Implement Update Job Status for technician

<UserStory> SER1798: Update Job Status </UserStory>

<Changes>
    1. Renamed Controller and ServiceManagementService methods from completeJob to updateJobStatus for clarity and flexibility.
    2. Enhanced ServiceManagementService::updateJobStatus to support transitions:
       - STARTED → INPROGRESS
       - INPROGRESS → COMPLETED (with invoice generation and customer notification).
    3. Added INPROGRESS state to ServiceJobStatus enum and updated string conversion utilities.
    4. Introduced filterJobCards helper to generalize job filtering by status.
    5. Updated TechnicianMenu to allow technicians to select job type (Started/Inprogress) and update status accordingly.
    6. Improved job display to show current status and truncated service names for readability.
</Changes>

<Test>

 Acceptance Criteria:
 1. Technician can select a job with status STARTED and update it to INPROGRESS.
 2. Technician can select a job with status INPROGRESS and update it to COMPLETED.
 3. Completed bookings automatically generate invoices and send notifications to customers.
 4. Job status updates are reflected in the technician’s job list and customer view.

 Precondition:
 1. Technician is logged into the system.
 2. Assigned job cards exist with valid statuses (STARTED or INPROGRESS).
 3. Datastore and payment service are available.

 Steps:
 1. Navigate to Technician menu and choose "Update Job Status".
    - Verify that the system prompts for job type selection (Started/Inprogress).
 2. Select a job card from the filtered list.
    - Verify that the job card details are displayed with status.
 3. Confirm update.
    - Verify that the job status changes correctly.
 4. For jobs updated to COMPLETED:
    - Verify that the booking status is updated, invoice is generated, and notification is sent.
</Test>

<Review>
Sreeja Reghukumar, please review
</Review>

#1798

.gitignore

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

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

@@ -102,7 +102,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(ProjectDir)models;$(ProjectDir)controllers;$(ProjectDir)factories;$(ProjectDir)views;$(ProjectDir)services;$(ProjectDir)utilities;$(ProjectDir)core\patterns;$(ProjectDir)datastores;$(ProjectDir)core\sharedmemory;$(ProjectDir)core\events;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(ProjectDir)models;$(ProjectDir)controllers;$(ProjectDir)factories;$(ProjectDir)views;$(ProjectDir)services;$(ProjectDir)utilities;$(ProjectDir)core\patterns;$(ProjectDir)datastores;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -117,7 +117,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(ProjectDir)models;$(ProjectDir)controllers;$(ProjectDir)factories;$(ProjectDir)views;$(ProjectDir)services;$(ProjectDir)utilities;$(ProjectDir)core\patterns;$(ProjectDir)datastores;$(ProjectDir)core\sharedmemory;$(ProjectDir)core\events;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(ProjectDir)models;$(ProjectDir)controllers;$(ProjectDir)factories;$(ProjectDir)views;$(ProjectDir)services;$(ProjectDir)utilities;$(ProjectDir)core\patterns;$(ProjectDir)datastores;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -126,10 +126,8 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="controllers\Controller.cpp" />
-    <ClCompile Include="core\events\EventManager.cpp" />
     <ClCompile Include="core\patterns\Observer.cpp" />
     <ClCompile Include="core\patterns\Subject.cpp" />
-    <ClCompile Include="core\sharedmemory\SharedMemory.cpp" />
     <ClCompile Include="datastores\DataStore.cpp" />
     <ClCompile Include="models\ComboPackage.cpp" />
     <ClCompile Include="models\InventoryItem.cpp" />
@@ -141,6 +139,7 @@
     <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" />
@@ -149,23 +148,14 @@
     <ClCompile Include="utilities\Validator.cpp" />
     <ClCompile Include="views\AdminMenu.cpp" />
     <ClCompile Include="views\CustomerMenu.cpp" />
-    <ClCompile Include="views\Menu.cpp" />
     <ClCompile Include="views\TechnicianMenu.cpp" />
     <ClCompile Include="views\UserInterface.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="controllers\Controller.h" />
-    <ClInclude Include="core\events\EventManager.h" />
     <ClInclude Include="core\patterns\Observer.h" />
     <ClInclude Include="core\patterns\Subject.h" />
-    <ClInclude Include="core\sharedmemory\FileHeader.h" />
-    <ClInclude Include="core\sharedmemory\MappingInfo.h" />
-    <ClInclude Include="core\sharedmemory\RecordState.h" />
-    <ClInclude Include="core\sharedmemory\SerializedRecords.h" />
-    <ClInclude Include="core\sharedmemory\SharedMemory.h" />
-    <ClInclude Include="core\sharedmemory\TrackedRecord.h" />
     <ClInclude Include="datastores\DataStore.h" />
-    <ClInclude Include="datastores\DataStoreLockGuard.h" />
     <ClInclude Include="factories\Factory.h" />
     <ClInclude Include="models\ComboPackage.h" />
     <ClInclude Include="models\InventoryItem.h" />
@@ -184,6 +174,7 @@
     <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" />
@@ -194,7 +185,6 @@
     <ClInclude Include="utilities\Vector.h" />
     <ClInclude Include="views\AdminMenu.h" />
     <ClInclude Include="views\CustomerMenu.h" />
-    <ClInclude Include="views\Menu.h" />
     <ClInclude Include="views\MenuHelper.h" />
     <ClInclude Include="views\TechnicianMenu.h" />
     <ClInclude Include="views\UserInterface.h" />

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

@@ -64,18 +64,6 @@
     <Filter Include="Source Files\Core\Patterns">
       <UniqueIdentifier>{8057b93d-51a9-42df-b06e-01ce395f6308}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Header Files\Core\SharedMemory">
-      <UniqueIdentifier>{d9da9793-fe6f-4914-bee3-99d5934da228}</UniqueIdentifier>
-    </Filter>
-    <Filter Include="Source Files\Core\SharedMemory">
-      <UniqueIdentifier>{0769afb6-f57d-4ae3-a1cf-ceca6e606af0}</UniqueIdentifier>
-    </Filter>
-    <Filter Include="Header Files\Core\Events">
-      <UniqueIdentifier>{85029bdb-6941-41dc-a3a7-9e5841671d8c}</UniqueIdentifier>
-    </Filter>
-    <Filter Include="Source Files\Core\Events">
-      <UniqueIdentifier>{1050aca7-6f2c-4ccb-a446-db9c898c3599}</UniqueIdentifier>
-    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="Trenser.VehicleServiceSystem.cpp">
@@ -120,6 +108,9 @@
     <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>
@@ -150,15 +141,6 @@
     <ClCompile Include="models\ComboPackage.cpp">
       <Filter>Source Files\Models</Filter>
     </ClCompile>
-    <ClCompile Include="core\sharedmemory\SharedMemory.cpp">
-      <Filter>Source Files\Core\SharedMemory</Filter>
-    </ClCompile>
-    <ClCompile Include="core\events\EventManager.cpp">
-      <Filter>Source Files\Core\Events</Filter>
-    </ClCompile>
-    <ClCompile Include="views\Menu.cpp">
-      <Filter>Source Files\Views</Filter>
-    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="utilities\InputHelper.h">
@@ -254,6 +236,9 @@
     <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>
@@ -266,32 +251,5 @@
     <ClInclude Include="views\MenuHelper.h">
       <Filter>Header Files\Views</Filter>
     </ClInclude>
-    <ClInclude Include="datastores\DataStoreLockGuard.h">
-      <Filter>Header Files\DataStores</Filter>
-    </ClInclude>
-    <ClInclude Include="core\sharedmemory\FileHeader.h">
-      <Filter>Header Files\Core\SharedMemory</Filter>
-    </ClInclude>
-    <ClInclude Include="core\sharedmemory\MappingInfo.h">
-      <Filter>Header Files\Core\SharedMemory</Filter>
-    </ClInclude>
-    <ClInclude Include="core\sharedmemory\RecordState.h">
-      <Filter>Header Files\Core\SharedMemory</Filter>
-    </ClInclude>
-    <ClInclude Include="core\sharedmemory\SerializedRecords.h">
-      <Filter>Header Files\Core\SharedMemory</Filter>
-    </ClInclude>
-    <ClInclude Include="core\sharedmemory\SharedMemory.h">
-      <Filter>Header Files\Core\SharedMemory</Filter>
-    </ClInclude>
-    <ClInclude Include="core\sharedmemory\TrackedRecord.h">
-      <Filter>Header Files\Core\SharedMemory</Filter>
-    </ClInclude>
-    <ClInclude Include="core\events\EventManager.h">
-      <Filter>Header Files\Core\Events</Filter>
-    </ClInclude>
-    <ClInclude Include="views\Menu.h">
-      <Filter>Header Files\Views</Filter>
-    </ClInclude>
   </ItemGroup>
 </Project>

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

@@ -6,7 +6,6 @@ Description: Implementation file containing the method definitions of the
 Author: Trenser
 Date:19-May-2026
 */
-
 #include "ComboPackage.h"
 #include "Controller.h"
 #include "Enums.h"
@@ -234,17 +233,6 @@ void Controller::removeInventoryItem(const std::string& inventoryItemID)
     m_inventoryManagementService.removeInventoryItem(inventoryItemID);
 }
 
-/*
-Function: removeServiceBooking
-Description: Removes a service booking from the service management system by its booking ID.
-Parameter: const std::string& bookingID - ID of the service booking
-Return type: void
-*/
-void Controller::removeServiceBooking(const std::string& bookingID)
-{
-    m_serviceManagementService.removeServiceBooking(bookingID);
-}
-
 /*
 Function: addInventoryItemStock
 Description: Adds stock to an existing inventory item in the inventory management service.
@@ -276,7 +264,6 @@ util::Map<std::string, const ServiceBooking*> Controller::getServiceBookings()
     return readOnlyServiceBookings;
 }
 
-
 /*
 Function: getServiceBookingsByUser
 Description: Retrieves all service bookings for a specific user.
@@ -475,38 +462,6 @@ util::Map<std::string, const Invoice*> Controller::getInvoicesByUser()
     return userInvoicesReadOnly;
 }
 
-/*
-Function: getAllInvoices
-Description: Retrieves all invoices from the PaymentManagementService and returns them as a read-only map.
-Parameters:
-    - none
-Returns:
-    - util::Map<std::string, const Invoice*>: Map of invoice IDs to invoice objects
-*/
-util::Map<std::string, const Invoice*> Controller::getAllInvoices()
-{
-    auto invoices = m_paymentManagementService.getAllInvoices();
-    util::Map<std::string, const Invoice*> readOnlyInvoice;
-    for (int iterator = 0; iterator < invoices.getSize(); iterator++)
-    {
-        readOnlyInvoice.insert(invoices.getKeyAt(iterator), invoices.getValueAt(iterator));
-    }
-    return readOnlyInvoice;
-}
-
-/*
-Function: confirmPayment
-Description: Delegates payment confirmation for a given invoice ID to the PaymentManagementService.
-Parameters:
-    - invoiceID: std::string, ID of the invoice to confirm
-Returns:
-    - void
-*/
-void Controller::confirmPayment(const std::string& invoiceID)
-{
-    m_paymentManagementService.confirmPayment(invoiceID);
-}
-
 /*
 Function: completePayment
 Description: Completes payment for a specific invoice using the given payment mode.
@@ -600,50 +555,63 @@ void Controller::configureNotifications(bool paymentNotifications, bool serviceN
 }
 
 /*
-Function: initialize
-Description: Initializes the system and run system checks to ensure critical configurations, such as verifying admin existence.
-Parameters:
-    - None
-Returns:
-    - bool
-*/
-bool Controller::initialize()
-{
-    auto& dataStore = DataStore::getInstance();
-
-    if (!dataStore.initialize())
-    {
-        return false;
-    }
-    m_userManagementService.ensureAdminExists();
-    m_inventoryManagementService.sendLowStockAlerts();
-    m_paymentManagementService.sendPaymentReminders();
-    return true;
-}
-
-/*
-Function: shutdown
-Description: Shutdown the system, and do necessary cleanups
+Function: loadSystemData
+Description: Loads all system data from persistent storage into memory.
+             Invokes the respective management services to load users, inventory items, services,
+             combo packages, service bookings, job cards, invoices, and observers.
 Parameters:
     - None
 Returns:
     - void
 */
-void Controller::shutdown()
+void Controller::loadSystemData()
 {
-    auto& dataStore = DataStore::getInstance();
-    dataStore.shutdown();
+    m_userManagementService.loadUsers();
+    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();
 }
 
 /*
-Function: registerEvents
-Description: Registers menu event handles with the authentication
-             service.
-Parameter: HANDLE accountDisabledEvent - account disabled event handle
-           HANDLE notificationAvailableEvent - notification event handle
+Function: saveSystemData
+Description: Saves all system data from memory back to persistent storage.
+             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::registerEvents(HANDLE accountDisabledEvent, HANDLE notificationAvailableEvent)
+void Controller::runSystemChecks()
 {
-    m_authenticationManagementService.registerEvents(accountDisabledEvent, notificationAvailableEvent);
+    m_userManagementService.ensureAdminExists();
+    m_inventoryManagementService.sendLowStockAlerts();
+    m_paymentManagementService.sendPaymentReminders();
 }
+

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

@@ -8,7 +8,6 @@ Date:19-May-2026
 */
 
 #pragma once
-#include <windows.h>
 #include <string>
 #include "AuthenticationManagementService.h"
 #include "Enums.h"
@@ -58,7 +57,6 @@ public:
     util::Map<std::string, const User*> getUsers(util::UserType userType);
     void createJobCard(const std::string& bookingID, const std::string& technicianID, const std::string& serviceID);
     void createService(const std::string& name, const util::Vector<std::string>& inventoryItemIDs, double laborCost);
-    void removeServiceBooking(const std::string& bookingID);
     void removeService(const std::string& serviceID);
     util::Map<std::string, const JobCard*> getJobCardsByUser();
     void updateJobStatus(const std::string& jobID);
@@ -66,13 +64,11 @@ public:
     void createComboPackage(const std::string& name, const util::Vector<std::string>& serviceIDs, double discountPercentage);
     void removeComboPackage(const std::string& comboPackageID);
     util::Map<std::string, const Invoice*> getInvoicesByUser();
-    util::Map<std::string, const Invoice*> getAllInvoices();
-    void confirmPayment(const std::string& invoiceID);
     void completePayment(const std::string& invoiceID, util::PaymentMode paymentMode);
     util::Vector<const Notification*> getNotifications();
     void deleteNotification(const std::string& notificationID);
     void configureNotifications(bool paymentNotifications, bool serviceNotifications);
-    bool initialize();
-    void shutdown();
-    void registerEvents(HANDLE accountDisabledEvent, HANDLE notificationAvailableEvent);
+    void loadSystemData();
+    void saveSystemData();
+    void runSystemChecks();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/events/EventManager.cpp

@@ -1,225 +0,0 @@
-/*
-File: EventManager.cpp
-Description: Implementation file containing the method definitions of the
-             EventManager class, including listener management and
-             interprocess event publishing.
-Author: Trenser
-Date:15-Jun-2026
-*/
-
-#include <iostream>
-#include <stdexcept>
-#include "EventManager.h"
-
-namespace
-{
-    const std::string USER_DISABLED_EVENT = "userDisabled_";
-
-    const std::string NOTIFICATION_AVAILABLE_EVENT = "notificationAvailable_";
-}
-
-/*
-Function: EventManager
-Description: Constructs an EventManager instance with default values.
-Parameter: None
-Return type: None
-*/
-EventManager::EventManager()
-    :
-    m_userDisabledEvent(NULL),
-    m_notificationAvailableEvent(NULL),
-    m_shutdownEvent(NULL),
-    m_running(false) {}
-
-/*
-Function: ~EventManager
-Description: Destroys the EventManager and performs final cleanup.
-Parameter: None
-Return type: None
-*/
-EventManager::~EventManager()
-{
-    shutdown();
-    if (m_listenerThread.joinable())
-    {
-        m_listenerThread.join();
-    }
-}
-
-/*
-Function: initialize
-Description: Creates the user-specific events and starts the listener
-             thread.
-Parameter: const std::string& userId - unique identifier of the user
-           std::function<void()> userDisabledCallback - callback for
-           user disable events
-           std::function<void()> notificationCallback - callback for
-           notification events
-Return type: bool - true if initialization succeeds, false otherwise
-*/
-bool EventManager::initialize(const std::string& userId, std::function<void()> userDisabledCallback, std::function<void()> notificationCallback)
-{
-    if (m_running.load())
-    {
-        return false;
-    }
-    m_userDisabledCallback = userDisabledCallback;
-    m_notificationCallback = notificationCallback;
-    m_userDisabledEvent = CreateEventA(NULL, FALSE, FALSE, (USER_DISABLED_EVENT + userId).c_str());
-    if (!m_userDisabledEvent)
-    {
-        return false;
-    }
-    if (GetLastError() == ERROR_ALREADY_EXISTS)
-    {
-        CloseHandle(m_userDisabledEvent);
-        m_userDisabledEvent = NULL;
-        throw std::runtime_error("Only one session allowed per user.");
-    }
-    m_notificationAvailableEvent = CreateEventA(NULL, FALSE, FALSE, (NOTIFICATION_AVAILABLE_EVENT + userId).c_str());
-    if (!m_notificationAvailableEvent)
-    {
-        CloseHandle(m_userDisabledEvent);
-        m_userDisabledEvent = NULL;
-        return false;
-    }
-    m_shutdownEvent = CreateEventA(NULL, FALSE, FALSE, NULL);
-    if (!m_shutdownEvent)
-    {
-        CloseHandle(m_userDisabledEvent);
-        CloseHandle(m_notificationAvailableEvent);
-        m_userDisabledEvent = NULL;
-        m_notificationAvailableEvent = NULL;
-        return false;
-    }
-    m_running.store(true);
-    m_listenerThread = std::thread(&EventManager::run, this);
-    return true;
-}
-
-/*
-Function: shutdown
-Description: Stops the listener thread and releases event resources.
-Parameter: None
-Return type: None
-*/
-void EventManager::shutdown()
-{
-    if (!m_running.load())
-    {
-        return;
-    }
-    m_running.store(false);
-    if (m_shutdownEvent)
-    {
-        SetEvent(m_shutdownEvent);
-    }
-    if (m_listenerThread.joinable())
-    {
-        if (std::this_thread::get_id() != m_listenerThread.get_id())
-        {
-            m_listenerThread.join();
-        }
-    }
-    if (m_userDisabledEvent)
-    {
-        CloseHandle(m_userDisabledEvent);
-        m_userDisabledEvent = NULL;
-    }
-    if (m_notificationAvailableEvent)
-    {
-        CloseHandle(m_notificationAvailableEvent);
-        m_notificationAvailableEvent = NULL;
-    }
-    if (m_shutdownEvent)
-    {
-        CloseHandle(m_shutdownEvent);
-        m_shutdownEvent = NULL;
-    }
-}
-
-/*
-Function: run
-Description: Waits for and dispatches user-related events.
-Parameter: None
-Return type: void
-*/
-void EventManager::run()
-{
-    HANDLE handles[3];
-    handles[0] = m_userDisabledEvent;
-    handles[1] = m_notificationAvailableEvent;
-    handles[2] = m_shutdownEvent;
-    while (m_running.load())
-    {
-        DWORD result = WaitForMultipleObjects(3, handles, FALSE, INFINITE);
-        switch (result)
-        {
-        case WAIT_OBJECT_0:
-            try
-            {
-                if (m_userDisabledCallback)
-                {
-                    m_userDisabledCallback();
-                }
-            }
-            catch (const std::exception& exception)
-            {
-                std::cout << exception.what() << std::endl;
-            }
-            break;
-        case WAIT_OBJECT_0 + 1:
-            try
-            {
-                if (m_notificationCallback)
-                {
-                    m_notificationCallback();
-                }
-            }
-            catch (const std::exception& exception)
-            {
-                std::cout << exception.what() << std::endl;
-            }
-            break;
-        case WAIT_OBJECT_0 + 2:
-            return;
-        default:
-            break;
-        }
-    }
-}
-
-/*
-Function: sendUserDisabledEvent
-Description: Publishes a user disabled event for a specific user.
-Parameter: const std::string& userId - target user identifier
-Return type: void
-*/
-void EventManager::sendUserDisabledEvent(const std::string& userId)
-{
-    HANDLE eventHandle = CreateEventA(NULL, FALSE, FALSE, (USER_DISABLED_EVENT + userId).c_str());
-    if (!eventHandle)
-    {
-        return;
-    }
-    SetEvent(eventHandle);
-    CloseHandle(eventHandle);
-}
-
-/*
-Function: sendNotificationAvailableEvent
-Description: Publishes a notification available event for a specific
-             user.
-Parameter: const std::string& userId - target user identifier
-Return type: void
-*/
-void EventManager::sendNotificationAvailableEvent(const std::string& userId)
-{
-    HANDLE eventHandle = CreateEventA(NULL, FALSE, FALSE, (NOTIFICATION_AVAILABLE_EVENT + userId).c_str());
-    if (!eventHandle)
-    {
-        return;
-    }
-    SetEvent(eventHandle);
-    CloseHandle(eventHandle);
-}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/events/EventManager.h

