIVE) {}
+    m_status(util::State::ACTIVE) {
+}
 
 /*
 Function: User (parameterized constructor with ID)
@@ -87,23 +89,6 @@ User::User(const std::string& userId, const std::string& userName, const std::st
     }
 }
 
-/*
-Function: ~User
-Description: Destructor that cleans up dynamically allocated notifications associated with the user.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-User::~User()
-{
-    auto values = m_notifications.getValues();
-    for (int index = 0; index < values.getSize(); index++)
-    {
-        delete values[index];
-    }
-}
-
 /*
 Function: getId
 Description: Retrieves the unique ID of the user.
@@ -170,17 +155,6 @@ const std::string& User::getEmail() const
     return m_email;
 }
 
-/*
-Function: getNotifications
-Description: Retrieves the map of notifications associated with the user.
-Returns:
-    - util::Map<std::string, Notification*>& representing the notifications.
-*/
-util::Map<std::string, Notification*>& User::getNotifications()
-{
-    return m_notifications;
-}
-
 /*
 Function: getUserType
 Description: Retrieves the role of the user.
@@ -281,22 +255,6 @@ void User::setEmail(const std::string& email)
     m_email = email;
 }
 
-/*
-Function: addNotification
-Description: Adds a new notification to the user’s notification map.
-Parameters:
-    - notification: Pointer to the Notification object.
-Returns:
-    - void
-*/
-void User::addNotification(Notification* notification)
-{
-    if (notification)
-    {
-        m_notifications.insert(notification->getId(), notification);
-    }
-}
-
 /*
 Function: setRole
 Description: Sets the role of the user.

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/models/User.h

@@ -26,21 +26,19 @@ private:
     std::string m_name;
     std::string m_phone;
     std::string m_email;
-    util::Map<std::string, Notification*> m_notifications;
     util::UserType m_type;
     util::State m_status;
 public:
     User();
     User(const std::string& userName, const std::string& password, const std::string& name, const std::string& phone, const std::string& email, util::UserType role);
     User(const std::string& userId, const std::string& userName, const std::string& password, const std::string& name, const std::string& phone, const std::string& email, util::UserType role, util::State status);
-    ~User();
+    ~User() = default;
     const std::string& getId() const;
     const std::string& getUserName() const;
     const std::string& getPassword() const;
     const std::string& getName() const;
     const std::string& getPhone() const;
     const std::string& getEmail() const;
-    util::Map<std::string, Notification*>& getNotifications();
     util::UserType getUserType() const;
     util::State getState() const;
     void setId(const std::string& id);
@@ -49,7 +47,6 @@ public:
     void setName(const std::string& name);
     void setPhone(const std::string& phone);
     void setEmail(const std::string& email);
-    void addNotification(Notification* notification) override;
     void setRole(util::UserType role);
     void setState(util::State status);
     SerializedUser serialize() const;

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/AuthenticationManagementService.cpp

@@ -10,6 +10,8 @@ Date:19-May-2026
 #include <stdexcept>
 #include "AuthenticationManagementService.h"
 #include "User.h"
+#include "Utility.h"
+#include "DataStoreLockGuard.h"
 
 User* AuthenticationManagementService::m_authenticatedUser = nullptr;
 
@@ -24,11 +26,12 @@ Return type: bool - true if login successful, false otherwise
 */
 bool AuthenticationManagementService::login(const std::string& username, const std::string& password)
 {
-	util::Map<std::string, User*> users = m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
-	int usersMapSize = users.getSize();
+	auto& trackedUserMap = m_dataStore.getUsers();
-	for (int index = 0; index < usersMapSize; index++)
+	int trackedUserMapSize = trackedUserMap.getSize();
+	for (int index = 0; index < trackedUserMapSize; index++)
 	{
-		User* user = users.getValueAt(index);
+		User* user = trackedUserMap.getValueAt(index).data;
 		if (username == user->getUserName())
 		{
 			if (password == user->getPassword())
@@ -74,9 +77,18 @@ Return type: void
 */
 void AuthenticationManagementService::changePassword(const std::string& newPassword)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
 	if (m_authenticatedUser == nullptr)
 	{
 		throw std::runtime_error("There is no user currently logged in!");
 	}
+	int index = trackedUsersMap.find(m_authenticatedUser->getId());
+	if (index == -1)
+	{
+		throw std::runtime_error("User does not exist!\n");
+	}
 	m_authenticatedUser->setPassword(newPassword);
+	trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
+	m_dataStore.saveUsers();
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/InventoryManagementService.cpp

@@ -12,14 +12,13 @@ Date: 22-May-2026
 #include "Config.h"
 #include "Enums.h"
 #include "Factory.h"
-#include "FileManager.h"
 #include "InventoryItem.h"
 #include "InventoryManagementService.h"
 #include "Timestamp.h"
 #include "User.h"
 #include "Utility.h"
 #include "Vector.h"
-
+#include "DataStoreLockGuard.h"
 
 util::Map<std::string, User*> InventoryManagementService::m_observers{};
 
@@ -90,95 +89,6 @@ void InventoryManagementService::sendLowStockAlerts()
 	}
 }
 
-/*
-Function: getObserverIDs
-Description: Retrieves the IDs of all observers currently attached to the
-			 InventoryManagementService.
-Parameters:
-	- None
-Returns:
-	- util::Vector<std::string>: Vector of observer user IDs
-*/
-util::Vector<std::string> InventoryManagementService::getObserverIDs()
-{
-	util::Vector<std::string> observerIDs;
-	int numberOfObservers = m_observers.getSize();
-	for (int index = 0; index < numberOfObservers; index++)
-	{
-		User* observer = m_observers.getValueAt(index);
-		if (observer)
-		{
-			observerIDs.push_back(observer->getId());
-		}
-	}
-	return observerIDs;
-}
-
-/*
-Function: loadInventoryItems
-Description: Loads inventory items from persistent storage into the datastore.
-			 Uses FileManager to deserialize inventory items from the configured file.
-Parameters:
-	- None
-Returns:
-	- void
-*/
-void InventoryManagementService::loadInventoryItems()
-{
-	util::FileManager<InventoryItem> inventoryItemFileManager(config::file::INVENTORYITEM_FILE);
-	auto& inventoryItems = m_dataStore.getInventoryItems();
-	auto inventoryItemsMap = inventoryItemFileManager.load();
-	int numberOfInventoryItems = inventoryItemsMap.getSize();
-	for (int index = 0; index < numberOfInventoryItems; index++)
-	{
-		inventoryItems[inventoryItemsMap.getKeyAt(index)] = inventoryItemsMap.getValueAt(index);
-	}
-}
-
-/*
-Function: saveInventoryItems
-Description: Saves inventory items from the datastore to persistent storage.
-			 Uses FileManager to serialize inventory items into the configured file.
-Parameters:
-	- None
-Returns:
-	- void
-*/
-void InventoryManagementService::saveInventoryItems()
-{
-	util::FileManager<InventoryItem> inventoryItemFileManager(config::file::INVENTORYITEM_FILE);
-	auto& inventoryItems = m_dataStore.getInventoryItems();
-	inventoryItemFileManager.save(inventoryItems);
-}
-
-/*
-Function: loadObservers
-Description: Loads observer IDs from persistent storage and attaches corresponding
-			 users as observers to the InventoryManagementService.
-Parameters:
-	- None
-Returns:
-	- void
-*/
-void InventoryManagementService::loadObservers()
-{
-	util::loadObservers(config::file::INVENTORYMANAGEMENTOBSERVERS, this, m_dataStore);
-}
-
-/*
-Function: saveObservers
-Description: Saves the current observer IDs of the InventoryManagementService
-			 to persistent storage for future retrieval.
-Parameters:
-	- None
-Returns:
-	- void
-*/
-void InventoryManagementService::saveObservers()
-{
-	util::saveObservers(config::file::INVENTORYMANAGEMENTOBSERVERS, this);
-}
-
 /*
 Function: addInventoryItem
 Description: Creates a new inventory item using the Factory and inserts it
@@ -271,6 +181,9 @@ Returns:
 */
 void InventoryManagementService::attach(User* user)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers.clear();
+	m_observers = m_dataStore.getInventoryManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -279,6 +192,7 @@ void InventoryManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
+	m_dataStore.saveInventoryManagementObservers(m_observers);
 }
 
