Merge branch 'feature-notification-management' into feature

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem.cpp

@@ -1,5 +1,22 @@
+/*
+File: Trenser.VehicleServiceSystem.cpp
+Description: Entry point for the Vehicle Service Management System.
+			 Initializes the UserInterface and starts the application loop.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "UserInterface.h"
 
+/*
+Function: main
+Description: The main entry point of the application.
+			 Creates a UserInterface object and invokes the run method to start the system.
+Parameters:
+	- None
+Returns:
+	- int: Exit status code (0 for successful execution).
+*/
 int main()
 {
 	UserInterface userInterface;

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

@@ -182,6 +182,7 @@
     <ClInclude Include="utilities\Vector.h" />
     <ClInclude Include="views\AdminMenu.h" />
     <ClInclude Include="views\CustomerMenu.h" />
+    <ClInclude Include="views\MenuHelper.h" />
     <ClInclude Include="views\TechnicianMenu.h" />
     <ClInclude Include="views\UserInterface.h" />
   </ItemGroup>

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

@@ -233,8 +233,14 @@
     <ClInclude Include="models\ComboPackage.h">
       <Filter>Header Files\Models</Filter>
     </ClInclude>
+    <ClInclude Include="views\MenuHelper.h">
+      <Filter>Header Files\Views</Filter>
+    </ClInclude>
     <ClInclude Include="utilities\Utility.h">
       <Filter>Header Files\Utilities</Filter>
     </ClInclude>
+    <ClInclude Include="utilities\Config.h">
+      <Filter>Header Files\Utilities</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

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

@@ -6,9 +6,8 @@ Description: Implementation file containing the method definitions
 Author: Trenser
 Date:19-May-2026
 */
-#include <stdexcept>
-#include "ComboPackage.h"
 #include "Controller.h"
+#include "ComboPackage.h"
 #include "Enums.h"
 #include "InventoryItem.h"
 #include "Invoice.h"
@@ -16,6 +15,8 @@ Date:19-May-2026
 #include "Service.h"
 #include "ServiceBooking.h"
 #include "User.h"
+#include "User.h"
+#include <stdexcept>
 
 /*
 Function: login
@@ -73,9 +74,9 @@ Parameter: const std::string& username - technician's username
            const std::string& phoneNumber - technician's phone number
 Return type: void
 */
-void Controller::createTechnician(const std::string& username, const std::string& password, const std::string& email, const std::string& phoneNumber)
+void Controller::createTechnician(const std::string& username, const std::string& name, const std::string& password, const std::string& email, const std::string& phoneNumber)
 {
-    m_userManagementService.createUser(username, password, email, phoneNumber, util::UserType::TECHNICIAN);
+    m_userManagementService.createUser(username, name, password, email, phoneNumber, util::UserType::TECHNICIAN);
 }
 
 void Controller::updateUserDetails(const std::string& email, const std::string& phone)
@@ -344,21 +345,95 @@ void Controller::completePayment(const std::string& invoiceID, util::PaymentMode
     m_paymentManagementService.completePayment(invoiceID, paymentMode);
 }
 
+/*
+Function: getNotifications
+Description: Retrieves all notifications for the currently authenticated user.
+             Converts them into a read-only vector before returning.
+Parameters: None
+Return type: util::Vector<const Notification*>
+*/
 util::Vector<const Notification*> Controller::getNotifications()
 {
-    return util::Vector<const Notification*>();
+    const User* authenticatedUser = m_authenticationManagementService.getAuthenticatedUser();
+    if (!authenticatedUser)
+    {
+        throw std::runtime_error("No user is currently logged in!");
+    }
+    auto notifications = m_userManagementService.getUserNotifications(authenticatedUser->getId());
+    int numberOfNotifications = notifications.getSize();
+    util::Vector<const Notification*> readOnlyNotifications;
+    for (int index = 0; index < numberOfNotifications; index++)
+    {
+        readOnlyNotifications.push_back(notifications[index]);
+    }
+    return readOnlyNotifications;
 }
 