@@ -1,37 +0,0 @@
-/*
-File: EventManager.h
-Description: Header file declaring the EventManager class, which manages
-             user-specific interprocess events for user disable and
-             notification availability updates.
-Author: Trenser
-Date:15-Jun-2026
-*/
-
-#pragma once
-
-#include <windows.h>
-#include <atomic>
-#include <functional>
-#include <string>
-#include <thread>
-
-class EventManager
-{
-private:
-    HANDLE m_userDisabledEvent;
-    HANDLE m_notificationAvailableEvent;
-    HANDLE m_shutdownEvent;
-    std::atomic<bool> m_running;
-    std::thread m_listenerThread;
-    std::function<void()> m_userDisabledCallback;
-    std::function<void()> m_notificationCallback;
-    void run();
-
-public:
-    EventManager();
-    ~EventManager();
-    bool initialize(const std::string& userId, std::function<void()> userDisabledCallback, std::function<void()> notificationCallback);
-    void shutdown();
-    static void sendUserDisabledEvent(const std::string& userId);
-    static void sendNotificationAvailableEvent(const std::string& userId);
-};

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

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

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/sharedmemory/FileHeader.h

@@ -1,17 +0,0 @@
-/*
-File: FileHeader.h
-Description: Defines the FileHeader structure used to store
-             metadata for binary record files, including
-             record count and capacity.
-Author: Trenser
-Created: 10-June-2026
-*/
-
-#pragma once
-#include <cstddef>
-
-struct FileHeader
-{
-    size_t recordCount;
-    size_t capacity;
-};

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/sharedmemory/MappingInfo.h

@@ -1,29 +0,0 @@
-/*
-File: MappingInfo.h
-Description: Defines the MappingInfo structure used for
-             managing Windows file mapping operations.
-             Stores handles, mapped view pointer,
-             file metadata, and capacity information.
-Author: Trenser
-Created: 10-June-2026
-*/
-
-#pragma once
-#include <windows.h>
-#include <string>
-
-struct MappingInfo
-{
-    HANDLE fileHandle;
-    HANDLE mappingHandle;
-    void* mappedView;
-    std::string fileName;
-    size_t recordSize;
-    size_t mappedCapacity;
-    MappingInfo()
-        : fileHandle(NULL),
-        mappingHandle(NULL),
-        mappedView(nullptr),
-        recordSize(0),
-        mappedCapacity(0) {}
-};

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/sharedmemory/RecordState.h

@@ -1,17 +0,0 @@
-/*
-File: RecordState.h
-Description: Defines the RecordState enumeration used to
-             represent the state of a record in storage.
-             States include CLEAN, NEW_RECORD, and MODIFIED.
-Author: Trenser
-Created: 10-June-2026
-*/
-
-#pragma once
-
-enum class RecordState : int
-{
-    CLEAN,
-    NEW_RECORD,
-    MODIFIED
-};

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/sharedmemory/SerializedRecords.h

@@ -1,109 +0,0 @@
-/*
-File: SerializedRecords.h
-Description: Defines serialized structures for persistent storage
-             and retrieval of system entities including User,
-             Notification, Service, ComboPackage, InventoryItem,
-             ServiceBooking, JobCard, Invoice, and Observer.
-             These structures use fixed-size character arrays
-             and primitive types for binary serialization.
-Author: Trenser
-Created: 10-June-2026
-*/
-
-#pragma once
-#include "Utility.h"
-#include "Enums.h"
-#include "Timestamp.h"
-
-struct SerializedUser
-{
-    char id[64];
-    char username[64];
-    char password[64];
-    char name[128];
-    char phone[32];
-    char email[128];
-    util::UserType userType;
-    util::State status;
-};
-
-struct SerializedNotification
-{
-    char id[64];
-    char recipientUserId[64];
-    char title[128];
-    char message[1024];
-    util::Timestamp createdAt;
-    util::State state;
-};
-
-struct SerializedService
-{
-    char id[64];
-    char name[128];
-    char inventoryItemIDs[1024];
-    double laborCost;
-    util::State status;
-};
-
-struct SerializedComboPackage
-{
-    char id[64];
-    char packageName[128];
-    double discountPercentage;
-    char serviceIDs[1024];
-    util::State status;
-};
-
-struct SerializedInventoryItem
-{
-    char id[64];
-    char partName[128];
-    int quantity;
-    double price;
-    util::State status;
-};
-
-struct SerializedServiceBooking
-{
-    char id[64];
-    util::ServiceJobStatus status;
-    char serviceIDs[1024];
-    char customerId[64];
-    char vehicleNumber[64];
-    char vehicleBrand[64];
-    char vehicleModel[64];
-    char assignedTechnicianId[64];
-    double discountPercentage;
-};
-
-struct SerializedJobCard
-{
-    char id[64];
-    char bookingId[64];
-    char serviceId[64];
-    char technicianId[64];
-    util::Timestamp assignedDate;
-    util::ServiceJobStatus status;
-    util::Timestamp completionDate;
-};
-
-struct SerializedInvoice
-{
-    char id[64];
-    char bookingId[64];
-    util::Timestamp invoiceDate;
-    char partIDs[1024];
-    double laborCost;
-    double partsCost;
-    double discountPercentage;
-    double totalAmount;
-    util::Timestamp paymentDate;
-    util::PaymentMode paymentMethod;
-    util::PaymentStatus status;
-};
-
-struct SerializedObserver
-{
-    char id[64];
-};

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/sharedmemory/SharedMemory.cpp

@@ -1,386 +0,0 @@
-/*
-File: SharedMemory.cpp
-Description: Implements shared memory utilities for managing
-             Windows file mapping operations. Provides functions
-             to create, open, resize, and close mappings, as well
-             as access headers, records, and ensure synchronization
-             across processes.
-Author: Trenser
-Created: 11-June-2026
-*/
-
-#include "SharedMemory.h"
-#include "Windows.h"
-#include "Config.h"
-
-/*
-Function: invalidateMapping
-Description: Releases all mapping resources and resets the mapping to an invalid state.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-Returns:
-    - None
-*/
-static void invalidateMapping(MappingInfo& mapping)
-{
-    if (mapping.mappedView != nullptr)
-    {
-        UnmapViewOfFile(mapping.mappedView);
-        mapping.mappedView = nullptr;
-    }
-    if (mapping.mappingHandle != NULL)
-    {
-        CloseHandle(mapping.mappingHandle);
-        mapping.mappingHandle = NULL;
-    }
-    if (mapping.fileHandle != INVALID_HANDLE_VALUE)
-    {
-        CloseHandle(mapping.fileHandle);
-        mapping.fileHandle = INVALID_HANDLE_VALUE;
-    }
-    mapping.mappedCapacity = 0;
-}
-
-/*
-Function: createOrOpenMapping
-Description: Creates or opens a file mapping and maps it into the process address space.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-Returns:
-    - bool: True if the mapping was successfully created/opened, otherwise false
-*/
-bool SharedMemory::createOrOpenMapping(MappingInfo& mapping)
-{
-    if (mapping.recordSize == 0)
-    {
-        return false;
-    }
-    mapping.fileHandle =
-        CreateFileA(
-            mapping.fileName.c_str(),
-            GENERIC_READ | GENERIC_WRITE,
-            FILE_SHARE_READ | FILE_SHARE_WRITE,
-            NULL,
-            OPEN_ALWAYS,
-            FILE_ATTRIBUTE_NORMAL,
-            NULL);
-    if (mapping.fileHandle == INVALID_HANDLE_VALUE)
-    {
-        return false;
-    }
-    LARGE_INTEGER fileSize;
-    if (!GetFileSizeEx(mapping.fileHandle, &fileSize))
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    bool isNewFile = (fileSize.QuadPart == 0);
-    const size_t initialCapacity = config::file::INITIAL_CAPACITY;
-    if (isNewFile)
-    {
-        LARGE_INTEGER newSize;
-        newSize.QuadPart = sizeof(FileHeader) + initialCapacity * mapping.recordSize;
-        if (!SetFilePointerEx(mapping.fileHandle, newSize, NULL, FILE_BEGIN))
-        {
-            invalidateMapping(mapping);
-            return false;
-        }
-        if (!SetEndOfFile(mapping.fileHandle))
-        {
-            invalidateMapping(mapping);
-            return false;
-        }
-    }
-    mapping.mappingHandle =
-        CreateFileMappingA(
-            mapping.fileHandle,
-            NULL,
-            PAGE_READWRITE,
-            0,
-            0,
-            NULL);
-    if (mapping.mappingHandle == NULL)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    mapping.mappedView =
-        MapViewOfFile(
-            mapping.mappingHandle,
-            FILE_MAP_ALL_ACCESS,
-            0,
-            0,
-            0);
-    if (mapping.mappedView == nullptr)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    FileHeader* header = getHeader(mapping);
-    if (header == nullptr)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    if (isNewFile)
-    {
-        header->recordCount = 0;
-        header->capacity = initialCapacity;
-    }
-    mapping.mappedCapacity = header->capacity;
-    return true;
-}
-
-/*
-Function: closeMapping
-Description: Unmaps and closes all resources associated with a file mapping.
-Parameters:
-    - mapping: MappingInfo&, mapping to close
-Returns:
-    - None
-*/
-void SharedMemory::closeMapping(MappingInfo& mapping)
-{
-    invalidateMapping(mapping);
-}
-
-/*
-Function: getHeader
-Description: Returns the file header stored at the beginning of the mapped memory region.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-Returns:
-    - FileHeader*: Pointer to the file header, or nullptr if the mapping is not valid
-*/
-FileHeader* SharedMemory::getHeader(MappingInfo& mapping)
-{
-    if (mapping.mappedView == nullptr)
-    {
-        return nullptr;
-    }
-    return reinterpret_cast<FileHeader*>(mapping.mappedView);
-}
-
-/*
-Function: getRecordAddress
-Description: Returns the address of a record at the specified index within the mapped memory region.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-    - index: size_t, record index
-Returns:
-    - void*: Pointer to the record, or nullptr if the mapping is not valid
-*/
-void* SharedMemory::getRecordAddress(MappingInfo& mapping, size_t index)
-{
-    if (mapping.mappedView == nullptr)
-    {
-        return nullptr;
-    }
-    return reinterpret_cast<char*>(mapping.mappedView) + sizeof(FileHeader) + index * mapping.recordSize;
-}
-
-/*
-Function: getRecordCount
-Description: Returns the number of records currently stored in the mapping.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-Returns:
-    - size_t: Number of records in the mapping
-*/
-size_t SharedMemory::getRecordCount(MappingInfo& mapping)
-{
-    FileHeader* header = getHeader(mapping);
-    if (header == nullptr)
-    {
-        return 0;
-    }
-    return header->recordCount;
-}
-
-/*
-Function: setRecordCount
-Description: Updates the number of records stored in the mapping.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-    - count: size_t, new record count
-Returns:
-    - None
-*/
-void SharedMemory::setRecordCount(MappingInfo& mapping, size_t count)
-{
-    FileHeader* header = getHeader(mapping);
-    if (header == nullptr)
-    {
-        return;
-    }
-    header->recordCount = count;
-}
-
-/*
-Function: getCapacity
-Description: Returns the current capacity of the mapping.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-Returns:
-    - size_t: Maximum number of records that can be stored in the mapping
-*/
-size_t SharedMemory::getCapacity(MappingInfo& mapping)
-{
-    FileHeader* header = getHeader(mapping);
-    if (header == nullptr)
-    {
-        return 0;
-    }
-    return header->capacity;
-}
-
-/*
-Function: resizeMapping
-Description: Resizes the file mapping to the specified capacity.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-    - newCapacity: size_t, new mapping capacity
-Returns:
-    - bool: True if the resize succeeded, otherwise false
-*/
-bool SharedMemory::resizeMapping(MappingInfo& mapping, size_t newCapacity)
-{
-    FileHeader* header = getHeader(mapping);
-    if (header == nullptr)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    header->capacity = newCapacity;
-    if (!FlushViewOfFile(mapping.mappedView, sizeof(FileHeader)))
-    {
-        return false;
-    }
-    if (!UnmapViewOfFile(mapping.mappedView))
-    {
-        return false;
-    }
-    mapping.mappedView = nullptr;
-    CloseHandle(mapping.mappingHandle);
-    mapping.mappingHandle = NULL;
-    LARGE_INTEGER newSize;
-    newSize.QuadPart = sizeof(FileHeader) + newCapacity * mapping.recordSize;
-    if (!SetFilePointerEx(mapping.fileHandle, newSize, NULL, FILE_BEGIN))
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    if (!SetEndOfFile(mapping.fileHandle))
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    mapping.mappingHandle =
-        CreateFileMappingA(
-            mapping.fileHandle,
-            NULL,
-            PAGE_READWRITE,
-            0,
-            0,
-            NULL);
-    if (mapping.mappingHandle == NULL)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    mapping.mappedView =
-        MapViewOfFile(
-            mapping.mappingHandle,
-            FILE_MAP_ALL_ACCESS,
-            0,
-            0,
-            0);
-    if (mapping.mappedView == nullptr)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    mapping.mappedCapacity = newCapacity;
-    return true;
-}
-
-/*
-Function: ensureCapacityForInsert
-Description: Ensures that the mapping has space for at least one additional record, growing it if necessary.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-Returns:
-    - bool: True if capacity is available, otherwise false
-*/
-bool SharedMemory::ensureCapacityForInsert(MappingInfo& mapping)
-{
-    size_t recordCount = getRecordCount(mapping);
-    size_t capacity = getCapacity(mapping);
-    if (recordCount < capacity)
-    {
-        return true;
-    }
-    return resizeMapping(mapping, capacity * config::file::GROWTH_FACTOR);
-}
-
-/*
-Function: ensureLatestMapping
-Description: Remaps the file if another process has resized it.
-Parameters:
-    - mapping: MappingInfo&, mapping information and handles
-Returns:
-    - bool: True if the mapping is valid and up to date, otherwise false
-*/
-bool SharedMemory::ensureLatestMapping(MappingInfo& mapping)
-{
-    FileHeader* header = getHeader(mapping);
-    if (header == nullptr)
-    {
-        return false;
-    }
-    if (header->capacity == mapping.mappedCapacity)
-    {
-        return true;
-    }
-    if (!UnmapViewOfFile(mapping.mappedView))
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    mapping.mappedView = nullptr;
-    CloseHandle(mapping.mappingHandle);
-    mapping.mappingHandle = NULL;
-    mapping.mappingHandle =
-        CreateFileMappingA(
-            mapping.fileHandle,
-            NULL,
-            PAGE_READWRITE,
-            0,
-            0,
-            NULL);
-    if (mapping.mappingHandle == NULL)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    mapping.mappedView =
-        MapViewOfFile(
-            mapping.mappingHandle,
-            FILE_MAP_ALL_ACCESS,
-            0,
-            0,
-            0);
-    if (mapping.mappedView == nullptr)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    header = getHeader(mapping);
-    if (header == nullptr)
-    {
-        invalidateMapping(mapping);
-        return false;
-    }
-    mapping.mappedCapacity = header->capacity;
-    return true;
-}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/sharedmemory/SharedMemory.h

@@ -1,29 +0,0 @@
-/*
-File: SharedMemory.h
-Description: Declares functions for managing Windows file
-             mapping and shared memory operations. Provides
-             utilities for creating, resizing, and closing
-             mappings, as well as accessing headers and
-             record data.
-Author: Trenser
-Created: 10-June-2026
-*/
-
-#pragma once
-#include <cstddef>
-#include "MappingInfo.h"
-#include "FileHeader.h"
-
-namespace SharedMemory
-{
-    bool createOrOpenMapping(MappingInfo& mapping);
-    void closeMapping(MappingInfo& mapping);
-    bool ensureLatestMapping(MappingInfo& mapping);
-    bool resizeMapping(MappingInfo& mapping, size_t newCapacity);
-    FileHeader* getHeader(MappingInfo& mapping);
-    void* getRecordAddress(MappingInfo& mapping, size_t index);
-    size_t getRecordCount(MappingInfo& mapping);
-    void setRecordCount(MappingInfo& mapping, size_t count);
-    size_t getCapacity(MappingInfo& mapping);
-    bool ensureCapacityForInsert(MappingInfo& mapping);
-};

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/sharedmemory/TrackedRecord.h

@@ -1,33 +0,0 @@
-/*
-File: TrackedRecord.h
-Description: Defines the TrackedRecord template structure used
-             to manage objects with associated record state and
-             slot index. Supports tracking of CLEAN, NEW_RECORD,
-             and MODIFIED states for persistence and synchronization.
-Author: Trenser
-Created: 10-June-2026
-*/
-
-#pragma once
-#include "RecordState.h"
-
-static const size_t INVALID_SLOT = static_cast<size_t>(-1);
-
-template<typename T>
-struct TrackedRecord
-{
-    T* data;
-    RecordState state;
-    size_t slotIndex;
-    TrackedRecord()
-        : data(nullptr),
-        state(RecordState::CLEAN),
-        slotIndex(INVALID_SLOT) {}
-    TrackedRecord(
-        T* object,
-        RecordState recordState,
-        size_t slot)
-        : data(object),
-        state(recordState),
-        slotIndex(slot) {}
-};