 /*
@@ -291,6 +205,9 @@ Returns:
 */
 void InventoryManagementService::detach(User* user)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers.clear();
+	m_observers = m_dataStore.getInventoryManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -299,6 +216,7 @@ void InventoryManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
+	m_dataStore.saveInventoryManagementObservers(m_observers);
 }
 
 /*
@@ -315,27 +233,27 @@ Throws:
 */
 void InventoryManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (user)
+	if (!user)
 	{
-		if (m_observers.find(user->getId()) != -1)
+		return;
-		{
-			Notification* notification =
-				Factory::getObject<Notification>(
-					user->getId(),
-					user,
-					title,
-					message,
-					util::Timestamp()
-				);
-			if (notification)
-			{
-				user->addNotification(notification);
-			}
-			else
-			{
-				throw std::runtime_error("Failed to create notification");
-			}
-		}
 	}
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers = m_dataStore.getInventoryManagementObservers();
+	if (m_observers.find(user->getId()) == -1)
+	{
+		return;
+	}
+	Notification* notification = Factory::getObject<Notification>(
+		user->getId(),
+		title,
+		message,
+		util::Timestamp());
+	if (!notification)
+	{
+		throw std::runtime_error("Failed to create notification");
+	}
+	auto& trackedNotificationsMap = m_dataStore.getNotifications();
+	trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
+	m_dataStore.saveNotifications();
 }
 

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/InventoryManagementService.h

@@ -21,7 +21,6 @@ class InventoryManagementService : public NotificationManagementService
 private:
     DataStore& m_dataStore;
     static util::Map<std::string, User*> m_observers;
-    util::Vector<std::string> getObserverIDs() override;
 public:
     InventoryManagementService() : m_dataStore(DataStore::getInstance()) {}
     util::Map<std::string, InventoryItem*> getInventoryItems();
@@ -33,8 +32,4 @@ public:
     void sendNotification(User* user, const std::string& title, const std::string& message) override;
     void attach(User* user) override;
     void detach(User* user) override;
-    void loadInventoryItems();
-    void saveInventoryItems();
-    void loadObservers();
-    void saveObservers();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/NotificationManagementService.cpp

@@ -1 +0,0 @@
-#include "NotificationManagementService.h"

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/NotificationManagementService.h

@@ -19,5 +19,4 @@ public:
 	virtual void sendNotification(User* recipient, const std::string& title, const std::string& message) = 0;
 	virtual void attach(User* user) = 0;
 	virtual void detach(User* user) = 0;
-	virtual util::Vector<std::string> getObserverIDs() = 0;
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.cpp

@@ -11,7 +11,6 @@ Date: 20-May-2026
 #include "Config.h"
 #include "Enums.h"
 #include "Factory.h"
-#include "FileManager.h"
 #include "InventoryItem.h"
 #include "Invoice.h"
 #include "JobCard.h"
@@ -21,6 +20,7 @@ Date: 20-May-2026
 #include "Timestamp.h"
 #include "User.h"
 #include "Utility.h"
+#include "DataStoreLockGuard.h"
 
 util::Map<std::string, User*> PaymentManagementService::m_observers{};
 
@@ -34,6 +34,9 @@ Returns:
 */
 void PaymentManagementService::attach(User* user)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers.clear();
+	m_observers = m_dataStore.getPaymentManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -42,6 +45,7 @@ void PaymentManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
+	m_dataStore.savePaymentManagementObservers(m_observers);
 }
 
 /*
@@ -54,6 +58,9 @@ Returns:
 */
 void PaymentManagementService::detach(User* user)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers.clear();
+	m_observers = m_dataStore.getPaymentManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -62,6 +69,7 @@ void PaymentManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
+	m_dataStore.savePaymentManagementObservers(m_observers);
 }
 
 /*
@@ -78,28 +86,28 @@ Throws:
 */
 void PaymentManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (user)
+	if (!user)
 	{
-		if (m_observers.find(user->getId()) != -1)
+		return;
-		{
-			Notification* notification =
-				Factory::getObject<Notification>(
-					user->getId(),
-					user,
-					title,
-					message,
-					util::Timestamp()
-				);
-			if (notification)
-			{
-				user->addNotification(notification);
-			}
-			else
-			{
-				throw std::runtime_error("Failed to create notification");
-			}
-		}
 	}
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers = m_dataStore.getPaymentManagementObservers();
+	if (m_observers.find(user->getId()) == -1)
+	{
+		return;
+	}
+	Notification* notification = Factory::getObject<Notification>(
+		user->getId(),
+		title,
+		message,
+		util::Timestamp());
+	if (!notification)
+	{
+		throw std::runtime_error("Failed to create notification");
+	}
+	auto& trackedNotificationsMap = m_dataStore.getNotifications();
+	trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
+	m_dataStore.saveNotifications();
 }
 
 /*
@@ -140,123 +148,6 @@ void PaymentManagementService::sendPaymentReminders()
 	}
 }
 