+/*
+Function: deleteNotification
+Description: Deletes a specific notification for the currently authenticated user.
+Parameters:
+    - notificationID: std::string, the unique identifier of the notification
+Return type: void
+*/
 void Controller::deleteNotification(const std::string& notificationID)
 {
+    const User* authenticatedUser = m_authenticationManagementService.getAuthenticatedUser();
+    if (!authenticatedUser)
+    {
+        throw std::runtime_error("No user is currently logged in!");
+    }
+    m_userManagementService.deleteNotification(notificationID, authenticatedUser->getId());
 }
 
-void Controller::configureNotifications(const std::string& userID, bool paymentNotifications, bool serviceNotifications)
+/*
+Function: configureNotifications
+Description: Configures notification preferences for the authenticated user.
+             Attaches or detaches the user from payment and service notifications.
+Parameters:
+    - paymentNotifications: bool, enable/disable payment notifications
+    - serviceNotifications: bool, enable/disable service notifications
+Return type: void
+*/
+void Controller::configureNotifications(bool paymentNotifications, bool serviceNotifications)
 {
+    User* authenticatedUser = m_authenticationManagementService.getAuthenticatedUser();
+    if (authenticatedUser)
+    {
+        if (paymentNotifications)
+        {
+            m_paymentManagementService.attach(authenticatedUser);
+        }
+        else
+        {
+            m_paymentManagementService.detach(authenticatedUser);
+        }
+        if (serviceNotifications)
+        {
+            m_serviceManagementService.attach(authenticatedUser);
+        }
+        else
+        {
+            m_serviceManagementService.detach(authenticatedUser);
+        }
+    }
+    else
+    {
+        throw std::runtime_error("No user is currently logged in!");
+    }
 }
 
+/*
+Function: runSystemChecks
+Description: Executes system checks including sending low stock alerts
+             and payment reminders.
+Parameters: None
+Return type: void
+*/
 void Controller::runSystemChecks()
 {
     m_userManagementService.ensureAdminExists();
+    m_inventoryManagementService.sendLowStockAlerts();
+    m_paymentManagementService.sendPaymentReminders();
 }
 

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

@@ -39,7 +39,7 @@ public:
     void changePassword(const std::string& newPassword);
     void createCustomer(const std::string& username, const std::string& name, const std::string& password, const std::string& email, const std::string& phone);
     const User* getAuthenticatedUser();
-    void createTechnician(const std::string& username, const std::string& password, const std::string& email, const std::string& phoneNumber);
+    void createTechnician(const std::string& username, const std::string& name, const std::string& password, const std::string& email, const std::string& phoneNumber);
     void updateUserDetails(const std::string& email, const std::string& phone);
     util::Map<std::string, const Service*> getServices();
     util::Map<std::string, const ComboPackage*> getComboPackages();
@@ -48,6 +48,7 @@ public:
     util::Map<std::string, const InventoryItem*> getInventoryItems();
     const InventoryItem* getInventoryItem(const std::string& inventoryItemID);
     void addInventoryItem(const std::string& partName, int quantity, double price);
+    void addInventoryItemStock(const std::string& selectedItemId, int quantity);
     void removeInventoryItem(const std::string& inventoryItemID);
     util::Map<std::string, const ServiceBooking*> getServiceBookings();
     util::Map<std::string, const ServiceBooking*> getServiceBookingsByUser(const std::string userID);
@@ -65,7 +66,6 @@ public:
     void completePayment(const std::string& invoiceID, util::PaymentMode paymentMode);
     util::Vector<const Notification*> getNotifications();
     void deleteNotification(const std::string& notificationID);
-    void configureNotifications(const std::string& userID, bool paymentNotifications, bool serviceNotifications);
-    void addInventoryItemStock(const std::string& selectedItemId, int quantity);
+    void configureNotifications(bool paymentNotifications, bool serviceNotifications);
     void runSystemChecks();
 };

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

@@ -1,3 +1,10 @@
+/*
+File: Observer.h
+Description: Declares the Observer interface for handling notifications in the Vehicle Service Management System.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 
 class Notification;
@@ -6,5 +13,5 @@ class Observer
 {
 public:
     virtual ~Observer() = default;
-    virtual void update(Notification* notification) = 0;
+    virtual void addNotification(Notification* notification) = 0;
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/core/patterns/Subject.h

@@ -1,3 +1,10 @@
+/*
+File: Subject.h
+Description: Declares the Subject interface for managing user attachments and detachments in the Observer design pattern within the Vehicle Service Management System.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include <string>
 #include "Map.h"