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

@@ -9,197 +9,6 @@ Date: 19-May-2026
 */
 
 #include "DataStore.h"
-#include "Config.h"
-#include "SerializedRecords.h"
-#include "FileHelper.h"
-#include "ServiceBooking.h"
-#include "JobCard.h"
-#include "Invoice.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.
-             Creates or opens the global datastore mutex,
-             configures all mapping metadata, and creates
-             or opens the file mappings used to persist
-             application data. After successful completion,
-             all datastore files are mapped into memory and
-             ready for use by the application.
-Parameter: None
-Return type: bool
-             - true  : Initialization completed successfully.
-             - false : Failed to create the mutex or open
-                       one or more file mappings.
-*/
-bool DataStore::initialize()
-{
-    m_globalMutex = CreateMutexA(NULL, FALSE, "VehicleServiceSystemMutex");
-    if (m_globalMutex == NULL)
-    {
-        return false;
-    }
-    if (!lockDataStore())
-    {
-        CloseHandle(m_globalMutex);
-        m_globalMutex = NULL;
-        return false;
-    }
-    bool success = true;
-    do
-    {
-        util::ensureDirectoryExists(config::file::DIRECTORY);
-        m_users.fileName = config::file::USER_FILE;
-        m_users.recordSize = sizeof(SerializedUser);
-        m_notifications.fileName = config::file::NOTIFICATION_FILE;
-        m_notifications.recordSize = sizeof(SerializedNotification);
-        m_services.fileName = config::file::SERVICE_FILE;
-        m_services.recordSize = sizeof(SerializedService);
-        m_comboPackages.fileName = config::file::COMBOPACKAGE_FILE;
-        m_comboPackages.recordSize = sizeof(SerializedComboPackage);
-        m_inventoryItems.fileName = config::file::INVENTORYITEM_FILE;
-        m_inventoryItems.recordSize = sizeof(SerializedInventoryItem);
-        m_serviceBookings.fileName = config::file::SERVICEBOOKING_FILE;
-        m_serviceBookings.recordSize = sizeof(SerializedServiceBooking);
-        m_jobCards.fileName = config::file::JOBCARD_FILE;
-        m_jobCards.recordSize = sizeof(SerializedJobCard);
-        m_invoices.fileName = config::file::INVOICE_FILE;
-        m_invoices.recordSize = sizeof(SerializedInvoice);
-        m_serviceManagementObservers.fileName = config::file::SERVICEMANAGEMENTOBSERVERS;
-        m_serviceManagementObservers.recordSize = sizeof(SerializedObserver);
-        m_paymentManagementObservers.fileName = config::file::PAYMENTMANAGEMENTOBSERVERS;
-        m_paymentManagementObservers.recordSize = sizeof(SerializedObserver);
-        m_inventoryManagementObservers.fileName = config::file::INVENTORYMANAGEMENTOBSERVERS;
-        m_inventoryManagementObservers.recordSize = sizeof(SerializedObserver);
-        if (!SharedMemory::createOrOpenMapping(m_users))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_notifications))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_services))
-        {
-            success = false;
-            break;
-        }
-
-        if (!SharedMemory::createOrOpenMapping(m_comboPackages))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_inventoryItems))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_serviceBookings))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_jobCards))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_invoices))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_serviceManagementObservers))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_paymentManagementObservers))
-        {
-            success = false;
-            break;
-        }
-        if (!SharedMemory::createOrOpenMapping(m_inventoryManagementObservers))
-        {
-            success = false;
-            break;
-        }
-    } while (false);
-    unlockDataStore();
-    if (!success)
-    {
-        shutdown();
-    }
-    return success;
-}
-
-/*
-Function: shutdown
-Description: Releases all shared-memory resources owned by the
-             datastore. Closes every file mapping, unmaps all
-             mapped views, and releases the datastore mutex.
-             After this call, the datastore must be initialized
-             again before use.
-Parameter: None
-Return type: void
-*/
-void DataStore::shutdown()
-{
-    SharedMemory::closeMapping(m_users);
-    SharedMemory::closeMapping(m_notifications);
-    SharedMemory::closeMapping(m_services);
-    SharedMemory::closeMapping(m_comboPackages);
-    SharedMemory::closeMapping(m_inventoryItems);
-    SharedMemory::closeMapping(m_serviceBookings);
-    SharedMemory::closeMapping(m_jobCards);
-    SharedMemory::closeMapping(m_invoices);
-    SharedMemory::closeMapping(m_serviceManagementObservers);
-    SharedMemory::closeMapping(m_paymentManagementObservers);
-    SharedMemory::closeMapping(m_inventoryManagementObservers);
-    if (m_globalMutex != NULL)
-    {
-        CloseHandle(m_globalMutex);
-        m_globalMutex = NULL;
-    }
-}
 
 /*
 Function: getInstance
@@ -217,567 +26,104 @@ DataStore& DataStore::getInstance()
 
 /*
 Function: getUsers
-Description: Retrieves all user records from the datastore.
+Description: Retrieves the internal map of users.
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<User>>: Collection of user records
+    - Reference to util::Map<std::string, User*> containing all users.
 */
-util::Map<std::string, TrackedRecord<User>>& DataStore::getUsers()
+util::Map<std::string, User*>& DataStore::getUsers()
 {
-    auto users = loadRecords<User, SerializedUser>(m_users);
-    refreshCache(m_userCache, users);
-    return m_userCache;
-}
-
-/*
-Function: getNotifications
-Description: Retrieves all notification records from the datastore.
-Parameters:
-    - None
-Returns:
-    - util::Map<std::string, TrackedRecord<Notification>>: Collection of notification records
-*/
-util::Map<std::string, TrackedRecord<Notification>>& DataStore::getNotifications()
-{
-    auto notifications = loadRecords<Notification, SerializedNotification>(m_notifications);
-    refreshCache(m_notificationCache, notifications);
-    return m_notificationCache;
+    return m_users;
 }
 
 /*
 Function: getServices
-Description: Retrieves all service records from the datastore.
+Description: Retrieves the internal map of services.
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<Service>>: Collection of service records
+    - Reference to util::Map<std::string, Service*> containing all services.
 */
-util::Map<std::string, TrackedRecord<Service>>& DataStore::getServices()
+util::Map<std::string, Service*>& DataStore::getServices()
 {
-    util::Map<std::string, TrackedRecord<Service>> services = loadRecords<Service, SerializedService>(m_services);
-    refreshCache(m_serviceCache, services);
-    util::Map<std::string, TrackedRecord<InventoryItem>>& inventoryItems = getInventoryItems();
-    size_t numberOfServices = m_serviceCache.getSize();
-    for (int iteratorOne =0; iteratorOne < numberOfServices; iteratorOne++)
-    {
-        Service* currentService = m_serviceCache.getValueAt(iteratorOne).data;
-        util::Map<std::string, InventoryItem*> inventoryItemMap;
-        util::Vector<std::string> currentServiceInventoryItem = currentService->getRequiredInventoryItemIDs();
-        for (int iteratorTwo = 0; iteratorTwo < currentServiceInventoryItem.getSize(); iteratorTwo++)
-        {
-            const std::string& currentInventoryItemId = currentServiceInventoryItem[iteratorTwo];
-            int currentInventoryItemIndex = inventoryItems.find(currentInventoryItemId);
-            if (currentInventoryItemIndex == -1)
-            {
-                throw std::runtime_error("Invalid inventory item ID");
-            }
-            InventoryItem* currentItem = inventoryItems.getValueAt(currentInventoryItemIndex).data;
-            inventoryItemMap[currentInventoryItemId] = currentItem;
-        }
-        currentService->setRequiredInventoryItems(inventoryItemMap);
-    }
-    return m_serviceCache;
+    return m_services;
 }
 
 /*
 Function: getComboPackages
-Description: Retrieves all combo package records from the datastore.
+Description: Retrieves the internal map of combo packages.
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<ComboPackage>>: Collection of combo package records
+    - Reference to util::Map<std::string, ComboPackage*> containing all combo packages.
 */
-util::Map<std::string, TrackedRecord<ComboPackage>>& DataStore::getComboPackages()
+util::Map<std::string, ComboPackage*>& DataStore::getComboPackages()
 {
-    util::Map<std::string, TrackedRecord<ComboPackage>> comboPackages = loadRecords<ComboPackage, SerializedComboPackage>(m_comboPackages);
-    refreshCache(m_comboPackageCache, comboPackages);
-    util::Map<std::string, TrackedRecord<Service>>& services = getServices();
-    size_t numberOfComboPackages = m_comboPackageCache.getSize();
-    for (int iteratorOne = 0; iteratorOne < numberOfComboPackages; iteratorOne++)
-    {
-        ComboPackage* currentComboPackage =  m_comboPackageCache.getValueAt(iteratorOne).data;
-        util::Vector<std::string> currentServiceIds = currentComboPackage->getServiceIDs();
-        util::Map<std::string, Service*> currentComboPackageServices;
-        for (int iteratorTwo = 0; iteratorTwo < currentServiceIds.getSize(); iteratorTwo++)
-        {
-            const std::string& currentServiceId = currentServiceIds[iteratorTwo];
-            int serviceIndex = services.find(currentServiceId);
-            if (serviceIndex == -1)
-            {
-                throw std::runtime_error("Invalid service ID");
-            }
-            Service* currentService = services.getValueAt(serviceIndex).data;
-            currentComboPackageServices[currentServiceId] = currentService;
-        }
-        currentComboPackage->setServices(currentComboPackageServices);
-    }
-    return m_comboPackageCache;
-}
-
-/*
-Function: getInventoryItems
-Description: Retrieves all inventory item records from the datastore.
-Parameters:
-    - None
-Returns:
-    - util::Map<std::string, TrackedRecord<InventoryItem>>: Collection of inventory item records
-*/
-util::Map<std::string, TrackedRecord<InventoryItem>>& DataStore::getInventoryItems()
-{
-    auto inventoryItems = loadRecords<InventoryItem, SerializedInventoryItem>(m_inventoryItems);
-    refreshCache(m_inventoryItemCache, inventoryItems);
-    return m_inventoryItemCache;
+    return m_comboPackages;
 }
 
 /*
 Function: getServiceBookings
-Description: Retrieves all service booking records from the datastore.
+Description: Retrieves the internal map of service bookings.
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<ServiceBooking>>: Collection of service booking records
+    - Reference to util::Map<std::string, ServiceBooking*> containing all service bookings.
 */
-util::Map<std::string, TrackedRecord<ServiceBooking>>& DataStore::getServiceBookings()
+util::Map<std::string, ServiceBooking*>& DataStore::getServiceBookings()
 {
-    util::Map<std::string, TrackedRecord<ServiceBooking>> serviceBookings = loadRecords<ServiceBooking, SerializedServiceBooking>(m_serviceBookings);
-    refreshCache(m_serviceBookingCache, serviceBookings);
-    auto& users = getUsers();
-    auto& services = getServices();
-    size_t numberOfServiceBookings = m_serviceBookingCache.getSize();
-    for (int iteratorOne = 0; iteratorOne < numberOfServiceBookings; iteratorOne++)
-    {
-        ServiceBooking* serviceBooking = m_serviceBookingCache.getValueAt(iteratorOne).data;
-        auto& serviceIds = serviceBooking->getServiceIDs();
-        util::Map<std::string, Service*> servicesInBooking;
-        for (int iteratorTwo = 0; iteratorTwo < serviceIds.getSize(); iteratorTwo++)
-        {
-            const std::string& currentServiceId = serviceIds[iteratorTwo];
-            int serviceIndex = services.find(currentServiceId);
-            if (serviceIndex == -1)
-            {
-                throw std::runtime_error("Invalid service index.");
-            }
-            auto& currentService = services.getValueAt(serviceIndex);
-            servicesInBooking[currentServiceId] = currentService.data;
-        }
-        serviceBooking->setServices(servicesInBooking);
-        if (!serviceBooking->getCustomerId().empty())
-        {
-            int userIndex = users.find(serviceBooking->getCustomerId());
-            if (userIndex == -1)
-            {
-                throw std::runtime_error("Invalid user index.");
-            }
-            auto& customer = users.getValueAt(userIndex);
-            serviceBooking->setCustomer(customer.data);
-        }
-        if (!serviceBooking->getAssignedTechnicianId().empty())
-        {
-            int technicianIndex = users.find(serviceBooking->getAssignedTechnicianId());
-            if (technicianIndex == -1)
-            {
-                throw std::runtime_error("Invalid technician index.");
-            }
-            auto& technician = users.getValueAt(technicianIndex);
-            serviceBooking->setAssignedTechnician(technician.data);
-        }
-    }
-    return m_serviceBookingCache;
+    return m_serviceBookings;
 }
 
 /*
 Function: getJobCards
-Description: Retrieves all job card records from the datastore.
+Description: Retrieves the internal map of job cards.
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<JobCard>>: Collection of job card records
+    - Reference to util::Map<std::string, JobCard*> containing all job cards.
 */
-util::Map<std::string, TrackedRecord<JobCard>>& DataStore::getJobCards()
+util::Map<std::string, JobCard*>& DataStore::getJobCards()
 {
-    util::Map<std::string, TrackedRecord<JobCard>> jobCards = loadRecords<JobCard, SerializedJobCard>(m_jobCards);
-    refreshCache(m_jobCardCache, jobCards);
-    auto& serviceBookings = getServiceBookings();
-    auto& services = getServices();
-    auto& users = getUsers();
-    int numberOfJobCards = m_jobCardCache.getSize();
-    for (int iterator = 0; iterator < numberOfJobCards; iterator++)
-    {
-        JobCard* jobCard = m_jobCardCache.getValueAt(iterator).data;
-        if (!jobCard)
-        {
-            continue;
-        }
-        const std::string& bookingId = jobCard->getBookingId();
-        int bookingIndex = serviceBookings.find(bookingId);
-        if (bookingIndex == -1)
-        {
-            throw std::runtime_error("Invalid booking ID: " + bookingId);
-        }
-        auto& trackedBooking = serviceBookings.getValueAt(bookingIndex);
-        jobCard->setBooking(trackedBooking.data);
-        const std::string& serviceId = jobCard->getServiceId();
-        int serviceIndex = services.find(serviceId);
-        if (serviceIndex == -1)
-        {
-            throw std::runtime_error("Invalid service ID: " + serviceId);
-        }
-        auto& trackedService = services.getValueAt(serviceIndex);
-        jobCard->setService(trackedService.data);
-        const std::string& technicianId = jobCard->getTechnicianId();
-        if (!technicianId.empty())
-        {
-            int technicianIndex = users.find(technicianId);
-            if (technicianIndex == -1)
-            {
-                throw std::runtime_error("Invalid technician ID: " + technicianId);
-            }
-            auto& trackedTechnician = users.getValueAt(technicianIndex);
-            jobCard->setTechnician(trackedTechnician.data);
-        }
-    }
-    return m_jobCardCache;
+    return m_jobCards;
 }
 
+/*
+Function: getInventoryItems
+Description: Retrieves the internal map of inventory items.
+Parameters:
+    - None
+Returns:
+    - Reference to util::Map<std::string, InventoryItem*> containing all inventory items.
+*/
+util::Map<std::string, InventoryItem*>& DataStore::getInventoryItems()
+{
+    return m_inventoryItems;
+}
 
 /*
 Function: getInvoices
-Description: Retrieves all invoice records from the datastore.
+Description: Retrieves the internal map of invoices.
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, TrackedRecord<Invoice>>: Collection of invoice records
+    - Reference to util::Map<std::string, Invoice*> containing all invoices.
 */
-util::Map<std::string, TrackedRecord<Invoice>>& DataStore::getInvoices()
+util::Map<std::string, Invoice*>& DataStore::getInvoices()
 {
-    auto& serviceBookings = getServiceBookings();
-    auto& inventoryItems = getInventoryItems();
-    util::Map<std::string, TrackedRecord<Invoice>> invoices = loadRecords<Invoice, SerializedInvoice>(m_invoices);
-    refreshCache(m_invoiceCache, invoices);
-    for (int iterator = 0; iterator < m_invoiceCache.getSize(); iterator++)
-    {
-        auto& trackedInvoice = m_invoiceCache.getValueAt(iterator);
-        Invoice* invoice = trackedInvoice.data;
-        if (!invoice)
-        {
-            continue;
-        }
-        const std::string& currentBookingId = invoice->getBookingId();
-        int currentBookingIndex = serviceBookings.find(currentBookingId);
-        if (currentBookingIndex == -1)
-        {
-            throw std::runtime_error("Invalid Service Booking Index.");
-        }
-        ServiceBooking* currentBooking = serviceBookings.getValueAt(currentBookingIndex).data;
-        auto& currentInventoryItemIds = invoice->getPartIDs();
-        util::Map<std::string, InventoryItem*> currentInventoryItems;
-        for (int iterator = 0; iterator < currentInventoryItemIds.getSize(); iterator++)
-        {
-            const std::string& currentItemId = currentInventoryItemIds[iterator];
-            int currentItemIndex = inventoryItems.find(currentItemId);
-            if (currentItemIndex == -1)
-            {
-                throw std::runtime_error("Invalid Inventory item id.");
-            }
-            InventoryItem* currentItem = inventoryItems.getValueAt(currentItemIndex).data;
-            if (!currentItem)
-            {
-                continue;
-            }
-            currentInventoryItems[currentItemId] = currentItem;
-        }
-        invoice->setBooking(currentBooking);
-        invoice->setParts(currentInventoryItems);
-    }
-    return m_invoiceCache;
+    return m_invoices;
 }
 
 /*
-Function: getObservers
-Description: Retrieves observer records from the specified observer mapping
-             and resolves them to User objects.
-Parameters:
-    - mapping: Observer mapping to read from
-Returns:
-    - 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, User*> DataStore::getObservers(MappingInfo& mapping)
-{
-    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;
-}
-
-/*
-Function: getServiceManagementObservers
-Description: Retrieves all service management observer records from the datastore.
+Function: getPayments
+Description: Retrieves the internal map of payments.
 Parameters:
     - None
 Returns:
-    - util::Map<std::string, User*>: Collection of observer records
+    - Reference to util::Map<std::string, Payment*> containing all payments.
 */
-util::Map<std::string, User*> DataStore::getServiceManagementObservers()
+util::Map<std::string, Payment*>& DataStore::getPayments()
 {
-    return getObservers(m_serviceManagementObservers);
-}
-
-/*
-Function: getPaymentManagementObservers
-Description: Retrieves all payment management observer records from the datastore.
-Parameters:
-    - None
-Returns:
-    - util::Map<std::string, User*>: Collection of observer records
-*/
-util::Map<std::string, User*> DataStore::getPaymentManagementObservers()
-{
-    return getObservers(m_paymentManagementObservers);
-}
-
-/*
-Function: getInventoryManagementObservers
-Description: Retrieves all inventory management observer records from the datastore.
-Parameters:
-    - None
-Returns:
-    - util::Map<std::string, User*>: Collection of observer records
-*/
-util::Map<std::string, User*> DataStore::getInventoryManagementObservers()
-{
-    return getObservers(m_inventoryManagementObservers);
-}
-
-/*
-Function: saveUsers
-Description: Persists all user records to the datastore.
-Parameters:
-    - None
-Returns:
-    - None
-*/
-void DataStore::saveUsers()
-{
-    saveRecords<User, SerializedUser>(m_users, m_userCache);
-}
-
-/*
-Function: saveNotifications
-Description: Persists all notification records to the datastore.
-Parameters:
-    - None
-Returns:
-    - None
-*/
-void DataStore::saveNotifications()
-{
-    saveRecords<Notification, SerializedNotification>(m_notifications, m_notificationCache);
-}
-
-/*
-Function: saveServices
-Description: Persists all service records to the datastore.
-Parameters:
-    - None
-Returns:
-    - None
-*/
-void DataStore::saveServices()
-{
-    saveRecords<Service, SerializedService>(m_services, m_serviceCache);
-}
-
-/*
-Function: saveComboPackages
-Description: Persists all combo package records to the datastore.
-Parameters:
-    - None
-Returns:
-    - None
-*/
-void DataStore::saveComboPackages()
-{
-    saveRecords<ComboPackage, SerializedComboPackage>(m_comboPackages, m_comboPackageCache);
-}
-
-/*
-Function: saveInventoryItems
-Description: Persists all inventory item records to the datastore.
-Parameters:
-    - None
-Returns:
-    - None
-*/
-void DataStore::saveInventoryItems()
-{
-    saveRecords<InventoryItem, SerializedInventoryItem>(m_inventoryItems, m_inventoryItemCache);
-}
-
-/*
-Function: saveServiceBookings
-Description: Persists all service booking records to the datastore.
-Parameters:
-    - None
-Returns:
-    - None
-*/
-void DataStore::saveServiceBookings()
-{
-    saveRecords<ServiceBooking, SerializedServiceBooking>(m_serviceBookings, m_serviceBookingCache);
-}
-
-/*
-Function: saveJobCards
-Description: Persists all job card records to the datastore.
-Parameters:
-    - None
-Returns:
-    - None
-*/
-void DataStore::saveJobCards()
-{
-    saveRecords<JobCard, SerializedJobCard>(m_jobCards, m_jobCardCache);
-}
-
-/*
-Function: saveInvoices
-Description: Persists all invoice records to the datastore.
-Parameters:
-    - None
-Returns:
-    - None
-*/
-void DataStore::saveInvoices()
-{
-    saveRecords<Invoice, SerializedInvoice>(m_invoices, m_invoiceCache);
-}
-
-/*
-Function: saveObservers
-Description: Persists observer records to the specified observer mapping.
-Parameters:
-    - mapping: MappingInfo&, observer mapping to save to
-    - observers: util::Map<std::string, User*>&, collection of observer records
-Returns:
-    - None
-*/
-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, User*>&, collection of observer records
-Returns:
-    - None
-*/
-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, User*>&, collection of observer records
-Returns:
-    - None
-*/
-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, User*>&, collection of observer records
-Returns:
-    - None
-*/
-void DataStore::saveInventoryManagementObservers(util::Map<std::string, User*>& observers)
-{
-    saveObservers(m_inventoryManagementObservers, observers);
-}
-
-/*
-Function: lockDataStore
-Description: Acquires the datastore mutex, providing
-             exclusive access to the shared-memory
-             datastore. This function blocks until
-             the mutex becomes available or an error
-             occurs.
-Parameter: None
-Return type:
-    bool
-    - true  : Mutex successfully acquired.
-    - false : Failed to acquire the mutex.
-*/
-bool DataStore::lockDataStore()
-{
-    if (m_globalMutex == NULL)
-    {
-        return false;
-    }
-    DWORD result = WaitForSingleObject(m_globalMutex, INFINITE);
-    return result == WAIT_OBJECT_0;
-}
-
-/*
-Function: unlockDataStore
-Description: Releases the datastore mutex after a
-             successful call to lockDataStore(),
-             allowing other processes to access the
-             shared-memory datastore.
-Parameter: None
-Return type:
-    bool
-    - true  : Mutex successfully released.
-    - false : Failed to release the mutex.
-*/
-bool DataStore::unlockDataStore()
-{
-    if (m_globalMutex == NULL)
-    {
-        return false;
-    }
-    return ReleaseMutex(m_globalMutex) != 0;
+    return m_payments;
 }