-/*
-Function: getObserverIDs
-Description: Retrieves the IDs of all observers currently attached to the
-             PaymentManagementService.
-Parameters:
-    - None
-Returns:
-    - util::Vector<std::string>: Vector of observer user IDs
-*/
-util::Vector<std::string> PaymentManagementService::getObserverIDs()
-{
-	util::Vector<std::string> observerIDs;
-	int numberOfObservers = m_observers.getSize();
-	for (int index = 0; index < numberOfObservers; index++)
-	{
-		User* observer = m_observers.getValueAt(index);
-		if (observer)
-		{
-			observerIDs.push_back(observer->getId());
-		}
-	}
-	return observerIDs;
-}
-
-/*
-Function: loadInvoices
-Description: Loads invoices from persistent storage into the datastore.
-             Validates associated service bookings and inventory parts before
-             attaching them to each invoice. Throws exceptions if invalid IDs
-             are encountered.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a booking ID or part ID is invalid
-*/
-void PaymentManagementService::loadInvoices()
-{
-    util::FileManager<Invoice> invoiceFileManager(config::file::INVOICE_FILE);
-    auto& invoices = m_dataStore.getInvoices();
-    auto& serviceBookings = m_dataStore.getServiceBookings();
-    auto& inventoryItems = m_dataStore.getInventoryItems();
-    auto invoicesMap = invoiceFileManager.load();
-    for (int invoiceIndex = 0; invoiceIndex < invoicesMap.getSize(); invoiceIndex++)
-    {
-        Invoice* invoice = invoicesMap.getValueAt(invoiceIndex);
-        int bookingIndex = serviceBookings.find(invoice->getBookingId());
-        if (bookingIndex == -1)
-        {
-            throw std::runtime_error("Invalid Booking ID");
-        }
-        ServiceBooking* booking = serviceBookings.getValueAt(bookingIndex);
-        invoice->setBooking(booking);
-        util::Map<std::string, InventoryItem*> invoiceParts;
-        auto& partIDs = invoice->getPartIDs();
-        for (int partIndex = 0; partIndex < partIDs.getSize(); partIndex++)
-        {
-            const std::string& partID = partIDs[partIndex];
-            int inventoryIndex = inventoryItems.find(partID);
-            if (inventoryIndex == -1)
-            {
-                throw std::runtime_error("Invalid Part ID");
-            }
-            invoiceParts[partID] = inventoryItems.getValueAt(inventoryIndex);
-        }
-        invoice->setParts(invoiceParts);
-        invoices[invoice->getId()] = invoice;
-    }
-}
-
-/*
-Function: saveInvoices
-Description: Saves invoices from the datastore to persistent storage.
-             Uses FileManager to serialize invoices into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void PaymentManagementService::saveInvoices()
-{
-    util::FileManager<Invoice> invoiceFileManager(config::file::INVOICE_FILE);
-    auto& invoices = m_dataStore.getInvoices();
-    invoiceFileManager.save(invoices);
-}
-
-/*
-Function: loadObservers
-Description: Loads observer IDs from persistent storage and attaches corresponding
-             users as observers to the PaymentManagementService.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if an observer ID is invalid (not found in datastore)
-*/
-void PaymentManagementService::loadObservers()
-{
-    util::loadObservers(config::file::PAYMENTMANAGEMENTOBSERVERS, this, m_dataStore);
-}
-
-/*
-Function: saveObservers
-Description: Saves the current observer IDs of the PaymentManagementService
-             to persistent storage for future retrieval.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void PaymentManagementService::saveObservers()
-{
-    util::saveObservers(config::file::PAYMENTMANAGEMENTOBSERVERS, this);
-}
-
 /*
 Function: createInventoryItemsMap (static helper)
 Description: Builds a map of inventory items required for a given service and adds them to the booking’s inventory map.

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.h

@@ -22,7 +22,6 @@ class PaymentManagementService : public NotificationManagementService
 private:
     DataStore& m_dataStore;
     static util::Map<std::string, User*> m_observers;
-    util::Vector<std::string> getObserverIDs() override;
 public:
     PaymentManagementService() : m_dataStore(DataStore::getInstance()) {}
     void generateInvoice(ServiceBooking* booking);
@@ -34,8 +33,4 @@ public:
     void sendNotification(User* user, const std::string& title, const std::string& message) override;
     void attach(User* user) override;
     void detach(User* user) override;
-    void loadInvoices();
-    void saveInvoices();
-    void loadObservers();
-    void saveObservers();
 };

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

@@ -14,7 +14,6 @@ Date:19-May-2026
 #include "DataStore.h"
 #include "Enums.h"
 #include "Factory.h"
-#include "FileManager.h"
 #include "InventoryItem.h"
 #include "JobCard.h"
 #include "NotificationManagementService.h"
@@ -26,6 +25,7 @@ Date:19-May-2026
 #include "User.h"
 #include "UserManagementService.h"
 #include "Utility.h"
+#include "DataStoreLockGuard.h"
 
 /*
 Function: purchaseService
@@ -122,6 +122,9 @@ Returns:
 */
 void ServiceManagementService::attach(User* user)
 {
+    DataStoreLockGuard lock(m_dataStore);
+    m_observers.clear();
+    m_observers = m_dataStore.getServiceManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -130,6 +133,7 @@ void ServiceManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
+    m_dataStore.saveServiceManagementObservers(m_observers);
 }
 
 /*
@@ -142,6 +146,9 @@ Returns:
 */
 void ServiceManagementService::detach(User* user)
 {
+    DataStoreLockGuard lock(m_dataStore);
+    m_observers.clear();
+    m_observers = m_dataStore.getServiceManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -150,6 +157,7 @@ void ServiceManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
+    m_dataStore.saveServiceManagementObservers(m_observers);
 }
 