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

@@ -1,46 +1,128 @@
+/*
+File: DataStore.cpp
+Description: Implements the DataStore class which provides a centralized singleton repository
+             for managing system data in the Vehicle Service Management System.
+             Includes accessors for users, services, combo packages, service bookings,
+             job cards, inventory items, invoices, and payments.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "DataStore.h"
 
+/*
+Function: getInstance
+Description: Provides a singleton instance of the DataStore class.
+Parameters:
+    - None
+Returns:
+    - Reference to the single DataStore instance.
+*/
 DataStore& DataStore::getInstance()
 {
     static DataStore dataStore;
     return dataStore;
 }
 
+/*
+Function: getUsers
+Description: Retrieves the internal map of users.
+Parameters:
+    - None
+Returns:
+    - Reference to util::Map<std::string, User*> containing all users.
+*/
 util::Map<std::string, User*>& DataStore::getUsers()
 {
     return m_users;
 }
 
+/*
+Function: getServices
+Description: Retrieves the internal map of services.
+Parameters:
+    - None
+Returns:
+    - Reference to util::Map<std::string, Service*> containing all services.
+*/
 util::Map<std::string, Service*>& DataStore::getServices()
 {
     return m_services;
 }
 
+/*
+Function: getComboPackages
+Description: Retrieves the internal map of combo packages.
+Parameters:
+    - None
+Returns:
+    - Reference to util::Map<std::string, ComboPackage*> containing all combo packages.
+*/
 util::Map<std::string, ComboPackage*>& DataStore::getComboPackages()
 {
     return m_comboPackages;
 }
 
+/*
+Function: getServiceBookings
+Description: Retrieves the internal map of service bookings.
+Parameters:
+    - None
+Returns:
+    - Reference to util::Map<std::string, ServiceBooking*> containing all service bookings.
+*/
 util::Map<std::string, ServiceBooking*>& DataStore::getServiceBookings()
 {
     return m_serviceBookings;
 }
 
+/*
+Function: getJobCards
+Description: Retrieves the internal map of job cards.
+Parameters:
+    - None
+Returns:
+    - Reference to util::Map<std::string, JobCard*> containing all job cards.
+*/
 util::Map<std::string, JobCard*>& DataStore::getJobCards()
 {
     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 the internal map of invoices.
+Parameters:
+    - None
+Returns:
+    - Reference to util::Map<std::string, Invoice*> containing all invoices.
+*/
 util::Map<std::string, Invoice*>& DataStore::getInvoices()
 {
     return m_invoices;
 }
 
+/*
+Function: getPayments
+Description: Retrieves the internal map of payments.
+Parameters:
+    - None
+Returns:
+    - Reference to util::Map<std::string, Payment*> containing all payments.
+*/
 util::Map<std::string, Payment*>& DataStore::getPayments()
 {
     return m_payments;

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

@@ -1,5 +1,11 @@
-#pragma once
+/*
+File: DataStore.h
+Description: Declares the DataStore singleton class responsible for managing collections of users, services, combo packages, service bookings, job cards, inventory items, invoices, and payments in the Vehicle Service Management System.
+Author: Trenser
+Date: 19-May-2026
+*/
 
+#pragma once
 #include <string>
 #include "Map.h"
 

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

@@ -1,12 +1,41 @@
+/*
+File: ComboPackage.cpp
+Description: Implements the ComboPackage class which represents a bundled set of services in the Vehicle Service Management System.
+             Provides constructors, accessors, and mutators for package details such as ID, name, discount percentage, state,
+             and associated services.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "ComboPackage.h"
 
 int ComboPackage::m_uid = 0;
 
+/*
+Function: ComboPackage
+Description: Default constructor that initializes a new combo package with a unique ID,
+             active state, and zero discount percentage.
+Parameters:
+    - None
+Returns:
+    - A new ComboPackage object.
+*/
 ComboPackage::ComboPackage()
     : m_id("CMP" + std::to_string(++m_uid)),
     m_status(util::State::ACTIVE),
     m_discountPercentage(0.0) {}
 