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

@@ -6,248 +6,42 @@ Date: 19-May-2026
 */
 
 #pragma once
-#include <windows.h>
 #include <string>
 #include "Map.h"
-#include "MappingInfo.h"
-#include "TrackedRecord.h"
-#include "SerializedRecords.h"
-#include "SharedMemory.h"
-#include "User.h"
-#include "Notification.h"
-#include "Service.h"
-#include "ComboPackage.h"
-#include "InventoryItem.h"
-#include "ServiceBooking.h"
-#include "JobCard.h"
-#include "Invoice.h"
+
+class User;
+class Service;
+class ComboPackage;
+class ServiceBooking;
+class JobCard;
+class InventoryItem;
+class Invoice;
+class Payment;
 
 class DataStore
 {
 private:
-    DataStore();
-    ~DataStore();
+    util::Map<std::string, User*> m_users;
+    util::Map<std::string, Service*> m_services;
+    util::Map<std::string, ComboPackage*> m_comboPackages;
+    util::Map<std::string, ServiceBooking*> m_serviceBookings;
+    util::Map<std::string, JobCard*> m_jobCards;
+    util::Map<std::string, InventoryItem*> m_inventoryItems;
+    util::Map<std::string, Invoice*> m_invoices;
+    util::Map<std::string, Payment*> m_payments;
+    DataStore() {}
+public:
+    static DataStore& getInstance();
     DataStore(const DataStore&) = delete;
     DataStore& operator=(const DataStore&) = delete;
     DataStore(DataStore&&) = delete;
     DataStore& operator=(DataStore&&) = delete;
-    HANDLE m_globalMutex;
-    MappingInfo m_users;
-    MappingInfo m_notifications;
-    MappingInfo m_services;
-    MappingInfo m_comboPackages;
-    MappingInfo m_inventoryItems;
-    MappingInfo m_serviceBookings;
-    MappingInfo m_jobCards;
-    MappingInfo m_invoices;
-    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<Notification>>& getNotifications();
-    util::Map<std::string, TrackedRecord<Service>>& getServices();
-    util::Map<std::string, TrackedRecord<ComboPackage>>& getComboPackages();
-    util::Map<std::string, TrackedRecord<InventoryItem>>& getInventoryItems();
-    util::Map<std::string, TrackedRecord<ServiceBooking>>& getServiceBookings();
-    util::Map<std::string, TrackedRecord<JobCard>>& getJobCards();
-    util::Map<std::string, TrackedRecord<Invoice>>& getInvoices();
-    util::Map<std::string, User*> getServiceManagementObservers();
-    util::Map<std::string, User*> getPaymentManagementObservers();
-    util::Map<std::string, User*> getInventoryManagementObservers();
-    void saveUsers();
-    void saveNotifications();
-    void saveServices();
-    void saveComboPackages();
-    void saveInventoryItems();
-    void saveServiceBookings();
-    void saveJobCards();
-    void saveInvoices();
-    void saveServiceManagementObservers(util::Map<std::string, User*>& observers);
-    void savePaymentManagementObservers(util::Map<std::string, User*>& observers);
-    void saveInventoryManagementObservers(util::Map<std::string, User*>& observers);
-    bool lockDataStore();
-    bool unlockDataStore();
-private:
-    template<typename TObject, typename TSerialized>
-    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);
+    util::Map<std::string, User*>& getUsers();
+    util::Map<std::string, Service*>& getServices();
+    util::Map<std::string, ComboPackage*>& getComboPackages();
+    util::Map<std::string, ServiceBooking*>& getServiceBookings();
+    util::Map<std::string, JobCard*>& getJobCards();
+    util::Map<std::string, InventoryItem*>& getInventoryItems();
+    util::Map<std::string, Invoice*>& getInvoices();
+    util::Map<std::string, Payment*>& getPayments();
 };
-
-/*
-Function: loadRecords
-Description: Loads all serialized records from the specified
-             shared-memory mapping, deserializes them into
-             application objects, and returns them as a map
-             of tracked records. Each loaded record is marked
-             as CLEAN and assigned its corresponding slot index
-             within the mapping so that future modifications
-             can be written back efficiently.
-Parameter:
-    - mapping: Reference to the mapping containing the
-               serialized records.
-Return type:
-    util::Map<std::string, TrackedRecord<TObject>>
-             A map containing all loaded records keyed by
-             their unique identifier.
-*/
-template<typename TObject, typename TSerialized>
-util::Map<std::string, TrackedRecord<TObject>> DataStore::loadRecords(MappingInfo& mapping)
-{
-    util::Map<std::string, TrackedRecord<TObject>> records;
-    SharedMemory::ensureLatestMapping(mapping);
-    size_t recordCount = SharedMemory::getRecordCount(mapping);
-    for (size_t index = 0; index < recordCount; ++index)
-    {
-        TSerialized* serialized = static_cast<TSerialized*>(SharedMemory::getRecordAddress(mapping,index));
-        TObject* object = TObject::deserialize(*serialized);
-        TrackedRecord<TObject> trackedRecord;
-        trackedRecord.data = object;
-        trackedRecord.state = RecordState::CLEAN;
-        trackedRecord.slotIndex = index;
-        records.insert(object->getId(), trackedRecord);
-    }
-    return records;
-}
-
-/*
-Function: saveRecords
-Description: Persists all modified and newly added records
-             contained in the provided map to the specified
-             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.
-Parameter:
-    - mapping: Reference to the mapping where records are
-               stored.
-    - records: Map containing the records to be persisted.
-Return type: void
-*/
-template<typename TObject, typename TSerialized> void DataStore::saveRecords(MappingInfo& mapping, util::Map<std::string, TrackedRecord<TObject>>& records)
-{
-    SharedMemory::ensureLatestMapping(mapping);
-    for (int index = 0; index < records.getSize(); ++index)
-    {
-        TrackedRecord<TObject>& record = records.getValueAt(index);
-        if (record.state == RecordState::CLEAN)
-        {
-            continue;
-        }
-        TSerialized serialized = record.data->serialize();
-        if (record.state == RecordState::MODIFIED)
-        {
-            TSerialized* destination = static_cast<TSerialized*>(SharedMemory::getRecordAddress(mapping, record.slotIndex));
-            if (destination)
-            {
-                *destination = serialized;
-            }
-        }
-        else if (record.state == RecordState::NEW_RECORD)
-        {
-            if (!SharedMemory::ensureCapacityForInsert(mapping))
-            {
-                continue;
-            }
-            size_t recordCount = SharedMemory::getRecordCount(mapping);
-            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);
-            if (oldRecord.state == RecordState::MODIFIED)
-            {
-                delete refreshedRecord.data;
-                cache.insert(id, oldRecord);
-                continue;
-            }
-            *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;
-            }
-        }
-    }
-}

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

@@ -1,28 +0,0 @@
-/*
-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/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"
@@ -29,8 +28,7 @@ Returns:
 ComboPackage::ComboPackage()
     : m_id("CMP" + std::to_string(++m_uid)),
     m_status(util::State::ACTIVE),
-    m_discountPercentage(0.0) {
-}
+    m_discountPercentage(0.0) {}
 
 /*
 Function: ComboPackage
@@ -272,38 +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 = {};
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
-    strcpy_s(serialized.packageName, sizeof(serialized.packageName), m_packageName.c_str());
-    strcpy_s(serialized.serviceIDs, sizeof(serialized.serviceIDs), getServiceIDsAsString(m_serviceIDs).c_str());
-    serialized.discountPercentage = m_discountPercentage;
-    serialized.status = m_status;
-    return serialized;
+    std::ostringstream serializedComboPackage;
+    serializedComboPackage << m_id << ','
+        << m_packageName << ','
+        << m_discountPercentage << ','
+        << getServiceIDsAsString(m_serviceIDs) << ','
+        << util::getStateString(m_status);
+    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);
-    return Factory::getObject<ComboPackage>(
-        serializedComboPackage.id,
-        serializedComboPackage.packageName,
-        serializedComboPackage.discountPercentage,
-        serviceIDs,
-        serializedComboPackage.status);
+    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>(
+        id,
+        packageName,
+        discountPercentage,
+        serviceIDs,
+        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 +12,6 @@ Date: 19-May-2026
 #include "Enums.h"
 
 class Service;
-struct SerializedComboPackage;
 
 class ComboPackage
 {
@@ -39,6 +38,7 @@ public:
     void setDiscountPercentage(double discountPercentage);
     void setServices(const util::Map<std::string, Service*>& services);
     void setState(util::State status);
-    SerializedComboPackage serialize() const;
-    static ComboPackage* deserialize(const SerializedComboPackage&);
+    std::string serialize() const;
+    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"
@@ -28,8 +27,7 @@ InventoryItem::InventoryItem()
     : m_id("IIM" + std::to_string(++m_uid)),
     m_quantity(0),
     m_status(util::State::ACTIVE),
-    m_price(0.0) {
-}
+    m_price(0.0) {}
 
 /*
 Function: InventoryItem
@@ -47,8 +45,7 @@ InventoryItem::InventoryItem(const std::string& partName, int quantity, double p
     m_partName(partName),
     m_quantity(quantity),
     m_status(util::State::ACTIVE),
-    m_price(price) {
-}
+    m_price(price) {}
 
 /*
 Function: InventoryItem (parameterized constructor with ID)
@@ -209,37 +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 = {};
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
-    strcpy_s(serialized.partName, sizeof(serialized.partName), m_partName.c_str());
-    serialized.quantity = m_quantity;
-    serialized.price = m_price;
-    serialized.status = m_status;
-    return serialized;
+    std::ostringstream serializedInventoryItem;
+    serializedInventoryItem << m_id << ','
+        << m_partName << ','
+        << m_quantity << ','
+        << m_price << ','
+        << util::getStateString(m_status);
+    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)
 {
-    return Factory::getObject<InventoryItem>(
-        serializedInventoryItem.id,
-        serializedInventoryItem.partName,
-        serializedInventoryItem.quantity,
-        serializedInventoryItem.price,
-        serializedInventoryItem.status);
+    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>(
+        id,
+        partName,
+        quantity,
+        price,
+        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;
-    static InventoryItem* deserialize(const SerializedInventoryItem&);
+    std::string serialize() const;
+    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"
@@ -35,8 +34,7 @@ Invoice::Invoice()
     m_discountPercentage(0.0),
     m_totalAmount(0.0),
     m_paymentMethod(util::PaymentMode()),
-    m_status(util::PaymentStatus()) {
-}
+    m_status(util::PaymentStatus()) {}
 
 /*
 Function: Invoice
@@ -475,50 +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 = {};
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
-    strcpy_s(serialized.bookingId, sizeof(serialized.bookingId), m_bookingId.c_str());
-    strcpy_s(serialized.partIDs, sizeof(serialized.partIDs), getPartIDsAsString(m_partIDs).c_str());
-    serialized.invoiceDate = m_invoiceDate;
-    serialized.laborCost = m_laborCost;
-    serialized.partsCost = m_partsCost;
-    serialized.discountPercentage = m_discountPercentage;
-    serialized.totalAmount = m_totalAmount;
-    serialized.paymentDate = m_paymentDate;
-    serialized.paymentMethod = m_paymentMethod;
-    serialized.status = m_status;
-    return serialized;
+    std::ostringstream serializedInvoice;
+    serializedInvoice << m_id << ','
+        << m_bookingId << ','
+        << m_invoiceDate.toString() << ','
+        << m_laborCost << ','
+        << getPartIDsAsString(m_partIDs) << ','
+        << m_partsCost << ','
+        << m_discountPercentage << ','
+        << m_totalAmount << ','
+        << m_paymentDate.toString() << ','
+        << util::getPaymentModeString(m_paymentMethod) << ','
+        << util::getPaymentStatusString(m_status);
+    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);
-    return Factory::getObject<Invoice>(
-        serializedInvoice.id,
-        serializedInvoice.bookingId,
-        serializedInvoice.invoiceDate,
-        partIDs,
-        serializedInvoice.laborCost,
-        serializedInvoice.partsCost,
-        serializedInvoice.discountPercentage,
-        serializedInvoice.totalAmount,
-        serializedInvoice.paymentDate,
-        serializedInvoice.paymentMethod,
-        serializedInvoice.status);
+    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>(
+        id,
+        bookingId,
+        invoiceDate,
+        partIDs,
+        laborCost,
+        partsCost,
+        discountPercentage,
+        totalAmount,
+        paymentDate,
+        paymentMethod,
+        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

@@ -6,6 +6,7 @@ Author: Trenser
 Date: 19-May-2026
 */
 
+
 #pragma once
 #include <string>
 #include "Map.h"
@@ -15,7 +16,6 @@ Date: 19-May-2026
 
 class ServiceBooking;
 class InventoryItem;
-struct SerializedInvoice;
 
 class Invoice
 {
@@ -87,6 +87,7 @@ public:
     void setPaymentDate(const util::Timestamp& paymentDate);
     void setPaymentMethod(util::PaymentMode paymentMethod);
     void setStatus(util::PaymentStatus status);
-    SerializedInvoice serialize() const;
-    static Invoice* deserialize(const SerializedInvoice&);
+    std::string serialize() const;
+    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"
@@ -29,8 +28,7 @@ JobCard::JobCard()
     m_booking(nullptr),
     m_service(nullptr),
     m_technician(nullptr),
-    m_status(util::ServiceJobStatus()) {
-}
+    m_status(util::ServiceJobStatus()) {}
 
 /*
 Function: JobCard
@@ -67,8 +65,7 @@ JobCard::JobCard(const std::string& bookingId,
     m_technician(technician),
     m_assignedDate(assignedDate),
     m_status(status),
-    m_completionDate(completionDate) {
-}
+    m_completionDate(completionDate) {}
 
 /*
 Function: JobCard (parameterized constructor with ID)
@@ -354,41 +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 = {};
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
-    strcpy_s(serialized.bookingId, sizeof(serialized.bookingId), m_bookingId.c_str());
-    strcpy_s(serialized.serviceId, sizeof(serialized.serviceId), m_serviceId.c_str());
-    strcpy_s(serialized.technicianId, sizeof(serialized.technicianId), m_technicianId.c_str());
-    serialized.assignedDate = m_assignedDate;
-    serialized.status = m_status;
-    serialized.completionDate = m_completionDate;
-    return serialized;
+    std::ostringstream serializedJobCard;
+    serializedJobCard << m_id << ','
+        << m_bookingId << ','
+        << m_serviceId << ','
+        << m_technicianId << ','
+        << m_assignedDate.toString() << ','
+        << util::getServiceJobStatusString(m_status) << ','
+        << m_completionDate.toString();
+    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)
 {
-    return Factory::getObject<JobCard>(
-        serializedJobCard.id,
-        serializedJobCard.bookingId,
-        serializedJobCard.serviceId,
-        serializedJobCard.technicianId,
-        serializedJobCard.assignedDate,
-        serializedJobCard.status,
-        serializedJobCard.completionDate);
+    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>(
+        id,
+        bookingId,
+        serviceId,
+        technicianId,
+        assignedDate,
+        status,
+        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;
-    static JobCard* deserialize(const SerializedJobCard&);
+    std::string serialize() const;
+    static JobCard* deserialize(const std::string&);
+    static std::string getHeaders();
 };

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

@@ -1,13 +1,12 @@
 /*
 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, recipientID, title, message, and timestamp.
+             Provides constructors, accessors, and mutators for notification details such as ID, recipient, title, message, and timestamp.
 Author: Trenser
 Date: 19-May-2026
 */
 
 #include <sstream>
-#include "SerializedRecords.h"
 #include "Notification.h"
 #include "StringHelper.h"
 #include "Factory.h"
@@ -24,7 +23,7 @@ Returns:
 */
 Notification::Notification()
     : m_id("NOT" + std::to_string(++m_uid)),
-    m_state(util::State::ACTIVE) {}
+    m_recipient(nullptr) {}
 
 /*
 Function: Notification
@@ -38,14 +37,13 @@ Parameters:
 Returns:
     - A new Notification object.
 */
-Notification::Notification(const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt)
+Notification::Notification(const std::string& recipientUserId, User* recipient, 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)
@@ -60,13 +58,13 @@ Parameters:
 Returns:
     - A new Notification object
 */
-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)
+Notification::Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt)
     : m_id(id),
     m_recipientUserId(recipientUserId),
+    m_recipient(nullptr),
     m_title(title),
     m_message(message),
-    m_createdAt(createdAt),
-    m_state(state)
+    m_createdAt(createdAt) 
 {
     int idNumber = util::extractNumber(m_id);
     if (idNumber > m_uid)
@@ -97,6 +95,17 @@ 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.
@@ -130,17 +139,6 @@ 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.
@@ -167,6 +165,19 @@ 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.
@@ -206,54 +217,71 @@ 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.
+Description: Serializes the notification into a CSV-formatted string.
 Parameters:
     - None
 Returns:
-    - SerializedNotification: Serialized representation of the notification
+    - std::string: Serialized notification record
 */
-SerializedNotification Notification::serialize() const
+std::string Notification::serialize() const
 {
-    SerializedNotification serialized = {};
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
-    strcpy_s(serialized.recipientUserId, sizeof(serialized.recipientUserId), m_recipientUserId.c_str());
-    strcpy_s(serialized.title, sizeof(serialized.title), m_title.c_str());
-    strcpy_s(serialized.message, sizeof(serialized.message), m_message.c_str());
-    serialized.createdAt = m_createdAt;
-    serialized.state = m_state;
-    return serialized;
+    std::ostringstream serializedNotification;
+    serializedNotification << m_id << ','
+        << m_recipientUserId << ','
+        << m_title << ','
+        << m_message << ','
+        << m_createdAt.toString();
+    return serializedNotification.str();
 }
 