 /*
@@ -166,345 +174,28 @@ Throws:
 */
 void ServiceManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (user)
+    if (!user)
-	{
-		if (m_observers.find(user->getId()) != -1)
-		{
-			Notification* notification =
-				Factory::getObject<Notification>(
-					user->getId(),
-					user,
-					title,
-					message,
-					util::Timestamp()
-				);
-			if (notification)
-			{
-				user->addNotification(notification);
-			}
-			else
-			{
-				throw std::runtime_error("Failed to create notification");
-			}
-		}
-	}
-}
-
-/*
-Function: getObserverIDs
-Description: Retrieves the IDs of all observers currently attached to the
-             ServiceManagementService.
-Parameters:
-    - None
-Returns:
-    - util::Vector<std::string>: Vector of observer user IDs
-*/
-util::Vector<std::string> ServiceManagementService::getObserverIDs()
-{
-	util::Vector<std::string> observerIDs;
-	int numberOfObservers = m_observers.getSize();
-	for (int index = 0; index < numberOfObservers; index++)
-	{
-		User* observer = m_observers.getValueAt(index);
-		if (observer)
-		{
-			observerIDs.push_back(observer->getId());
-		}
-	}
-	return observerIDs;
-}
-
-/*
-Function: loadServices
-Description: Loads services from persistent storage into the datastore.
-             Validates required inventory items and attaches them to each service.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if an inventory item ID is invalid
-*/
-void ServiceManagementService::loadServices()
-{
-    util::FileManager<Service> serviceFileManager(config::file::SERVICE_FILE);
-    auto& services = m_dataStore.getServices();
-    auto& inventoryItems = m_dataStore.getInventoryItems();
-    auto servicesMap = serviceFileManager.load();
-    for (int serviceIndex = 0; serviceIndex < servicesMap.getSize(); serviceIndex++)
     {
-        Service* service = servicesMap.getValueAt(serviceIndex);
+        return;
-        services[service->getId()] = service;
-        util::Map<std::string, InventoryItem*> inventoryItemsMap;
-        auto& inventoryItemIDs = service->getRequiredInventoryItemIDs();
-        for (int inventoryItemIndex = 0; inventoryItemIndex < inventoryItemIDs.getSize(); inventoryItemIndex++)
-        {
-            const std::string& inventoryItemID = inventoryItemIDs[inventoryItemIndex];
-            int index = inventoryItems.find(inventoryItemID);
-            if (index == -1)
-            {
-                throw std::runtime_error("Invalid Inventory Item ID");
-            }
-            inventoryItemsMap[inventoryItemID] = inventoryItems.getValueAt(index);
-        }
-        service->setRequiredInventoryItems(inventoryItemsMap);
     }
-}
+    DataStoreLockGuard lock(m_dataStore);
-
+    m_observers = m_dataStore.getServiceManagementObservers();
-/*
+    if (m_observers.find(user->getId()) == -1)
-Function: saveServices
-Description: Saves services from the datastore to persistent storage.
-             Uses FileManager to serialize services into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveServices()
-{
-	util::FileManager<Service> serviceFileManager(config::file::SERVICE_FILE);
-	auto& services = m_dataStore.getServices();
-	serviceFileManager.save(services);
-}
-
-/*
-Function: loadComboPackages
-Description: Loads combo packages from persistent storage into the datastore.
-             Validates associated services and attaches them to each package.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a service ID is invalid
-*/
-void ServiceManagementService::loadComboPackages()
-{
-    util::FileManager<ComboPackage> comboPackageFileManager(config::file::COMBOPACKAGE_FILE);
-    auto& comboPackages = m_dataStore.getComboPackages();
-    auto& services = m_dataStore.getServices();
-    auto comboPackagesMap = comboPackageFileManager.load();
-    for (int packageIndex = 0; packageIndex < comboPackagesMap.getSize(); packageIndex++)
     {
-        ComboPackage* comboPackage = comboPackagesMap.getValueAt(packageIndex);
+        return;
-        util::Map<std::string, Service*> packageServices;
-        auto& serviceIDs = comboPackage->getServiceIDs();
-        for (int serviceIndex = 0; serviceIndex < serviceIDs.getSize(); serviceIndex++)
-        {
-            const std::string& serviceID = serviceIDs[serviceIndex];
-            int serviceMapIndex = services.find(serviceID);
-            if (serviceMapIndex == -1)
-            {
-                throw std::runtime_error("Invalid Service ID");
-            }
-            packageServices[serviceID] = services.getValueAt(serviceMapIndex);
-        }
-        comboPackage->setServices(packageServices);
-        comboPackages[comboPackage->getId()] = comboPackage;
     }
-}
+    Notification* notification = Factory::getObject<Notification>(
-
+        user->getId(),
-/*
+        title,
-Function: saveComboPackages
+        message,
-Description: Saves combo packages from the datastore to persistent storage.
+        util::Timestamp());
-             Uses FileManager to serialize combo packages into the configured file.
+    if (!notification)
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveComboPackages()
-{
-    util::FileManager<ComboPackage> comboPackageFileManager(config::file::COMBOPACKAGE_FILE);
-    auto& comboPackages = m_dataStore.getComboPackages();
-    comboPackageFileManager.save(comboPackages);
-}
-
-/*
-Function: loadServiceBookings
-Description: Loads service bookings from persistent storage into the datastore.
-             Validates associated services, customers, and technicians before
-             attaching them to each booking.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a service ID, customer ID, or technician ID is invalid
-    - std::runtime_error if a user is not of the expected type (customer/technician)
-*/
-void ServiceManagementService::loadServiceBookings()
-{
-    util::FileManager<ServiceBooking> bookingFileManager(config::file::SERVICEBOOKING_FILE);
-    auto& serviceBookings = m_dataStore.getServiceBookings();
-    auto& services = m_dataStore.getServices();
-    auto& users = m_dataStore.getUsers();
-    auto bookingsMap = bookingFileManager.load();
-    for (int bookingIndex = 0; bookingIndex < bookingsMap.getSize(); bookingIndex++)
     {
-        ServiceBooking* booking = bookingsMap.getValueAt(bookingIndex);
+        throw std::runtime_error("Failed to create notification");
-        util::Map<std::string, Service*> bookingServices;
-        auto& serviceIDs = booking->getServiceIDs();
-        for (int serviceIndex = 0; serviceIndex < serviceIDs.getSize(); serviceIndex++)
-        {
-            const std::string& serviceID = serviceIDs[serviceIndex];
-            int serviceMapIndex = services.find(serviceID);
-            if (serviceMapIndex == -1)
-            {
-                throw std::runtime_error("Invalid Service ID");
-            }
-
-            bookingServices[serviceID] = services.getValueAt(serviceMapIndex);
-        }
-        booking->setServices(bookingServices);
-        int customerIndex = users.find(booking->getCustomerId());
-        if (customerIndex == -1)
-        {
-            throw std::runtime_error("Invalid Customer ID");
-        }
-        User* customer = users.getValueAt(customerIndex);
-        if (customer->getUserType() != util::UserType::CUSTOMER)
-        {
-            throw std::runtime_error("User is not a customer");
-        }
-        booking->setCustomer(customer);
-        const std::string& technicianId = booking->getAssignedTechnicianId();
-        if (!technicianId.empty())
-        {
-            int technicianIndex = users.find(technicianId);
-            if (technicianIndex == -1)
-            {
-                throw std::runtime_error("Invalid Technician ID");
-            }
-            User* technician = users.getValueAt(technicianIndex);
-            if (technician->getUserType() != util::UserType::TECHNICIAN)
-            {
-                throw std::runtime_error("User is not a technician");
-            }
-            booking->setAssignedTechnician(technician);
-        }
-        serviceBookings[booking->getId()] = booking;
     }
-}
+    auto& trackedNotificationsMap = m_dataStore.getNotifications();
-
+    trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
-/*
+    m_dataStore.saveNotifications();
-Function: saveServiceBookings
-Description: Saves service bookings from the datastore to persistent storage.
-             Uses FileManager to serialize bookings into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveServiceBookings()
-{
-    util::FileManager<ServiceBooking> bookingFileManager(config::file::SERVICEBOOKING_FILE);
-    auto& serviceBookings = m_dataStore.getServiceBookings();
-    bookingFileManager.save(serviceBookings);
-}
-
-/*
-Function: loadJobCards
-Description: Loads job cards from persistent storage into the datastore.
-             Validates associated bookings, services, and technicians before
-             attaching them to each job card.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a booking ID, service ID, or technician ID is invalid
-    - std::runtime_error if a service does not belong to the booking
-    - std::runtime_error if a user is not a technician
-*/
-void ServiceManagementService::loadJobCards()
-{
-    util::FileManager<JobCard> jobCardFileManager(config::file::JOBCARD_FILE);
-    auto& jobCards = m_dataStore.getJobCards();
-    auto& serviceBookings = m_dataStore.getServiceBookings();
-    auto& services = m_dataStore.getServices();
-    auto& users = m_dataStore.getUsers();
-    auto jobCardsMap = jobCardFileManager.load();
-    for (int jobCardIndex = 0; jobCardIndex < jobCardsMap.getSize(); jobCardIndex++)
-    {
-        JobCard* jobCard = jobCardsMap.getValueAt(jobCardIndex);
-        int bookingIndex = serviceBookings.find(jobCard->getBookingId());
-        if (bookingIndex == -1)
-        {
-            throw std::runtime_error("Invalid Booking ID");
-        }
-        ServiceBooking* booking = serviceBookings.getValueAt(bookingIndex);
-        jobCard->setBooking(booking);
-        int serviceIndex = services.find(jobCard->getServiceId());
-        if (serviceIndex == -1)
-        {
-            throw std::runtime_error("Invalid Service ID");
-        }
-        Service* service = services.getValueAt(serviceIndex);
-        if (booking->getServices().find(jobCard->getServiceId()) == -1)
-        {
-            throw std::runtime_error("Service does not belong to booking");
-        }
-        jobCard->setService(service);
-        int technicianIndex = users.find(jobCard->getTechnicianId());
-        if (technicianIndex == -1)
-        {
-            throw std::runtime_error("Invalid Technician ID");
-        }
-        User* technician = users.getValueAt(technicianIndex);
-        if (technician->getUserType() != util::UserType::TECHNICIAN)
-        {
-            throw std::runtime_error("User is not a technician");
-        }
-        jobCard->setTechnician(technician);
-        jobCards[jobCard->getId()] = jobCard;
-    }
-}
-
-/*
-Function: saveJobCards
-Description: Saves job cards from the datastore to persistent storage.
-             Uses FileManager to serialize job cards into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveJobCards()
-{
-    util::FileManager<JobCard> jobCardFileManager(config::file::JOBCARD_FILE);
-    auto& jobCards = m_dataStore.getJobCards();
-    jobCardFileManager.save(jobCards);
-}
-
-/*
-Function: loadObservers
-Description: Loads observer IDs from persistent storage and attaches corresponding
-             users as observers to the ServiceManagementService.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if an observer ID is invalid (not found in datastore)
-*/
-void ServiceManagementService::loadObservers()
-{
-    util::loadObservers(config::file::SERVICEMANAGEMENTOBSERVERS, this, m_dataStore);
-}
-
-/*
-Function: saveObservers
-Description: Saves the current observer IDs of the ServiceManagementService
-             to persistent storage for future retrieval.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveObservers()
-{
-    util::saveObservers(config::file::SERVICEMANAGEMENTOBSERVERS, this);
 }
 