+/*
+Function: ComboPackage
+Description: Parameterized constructor that initializes a new combo package with a unique ID,
+             specified package name, discount percentage, active state, and associated services.
+Parameters:
+    - packageName: Name of the combo package.
+    - discountPercentage: Discount percentage applied to the package.
+    - services: Map of services included in the package.
+Returns:
+    - A new ComboPackage object.
+*/
 ComboPackage::ComboPackage(const std::string& packageName, double discountPercentage, const util::Map<std::string, Service*>& services)
     : m_id("CMP" + std::to_string(++m_uid)),
     m_packageName(packageName),
@@ -14,51 +43,131 @@ ComboPackage::ComboPackage(const std::string& packageName, double discountPercen
     m_status(util::State::ACTIVE),
     m_services(services) {}
 
+/*
+Function: getId
+Description: Retrieves the unique ID of the combo package.
+Parameters:
+    - None
+Returns:
+    - const std::string& representing the package ID.
+*/
 const std::string& ComboPackage::getId() const
 {
     return m_id;
 }
 
+/*
+Function: getPackageName
+Description: Retrieves the name of the combo package.
+Parameters:
+    - None
+Returns:
+    - const std::string& representing the package name.
+*/
 const std::string& ComboPackage::getPackageName() const
 {
     return m_packageName;
 }
 
+/*
+Function: getDiscountPercentage
+Description: Retrieves the discount percentage applied to the combo package.
+Parameters:
+    - None
+Returns:
+    - double representing the discount percentage.
+*/
 double ComboPackage::getDiscountPercentage() const
 {
     return m_discountPercentage;
 }
 
+/*
+Function: getState
+Description: Retrieves the current state (ACTIVE/INACTIVE) of the combo package.
+Parameters:
+    - None
+Returns:
+    - util::State representing the package state.
+*/
 util::State ComboPackage::getState() const
 {
     return m_status;
 }
 
+/*
+Function: getServices
+Description: Retrieves the map of services included in the combo package.
+Parameters:
+    - None
+Returns:
+    - const util::Map<std::string, Service*>& representing the services.
+*/
 const util::Map<std::string, Service*>& ComboPackage::getServices() const
 {
     return m_services;
 }
 
+/*
+Function: setId
+Description: Sets the unique ID of the combo package.
+Parameters:
+    - id: New ID string.
+Returns:
+    - void
+*/
 void ComboPackage::setId(const std::string& id)
 {
     m_id = id;
 }
 
+/*
+Function: setPackageName
+Description: Sets the name of the combo package.
+Parameters:
+    - packageName: New package name string.
+Returns:
+    - void
+*/
 void ComboPackage::setPackageName(const std::string& packageName)
 {
     m_packageName = packageName;
 }
 
+/*
+Function: setDiscountPercentage
+Description: Sets the discount percentage for the combo package.
+Parameters:
+    - discountPercentage: New discount percentage value.
+Returns:
+    - void
+*/
 void ComboPackage::setDiscountPercentage(double discountPercentage)
 {
     m_discountPercentage = discountPercentage;
 }
 
+/*
+Function: setServices
+Description: Sets the services included in the combo package.
+Parameters:
+    - services: Map of services to be associated with the package.
+Returns:
+    - void
+*/
 void ComboPackage::setServices(const util::Map<std::string, Service*>& services)
 {
     m_services = services;
 }
 
+/*
+Function: setState
+Description: Sets the state (ACTIVE/INACTIVE) of the combo package.
+Parameters:
+    - status: New state value.
+Returns:
+    - void
+*/
 void ComboPackage::setState(util::State status)
 {
     m_status = status;

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

@@ -1,3 +1,10 @@
+/*
+File: ComboPackage.h
+Description: Declares the ComboPackage class which represents a service package with a unique ID, package name, discount percentage, associated services, and status in the Vehicle Service Management System.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include <string>
 #include "Map.h"

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

@@ -1,13 +1,41 @@
+/*
+File: InventoryItem.cpp
+Description: Implements the InventoryItem class which represents an inventory item in the Vehicle Service Management System.
+             Provides constructors, accessors, and mutators for item details such as ID, part name, quantity, price, and state.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "InventoryItem.h"
 
 int InventoryItem::m_uid = 0;
 