 /*
 Function: deserialize
-Description: Deserializes a SerializedNotification record into a Notification object.
+Description: Deserializes a CSV-formatted string into a Notification object.
 Parameters:
-    - serializedNotification: const SerializedNotification&, serialized notification record
+    - record: const std::string&, serialized notification record
 Returns:
     - Notification*: Pointer to the deserialized Notification object
+Throws:
+    - std::runtime_error if timestamp parsing fails
 */
-Notification* Notification::deserialize(const SerializedNotification& serializedNotification)
+Notification* Notification::deserialize(const std::string& record)
 {
-    return Factory::getObject<Notification>(
-        serializedNotification.id,
-        serializedNotification.recipientUserId,
-        serializedNotification.title,
-        serializedNotification.message,
-        serializedNotification.createdAt,
-        serializedNotification.state);
+    std::string id, recipientUserId, title, message, createdAtTimestampString;
+    std::istringstream serializedNotification(record);
+    getline(serializedNotification, id, ',');
+    getline(serializedNotification, recipientUserId, ',');
+    getline(serializedNotification, title, ',');
+    getline(serializedNotification, message, ',');
+    getline(serializedNotification, createdAtTimestampString, ',');
+    util::Timestamp createdAtTimestamp;
+    try
+    {
+        createdAtTimestamp = util::Timestamp::fromString(createdAtTimestampString);
+    }
+    catch (...)
+    {
+        throw std::runtime_error("Invalid createdAt timestamp");
+    }
+    return Factory::getObject<Notification>(
+        id,
+        recipientUserId,
+        title,
+        message,
+        createdAtTimestamp
+    );
+}
+
+/*
+Function: getHeaders
+Description: Retrieves the CSV headers for notification serialization.
+Parameters:
+    - None
+Returns:
+    - std::string: Header string ("ID,RecipientID,Title,Message,Timestamp")
+*/
+std::string Notification::getHeaders()
+{
+    return "ID,RecipientID,Title,Message,Timestamp";
 }

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

@@ -9,10 +9,8 @@ Date: 19-May-2026
 #pragma once
 #include <string>
 #include "Timestamp.h"
-#include "Enums.h"
 
 class User;
-struct SerializedNotification;
 
 class Notification
 {
@@ -20,26 +18,27 @@ 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, 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);
+    Notification(const std::string& recipientUserId, User* recipient, 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 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() const;
-    void setState(util::State state);
-    SerializedNotification serialize() const;
-    static Notification* deserialize(const SerializedNotification&);
+    std::string serialize() const;
+    static Notification* deserialize(const std::string&);
+    static std::string getHeaders();
 };

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"
@@ -28,8 +27,7 @@ Returns:
 Service::Service()
     : m_id("SRV" + std::to_string(++m_uid)),
     m_status(util::State::ACTIVE),
-    m_laborCost(0.0) {
-}
+    m_laborCost(0.0) {}
 
 /*
 Function: Service
@@ -268,38 +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 = {};
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
-    strcpy_s(serialized.name, sizeof(serialized.name), m_name.c_str());
-    strcpy_s(serialized.inventoryItemIDs, sizeof(serialized.inventoryItemIDs), getInventoryItemIDsAsString(m_requiredInventoryItemIDs).c_str());
-    serialized.laborCost = m_laborCost;
-    serialized.status = m_status;
-    return serialized;
+    std::ostringstream serializedService;
+    serializedService << m_id << ','
+        << m_name << ','
+        << getInventoryItemIDsAsString(m_requiredInventoryItemIDs) << ','
+        << m_laborCost << ','
+        << util::getStateString(m_status);
+    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);
-    return Factory::getObject<Service>(
-        serializedService.id,
-        serializedService.name,
-        inventoryItemIDs,
-        serializedService.laborCost,
-        serializedService.status);
+    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>(
+        id,
+        name,
+        inventoryItemIDs,
+        laborCost,
+        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;
-    static Service* deserialize(const SerializedService&);
+    std::string serialize() const;
+    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"
@@ -30,8 +28,7 @@ ServiceBooking::ServiceBooking()
     m_customer(nullptr),
     m_assignedTechnician(nullptr),
     m_status(util::ServiceJobStatus::PENDING),
-    m_discountPercentage(0.0) {
-}
+    m_discountPercentage(0.0) {}
 
 /*
 Function: ServiceBooking
@@ -440,46 +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 = {};
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
-    strcpy_s(serialized.serviceIDs, sizeof(serialized.serviceIDs), getServiceIDsAsString(m_serviceIDs).c_str());
-    strcpy_s(serialized.customerId, sizeof(serialized.customerId), m_customerId.c_str());
-    strcpy_s(serialized.vehicleNumber, sizeof(serialized.vehicleNumber), m_vehicleNumber.c_str());
-    strcpy_s(serialized.vehicleBrand, sizeof(serialized.vehicleBrand), m_vehicleBrand.c_str());
-    strcpy_s(serialized.vehicleModel, sizeof(serialized.vehicleModel), m_vehicleModel.c_str());
-    strcpy_s(serialized.assignedTechnicianId, sizeof(serialized.assignedTechnicianId), m_assignedTechnicianId.c_str());
-    serialized.status = m_status;
-    serialized.discountPercentage = m_discountPercentage;
-    return serialized;
+    std::ostringstream serializedBooking;
+    serializedBooking << m_id << ','
+        << util::getServiceJobStatusString(m_status) << ','
+        << getServiceIDsAsString(m_serviceIDs) << ','
+        << m_customerId << ','
+        << m_vehicleNumber << ','
+        << m_vehicleBrand << ','
+        << m_vehicleModel << ','
+        << m_assignedTechnicianId << ','
+        << m_discountPercentage << ',';
+    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);
-    return Factory::getObject<ServiceBooking>(
-        serializedServiceBooking.id,
-        serializedServiceBooking.status,
-        serviceIDs,
-        serializedServiceBooking.customerId,
-        serializedServiceBooking.vehicleNumber,
-        serializedServiceBooking.vehicleBrand,
-        serializedServiceBooking.vehicleModel,
-        serializedServiceBooking.assignedTechnicianId,
-        serializedServiceBooking.discountPercentage);
+    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>(
+        id,
+        status,
+        serviceIDs,
+        customerId,
+        vehicleNumber,
+        vehicleBrand,
+        vehicleModel,
+        assignedTechnicianId,
+        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;
-    static ServiceBooking* deserialize(const SerializedServiceBooking&);
+    std::string serialize() const;
+    static ServiceBooking* deserialize(const std::string&);
+    static std::string getHeaders();
 };

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

@@ -8,7 +8,6 @@ Date: 19-May-2026
 */
 
 #include <sstream>
-#include "SerializedRecords.h"
 #include "User.h"
 #include "Notification.h"
 #include "Enums.h"
@@ -29,8 +28,7 @@ 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
@@ -53,8 +51,7 @@ 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)
@@ -89,6 +86,23 @@ 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.
@@ -155,6 +169,17 @@ 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.
@@ -255,6 +280,22 @@ 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.
@@ -283,43 +324,68 @@ void User::setState(util::State status)
 
 /*
 Function: serialize
-Description: Serializes the User object into a SerializedUser record.
+Description: Serializes the user into a CSV-formatted string.
 Parameters:
     - None
 Returns:
-    - SerializedUser: Serialized representation of the user
+    - std::string: Serialized user record
 */
-SerializedUser User::serialize() const
+std::string User::serialize() const
 {
-    SerializedUser serialized = {};
-    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
-    strcpy_s(serialized.username, sizeof(serialized.username), m_userName.c_str());
-    strcpy_s(serialized.password, sizeof(serialized.password), m_password.c_str());
-    strcpy_s(serialized.name, sizeof(serialized.name), m_name.c_str());
-    strcpy_s(serialized.phone, sizeof(serialized.phone), m_phone.c_str());
-    strcpy_s(serialized.email, sizeof(serialized.email), m_email.c_str());
-    serialized.userType = m_type;
-    serialized.status = m_status;
-    return serialized;
+    std::ostringstream serializedUser;
+    serializedUser << m_id << ','
+        << m_userName << ','
+        << m_password << ','
+        << m_name << ','
+        << m_phone << ','
+        << m_email << ','
+        << util::getUserTypeString(m_type) << ','
+        << util::getStateString(m_status);
+    return serializedUser.str();
 }
 
 /*
 Function: deserialize
-Description: Deserializes a SerializedUser record into a User object.
+Description: Deserializes a CSV-formatted string into a User object.
 Parameters:
-    - serializedUser: const SerializedUser&, serialized user record
+    - record: const std::string&, serialized user record
 Returns:
     - User*: Pointer to the deserialized User object
 */
-User* User::deserialize(const SerializedUser& serializedUser)
+User* User::deserialize(const std::string& record)
 {
-    return Factory::getObject<User>(
-        serializedUser.id,
-        serializedUser.username,
-        serializedUser.password,
-        serializedUser.name,
-        serializedUser.phone,
-        serializedUser.email,
-        serializedUser.userType,
-        serializedUser.status);
+    std::string id, name, username, phone, password, email;
+    std::string userTypeString, stateString;
+    std::istringstream serializedUser(record);
+    getline(serializedUser, id, ',');
+    getline(serializedUser, username, ',');
+    getline(serializedUser, password, ',');
+    getline(serializedUser, name, ',');
+    getline(serializedUser, phone, ',');
+    getline(serializedUser, email, ',');
+    getline(serializedUser, userTypeString, ',');
+    getline(serializedUser, stateString);
+    util::UserType userType = util::getUserType(userTypeString);
+    util::State status = util::getState(stateString);
+    return Factory::getObject<User>(id,
+        username,
+        password,
+        name,
+        phone,
+        email,
+        userType,
+        status);
+}
+
+/*
+Function: getHeaders
+Description: Retrieves the CSV headers for user serialization.
+Parameters:
+    - None
+Returns:
+    - std::string: Header string ("ID,Username,Password,Name,Phone,Email,UserType,UserStatus")
+*/
+std::string User::getHeaders()
+{
+    return "ID,Username,Password,Name,Phone,Email,UserType,UserStatus";
 }

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

@@ -14,7 +14,6 @@ Date: 19-May-2026
 #include "Enums.h"
 
 class Notification;
-struct SerializedUser;
 
 class User : public Observer
 {
@@ -26,19 +25,21 @@ 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() = default;
+    ~User();
     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);
@@ -47,8 +48,10 @@ 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;
-    static User* deserialize(const SerializedUser& serializedUser);
+    std::string serialize() const;
+    static User* deserialize(const std::string&);
+    static std::string getHeaders();
 };

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

@@ -10,32 +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;
-bool AuthenticationManagementService::m_isAuthorized = false;
-EventManager AuthenticationManagementService::m_eventManager;
-HANDLE AuthenticationManagementService::m_accountDisabledEvent = NULL;
-HANDLE AuthenticationManagementService::m_notificationsAvailableEvent = NULL;
-
-
-/*
-Function: ensureAuthorization
-Description: Verifies that a user is currently authenticated before allowing
-			 access to a protected operation. Throws an exception if no
-			 authorized user session exists.
-Parameter: None
-Return type: void
-Throws: std::runtime_error - if the user is not authorized
-*/
-void AuthenticationManagementService::ensureAuthorization()
-{
-	if (!m_authenticatedUser || !m_isAuthorized)
-	{
-		throw std::runtime_error("You are not authorized to do this operation!");
-	}
-}
 
 /*
 Function: login
@@ -48,35 +24,16 @@ Return type: bool - true if login successful, false otherwise
 */
 bool AuthenticationManagementService::login(const std::string& username, const std::string& password)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUserMap = m_dataStore.getUsers();
-	int trackedUserMapSize = trackedUserMap.getSize();
-	for (int index = 0; index < trackedUserMapSize; index++)
+	util::Map<std::string, User*> users = m_dataStore.getUsers();
+	int usersMapSize = users.getSize();
+	for (int index = 0; index < usersMapSize; index++)
 	{
-		User* user = trackedUserMap.getValueAt(index).data;
+		User* user = users.getValueAt(index);
 		if (username == user->getUserName())
 		{
 			if (password == user->getPassword())
 			{
 				m_authenticatedUser = user;
-				m_isAuthorized = true;
-				m_eventManager.initialize(
-					user->getId(),
-					[]()
-					{
-						if (m_accountDisabledEvent)
-						{
-							AuthenticationManagementService::m_isAuthorized = false;
-							SetEvent(m_accountDisabledEvent);
-						}
-					},
-					[]()
-					{
-						if (m_notificationsAvailableEvent)
-						{
-							SetEvent(m_notificationsAvailableEvent);
-						}
-					});
 				return true;
 			}
 			return false;
@@ -105,11 +62,7 @@ Return type: void
 */
 void AuthenticationManagementService::logout()
 {
-	m_eventManager.shutdown();
 	m_authenticatedUser = nullptr;
-	m_isAuthorized = false;
-	m_accountDisabledEvent = NULL;
-	m_notificationsAvailableEvent = NULL;
 }
 
 /*
@@ -121,33 +74,9 @@ Return type: void
 */
 void AuthenticationManagementService::changePassword(const std::string& newPassword)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	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();
-}
-
-/*
-Function: registerEvents
-Description: Registers menu event handles used to notify the active
-			 menu of account disable and notification events.
-Parameter: HANDLE accountDisabledEvent - account disabled event handle
-		   HANDLE notificationAvailableEvent - notification event handle
-Return type: void
-*/
-void AuthenticationManagementService::registerEvents(HANDLE accountDisabledEvent, HANDLE notificationAvailableEvent)
-{
-	m_accountDisabledEvent = accountDisabledEvent;
-	m_notificationsAvailableEvent = notificationAvailableEvent;
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/AuthenticationManagementService.h

@@ -9,8 +9,6 @@ Date:19-May-2026
 
 #pragma once
 #include <string>
-#include <windows.h>
-#include "EventManager.h"
 #include "DataStore.h"
 
 class User;
@@ -19,17 +17,11 @@ class AuthenticationManagementService
 {
 private:
     static User* m_authenticatedUser;
-    static bool m_isAuthorized;
-    static EventManager m_eventManager;
-    static HANDLE m_accountDisabledEvent;
-    static HANDLE m_notificationsAvailableEvent;
     DataStore& m_dataStore;
 public:
     AuthenticationManagementService() : m_dataStore(DataStore::getInstance()) {}
-    static void ensureAuthorization();
     bool login(const std::string& username, const std::string& password);
     void logout();
     void changePassword(const std::string& newPassword);
     User* getAuthenticatedUser();
-    void registerEvents(HANDLE accountDisabledEvent, HANDLE notificationAvailableEvent);
 };

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

@@ -12,15 +12,14 @@ Date: 22-May-2026
 #include "Config.h"
 #include "Enums.h"
 #include "Factory.h"
+#include "FileManager.h"
 #include "InventoryItem.h"
 #include "InventoryManagementService.h"
-#include "AuthenticationManagementService.h"
 #include "Timestamp.h"
 #include "User.h"
 #include "Utility.h"
 #include "Vector.h"
-#include "DataStoreLockGuard.h"
-#include "EventManager.h"
+
 
 util::Map<std::string, User*> InventoryManagementService::m_observers{};
 
@@ -59,19 +58,18 @@ Returns:
 */
 void InventoryManagementService::sendLowStockAlerts()
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedInventoryItemsMap = m_dataStore.getInventoryItems();
-	auto& trackedUserMap = m_dataStore.getUsers();
-	if (trackedInventoryItemsMap.isEmpty())
+	auto& inventoryItems = m_dataStore.getInventoryItems();
+	if (inventoryItems.isEmpty())
 	{
 		return;
 	}
-	int inventoryItemsSize = trackedInventoryItemsMap.getSize();
-	int usersMapSize = trackedUserMap.getSize();
+	int inventoryItemsSize = inventoryItems.getSize();
+	auto& usersMap = m_dataStore.getUsers();
+	int usersMapSize = usersMap.getSize();
 	util::Vector<User*> adminUsers;
 	for (int index = 0; index < usersMapSize; index++)
 	{
-		User* user = trackedUserMap.getValueAt(index).data;
+		User* user = usersMap.getValueAt(index);
 		if (user->getUserType() == util::UserType::ADMIN)
 		{
 			adminUsers.push_back(user);
@@ -84,7 +82,7 @@ void InventoryManagementService::sendLowStockAlerts()
 	}
 	for (int index = 0; index < inventoryItemsSize; index++)
 	{
-		InventoryItem* inventoryItem = trackedInventoryItemsMap.getValueAt(index).data;
+		InventoryItem* inventoryItem = inventoryItems.getValueAt(index);
 		if (inventoryItem && inventoryItem->getQuantity() < config::threshold::INVENTORY_LOW_STOCK_THRESHOLD)
 		{
 			sendLowStockAlertsToAdmins(*this, inventoryItem, adminUsers);
@@ -92,6 +90,95 @@ 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
@@ -103,12 +190,8 @@ Return type: void
 */
 void InventoryManagementService::addInventoryItem(const std::string& partName, int quantity, double price)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
     InventoryItem* newItem = Factory::getObject<InventoryItem>(partName, quantity, price);
-	trackedInventoryItemMap.insert(newItem->getId(), util::createNewRecord(newItem));
-	m_dataStore.saveInventoryItems();
+    m_dataStore.getInventoryItems().insert(newItem->getId(), newItem);
 }
 
 /*
@@ -120,23 +203,16 @@ Return type: void
 */
 void InventoryManagementService::addInventoryItemStock(const std::string& selectedItemId, int quantity)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
-	int index = trackedInventoryItemMap.find(selectedItemId);
-	if (index == -1)
+    int index = m_dataStore.getInventoryItems().find(selectedItemId);
+    if (index != -1)
     {
-		throw std::runtime_error("Inventory update failed: Item ID '" + selectedItemId + "' not found.");
-	}
-	InventoryItem* item = trackedInventoryItemMap.getValueAt(index).data;
-	if (item == nullptr)
+        InventoryItem* item = m_dataStore.getInventoryItems().getValueAt(index);
+        if (item != nullptr)
         {
-		throw std::runtime_error("Inventory update failed. Item does not exist.\n");
-	}
             int totalQuantity = item->getQuantity() + quantity;
             item->setQuantity(totalQuantity);
-	trackedInventoryItemMap.getValueAt(index).state = RecordState::MODIFIED;
-	m_dataStore.saveInventoryItems();
+        }
+    }
 }
 
 /*
@@ -147,11 +223,7 @@ Return type: util::Map<std::string, InventoryItem*>
 */
 util::Map<std::string, InventoryItem*> InventoryManagementService::getInventoryItems()
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
-	auto inventoryMap = util::getObjects(trackedInventoryItemMap);
-	return inventoryMap;
+	return m_dataStore.getInventoryItems();
 }
 
 /*
@@ -162,22 +234,15 @@ Return type: void
 */
 void InventoryManagementService::removeInventoryItem(const std::string& inventoryItemID)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
-	int index = trackedInventoryItemMap.find(inventoryItemID);
-	if (index == -1)
+    int index = m_dataStore.getInventoryItems().find(inventoryItemID);
+    if (index != -1)
     {
-		throw std::runtime_error("Inventory removal failed: Item ID '" + inventoryItemID + "' not found.");
-	}
-	InventoryItem* item = trackedInventoryItemMap.getValueAt(index).data;
-	if (item == nullptr)
+        InventoryItem* item = m_dataStore.getInventoryItems().getValueAt(index);
+        if (item != nullptr)
         {
-		throw std::runtime_error("Inventory removal failed: Item ID does not exist.");
-	}
             item->setState(util::State::INACTIVE);
-	trackedInventoryItemMap.getValueAt(index).state = RecordState::MODIFIED;
-	m_dataStore.saveInventoryItems();
+        }
+    }
 }
 
 /*
@@ -188,21 +253,13 @@ Return type: InventoryItem*
 */
 InventoryItem* InventoryManagementService::getInventoryItem(const std::string& inventoryItemID)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedInventoryItemMap = m_dataStore.getInventoryItems();
-    int index = trackedInventoryItemMap.find(inventoryItemID);
-    if (index == -1)
+    int index = m_dataStore.getInventoryItems().find(inventoryItemID);
+    if (index != -1)
     {
+        return m_dataStore.getInventoryItems().getValueAt(index);
+    }
     return nullptr;
 }
-	InventoryItem* inventoryItem = trackedInventoryItemMap.getValueAt(index).data;
-	if (inventoryItem == nullptr)
-	{
-		throw std::runtime_error("Item ID does not exist.");
-	}
-	return inventoryItem;
-}
 
 /*
 Function: attach
@@ -214,9 +271,6 @@ 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();
@@ -225,7 +279,6 @@ void InventoryManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
-	m_dataStore.saveInventoryManagementObservers(m_observers);
 }
 
 /*
@@ -238,9 +291,6 @@ 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();
@@ -249,7 +299,6 @@ void InventoryManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
-	m_dataStore.saveInventoryManagementObservers(m_observers);
 }
 