 /*

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/ServiceManagementService.h

@@ -23,7 +23,6 @@ class ServiceManagementService : public NotificationManagementService
 private:
     DataStore& m_dataStore;
     static util::Map<std::string, User*> m_observers;
-    util::Vector<std::string> getObserverIDs() override;
 public:
     ServiceManagementService() : m_dataStore(DataStore::getInstance()) {}
     util::Map<std::string, Service*> getServices();
@@ -45,14 +44,4 @@ public:
     void sendNotification(User* user, const std::string& title, const std::string& message) override;
     void attach(User* user) override;
     void detach(User* user) override;
-    void loadServices();
-    void saveServices();
-    void loadComboPackages();
-    void saveComboPackages();
-    void loadServiceBookings();
-    void saveServiceBookings();
-    void loadJobCards();
-    void saveJobCards();
-    void loadObservers();
-    void saveObservers();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/UserManagementService.cpp

@@ -11,7 +11,6 @@ Date:19-May-2026
 #include "Config.h"
 #include "Enums.h"
 #include "Factory.h"
-#include "FileManager.h"
 #include "InventoryManagementService.h"
 #include "Notification.h"
 #include "PaymentManagementService.h"
@@ -20,6 +19,9 @@ Date:19-May-2026
 #include "UserManagementService.h"
 #include "Vector.h"
 #include "Validator.h"
+#include "Utility.h"
+#include "TrackedRecord.h"
+#include "DataStoreLockGuard.h"
 
 /*
 Function: ensureAdminExists
@@ -31,12 +33,13 @@ Return type: void
 */
 void UserManagementService::ensureAdminExists()
 {
+	DataStoreLockGuard lock(m_dataStore);
 	auto& usersMap = m_dataStore.getUsers();
 	int usersMapSize = usersMap.getSize();
 	bool isAdminFound = false;
 	for (int index = 0; index < usersMapSize; index++)
 	{
-		User* user = usersMap.getValueAt(index);
+		User* user = usersMap.getValueAt(index).data;
 		if (user && user->getUserType() == util::UserType::ADMIN)
 		{
 			isAdminFound = true;
@@ -73,7 +76,9 @@ void UserManagementService::createUser(const std::string& username, const std::s
 	InventoryManagementService inventoryManagementService;
 	PaymentManagementService paymentManagementService;
 	ServiceManagementService serviceManagementService;
-	auto& usersMap = m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	auto usersMap = util::getObjects(trackedUsersMap);
 	if (util::isUsernameDuplicate(username, usersMap))
 	{
 		throw std::runtime_error("Username already exists");
@@ -87,13 +92,14 @@ void UserManagementService::createUser(const std::string& username, const std::s
 		throw std::runtime_error("Phone already exists");
 	}
 	User* newUser = Factory::getObject<User>(username, password, name, phone, email, type);
-	usersMap.insert(newUser->getId(), newUser);
+	trackedUsersMap.insert(newUser->getId(), util::createNewRecord(newUser));
 	paymentManagementService.attach(newUser);
 	serviceManagementService.attach(newUser);
 	if (newUser->getUserType() == util::UserType::ADMIN)
 	{
 		inventoryManagementService.attach(newUser);
 	}
+	m_dataStore.saveUsers();
 }
 
 /*
@@ -107,19 +113,24 @@ Return type: void
 */
 void UserManagementService::updateUserDetails(const std::string& userID, const std::string& email, const std::string& phone)
 {
-	auto& usersMap = m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
-	int index = usersMap.find(userID);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	auto usersMap = util::getObjects(trackedUsersMap);
+	int index = trackedUsersMap.find(userID);
 	if (index == -1)
 	{
 		throw std::runtime_error("User does not exist!\n");
 	}
-	User* user = usersMap.getValueAt(index);
+	User* user = trackedUsersMap.getValueAt(index).data;
+	bool isModified = false;
 	if (email != user->getEmail())
 	{
 		if (util::isEmailDuplicate(email, usersMap))
 		{
 			throw std::runtime_error("Email already exists!\n");
 		}
+		user->setEmail(email);
+		isModified = true;
 	}
 	if (phone != user->getPhone())
 	{
@@ -127,9 +138,14 @@ void UserManagementService::updateUserDetails(const std::string& userID, const s
 		{
 			throw std::runtime_error("Phone number already exists!\n");
 		}
+		user->setPhone(phone);
+		isModified = true;
+	}
+	if (isModified)
+	{
+		trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
+		m_dataStore.saveUsers();
 	}
-	user->setEmail(email);
-	user->setPhone(phone);
 }
 