+/*
+Function: InventoryItem
+Description: Default constructor that initializes a new inventory item with a unique ID,
+             active state, zero quantity, and zero price.
+Parameters:
+    - None
+Returns:
+    - A new InventoryItem object.
+*/
 InventoryItem::InventoryItem()
     : m_id("IIM" + std::to_string(++m_uid)),
     m_quantity(0),
     m_status(util::State::ACTIVE),
     m_price(0.0) {}
 
+/*
+Function: InventoryItem
+Description: Parameterized constructor that initializes a new inventory item with a unique ID,
+             specified part name, quantity, price, and active state.
+Parameters:
+    - partName: Name of the inventory item.
+    - quantity: Initial quantity of the item.
+    - price: Price of the item.
+Returns:
+    - A new InventoryItem object.
+*/
 InventoryItem::InventoryItem(const std::string& partName, int quantity, double price)
     : m_id("IIM" + std::to_string(++m_uid)),
     m_partName(partName),
@@ -15,51 +43,131 @@ InventoryItem::InventoryItem(const std::string& partName, int quantity, double p
     m_status(util::State::ACTIVE),
     m_price(price) {}
 
+/*
+Function: getId
+Description: Retrieves the unique ID of the inventory item.
+Parameters:
+    - None
+Returns:
+    - const std::string& representing the item ID.
+*/
 const std::string& InventoryItem::getId() const
 {
     return m_id;
 }
 
+/*
+Function: getPartName
+Description: Retrieves the part name of the inventory item.
+Parameters:
+    - None
+Returns:
+    - const std::string& representing the part name.
+*/
 const std::string& InventoryItem::getPartName() const
 {
     return m_partName;
 }
 
+/*
+Function: getQuantity
+Description: Retrieves the current quantity of the inventory item.
+Parameters:
+    - None
+Returns:
+    - int representing the quantity.
+*/
 int InventoryItem::getQuantity() const
 {
     return m_quantity;
 }
 
+/*
+Function: getPrice
+Description: Retrieves the price of the inventory item.
+Parameters:
+    - None
+Returns:
+    - double representing the price.
+*/
 double InventoryItem::getPrice() const
 {
     return m_price;
 }
 
+/*
+Function: getState
+Description: Retrieves the current state (ACTIVE/INACTIVE) of the inventory item.
+Parameters:
+    - None
+Returns:
+    - util::State representing the item state.
+*/
 util::State InventoryItem::getState() const
 {
     return m_status;
 }
 
+/*
+Function: setId
+Description: Sets the unique ID of the inventory item.
+Parameters:
+    - id: New ID string.
+Returns:
+    - void
+*/
 void InventoryItem::setId(const std::string& id)
 {
     m_id = id;
 }
 
+/*
+Function: setPartName
+Description: Sets the part name of the inventory item.
+Parameters:
+    - partName: New part name string.
+Returns:
+    - void
+*/
 void InventoryItem::setPartName(const std::string& partName)
 {
     m_partName = partName;
 }
 
+/*
+Function: setQuantity
+Description: Sets the quantity of the inventory item.
+Parameters:
+    - quantity: New quantity value.
+Returns:
+    - void
+*/
 void InventoryItem::setQuantity(int quantity)
 {
     m_quantity = quantity;
 }
 
+/*
+Function: setPrice
+Description: Sets the price of the inventory item.
+Parameters:
+    - price: New price value.
+Returns:
+    - void
+*/
 void InventoryItem::setPrice(double price)
 {
     m_price = price;
 }
 
+/*
+Function: setState
+Description: Sets the state (ACTIVE/INACTIVE) of the inventory item.
+Parameters:
+    - status: New state value.
+Returns:
+    - void
+*/
 void InventoryItem::setState(util::State status)
 {
     m_status = status;

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

@@ -1,3 +1,12 @@
+/*
+File: InventoryItem.h
+Description: Declares the InventoryItem class which represents parts in the Vehicle Service Management System.
+             Each item has a unique ID, part name, quantity, price, and status.
+Author: Trenser
+Date: 19-May-2026
+*/
+
+
 #pragma once
 #include <string>
 #include "Enums.h"

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

@@ -1,7 +1,26 @@
+/*
+File: Invoice.cpp
+Description: Implements the Invoice class which represents an invoice in the Vehicle Service Management System.
+             Provides constructors, accessors, and mutators for invoice details such as ID, booking, costs,
+             discount percentage, total amount, payment details, and status.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "Invoice.h"
 
 int Invoice::m_uid = 0;
 