 /*
@@ -266,28 +315,27 @@ Throws:
 */
 void InventoryManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (!user)
+	if (user)
 	{
-		return;
-	}
-	DataStoreLockGuard lock(m_dataStore);
-	m_observers = m_dataStore.getInventoryManagementObservers();
-	if (m_observers.find(user->getId()) == -1)
+		if (m_observers.find(user->getId()) != -1)
 		{
-		return;
-	}
-	auto& trackedNotificationsMap = m_dataStore.getNotifications();
-	Notification* notification = Factory::getObject<Notification>(
+			Notification* notification =
+				Factory::getObject<Notification>(
 					user->getId(),
+					user,
 					title,
 					message,
-		util::Timestamp());
-	if (!notification)
+					util::Timestamp()
+				);
+			if (notification)
+			{
+				user->addNotification(notification);
+			}
+			else
 			{
 				throw std::runtime_error("Failed to create notification");
 			}
-	trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
-	m_dataStore.saveNotifications();
-	EventManager::sendNotificationAvailableEvent(user->getId());
+		}
+	}
 }
 

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

@@ -21,6 +21,7 @@ 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();
@@ -32,4 +33,8 @@ 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

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

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

@@ -19,4 +19,5 @@ 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

@@ -11,19 +11,16 @@ 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"
 #include "PaymentManagementService.h"
-#include "AuthenticationManagementService.h"
-#include "DataStoreLockGuard.h"
 #include "Service.h"
 #include "ServiceBooking.h"
 #include "Timestamp.h"
 #include "User.h"
 #include "Utility.h"
-#include "DataStoreLockGuard.h"
-#include "EventManager.h"
 
 util::Map<std::string, User*> PaymentManagementService::m_observers{};
 
@@ -37,9 +34,6 @@ 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();
@@ -48,7 +42,6 @@ void PaymentManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
-	m_dataStore.savePaymentManagementObservers(m_observers);
 }
 
 /*
@@ -61,9 +54,6 @@ 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();
@@ -72,7 +62,6 @@ void PaymentManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
-	m_dataStore.savePaymentManagementObservers(m_observers);
 }
 
 /*
@@ -89,29 +78,28 @@ Throws:
 */
 void PaymentManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (!user)
+	if (user)
 	{
-		return;
-	}
-	DataStoreLockGuard lock(m_dataStore);
-	m_observers = m_dataStore.getPaymentManagementObservers();
-	if (m_observers.find(user->getId()) == -1)
+		if (m_observers.find(user->getId()) != -1)
 		{
-		return;
-	}
-	auto& trackedNotificationsMap = m_dataStore.getNotifications();
-	Notification* notification = Factory::getObject<Notification>(
+			Notification* notification =
+				Factory::getObject<Notification>(
 					user->getId(),
+					user,
 					title,
 					message,
-		util::Timestamp());
-	if (!notification)
+					util::Timestamp()
+				);
+			if (notification)
+			{
+				user->addNotification(notification);
+			}
+			else
 			{
 				throw std::runtime_error("Failed to create notification");
 			}
-	trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
-	m_dataStore.saveNotifications();
-	EventManager::sendNotificationAvailableEvent(user->getId());
+		}
+	}
 }
 
 /*
@@ -125,12 +113,11 @@ Returns:
 */
 void PaymentManagementService::sendPaymentReminders()
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedInvoicesMap = m_dataStore.getInvoices();
-	int invoicesMapSize = trackedInvoicesMap.getSize();
+	auto& invoicesMap = m_dataStore.getInvoices();
+	int invoicesMapSize = invoicesMap.getSize();
 	for (int index = 0; index < invoicesMapSize; index++)
 	{
-		const Invoice* invoice = trackedInvoicesMap.getValueAt(index).data;
+		const Invoice* invoice = invoicesMap.getValueAt(index);
 		if (invoice && invoice->getStatus() == util::PaymentStatus::PENDING)
 		{
 			util::Timestamp invoiceCreationTimestamp = invoice->getInvoiceDate();
@@ -153,6 +140,123 @@ 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.
@@ -186,7 +290,6 @@ Throws:
 */
 void PaymentManagementService::generateInvoice(ServiceBooking* booking)
 {
-	DataStoreLockGuard lock(m_dataStore);
 	if (!booking)
 	{
 		throw std::runtime_error("Invoice generation failed: booking is null.");
@@ -196,10 +299,10 @@ void PaymentManagementService::generateInvoice(ServiceBooking* booking)
 	std::string bookingID = booking->getId();
 	util::Map<std::string, Service*> servicesInTheBookedService = booking->getServices();
 	util::Map<std::string, InventoryItem*> completeInventoryItemMapOfBooking;
-	auto& currentTrackedJobCards = m_dataStore.getJobCards();
-	for (int iterator = 0; iterator < currentTrackedJobCards.getSize(); iterator++)
+	util::Map<std::string, JobCard*> currentJobCards = m_dataStore.getJobCards();
+	for (int iterator = 0; iterator < currentJobCards.getSize(); iterator++)
 	{
-		JobCard* currentJobCard = currentTrackedJobCards.getValueAt(iterator).data;
+		JobCard* currentJobCard = currentJobCards.getValueAt(iterator);
 		util::ServiceJobStatus currentJobCardStatus = currentJobCard->getStatus();
 		if (currentJobCard->getBookingId() == bookingID && currentJobCardStatus != util::ServiceJobStatus::CANCELLED && currentJobCardStatus != util::ServiceJobStatus::COMPLETED)
 		{
@@ -219,9 +322,8 @@ void PaymentManagementService::generateInvoice(ServiceBooking* booking)
 	totalServiceCost = totalLaborCost + totalPartsCost;
 	totalServiceCost -= (totalServiceCost * (discountPercentage / 100));
 	Invoice* invoice = Factory::getObject<Invoice>(bookingID, booking, util::Timestamp(), totalLaborCost, completeInventoryItemMapOfBooking, totalPartsCost, discountPercentage, totalServiceCost, util::Timestamp(), util::PaymentMode::NOTSET, util::PaymentStatus::PENDING);
-	auto& currentTrackedInvoices = m_dataStore.getInvoices();
-	currentTrackedInvoices.insert(invoice->getId(), util::createNewRecord(invoice));
-	m_dataStore.saveInvoices();
+	util::Map<std::string, Invoice*>& currentInvoices = m_dataStore.getInvoices();
+	currentInvoices.insert(invoice->getId(), invoice);
 }
 
 /*
@@ -234,13 +336,11 @@ Returns:
 */
 util::Map<std::string, Invoice*> PaymentManagementService::getInvoices(const std::string& customerID)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& currentTrackedInvoices = m_dataStore.getInvoices();
+	util::Map<std::string, Invoice*>& currentInvoices = m_dataStore.getInvoices();
 	util::Map<std::string, Invoice*> currentUserInvoices;
-	for (int iterator = 0; iterator < currentTrackedInvoices.getSize(); iterator++)
+	for (int iterator = 0; iterator < currentInvoices.getSize(); iterator++)
 	{
-		Invoice* currentInvoice = currentTrackedInvoices.getValueAt(iterator).data;
+		Invoice* currentInvoice = currentInvoices.getValueAt(iterator);
 		if (currentInvoice->getBooking()->getCustomerId() == customerID)
 		{
 			currentUserInvoices.insert(currentInvoice->getId(), currentInvoice);
@@ -263,83 +363,25 @@ Throws:
 */
 void PaymentManagementService::completePayment(const std::string& invoiceID, util::PaymentMode paymentMode)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& currentTrackedInvoices = m_dataStore.getInvoices();
-	int invoiceIndex = currentTrackedInvoices.find(invoiceID);
+	auto& currentInvoices = m_dataStore.getInvoices();
+	int invoiceIndex = currentInvoices.find(invoiceID);
 	if (invoiceIndex != -1)
 	{
-		auto& trackedInvoice = currentTrackedInvoices.getValueAt(invoiceIndex);
-		Invoice* invoice = trackedInvoice.data;
-		if (invoice && invoice->getStatus() != util::PaymentStatus::PAID)
+		Invoice* invoice = currentInvoices.getValueAt(invoiceIndex);
+		if (invoice && invoice->getStatus() != util::PaymentStatus::COMPLETED)
 		{
 			User* currentUser = invoice->getBooking()->getCustomer();
 			invoice->setPaymentMethod(paymentMode);
 			invoice->setPaymentDate(util::Timestamp());
-			invoice->setStatus(util::PaymentStatus::PAID);
+			invoice->setStatus(util::PaymentStatus::COMPLETED);
 			std::string title, message;
 			title = "Payment successful";
 			message = "Payment successful for Invoice ID " + invoiceID;
 			sendNotification(currentUser, title, message);
-			trackedInvoice.state = RecordState::MODIFIED;
 		}
 	}
 	else
 	{
 		throw std::runtime_error("Payment failed: invalid invoice ID.");
 	}
-	m_dataStore.saveInvoices();
-}
-
-/*
-Function: getAllInvoices
-Description: Provides access to all invoices stored in the data store.
-Parameters:
-	- none
-Returns:
-	- util::Map<std::string, Invoice*>: Map of invoice IDs to invoice objects
-*/
-util::Map<std::string, Invoice*> PaymentManagementService::getAllInvoices()
-{
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	util::Map<std::string, Invoice*> invoices;
-	invoices = util::getObjects(m_dataStore.getInvoices());
-	return invoices;
-}
-
-/*
-Function: confirmPayment
-Description: Confirms payment for a specific invoice. Updates payment date and status,
-			 then sends a notification to the customer.
-Parameters:
-	- invoiceID: std::string, ID of the invoice to confirm
-Returns:
-	- void
-Throws:
-	- std::runtime_error if the invoice ID is invalid
-*/
-void PaymentManagementService::confirmPayment(const std::string& invoiceID)
-{
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& currentTrackedInvoices = m_dataStore.getInvoices();
-	int invoiceIndex = currentTrackedInvoices.find(invoiceID);
-	if (invoiceIndex == -1)
-	{
-		throw std::runtime_error("Payment confirmation failed: invalid invoice ID.");
-	}
-	auto& trackedInvoice = currentTrackedInvoices.getValueAt(invoiceIndex);
-	Invoice* invoice = trackedInvoice.data;
-	if (!invoice || invoice->getStatus() != util::PaymentStatus::PAID)
-	{
-		throw std::runtime_error("Payment confirmation failed: invoice is not awaiting confirmation.");
-	}
-	User* currentUser = invoice->getBooking()->getCustomer();
-	invoice->setStatus(util::PaymentStatus::COMPLETED);
-	trackedInvoice.state = RecordState::MODIFIED;
-	std::string title = "Payment Confirmed";
-	std::string message = "Payment Confirmed for Invoice ID " + invoiceID;
-	sendNotification(currentUser, title, message);
-	m_dataStore.saveInvoices();
 }

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

@@ -22,15 +22,18 @@ 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);
     util::Map<std::string, Invoice*> getInvoices(const std::string& customerID);
     void completePayment(const std::string& invoiceID, util::PaymentMode paymentMode);
-    util::Map<std::string, Invoice*> getAllInvoices();
-    void confirmPayment(const std::string& invoiceID);
     void sendPaymentReminders();
     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.h

@@ -23,6 +23,7 @@ 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();
@@ -35,7 +36,6 @@ public:
     void createJobCard(const std::string& bookingID, const std::string& technicianID, const std::string& serviceID);
     void createService(const std::string& name, const util::Vector<std::string>& inventoryItemIDs, double laborCost);
     void removeService(const std::string& serviceID);
-    void removeServiceBooking(const std::string& bookingID);
     util::Map<std::string, JobCard*> getJobCards(const std::string& technicianID);
     void updateJobStatus(const std::string& jobID);
     void cancelCustomerServiceBookings(const std::string& customerID);
@@ -45,4 +45,14 @@ 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

@@ -11,19 +11,15 @@ 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"
 #include "ServiceManagementService.h"
-#include "AuthenticationManagementService.h"
 #include "User.h"
 #include "UserManagementService.h"
 #include "Vector.h"
 #include "Validator.h"
-#include "Utility.h"
-#include "TrackedRecord.h"
-#include "DataStoreLockGuard.h"
-#include "EventManager.h"
 
 /*
 Function: ensureAdminExists
@@ -35,13 +31,12 @@ 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).data;
+		User* user = usersMap.getValueAt(index);
 		if (user && user->getUserType() == util::UserType::ADMIN)
 		{
 			isAdminFound = true;
@@ -78,9 +73,7 @@ void UserManagementService::createUser(const std::string& username, const std::s
 	InventoryManagementService inventoryManagementService;
 	PaymentManagementService paymentManagementService;
 	ServiceManagementService serviceManagementService;
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	auto usersMap = util::getObjects(trackedUsersMap);
+	auto& usersMap = m_dataStore.getUsers();
 	if (util::isUsernameDuplicate(username, usersMap))
 	{
 		throw std::runtime_error("Username already exists");
@@ -94,14 +87,13 @@ 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);
-	trackedUsersMap.insert(newUser->getId(), util::createNewRecord(newUser));
+	usersMap.insert(newUser->getId(), newUser);
 	paymentManagementService.attach(newUser);
 	serviceManagementService.attach(newUser);
 	if (newUser->getUserType() == util::UserType::ADMIN)
 	{
 		inventoryManagementService.attach(newUser);
 	}
-	m_dataStore.saveUsers();
 }
 
 /*
@@ -115,25 +107,19 @@ Return type: void
 */
 void UserManagementService::updateUserDetails(const std::string& userID, const std::string& email, const std::string& phone)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	auto usersMap = util::getObjects(trackedUsersMap);
-	int index = trackedUsersMap.find(userID);
+	auto& usersMap = m_dataStore.getUsers();
+	int index = usersMap.find(userID);
 	if (index == -1)
 	{
 		throw std::runtime_error("User does not exist!\n");
 	}
-	User* user = trackedUsersMap.getValueAt(index).data;
-	bool isModified = false;
+	User* user = usersMap.getValueAt(index);
 	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())
 	{
@@ -141,14 +127,9 @@ void UserManagementService::updateUserDetails(const std::string& userID, const s
 		{
 			throw std::runtime_error("Phone number already exists!\n");
 		}
+	}
+	user->setEmail(email);
 	user->setPhone(phone);
-		isModified = true;
-	}
-	if (isModified)
-	{
-		trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
-		m_dataStore.saveUsers();
-	}
 }
 
 /*
@@ -163,26 +144,20 @@ Throws:
 */
 util::Vector<Notification*> UserManagementService::getUserNotifications(const std::string& userID)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers(); 
-	if (trackedUsersMap.find(userID) == -1)
+	auto& usersMap = m_dataStore.getUsers();
+	if (usersMap.find(userID) == -1)
 	{
 		throw std::runtime_error("No user found with given UserID");
 	}
-	User* user = trackedUsersMap[userID].data;
+	User* user = usersMap[userID];
 	if (user)
 	{
-		auto& trackedNotificationMap = m_dataStore.getNotifications();
-		int numberOfNotifications = trackedNotificationMap.getSize();
+		auto& notifications = user->getNotifications();
+		int numberOfNotifications = notifications.getSize();
 		util::Vector<Notification*> notificationsVector;
 		for (int index = 0; index < numberOfNotifications; index++)
 		{
-			Notification* notification = trackedNotificationMap.getValueAt(index).data;
-			if (notification->getRecipientUserId() == userID && notification->getState() == util::State::ACTIVE)
-			{
-				notificationsVector.push_back(notification);
-			}
+		    notificationsVector.push_back(notifications.getValueAt(index));
 		}
 		return notificationsVector;
 	}
@@ -194,40 +169,97 @@ util::Vector<Notification*> UserManagementService::getUserNotifications(const st
 
 /*
 Function: deleteNotification
-Description: Marks a specific notification associated with a given user
-			 as inactive.
+Description: Deletes a specific notification associated with a given user ID.
 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)
 {
-    AuthenticationManagementService::ensureAuthorization();
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	auto& trackedNotificationsMap = m_dataStore.getNotifications();
-	int userIndex = trackedUsersMap.find(userID);
-	if (userIndex == -1)
+	auto& usersMap = m_dataStore.getUsers();
+	if (usersMap.find(userID) == -1)
 	{
 		throw std::runtime_error("No user found with given UserID");
 	}
-	int notificationIndex = trackedNotificationsMap.find(notificationID);
-	if (notificationIndex == -1)
+	User* user = usersMap[userID];
+	auto& notifications = user->getNotifications();
+	if (notifications.find(notificationID) == -1)
 	{
 		throw std::runtime_error("No notification found with given NotificationID");
 	}
-	Notification* notification = trackedNotificationsMap.getValueAt(notificationIndex).data;
-	if (notification->getRecipientUserId() == userID)
-	{
-		notification->setState(util::State::INACTIVE);
-		trackedNotificationsMap.getValueAt(notificationIndex).state = RecordState::MODIFIED;
-		m_dataStore.saveNotifications();
+	notifications.remove(notificationID);
 }
+
+/*
+Function: loadUsers
+Description: Loads users and notifications from persistent storage into the datastore.
+             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);
 }
 
 /*
@@ -238,9 +270,7 @@ Return type: util::Map<std::string, User*>
 */
 util::Map<std::string, User*> UserManagementService::getUsers()
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto users = util::getObjects(m_dataStore.getUsers());
-	return users;
+	return m_dataStore.getUsers();
 }
 
 /*
@@ -251,12 +281,10 @@ Return type: User*
 */
 User* UserManagementService::getUser(const std::string& userID)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	int index = trackedUsersMap.find(userID);
+	int index = m_dataStore.getUsers().find(userID);
 	if (index != -1)
 	{
-		return trackedUsersMap.getValueAt(index).data;
+		return m_dataStore.getUsers().getValueAt(index);
 	}
 	return nullptr;
 }
@@ -269,18 +297,13 @@ Return type: void
 */
 void UserManagementService::removeUser(const std::string& userID)
 {
-    AuthenticationManagementService::ensureAuthorization();
 	InventoryManagementService inventoryManagementService;
 	PaymentManagementService paymentManagementService;
 	ServiceManagementService serviceManagementService;
-	std::string removedUserID;
-	{
-		DataStoreLockGuard lock(m_dataStore);
-		auto& trackedUsersMap = m_dataStore.getUsers();
-		int index = trackedUsersMap.find(userID);
+	int index = m_dataStore.getUsers().find(userID);
 	if (index != -1)
 	{
-			User* user = trackedUsersMap.getValueAt(index).data;
+		User* user = m_dataStore.getUsers().getValueAt(index);
 		if (user != nullptr)
 		{
 			if (user->getUserType() == util::UserType::CUSTOMER)
@@ -291,43 +314,21 @@ void UserManagementService::removeUser(const std::string& userID)
 			{
 				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;
-				removedUserID = user->getId();
-				m_dataStore.saveUsers();
 		}
 	}
 }
-	if (!removedUserID.empty())
-	{
-		EventManager::sendUserDisabledEvent(removedUserID);
-	}
-}
 
-/*
-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)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	util::Map<std::string, User*> currentUsers = util::getObjects(trackedUsersMap);
+	util::Map<std::string, User*>& currentUsers = m_dataStore.getUsers();
 	util::Map<std::string, User*> filteredUsersMap;
-	for (int index = 0; index < currentUsers.getSize(); index++)
+	for (int iterator = 0; iterator < currentUsers.getSize(); iterator++)
 	{
-		User* currentUser = currentUsers.getValueAt(index);
+		User* currentUser = currentUsers.getValueAt(iterator);
 		if (currentUser && currentUser->getState() == util::State::ACTIVE && currentUser->getUserType() == type)
 		{
 			filteredUsersMap.insert(currentUser->getId(), currentUser);

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

@@ -6,7 +6,6 @@ Description: Header file declaring the UserManagementService class, which manage
 Author: Trenser
 Date:19-May-2026
 */
-
 #pragma once
 #include <string>
 #include "Map.h"
@@ -31,4 +30,6 @@ 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