 /*
@@ -144,20 +160,25 @@ Throws:
 */
 util::Vector<Notification*> UserManagementService::getUserNotifications(const std::string& userID)
 {
-	auto& usersMap = m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
-	if (usersMap.find(userID) == -1)
+	auto& trackedUsersMap = m_dataStore.getUsers(); 
+	if (trackedUsersMap.find(userID) == -1)
 	{
 		throw std::runtime_error("No user found with given UserID");
 	}
-	User* user = usersMap[userID];
+	User* user = trackedUsersMap[userID].data;
 	if (user)
 	{
-		auto& notifications = user->getNotifications();
+		auto& trackedNotificationMap = m_dataStore.getNotifications();
-		int numberOfNotifications = notifications.getSize();
+		int numberOfNotifications = trackedNotificationMap.getSize();
 		util::Vector<Notification*> notificationsVector;
 		for (int index = 0; index < numberOfNotifications; index++)
 		{
-		    notificationsVector.push_back(notifications.getValueAt(index));
+			Notification* notification = trackedNotificationMap.getValueAt(index).data;
+			if (notification->getRecipientUserId() == userID && notification->getState() == util::State::ACTIVE)
+			{
+				notificationsVector.push_back(notification);
+			}
 		}
 		return notificationsVector;
 	}
@@ -169,97 +190,39 @@ util::Vector<Notification*> UserManagementService::getUserNotifications(const st
 
 /*
 Function: deleteNotification
-Description: Deletes a specific notification associated with a given user ID.
+Description: Marks a specific notification associated with a given user
+			 as inactive.
 Parameters:
 	- notificationID: The unique ID of the notification to be deleted.
 	- userID: The unique ID of the user whose notification is to be deleted.
 Returns:
 	- void
 Throws:
-	- std::runtime_error if no user is found with the given UserID or if no notification is found with the given NotificationID.
+	- std::runtime_error if no user is found with the given UserID or
+	  if no notification is found with the given NotificationID.
 */
 void UserManagementService::deleteNotification(const std::string& notificationID, const std::string& userID)
 {
-	auto& usersMap = m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
-	if (usersMap.find(userID) == -1)
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	auto& trackedNotificationsMap = m_dataStore.getNotifications();
+	int userIndex = trackedUsersMap.find(userID);
+	if (userIndex == -1)
 	{
 		throw std::runtime_error("No user found with given UserID");
 	}
-	User* user = usersMap[userID];
+	int notificationIndex = trackedNotificationsMap.find(notificationID);
-	auto& notifications = user->getNotifications();
+	if (notificationIndex == -1)
-	if (notifications.find(notificationID) == -1)
 	{
 		throw std::runtime_error("No notification found with given NotificationID");
 	}
-	notifications.remove(notificationID);
+	Notification* notification = trackedNotificationsMap.getValueAt(notificationIndex).data;
-}
+	if (notification->getRecipientUserId() == userID)
-
+	{
-/*
+		notification->setState(util::State::INACTIVE);
-Function: loadUsers
+		trackedNotificationsMap.getValueAt(notificationIndex).state = RecordState::MODIFIED;
-Description: Loads users and notifications from persistent storage into the datastore.
+		m_dataStore.saveNotifications();
-             Validates that each notification’s recipient exists and attaches the
+	}
-             notification to the corresponding user.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a notification recipient user ID is invalid
-*/
-void UserManagementService::loadUsers()
-{
-    util::FileManager<User> userFileManager(config::file::USER_FILE);
-    util::FileManager<Notification> notificationFileManager(config::file::NOTIFICATION_FILE);
-    auto& users = m_dataStore.getUsers();
-    auto usersMap = userFileManager.load();
-    auto notificationsMap = notificationFileManager.load();
-    int numberOfUsers = usersMap.getSize();
-    int numberOfNotifications = notificationsMap.getSize();
-    for (int index = 0; index < numberOfUsers; index++)
-    {
-        users[usersMap.getKeyAt(index)] = usersMap.getValueAt(index);
-    }
-    for (int index = 0; index < numberOfNotifications; index++)
-    {
-        Notification* notification = notificationsMap.getValueAt(index);
-        const std::string& recipientUserId = notification->getRecipientUserId();
-        int userIndex = users.find(recipientUserId);
-        if (userIndex == -1)
-        {
-            throw std::runtime_error("Invalid recipient user ID");
-        }
-        User* user = users.getValueAt(userIndex);
-        user->addNotification(notification);
-    }
-}
-
-/*
-Function: saveUsers
-Description: Saves users and their notifications from the datastore to persistent storage.
-             Collects notifications from all users into a single map before saving.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void UserManagementService::saveUsers()
-{
-    util::FileManager<User> userFileManager(config::file::USER_FILE);
-    util::FileManager<Notification> notificationFileManager(config::file::NOTIFICATION_FILE);
-    auto& users = m_dataStore.getUsers();
-    util::Map<std::string, Notification*> notifications;
-    for (int userIndex = 0; userIndex < users.getSize(); userIndex++)
-    {
-        User* user = users.getValueAt(userIndex);
-        auto& userNotifications = user->getNotifications();
-        for (int notificationIndex = 0; notificationIndex < userNotifications.getSize(); notificationIndex++)
-        {
-            notifications[userNotifications.getKeyAt(notificationIndex)] =
-                userNotifications.getValueAt(notificationIndex);
-        }
-    }
-    userFileManager.save(users);
-    notificationFileManager.save(notifications);
 }
 
 /*
@@ -270,7 +233,9 @@ Return type: util::Map<std::string, User*>
 */
 util::Map<std::string, User*> UserManagementService::getUsers()
 {
-	return m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
+	auto users = util::getObjects(m_dataStore.getUsers());
+	return users;
 }
 