+/*
+Function: Invoice
+Description: Default constructor that initializes a new invoice with a unique ID,
+             null booking, zero costs, zero discount, zero total amount,
+             and default payment method and status.
+Parameters:
+    - None
+Returns:
+    - A new Invoice object.
+*/
 Invoice::Invoice()
     : m_id("INV" + std::to_string(++m_uid)),
     m_booking(nullptr),
@@ -12,6 +31,24 @@ Invoice::Invoice()
     m_paymentMethod(util::PaymentMode()),
     m_status(util::PaymentStatus()) {}
 
+/*
+Function: Invoice
+Description: Parameterized constructor that initializes a new invoice with a unique ID and specified details.
+Parameters:
+    - bookingId: ID of the associated service booking.
+    - booking: Pointer to the ServiceBooking object.
+    - invoiceDate: Timestamp of when the invoice was created.
+    - laborCost: Cost of labor for the service.
+    - parts: Map of inventory items used in the service.
+    - partsCost: Total cost of parts.
+    - discountPercentage: Discount applied to the invoice.
+    - totalAmount: Final total amount after discount.
+    - paymentDate: Timestamp of when payment was made.
+    - paymentMethod: Payment mode (ONLINE/OFFLINE).
+    - status: Payment status (PENDING/COMPLETED).
+Returns:
+    - A new Invoice object.
+*/
 Invoice::Invoice(
     const std::string& bookingId,
     ServiceBooking* booking,
@@ -39,121 +76,289 @@ Invoice::Invoice(
     m_paymentMethod(paymentMethod),
     m_status(status) {}
 
+/*
+Function: getId
+Description: Retrieves the unique ID of the invoice.
+Returns:
+    - const std::string& representing the invoice ID.
+*/
 const std::string& Invoice::getId() const
 {
     return m_id;
 }
 
+/*
+Function: getBookingId
+Description: Retrieves the booking ID associated with the invoice.
+Returns:
+    - const std::string& representing the booking ID.
+*/
 const std::string& Invoice::getBookingId() const
 {
     return m_bookingId;
 }
 
+/*
+Function: getBooking
+Description: Retrieves the pointer to the associated ServiceBooking.
+Returns:
+    - ServiceBooking* representing the booking.
+*/
 ServiceBooking* Invoice::getBooking() const
 {
     return m_booking;
 }
 
+/*
+Function: getInvoiceDate
+Description: Retrieves the timestamp of the invoice creation date.
+Returns:
+    - const util::Timestamp& representing the invoice date.
+*/
 const util::Timestamp& Invoice::getInvoiceDate() const
 {
     return m_invoiceDate;
 }
 
+/*
+Function: getLaborCost
+Description: Retrieves the labor cost associated with the invoice.
+Returns:
+    - double representing the labor cost.
+*/
 double Invoice::getLaborCost() const
 {
     return m_laborCost;
 }
 
+/*
+Function: getParts
+Description: Retrieves the map of inventory items used in the service.
+Returns:
+    - const util::Map<std::string, InventoryItem*>& representing the parts.
+*/
 const util::Map<std::string, InventoryItem*>& Invoice::getParts() const
 {
     return m_parts;
 }
 
+/*
+Function: getPartsCost
+Description: Retrieves the total cost of parts used in the service.
+Returns:
+    - double representing the parts cost.
+*/
 double Invoice::getPartsCost() const
 {
     return m_partsCost;
 }
 
+/*
+Function: getDiscountPercentage
+Description: Retrieves the discount percentage applied to the invoice.
+Returns:
+    - double representing the discount percentage.
+*/
 double Invoice::getDiscountPercentage() const
 {
     return m_discountPercentage;
 }
 
+/*
+Function: getTotalAmount
+Description: Retrieves the total amount of the invoice after discount.
+Returns:
+    - double representing the total amount.
+*/
 double Invoice::getTotalAmount() const
 {
     return m_totalAmount;
 }
 
+/*
+Function: getPaymentDate
+Description: Retrieves the timestamp of the payment date.
+Returns:
+    - const util::Timestamp& representing the payment date.
+*/
 const util::Timestamp& Invoice::getPaymentDate() const
 {
     return m_paymentDate;
 }
 