@@ -28,19 +28,16 @@ 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";
-		constexpr const char* NOTIFICATION_FILE = "files/Notification.dat";
-		constexpr const char* SERVICE_FILE = "files/Service.dat";
-		constexpr const char* COMBOPACKAGE_FILE = "files/ComboPackage.dat";
-		constexpr const char* SERVICEBOOKING_FILE = "files/ServiceBooking.dat";
-		constexpr const char* JOBCARD_FILE = "files/JobCard.dat";
-		constexpr const char* INVOICE_FILE = "files/Invoice.dat";
-		constexpr const char* SERVICEMANAGEMENTOBSERVERS = "files/ServiceManagementObservers.dat";
-		constexpr const char* PAYMENTMANAGEMENTOBSERVERS = "files/PaymentManagementObservers.dat";
-		constexpr const char* INVENTORYMANAGEMENTOBSERVERS = "files/InventoryManagementObservers.dat";
+		constexpr const char* INVENTORYITEM_FILE = "files/InventoryItem.csv";
+		constexpr const char* USER_FILE = "files/User.csv";
+		constexpr const char* NOTIFICATION_FILE = "files/Notification.csv";
+		constexpr const char* SERVICE_FILE = "files/Service.csv";
+		constexpr const char* COMBOPACKAGE_FILE = "files/ComboPackage.csv";
+		constexpr const char* SERVICEBOOKING_FILE = "files/ServiceBooking.csv";
+		constexpr const char* JOBCARD_FILE = "files/JobCard.csv";
+		constexpr const char* INVOICE_FILE = "files/Invoice.csv";
+		constexpr const char* SERVICEMANAGEMENTOBSERVERS = "files/ServiceManagementObservers.csv";
+		constexpr const char* PAYMENTMANAGEMENTOBSERVERS = "files/PaymentManagementObservers.csv";
+		constexpr const char* INVENTORYMANAGEMENTOBSERVERS = "files/InventoryManagementObservers.csv";
 	}
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/utilities/Enums.h

@@ -12,37 +12,36 @@ Date: 19-May-2026
 
 namespace util
 {
-	enum class UserType : int
+	enum class UserType
 	{
 		ADMIN,
 		TECHNICIAN,
 		CUSTOMER
 	};
 
-	enum class PaymentMode : int
+	enum class PaymentMode
 	{
 		ONLINE,
 		OFFLINE,
         NOTSET
 	};
 
-	enum class PaymentStatus : int
+	enum class PaymentStatus
 	{
 		PENDING,
-		COMPLETED,
-        PAID
+		COMPLETED
 	};
 
-	enum class ServiceJobStatus : int
+	enum class ServiceJobStatus
 	{
         PENDING,
 		STARTED,
 		COMPLETED,
-        IN_PROGRESS,
+        INPROGRESS,
         CANCELLED
 	};
 
-    enum class State : int
+    enum class State
     {
         ACTIVE,
         INACTIVE
@@ -162,8 +161,6 @@ namespace util
             return "PENDING";
         case PaymentStatus::COMPLETED:
             return "COMPLETED";
-        case PaymentStatus::PAID:
-            return "PAID";
         }
         throw std::invalid_argument("Invalid PaymentStatus");
     }
@@ -213,8 +210,8 @@ namespace util
             return "COMPLETED";
         case ServiceJobStatus::CANCELLED:
             return "CANCELLED";
-        case ServiceJobStatus::IN_PROGRESS:
-            return "IN_PROGRESS";
+        case ServiceJobStatus::INPROGRESS:
+            return "INPROGRESS";
         }
         throw std::invalid_argument("Invalid ServiceJobStatus");
     }
@@ -247,9 +244,9 @@ namespace util
         {
             return ServiceJobStatus::CANCELLED;
         }
-        if (value == "IN_PROGRESS")
+        if (value == "INPROGRESS")
         {
-            return ServiceJobStatus::IN_PROGRESS;
+            return ServiceJobStatus::INPROGRESS;
         }
         throw std::invalid_argument("Invalid ServiceJobStatus string");
     }

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

@@ -43,4 +43,67 @@ 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

@@ -0,0 +1,119 @@
+/*
+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

@@ -10,7 +10,6 @@
 #include <limits>
 #include <string>
 #include <stdexcept>
-#include <conio.h>
 
 namespace util
 {
@@ -28,7 +27,7 @@ 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");
         }
     }
@@ -55,48 +54,6 @@ namespace util
         value = cleanedValue;
     }
 
-    /*
-     * Function: readPassword
-     * Description: Reads a password from console without echoing characters;
-     *              displays '*' for each character typed, handles backspace,
-     *              and cleans commas from the result.
-     * Parameters:
-     *     value - reference to a string where the password will be stored
-     * Returns:
-     *     void - no return value
-     */
-    inline void readPassword(std::string& value)
-    {
-        value.clear();
-        char currentCharacter;
-        while ((currentCharacter = _getch()) != '\r')
-        {
-            if (currentCharacter == '\b')
-            {
-                if (!value.empty())
-                {
-                    value.pop_back();
-                    std::cout << "\b \b";
-                }
-            }
-            else
-            {
-                value += currentCharacter;
-                std::cout << '*';
-            }
-        }
-        std::cout << std::endl;
-        std::string cleanedValue;
-        for (int iterator = 0; iterator < value.length(); iterator++)
-        {
-            if (value[iterator] != ',')
-            {
-                cleanedValue += value[iterator];
-            }
-        }
-        value = cleanedValue;
-    }
-
     /*
      * Function: pressEnter
      * Description: Pauses execution until the user presses Enter.

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

@@ -54,79 +54,49 @@ namespace util
         return cost;
     }
 
-    template<typename TObject>
-    Map<std::string, TObject*> getObjects(const Map<std::string, TrackedRecord<TObject>>& trackedRecords);
-
-    template<typename TObject>
-    Map<std::string, const TObject*> getConstObjects(const Map<std::string, TrackedRecord<TObject>>& trackedRecords);
-
-    template<typename TObject>
-    TrackedRecord<TObject> createNewRecord(TObject* object);
+    /*
+    Function: loadObservers
+    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));
+        }
     }
 
     /*
-Function: getObjects
-Description: Extracts the object pointers from a tracked-record
-             collection and returns them as a map keyed by the
-             same identifiers.
+    Function: saveObservers
+    Description: Saves the current observer IDs from the notification management service
+                 to a file for persistence.
     Parameters:
-    - trackedRecords: Collection of tracked records.
+        - filePath: const std::string&, path to the file where observer IDs will be saved
+        - service: NotificationManagementService*, pointer to the notification service
     Returns:
-    - Map<std::string, TObject*>: Collection of object pointers.
+        - void
     */
-template<typename TObject>
-util::Map<std::string, TObject*> util::getObjects(const util::Map<std::string, TrackedRecord<TObject>>& trackedRecords)
+    inline void saveObservers(const std::string& filePath, NotificationManagementService* service)
     {
-    util::Map<std::string, TObject*> objects;
-    for (int index = 0; index < trackedRecords.getSize(); ++index)
-    {
-        const std::string& key = trackedRecords.getKeyAt(index);
-        TObject* object = trackedRecords.getValueAt(index).data;
-        objects.insert(key, object);
+        auto observerIDs = service->getObserverIDs();
+        util::saveRecords(filePath, observerIDs);
     }
-    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/utilities/Validator.cpp

@@ -116,13 +116,15 @@ bool util::isPasswordValid(const std::string& password)
  *     usersMap - map of user objects keyed by identifier
  * Returns:
  *     bool - true if the username is already in use by an active user, false otherwise
+ * Notes:
+ *     - Only considers users with state util::State::ACTIVE
  */
 bool util::isUsernameDuplicate(const std::string& username, const util::Map<std::string, User*>& usersMap)
 {
     int index = usersMap.findIf(
         [&](const std::string&, User* user)
         {
-            return (user->getUserName() == username);
+            return (user->getUserName() == username && user->getState() == util::State::ACTIVE);
         }
     );
     return index != -1;

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.cpp

@@ -30,16 +30,10 @@ Return type: void
 */
 void AdminMenu::showMenu()
 {
-	startEventListener();
     while (true)
     {
         try
         {
-			if (!m_isMenuActive)
-			{
-				logout();
-				break;
-			}
             int choice;
             util::clear();
             std::cout << "Admin Menu"
@@ -59,8 +53,7 @@ void AdminMenu::showMenu()
                 << "\n14. Remove Combo Package"
                 << "\n15. View Notifications"
                 << "\n16. Change Password"
-				<< "\n17. Confirm Payment"
-                << "\n18. Logout"
+                << "\n17. Logout"
                 << "\nEnter a choice: ";
             util::read(choice);
             if (!handleOperation(choice))
@@ -74,7 +67,6 @@ void AdminMenu::showMenu()
             util::pressEnter();
         }
     }
-	stopEventListener();
 }
 
 /*
@@ -85,11 +77,6 @@ Return type: bool - true if menu continues, false if logout
 */
 bool AdminMenu::handleOperation(int choice)
 {
-	if (!m_isMenuActive)
-	{
-		logout();
-		return false;
-	}
     switch (choice)
     {
     case 1:
@@ -141,9 +128,6 @@ bool AdminMenu::handleOperation(int choice)
         changePassword();
         break;
     case 17:
-		confirmPayment();
-		break;
-    case 18:
         logout();
         return false;
     default:
@@ -153,25 +137,6 @@ bool AdminMenu::handleOperation(int choice)
     return true;
 }
 
-/*
-Function: handleNotificationEvent
-Description: Retrieves and displays the latest notification for the
-			 currently logged in admin.
-Parameter: None
-Return type: void
-*/
-void AdminMenu::handleNotificationEvent()
-{
-	auto notifications = m_controller.getNotifications();
-	const User* authenticatedUser = m_controller.getAuthenticatedUser();
-	std::string name;
-	if (authenticatedUser)
-	{
-		name = authenticatedUser->getName();
-	}
-	displayNewNotification(notifications, name);
-}
-
 /*
 Function: logout
 Description: Logs out the currently authenticated admin user.
@@ -338,23 +303,6 @@ void AdminMenu::removeInventoryItem()
             std::string selectedItemId = selectedItem->getId();
             m_controller.removeInventoryItem(selectedItemId);
             std::cout << "Item " << selectedItem->getPartName() << " removed successfully." << std::endl;
-			const util::Map<std::string, const Service*>& listOfService = m_controller.getServices();
-			for (int serviceIndex = 0; serviceIndex < listOfService.getSize(); serviceIndex++)
-			{
-				const Service* service = listOfService.getValueAt(serviceIndex);
-				if (!service)
-				{
-					continue;
-				}
-				const util::Map<std::string, InventoryItem*>& requiredItems = service->getRequiredInventoryItems();
-				if (requiredItems.find(selectedItemId) != -1) 
-				{
-					m_controller.removeService(service->getId()); 
-					std::cout << "Service " << service->getName()
-						<< " removed as the item "
-						<< selectedItem->getPartName() << " required for the service has been removed." << std::endl;
-				}
-			}
         }
     }
     util::pressEnter();
@@ -548,54 +496,6 @@ void AdminMenu::displayUsers()
 	util::pressEnter();
 }
 
-/*
-Function: confirmPayment
-Description: Confirms payment for a selected invoice. Validates invoice status, updates payment date,
-			 sets status to COMPLETED, and sends a notification to the customer.
-Parameters:
-	- invoiceID: std::string, ID of the invoice to confirm
-Returns:
-	- void
-*/
-void AdminMenu::confirmPayment()
-{
-	util::clear();
-	std::cout << "Confirm Payment\n";
-	auto invoiceList = m_controller.getAllInvoices();
-	if (invoiceList.isEmpty())
-	{
-		std::cout << "No pending invoices available for confirmation.";
-		util::pressEnter();
-		return;
-	}
-	bool hasConfirmableInvoice = false;
-	for (int index = 0; index < invoiceList.getSize(); ++index)
-	{
-		const Invoice* invoice = invoiceList.getValueAt(index);
-		if (invoice && invoice->getStatus() == util::PaymentStatus::PAID)
-		{
-			hasConfirmableInvoice = true;
-			break;
-		}
-	}
-	if (!hasConfirmableInvoice)
-	{
-		std::cout << "No invoices awaiting confirmation.\n";
-		util::pressEnter();
-		return;
-	}
-	std::string selectedID = selectInvoiceFromUserForPayment(invoiceList, util::PaymentStatus::PAID);
-	if (selectedID == "")
-	{
-		std::cout << "Payment failed.\n";
-		util::pressEnter();
-		return;
-	}
-	m_controller.confirmPayment(selectedID);
-	std::cout << "Payment Confirmed successfully.\n";
-	util::pressEnter();
-}
-
 /*
 Function: addTechnician
 Description: Adds a new technician after validating username, password, email, and phone number.

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.h

@@ -9,13 +9,12 @@ Date:19-May-2026
 
 #pragma once
 #include "Controller.h"
-#include "Menu.h"
 
-class AdminMenu : public Menu
+class AdminMenu
 {
 private:
+    Controller m_controller;
     bool handleOperation(int choice);
-    void handleNotificationEvent() override;
 public:
     void showMenu();
     void logout();
@@ -29,7 +28,6 @@ public:
     void createService();
     void removeService();
     void displayUsers();
-    void confirmPayment();
     void addTechnician();
     void removeUser();
     void displayComboPackages();

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

@@ -30,19 +30,13 @@ Description: Displays the customer menu and handles user input until logout is s
 Parameter: None
 Return type: void
 */
+
 void CustomerMenu::showMenu()
 {
-
-    startEventListener();
     while (true)
     {
         try
         {
-            if (!m_isMenuActive)
-            {
-                logout();
-                break;
-            }
             int choice;
             util::clear();
             std::cout << "Customer Menu"
@@ -51,12 +45,11 @@ void CustomerMenu::showMenu()
                 << "\n3. Update Profile"
                 << "\n4. Change Password"
                 << "\n5. View Service History"
-                << "\n6. Cancel Service Booking"
-                << "\n7. Complete Payments"
-                << "\n8. View Invoices"
-                << "\n9. View Notifications"
-                << "\n10. Configure Notifications"
-                << "\n11. Logout"
+                << "\n6. Complete Payments"
+                << "\n7. View Invoices"
+                << "\n8. View Notifications"
+                << "\n9. Configure Notifications"
+                << "\n10. Logout"
                 << "\nEnter a choice: ";
             util::read(choice);
             if (!handleOperation(choice))
@@ -70,7 +63,6 @@ void CustomerMenu::showMenu()
             util::pressEnter();
         }
     }
-    stopEventListener();
 }
 
 /*
@@ -81,11 +73,6 @@ Return type: bool - true if menu continues, false if logout
 */
 bool CustomerMenu::handleOperation(int choice)
 {
-    if (!m_isMenuActive)
-    {
-        logout();
-        return false;
-    }
     switch (choice)
     {
     case 1:
@@ -104,21 +91,18 @@ bool CustomerMenu::handleOperation(int choice)
         viewServiceHistory();
         break;
     case 6:
-        cancelServiceBooking();
-        break;
-    case 7:
         completePayments();
         break;
-    case 8:
+    case 7:
         viewInvoices();
         break;
-    case 9:
+    case 8:
         viewNotifications();
         break;
-    case 10:
+    case 9:
         configureNotifications();
         break;
-    case 11:
+    case 10:
         logout();
         return false;
     default:
@@ -128,25 +112,6 @@ bool CustomerMenu::handleOperation(int choice)
     return true;
 }
 
-/*
-Function: handleNotificationEvent
-Description: Retrieves and displays the latest notification for the
-             currently logged in admin.
-Parameter: None
-Return type: void
-*/
-void CustomerMenu::handleNotificationEvent()
-{
-    auto notifications = m_controller.getNotifications();
-    const User* authenticatedUser = m_controller.getAuthenticatedUser();
-    std::string name;
-    if (authenticatedUser)
-    {
-        name = authenticatedUser->getName();
-    }
-    displayNewNotification(notifications, name);
-}
-
 /*
 Function: logout
 Description: Logs out the currently authenticated customer user.
@@ -337,46 +302,6 @@ void CustomerMenu::viewServiceHistory()
     util::pressEnter();
 }
 
-/*
-Function: cancelServiceBooking
-Description: Allows the customer to cancel a pending service booking.
-             Displays the list of active bookings, lets the user select one,
-             and removes it from the system. If no bookings are available,
-             an appropriate message is shown.
-Parameter: None
-Return type: void
-*/
-void CustomerMenu::cancelServiceBooking()
-{
-    util::clear();
-    std::cout << "Cancel Service Booking\n";
-    const User* currentUser = m_controller.getAuthenticatedUser();
-    std::string currentUserID = currentUser->getId();
-    util::Map<std::string, const ServiceBooking*> serviceBookingsByCurrentUser = m_controller.getServiceBookingsByUser(currentUserID);
-    util::Map<int, const ServiceBooking*> serviceBookingsMap;
-    auto currentPendingServiceBookings = filterActiveServiceBookings(serviceBookingsByCurrentUser);
-    int bookingsSize = currentPendingServiceBookings.getSize();
-    if (listServiceBookings(currentPendingServiceBookings, bookingsSize, serviceBookingsMap))
-    {
-        const ServiceBooking* selectedService = selectPendingServiceBookings(serviceBookingsMap);
-        if (selectedService)
-        {
-            m_controller.removeServiceBooking(selectedService->getId());
-            std::cout << "Cancelled Service booking of id " + selectedService->getId() << std::endl << std::endl;
-        }
-        else
-        {
-            std::cout << "Invalid service booking index.\n\n";
-            return;
-        }
-    }
-    else
-    {
-        std::cout << "No pending service bookings available.\n\n";
-    }
-    util::pressEnter();
-}
-
 /*
 Function: completePayments
 Description: Allows the customer to complete pending payments for invoices.
@@ -413,7 +338,7 @@ void CustomerMenu::completePayments()
         util::pressEnter();
         return;
     }
-	std::string selectedID = selectInvoiceFromUserForPayment(currentInvoices, util::PaymentStatus::PENDING);
+	std::string selectedID = selectInvoiceFromUserForPayment(currentInvoices);
     if (selectedID == "")
     {
         std::cout << "Payment failed.\n";

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/CustomerMenu.h

@@ -9,14 +9,13 @@ Date:19-May-2026
 */
 
 #pragma once
-#include "Menu.h"
 #include "Controller.h"
 
-class CustomerMenu : public Menu
+class CustomerMenu
 {
 private:
+    Controller m_controller;
     bool handleOperation(int choice);
-    void handleNotificationEvent();
 public:
     void showMenu();
     void logout();
@@ -28,6 +27,5 @@ public:
     void completePayments();
     void viewInvoices();
     void viewNotifications();
-    void cancelServiceBooking();
     void configureNotifications();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/Menu.cpp