 /*
@@ -281,10 +246,12 @@ Return type: User*
 */
 User* UserManagementService::getUser(const std::string& userID)
 {
-	int index = m_dataStore.getUsers().find(userID);
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	int index = trackedUsersMap.find(userID);
 	if (index != -1)
 	{
-		return m_dataStore.getUsers().getValueAt(index);
+		return trackedUsersMap.getValueAt(index).data;
 	}
 	return nullptr;
 }
@@ -300,35 +267,53 @@ void UserManagementService::removeUser(const std::string& userID)
 	InventoryManagementService inventoryManagementService;
 	PaymentManagementService paymentManagementService;
 	ServiceManagementService serviceManagementService;
-	int index = m_dataStore.getUsers().find(userID);
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	int index = trackedUsersMap.find(userID);
 	if (index != -1)
 	{
-		User* user = m_dataStore.getUsers().getValueAt(index);
+		User* user = trackedUsersMap.getValueAt(index).data;
 		if (user != nullptr)
 		{
 			if (user->getUserType() == util::UserType::CUSTOMER)
 			{
-				serviceManagementService.cancelCustomerServiceBookings(userID);	
+				serviceManagementService.cancelCustomerServiceBookings(userID);
 			}
 			if (user->getUserType() == util::UserType::TECHNICIAN)
 			{
 				serviceManagementService.cancelTechnicianJobs(userID);
 			}
-			user->setState(util::State::INACTIVE);
 			inventoryManagementService.detach(user);
 			paymentManagementService.detach(user);
 			serviceManagementService.detach(user);
+			user->setState(util::State::INACTIVE);
+			trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
+			m_dataStore.saveUsers();
 		}
 	}
 }
 
-util::Map<std::string, User*> UserManagementService::getUsers(util::UserType type)
+/*
+Function: getUsers
+Description: Retrieves all active users of the specified type from
+			 the DataStore.
+Parameters:
+	- type: The user type to filter by
+			(ADMIN, CUSTOMER, or TECHNICIAN).
+Returns:
+	- util::Map<std::string, User*>:
+	  Collection of active users matching the specified type,
+	  keyed by user ID.
+*/
+util::Map<std::string, User*> UserManagementService::getUsers(util::UserType type) 
 {
-	util::Map<std::string, User*>& currentUsers = m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	util::Map<std::string, User*> currentUsers = util::getObjects(trackedUsersMap);
 	util::Map<std::string, User*> filteredUsersMap;
-	for (int iterator = 0; iterator < currentUsers.getSize(); iterator++)
+	for (int index = 0; index < currentUsers.getSize(); index++)
 	{
-		User* currentUser = currentUsers.getValueAt(iterator);
+		User* currentUser = currentUsers.getValueAt(index);
 		if (currentUser && currentUser->getState() == util::State::ACTIVE && currentUser->getUserType() == type)
 		{
 			filteredUsersMap.insert(currentUser->getId(), currentUser);

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/UserManagementService.h

@@ -31,6 +31,4 @@ public:
     util::Vector<Notification*> getUserNotifications(const std::string& userID);
     void deleteNotification(const std::string& notificationID, const std::string& userID);
     void ensureAdminExists();
-    void loadUsers();
-    void saveUsers();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/utilities/Config.h

@@ -29,6 +29,7 @@ namespace config
 	namespace file
 	{
 		const size_t INITIAL_CAPACITY = 100;
+		const size_t GROWTH_FACTOR = 2;
 		constexpr const char* DIRECTORY = "files/";
 		constexpr const char* INVENTORYITEM_FILE = "files/InventoryItem.dat";
 		constexpr const char* USER_FILE = "files/User.dat";

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/utilities/FileHelper.h

@@ -43,67 +43,4 @@ namespace util
             position++;
         }
     }
-
-    /*
-    Function: loadRecords
-    Description: Loads records from a given file path into a vector of strings.
-                 Skips the header line if present. Creates the file if it does not exist.
-    Parameters:
-        - filePath: const std::string&, path to the file
-    Returns:
-        - util::Vector<std::string>: Vector containing all records (excluding header)
-    Throws:
-        - None (creates file if missing)
-    */
-    inline util::Vector<std::string> loadRecords(const std::string& filePath)
-    {
-        util::Vector<std::string> records;
-        std::ifstream file(filePath);
-        if (!file.is_open())
-        {
-            ensureDirectoryExists(filePath);
-            std::ofstream newFile(filePath);
-            newFile.close();
-            file.open(filePath);
-        }
-        std::string line;
-        bool isHeader = true;
-        while (std::getline(file, line))
-        {
-            if (isHeader)
-            {
-                isHeader = false;
-                continue;
-            }
-            records.push_back(line);
-        }
-        return records;
-    }
-
-    /*
-    Function: saveRecords
-    Description: Saves records to a given file path. Overwrites existing content
-                 and writes a header line followed by all records.
-    Parameters:
-        - filePath: const std::string&, path to the file
-        - records: const util::Vector<std::string>&, vector of records to save
-    Returns:
-        - void
-    Throws:
-        - std::runtime_error if the file cannot be opened for writing
-    */
-    inline void saveRecords(const std::string& filePath, const util::Vector<std::string>& records)
-    {
-        std::ofstream file(filePath, std::ios::trunc);
-        if (!file.is_open())
-        {
-            throw std::runtime_error("Failed to open file " + filePath);
-        }
-        file << "Values" << '\n';
-        int numberOfRecords = records.getSize();
-        for (int index = 0; index < numberOfRecords; index++)
-        {
-            file << records[index] << '\n';
-        }
-    }
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/utilities/FileManager.h

@@ -1,119 +0,0 @@
-/*
-File: FileManager.h
-Description: Declares and implements a generic FileManager template class for
-			 loading and saving objects to and from files. Uses serialization
-			 and deserialization methods defined in the object type T.
-			 Provides persistence support for system entities such as Users,
-			 Services, InventoryItems, etc.
-Author: Trenser
-Date: 22-May-2026
-*/
-
-#pragma once
-#include <stdexcept>
-#include <string>
-#include <fstream>
-#include "Vector.h"
-#include "Map.h"
-#include "FileHelper.h"
-
-namespace util
-{
-	template <typename T> using objects = util::Map<std::string, T*>;
-
-	template <typename T>
-	class FileManager
-	{
-	private:
-		std::string m_filePath;
-	public:
-		FileManager() : m_filePath("") {}
-		FileManager(const std::string& filePath) : m_filePath(filePath) {}
-		objects<T> load();
-		void save(const objects<T>&);
-	};
-
-	/*
-	Function: load
-	Description: Loads records from the file into a map of objects.
-				 Skips the header line, deserializes each record into an object of type T,
-				 and stores them in a map keyed by object ID.
-	Parameters:
-		- None
-	Returns:
-		- util::Map<std::string, T*> containing deserialized objects
-	Throws:
-		- std::runtime_error if deserialization fails for any record
-	*/
-	template <typename T>
-	objects<T> FileManager<T>::load()
-	{
-		objects<T> records;
-		std::ifstream file(m_filePath);
-		if (!file.is_open())
-		{
-			ensureDirectoryExists(m_filePath);
-			std::ofstream newFile(m_filePath);
-			newFile.close();
-			file.open(m_filePath);
-		}
-		util::Vector<std::string> lines;
-		std::string line;
-		while (std::getline(file, line))
-		{
-			lines.push_back(line);
-		}
-		int numberOfLines = lines.getSize();
-		bool isHeader = true;
-		for (int lineIndex = 0; lineIndex < numberOfLines; lineIndex++)
-		{
-			const auto& record = lines[lineIndex];
-			if (isHeader)
-			{
-				isHeader = false;
-				continue;
-			}
-			auto object = T::deserialize(record);
-			if (!object)
-			{
-				throw std::runtime_error("Failed to deserialize record");
-			}
-			records[object->getId()] = object;
-		}
-		return records;
-	}
-
-	/*
-	Function: save
-	Description: Saves records to the file. Serializes each object of type T into a string,
-				 writes a header line, and then writes all serialized records to the file.
-	Parameters:
-		- records: const util::Map<std::string, T*>&, map of objects to save
-	Returns:
-		- void
-	Throws:
-		- std::runtime_error if the file cannot be opened for writing
-	*/
-	template <typename T>
-	void FileManager<T>::save(const objects<T>& records)
-	{
-		util::Vector<std::string> lines;
-		lines.push_back(T::getHeaders());
-		int numberOfRecords = records.getSize();
-		for (int recordIndex = 0; recordIndex < numberOfRecords; recordIndex++)
-		{
-			const auto& record = records.getValueAt(recordIndex);
-			lines.push_back(record->serialize());
-		}
-		std::ofstream file(m_filePath, std::ios::trunc);
-		if (!file.is_open())
-		{
-			throw std::runtime_error("Failed to open file " + m_filePath);
-		}
-		int numberOfLines = lines.getSize();
-		for (int lineIndex = 0; lineIndex < numberOfLines; lineIndex++)
-		{
-			file << lines[lineIndex] << '\n';
-		}
-	}
-}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/utilities/InputHelper.h

@@ -28,7 +28,7 @@ namespace util
         if (!(std::cin >> value))
         {
             std::cin.clear();
-            std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
+            std::cin.ignore((std::numeric_limits<std::streamsize>::max)(), '\n');
             throw std::runtime_error("Invalid console input");
         }
     }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/utilities/Utility.h

@@ -54,49 +54,79 @@ namespace util
         return cost;
     }
 
-    /*
+    template<typename TObject>
-    Function: loadObservers
+    Map<std::string, TObject*> getObjects(const Map<std::string, TrackedRecord<TObject>>& trackedRecords);
-    Description: Loads observer IDs from a file and attaches the corresponding users
-                 to the notification management service. Validates that each observer ID
-                 exists in the datastore before attaching.
-    Parameters:
-        - filePath: const std::string&, path to the file containing observer IDs
-        - service: NotificationManagementService*, pointer to the notification service
-        - dataStore: DataStore&, reference to the datastore containing users
-    Returns:
-        - void
-    Throws:
-        - std::runtime_error if an observer ID is invalid (not found in datastore)
-    */
-    inline void loadObservers(const std::string& filePath, NotificationManagementService* service, DataStore& dataStore)
-    {
-        auto observerIDs = util::loadRecords(filePath);
-        auto& users = dataStore.getUsers();
-        for (int index = 0; index < observerIDs.getSize(); index++)
-        {
-            const std::string& observerID = observerIDs[index];
-            int userIndex = users.find(observerID);
-            if (userIndex == -1)
-            {
-                throw std::runtime_error("Invalid Observer ID");
-            }
-            service->attach(users.getValueAt(userIndex));
-        }
-    }
 
-    /*
+    template<typename TObject>
-    Function: saveObservers
+    Map<std::string, const TObject*> getConstObjects(const Map<std::string, TrackedRecord<TObject>>& trackedRecords);
-    Description: Saves the current observer IDs from the notification management service
+
-                 to a file for persistence.
+    template<typename TObject>
-    Parameters:
+    TrackedRecord<TObject> createNewRecord(TObject* object);
-        - filePath: const std::string&, path to the file where observer IDs will be saved
+}
-        - service: NotificationManagementService*, pointer to the notification service
+
-    Returns:
+/*
-        - void
+Function: getObjects
-    */
+Description: Extracts the object pointers from a tracked-record
-    inline void saveObservers(const std::string& filePath, NotificationManagementService* service)
+             collection and returns them as a map keyed by the
+             same identifiers.
+Parameters:
+    - trackedRecords: Collection of tracked records.
+Returns:
+    - Map<std::string, TObject*>: Collection of object pointers.
+*/
+template<typename TObject>
+util::Map<std::string, TObject*> util::getObjects(const util::Map<std::string, TrackedRecord<TObject>>& trackedRecords)
+{
+    util::Map<std::string, TObject*> objects;
+    for (int index = 0; index < trackedRecords.getSize(); ++index)
     {
-        auto observerIDs = service->getObserverIDs();
+        const std::string& key = trackedRecords.getKeyAt(index);
-        util::saveRecords(filePath, observerIDs);
+        TObject* object = trackedRecords.getValueAt(index).data;
+        objects.insert(key, object);
     }
+    return objects;
+}
+
+/*
+Function: getConstObjects
+Description: Extracts the object pointers from a tracked-record
+             collection and returns them as a read-only map
+             keyed by the same identifiers.
+Parameters:
+    - trackedRecords: Collection of tracked records.
+Returns:
+    - Map<std::string, const TObject*>:
+      Collection of read-only object pointers.
+*/
+template<typename TObject>
+util::Map<std::string, const TObject*> util::getConstObjects(
+    const util::Map<std::string, TrackedRecord<TObject>>& trackedRecords)
+{
+    util::Map<std::string, const TObject*> objects;
+    for (int index = 0; index < trackedRecords.getSize(); ++index)
+    {
+        const std::string& key = trackedRecords.getKeyAt(index);
+        const TObject* object = trackedRecords.getValueAt(index).data;
+        objects.insert(key, object);
+    }
+    return objects;
+}
+
+/*
+Function: createNewRecord
+Description: Creates a tracked record for a newly created
+             object. The record is initialized with
+             NEW_RECORD state.
+Parameters:
+    - object: Pointer to the newly created object.
+Returns:
+    - TrackedRecord<TObject>: Initialized tracked record.
+*/
+template<typename TObject>
+TrackedRecord<TObject> util::createNewRecord(TObject* object)
+{
+    TrackedRecord<TObject> record;
+    record.data = object;
+    record.state = RecordState::NEW_RECORD;
+    return record;
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/UserInterface.cpp

@@ -27,8 +27,11 @@ void UserInterface::run()
 {
 	try
 	{
-		m_controller.loadSystemData();
+		if (!m_controller.initialize())
-		m_controller.runSystemChecks();
+		{
+			std::cout << "Error: Failed to initialize the system!";
+			return;
+		}
 		bool isMenuActive = true;
 		while (isMenuActive)
 		{
@@ -49,7 +52,7 @@ void UserInterface::run()
 				util::pressEnter();
 			}
 		}
-		m_controller.saveSystemData();
+		m_controller.shutdown();
 	}
 	catch (const std::invalid_argument& exception)
 	{