@@ -1,150 +0,0 @@
-/*
-File: Menu.cpp
-Description: Implementation file containing common menu event listener
-             functionality, account disable handling, and notification
-             event dispatching for all menu types.
-Author: Trenser
-Date:16-Jun-2026
-*/
-
-#include "Menu.h"
-
-/*
-Function: Menu
-Description: Constructs a Menu object and initializes event handles
-             and menu state.
-Parameter: None
-Return type: None
-*/
-Menu::Menu()
-    :
-    m_isMenuActive(false),
-    m_accountDisabledEvent(NULL),
-    m_notificationAvailableEvent(NULL),
-    m_shutdownEvent(NULL) {}
-
-/*
-Function: ~Menu
-Description: Destroys the Menu object and performs event listener
-             cleanup.
-Parameter: None
-Return type: None
-*/
-Menu::~Menu()
-{
-    stopEventListener();
-}
-
-/*
-Function: startEventListener
-Description: Creates menu event handles, registers them with the
-             authentication service, and starts the event listener
-             thread.
-Parameter: None
-Return type: void
-*/
-void Menu::startEventListener()
-{
-    if (m_isMenuActive.load())
-    {
-        return;
-    }
-    m_isMenuActive.store(true);
-    m_accountDisabledEvent = CreateEventA(NULL, FALSE, FALSE, NULL);
-    m_notificationAvailableEvent = CreateEventA(NULL, FALSE, FALSE, NULL);
-    m_shutdownEvent = CreateEventA(NULL, FALSE, FALSE, NULL);
-    m_controller.registerEvents(m_accountDisabledEvent, m_notificationAvailableEvent);
-    m_eventListenerThread = std::thread(&Menu::eventListenerLoop, this);
-}
-
-/*
-Function: eventListenerLoop
-Description: Waits for account disabled, notification available,
-             and shutdown events and dispatches them to the
-             appropriate handlers.
-Parameter: None
-Return type: void
-*/
-void Menu::eventListenerLoop()
-{
-    HANDLE handles[3] = { NULL, NULL, NULL };
-    handles[0] = m_accountDisabledEvent;
-    handles[1] = m_notificationAvailableEvent;
-    handles[2] = m_shutdownEvent;
-    while (m_isMenuActive.load())
-    {
-        DWORD result = WaitForMultipleObjects(3, handles, FALSE, INFINITE);
-        switch (result)
-        {
-        case WAIT_OBJECT_0:
-            handleAccountDisabledEvent();
-            break;
-        case WAIT_OBJECT_0 + 1:
-            handleNotificationEvent();
-            break;
-        case WAIT_OBJECT_0 + 2:
-            return;
-        }
-    }
-}
-
-/*
-Function: stopEventListener
-Description: Stops the event listener thread and releases all
-             associated event handles.
-Parameter: None
-Return type: void
-*/
-void Menu::stopEventListener()
-{
-    m_isMenuActive.store(false);
-    if (m_shutdownEvent)
-    {
-        SetEvent(m_shutdownEvent);
-    }
-    if (m_eventListenerThread.joinable())
-    {
-        m_eventListenerThread.join();
-    }
-    if (m_accountDisabledEvent)
-    {
-        CloseHandle(m_accountDisabledEvent);
-    }
-    if (m_notificationAvailableEvent)
-    {
-        CloseHandle(m_notificationAvailableEvent);
-    }
-    if (m_shutdownEvent)
-    {
-        CloseHandle(m_shutdownEvent);
-    }
-    m_accountDisabledEvent = NULL;
-    m_notificationAvailableEvent = NULL;
-    m_shutdownEvent = NULL;
-}
-
-/*
-Function: handleAccountDisabledEvent
-Description: Handles an account disabled event by marking the menu
-             inactive and notifying the user.
-Parameter: None
-Return type: void
-*/
-void Menu::handleAccountDisabledEvent()
-{
-    m_isMenuActive.store(false);
-    const User* authenticatedUser = m_controller.getAuthenticatedUser();
-    std::string messageTitle = "Account Disabled";
-    if (authenticatedUser)
-    {
-        messageTitle += " - " + authenticatedUser->getName();
-    }
-    MessageBoxA(
-        GetConsoleWindow(),
-        "Your account has been disabled.",
-        messageTitle.c_str(),
-        MB_OK |
-        MB_ICONWARNING |
-        MB_SETFOREGROUND |
-        MB_TOPMOST);
-}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/Menu.h

@@ -1,33 +0,0 @@
-/*
-File: Menu.h
-Description: Base class providing common event listener functionality
-             for all menu implementations.
-Author: Trenser
-Date:16-Jun-2026
-*/
-
-#pragma once
-
-#include <windows.h>
-#include <atomic>
-#include <thread>
-#include "Controller.h"
-
-class Menu
-{
-protected:
-    Controller m_controller;
-    std::atomic<bool> m_isMenuActive;
-    HANDLE m_accountDisabledEvent;
-    HANDLE m_notificationAvailableEvent;
-    HANDLE m_shutdownEvent;
-    std::thread m_eventListenerThread;
-    void startEventListener();
-    void stopEventListener();
-    void eventListenerLoop();
-    void handleAccountDisabledEvent();
-    virtual void handleNotificationEvent() = 0;
-public:
-    Menu();
-    virtual ~Menu();
-};

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

@@ -28,7 +28,6 @@ Date: 21-May-2026
 #include "Utility.h"
 #include "Validator.h"
 #include "Vector.h"
-#include "StringHelper.h"
 
 /*
 Function: displayAllServices
@@ -366,17 +365,13 @@ inline const User* selectTechnician(util::Map<int, const User*>& currentAvailabl
 
 /*
 Function: selectInvoiceFromUserForPayment 
-Description: Displays a list of invoices filtered by the required payment status.
-             Allows the user to select an invoice by index and returns the corresponding invoice ID.
+Description: Lists all pending invoices for the customer and allows selection by index.
 Parameters:
-    - currentInvoices: const util::Map<std::string, const Invoice*>&,
-                       map of all invoices keyed by invoice ID
-    - requiredStatus: util::PaymentStatus,
-                      the status to filter invoices (e.g., PENDING, PAID, COMPLETED)
+	- currentInvoices: util::Map<std::string, const Invoice*>&, map of customer invoices
 Returns:
-    - std::string: ID of the selected invoice, or empty string if none selected or invalid index
+	- std::string: ID of the selected invoice, or empty string if none selected
 */
-inline std::string selectInvoiceFromUserForPayment(const util::Map<std::string, const Invoice*>& currentInvoices, util::PaymentStatus requiredStatus)
+inline std::string selectInvoiceFromUserForPayment(const util::Map<std::string, const Invoice*>& currentInvoices)
 {
 	int currentIndex = 1, choice;
 	util::Map<int, const Invoice*> pendingInvoicesForPayment;
@@ -394,7 +389,7 @@ inline std::string selectInvoiceFromUserForPayment(const util::Map<std::string,
 	for (int iterator = 0; iterator < currentInvoices.getSize(); iterator++)
 	{
 		const Invoice* currentInvoice = currentInvoices.getValueAt(iterator);
-		if (currentInvoice && currentInvoice->getStatus() == requiredStatus)
+		if (currentInvoice && currentInvoice->getStatus() == util::PaymentStatus::PENDING)
 {
 			const User* currentTechnician = currentInvoice->getBooking()->getAssignedTechnician();
             std::cout << std::left
@@ -588,7 +583,7 @@ inline void displayInvoices(util::Map<std::string, const Invoice*> currentUserIn
                     << util::getPaymentStatusString(selectedInvoice->getStatus()) << std::endl;
                 std::cout << std::left << std::setw(20) << "Payment Mode:"
                     << util::getPaymentModeString(selectedInvoice->getPaymentMethod()) << std::endl;
-                auto& inventoryItemsInInvoice = selectedInvoice->getParts();
+                auto inventoryItemsInInvoice = selectedInvoice->getParts();
                 if (inventoryItemsInInvoice.isEmpty())
                 {
                     std::cout << "No inventory items used.\n\n";
@@ -597,6 +592,7 @@ inline void displayInvoices(util::Map<std::string, const Invoice*> currentUserIn
                 std::cout << "\nItems Used:\n";
                 std::cout << std::left
                     << std::setw(20) << "ItemName"
+                    << std::setw(10) << "Quantity"
                     << std::setw(10) << "Price"
                     << std::endl;
                 std::cout << std::string(40, '-') << std::endl;
@@ -605,6 +601,7 @@ inline void displayInvoices(util::Map<std::string, const Invoice*> currentUserIn
                     InventoryItem* currentItem = inventoryItemsInInvoice.getValueAt(iterator);
                     std::cout << std::left
                         << std::setw(20) << currentItem->getPartName()
+                        << std::setw(10) << currentItem->getQuantity()
                         << std::setw(10) << currentItem->getPrice()
                         << std::endl;
                 }
@@ -630,6 +627,7 @@ inline void displayInvoices(util::Map<std::string, const Invoice*> currentUserIn
                 std::cout << "Unable to fetch the selected invoice\n";
                 doRun = false;
             }
+
         } while (doRun);
     }
 }
@@ -648,7 +646,7 @@ inline util::Map<std::string, const JobCard*> filterStartedJobCards(util::Map<st
     for (int iterator = 0; iterator  < assignedJobCards.getSize(); iterator++)
     {
         const JobCard* currentJobCard = assignedJobCards.getValueAt(iterator);
-        if (currentJobCard && (currentJobCard->getStatus() == util::ServiceJobStatus::STARTED || currentJobCard->getStatus() == util::ServiceJobStatus::IN_PROGRESS))
+        if (currentJobCard && (currentJobCard->getStatus() == util::ServiceJobStatus::STARTED || currentJobCard->getStatus() == util::ServiceJobStatus::INPROGRESS))
         {
             startedJobCards.insert(currentJobCard->getId(), currentJobCard);
         }
@@ -661,11 +659,13 @@ Function: filterJobCards
 Description:
     Filters the given list of job cards and returns only those
     whose status matches the specified ServiceJobStatus.
+
 Parameters:
     - assignedJobCards: util::Map<std::string, const JobCard*>&
         Map of job card IDs to JobCard pointers assigned to the technician.
     - selectedJobStatus: util::ServiceJobStatus
         The status type to filter job cards by.
+
 Returns:
     - util::Map<std::string, const JobCard*>
         A map containing only job cards with the specified status.
@@ -710,7 +710,7 @@ inline void displayAllJobs(util::Map<std::string, const JobCard*>& assignedJobCa
     for (int iterator = 0; iterator < assignedJobCards.getSize(); iterator++)
     {
         const JobCard* currentJobCard = assignedJobCards.getValueAt(iterator);
-        if (currentJobCard && (currentJobCard->getStatus() == util::ServiceJobStatus::STARTED || currentJobCard->getStatus() == util::ServiceJobStatus::IN_PROGRESS))
+        if (currentJobCard && (currentJobCard->getStatus() == util::ServiceJobStatus::STARTED || currentJobCard->getStatus() == util::ServiceJobStatus::INPROGRESS))
         {
             std::cout << std::left << std::setw(12) << currentJobCard->getBookingId()
                 << std::setw(12) << currentJobCard->getId()
@@ -735,7 +735,7 @@ inline std::string selectJobCardToUpdate(util::Map<std::string, const JobCard*>&
     util::Map<int, const JobCard* > incompleteJobCards;
     if (assignedJobCards.getSize() == 0)
     {
-        std::cout << "\nNo jobs available.\n\n";
+        std::cout << "No jobs available.\n\n";
         return "";
     }
     int currentIndex = 1;
@@ -743,12 +743,12 @@ inline std::string selectJobCardToUpdate(util::Map<std::string, const JobCard*>&
     if (selectedJobStatusType == util::ServiceJobStatus::STARTED)
     {
         util::clear();
-        std::cout << "Select a job to mark as In Progress\n";
+        std::cout << "Select a job to update to Inprogress\n";
     }
-    else if (selectedJobStatusType == util::ServiceJobStatus::IN_PROGRESS)
+    else if (selectedJobStatusType == util::ServiceJobStatus::INPROGRESS)
     {
         util::clear();
-        std::cout << "Select a job to mark as Completed\n";
+        std::cout << "Select a job to update to Completed\n";
     }
     else
     {
@@ -779,7 +779,7 @@ inline std::string selectJobCardToUpdate(util::Map<std::string, const JobCard*>&
             incompleteJobCards.insert(currentIndex++, currentJobCard);
         }
     }
-    std::cout << "Enter the job index to update: ";
+    std::cout << "Select the Job Card to Update (Index): ";
     util::read(choice);
     int selectedJobCardIndex = incompleteJobCards.find(choice);
     if (selectedJobCardIndex != -1)
@@ -913,7 +913,7 @@ inline void changePasswordHelper(Controller& controller)
         util::clear();
         std::cout << "Change Password\n";
         std::cout << "Enter new password: ";
-        util::readPassword(newPassword);
+        util::read(newPassword);
         if (!util::isPasswordValid(newPassword))
         {
             std::cout << "Error: Password is not strong enough!\n";
@@ -927,7 +927,7 @@ inline void changePasswordHelper(Controller& controller)
             continue;
         }
         std::cout << "Confirm new password: ";
-        util::readPassword(confirmedPassword);
+        util::read(confirmedPassword);
         if (confirmedPassword != newPassword)
         {
             std::cout << "Passwords are different. Try again\n";
@@ -1055,21 +1055,6 @@ inline const Service* selectServiceFromServices(const util::Map<std::string, con
         {
             continue;
         }
-        bool hasDepletedItem = false;
-        const util::Map<std::string, InventoryItem*>& requiredItems = currentService->getRequiredInventoryItems();
-        for (int itemIndex = 0; itemIndex < requiredItems.getSize(); itemIndex++)
-        {
-            const InventoryItem* item = requiredItems.getValueAt(itemIndex);
-            if (!item || item->getQuantity() < 1)
-            {
-                hasDepletedItem = true;
-                break;
-            }
-        }
-        if (hasDepletedItem)
-        {
-            continue; 
-        }
         activeServicesMap.insert(currentIndex, currentService);
         double partsCost = util::calculatePartsCost(currentService);
         std::cout << std::left
@@ -1144,9 +1129,7 @@ inline void displayAllComboPackages(util::Map<std::string, const ComboPackage*>
     for (int index = 0; index < comboPackages.getSize(); index++)
     {
         const ComboPackage* currentComboPackage = comboPackages.getValueAt(index);
-        if (currentComboPackage) 
-        {
-            if (currentComboPackage->getState() != util::State::ACTIVE)
+        if (currentComboPackage && currentComboPackage->getState() != util::State::ACTIVE)
         {
             continue;
         }
@@ -1157,7 +1140,6 @@ inline void displayAllComboPackages(util::Map<std::string, const ComboPackage*>
             << std::endl;
     }
 }
-}
 
 
 /*
@@ -1181,9 +1163,7 @@ inline const ComboPackage* selectComboPackageFromPackages(const util::Map<std::s
     for (int index = 0; index < comboPackages.getSize(); index++)
     {
         const ComboPackage* currentComboPackage = comboPackages.getValueAt(index);
-        if (currentComboPackage)
-        {
-            if (currentComboPackage->getState() != util::State::ACTIVE)
+        if (currentComboPackage && currentComboPackage->getState() != util::State::ACTIVE)
         {
             continue;
         }
@@ -1196,7 +1176,6 @@ inline const ComboPackage* selectComboPackageFromPackages(const util::Map<std::s
             << std::endl;
         currentIndex++;
     }
-    }
     if (activeComboPackages.getSize() == 0)
     {
         std::cout << "No active combo packages available." << std::endl;
@@ -1428,46 +1407,3 @@ inline std::string selectComboPackage(util::Map<std::string, const ComboPackage*
         return "";
     }
 }
-
-/*
-Function: displayNewNotification
-Description: Displays the most recent notification from the supplied
-             notification collection.
-Parameter: util::Vector<const Notification*> notifications -
-           collection of notifications
-           const std::string& - The name of the user currently authenticated with the system
-Return type: void
-*/
-inline void displayNewNotification(util::Vector<const Notification*> notifications, const std::string& name)
-{
-    const Notification* notification = nullptr;
-	size_t numberOfNotifications = notifications.getSize();
-	for (int index = 0; index < numberOfNotifications; index++)
-	{
-		if (!notification)
-		{
-			notification = notifications[index];
-		}
-		else
-		{
-            if (util::extractNumber(notification->getId()) < util::extractNumber(notifications[index]->getId()))
-			{
-				notification = notifications[index];
-			}
-		}
-	}
-    if (notification)
-    {
-        std::string messageTitle = notification->getTitle();
-        if (!name.empty())
-        {
-            messageTitle += " - " + name;
-        }
-        MessageBoxA(
-            GetConsoleWindow(),
-            notification->getMessage().c_str(),
-            messageTitle.c_str(),
-            MB_OK |
-            MB_ICONINFORMATION);
-    }
-}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/TechnicianMenu.cpp

@@ -27,16 +27,10 @@ Returns:
 */
 void TechnicianMenu::showMenu()
 {
-    startEventListener();
     while (true)
     {
         try
         {
-            if (!m_isMenuActive)
-            {
-                logout();
-                break;
-            }
             int choice;
             util::clear();
             std::cout << "Technician Menu"
@@ -58,7 +52,6 @@ void TechnicianMenu::showMenu()
             util::pressEnter();
         }
     }
-    stopEventListener();
 }
 
 /*
@@ -69,11 +62,6 @@ Return type: bool - true if menu continues, false if logout
 */
 bool TechnicianMenu::handleOperation(int choice)
 {
-    if (!m_isMenuActive)
-    {
-        logout();
-        return false;
-    }
     switch (choice)
     {
     case 1:
@@ -98,25 +86,6 @@ bool TechnicianMenu::handleOperation(int choice)
     return true;
 }
 
-/*
-Function: handleNotificationEvent
-Description: Retrieves and displays the latest notification for the
-             currently logged in admin.
-Parameter: None
-Return type: void
-*/
-void TechnicianMenu::handleNotificationEvent()
-{
-    auto notifications = m_controller.getNotifications();
-    const User* authenticatedUser = m_controller.getAuthenticatedUser();
-    std::string name;
-    if (authenticatedUser)
-    {
-        name = authenticatedUser->getName();
-    }
-    displayNewNotification(notifications, name);
-}
-
 /*
 Function: displayJobs
 Description: Displays all Jobs assigned to a Technician
@@ -150,9 +119,9 @@ void TechnicianMenu::updateJobStatus()
     std::cout << "Update Job Status\n";
     int choice;
     std::string selectedJobID;
-    util::ServiceJobStatus selectedJobStatus = util::ServiceJobStatus::PENDING;
+    util::ServiceJobStatus selectedJobStatus;
 	util::Map<std::string, const JobCard*> assignedJobCards = m_controller.getJobCardsByUser();
-    std::cout << "Select the type of job you want to update:\n1.Started\n2.In Progress\nChoice: ";
+    std::cout << "Select the type of job you want to update\n1.Started\n2.Inprogress\nChoice: ";
     util::read(choice);
     if (choice == 1)
     {
@@ -160,13 +129,11 @@ void TechnicianMenu::updateJobStatus()
     }
     else if (choice == 2)
     {
-        selectedJobStatus = util::ServiceJobStatus::IN_PROGRESS;
+        selectedJobStatus = util::ServiceJobStatus::INPROGRESS;
     }
     else
     {
-        std::cout << "Invalid choice. Please try again.\n";
-        util::pressEnter();
-        return;
+        throw std::runtime_error("Invalid Index");
     }
     util::Map<std::string, const JobCard*> selectedTypeJobCard = filterJobCards(assignedJobCards, selectedJobStatus);
 	selectedJobID = selectJobCardToUpdate(selectedTypeJobCard, selectedJobStatus);

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/TechnicianMenu.h

@@ -9,13 +9,12 @@ Date:19-May-2026
 
 #pragma once
 #include "Controller.h"
-#include "Menu.h"
 
-class TechnicianMenu : public Menu
+class TechnicianMenu
 {
 private:
+    Controller m_controller;
     bool handleOperation(int choice);
-    void handleNotificationEvent();
 public:
     void showMenu();
     void displayJobs();

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

@@ -27,11 +27,8 @@ void UserInterface::run()
 {
 	try
 	{
-		if (!m_controller.initialize())
-		{
-			std::cout << "Error: Failed to initialize the system!";
-			return;
-		}
+		m_controller.loadSystemData();
+		m_controller.runSystemChecks();
 		bool isMenuActive = true;
 		while (isMenuActive)
 		{
@@ -52,7 +49,7 @@ void UserInterface::run()
 				util::pressEnter();
 			}
 		}
-		m_controller.shutdown();
+		m_controller.saveSystemData();
 	}
 	catch (const std::invalid_argument& exception)
 	{
@@ -109,7 +106,7 @@ void UserInterface::login()
 	std::cout << "Enter username: ";
 	util::read(username);
 	std::cout << "Enter password: ";
-	util::readPassword(password);
+	util::read(password);
 	if (m_controller.login(username, password))
 	{
 		const User* authenticatedUser = m_controller.getAuthenticatedUser();
@@ -170,7 +167,7 @@ void UserInterface::registerCustomer()
 		return;
 	}
 	std::cout << "Enter password: ";
-	util::readPassword(password);
+	util::read(password);
 	if (!util::isPasswordValid(password))
 	{
 		std::cout << "Error: Password is invalid!";