+/*
+Function: getPaymentMethod
+Description: Retrieves the payment mode used for the invoice.
+Returns:
+    - util::PaymentMode representing the payment method.
+*/
 util::PaymentMode Invoice::getPaymentMethod() const
 {
     return m_paymentMethod;
 }
 
+/*
+Function: getStatus
+Description: Retrieves the payment status of the invoice.
+Returns:
+    - util::PaymentStatus representing the payment status.
+*/
 util::PaymentStatus Invoice::getStatus() const
 {
     return m_status;
 }
 
+/*
+Function: setId
+Description: Sets the unique ID of the invoice.
+Parameters:
+    - id: New invoice ID string.
+Returns:
+    - void
+*/
 void Invoice::setId(const std::string& id)
 {
     m_id = id;
 }
 
+/*
+Function: setBookingId
+Description: Sets the booking ID associated with the invoice.
+Parameters:
+    - bookingId: New booking ID string.
+Returns:
+    - void
+*/
 void Invoice::setBookingId(const std::string& bookingId)
 {
     m_bookingId = bookingId;
 }
 
+/*
+Function: setBooking
+Description: Sets the associated ServiceBooking pointer.
+Parameters:
+    - booking: Pointer to the ServiceBooking object.
+Returns:
+    - void
+*/
 void Invoice::setBooking(ServiceBooking* booking)
 {
     m_booking = booking;
 }
 
+/*
+Function: setInvoiceDate
+Description: Sets the invoice creation date.
+Parameters:
+    - invoiceDate: New timestamp for the invoice date.
+Returns:
+    - void
+*/
 void Invoice::setInvoiceDate(const util::Timestamp& invoiceDate)
 {
     m_invoiceDate = invoiceDate;
 }
 
+/*
+Function: setLaborCost
+Description: Sets the labor cost for the invoice.
+Parameters:
+    - laborCost: New labor cost value.
+Returns:
+    - void
+*/
 void Invoice::setLaborCost(double laborCost)
 {
     m_laborCost = laborCost;
 }
 
+/*
+Function: setParts
+Description: Sets the inventory items used in the service.
+Parameters:
+    - parts: Map of inventory items.
+Returns:
+    - void
+*/
 void Invoice::setParts(const util::Map<std::string, InventoryItem*>& parts)
 {
     m_parts = parts;
 }
 
+/*
+Function: setPartsCost
+Description: Sets the total cost of parts used in the service.
+Parameters:
+    - partsCost: New parts cost value.
+Returns:
+    - void
+*/
 void Invoice::setPartsCost(double partsCost)
 {
     m_partsCost = partsCost;
 }
 
+/*
+Function: setDiscountPercentage
+Description: Sets the discount percentage applied to the invoice.
+Parameters:
+    - discountPercentage: New discount percentage value.
+Returns:
+    - void
+*/
 void Invoice::setDiscountPercentage(double discountPercentage)
 {
     m_discountPercentage = discountPercentage;
 }
 
+/*
+Function: setTotalAmount
+Description: Sets the total amount of the invoice.
+Parameters:
+    - totalAmount: New total amount value.
+Returns:
+    - void
+*/
 void Invoice::setTotalAmount(double totalAmount)
 {
     m_totalAmount = totalAmount;
 }
 
+/*
+Function: setPaymentDate
+Description: Sets the payment date for the invoice.
+Parameters:
+    - paymentDate: New timestamp for the payment date.
+Returns:
+    - void
+*/
 void Invoice::setPaymentDate(const util::Timestamp& paymentDate)
 {
     m_paymentDate = paymentDate;
 }
 
+/*
+Function: setPaymentMethod
+Description: Sets the payment mode for the invoice.
+Parameters:
+    - paymentMethod: New payment mode value.
+Returns:
+    - void
+*/
 void Invoice::setPaymentMethod(util::PaymentMode paymentMethod)
 {
     m_paymentMethod = paymentMethod;
 }
 
+/*
+Function: setStatus
+Description: Sets the payment status of the invoice.
+Parameters:
+    - status: New payment status value.
+Returns:
+    - void
+*/
 void Invoice::setStatus(util::PaymentStatus status)
 {
     m_status = status;

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

@@ -1,3 +1,12 @@
+/*
+File: Invoice.h
+Description: Declares the Invoice class which represents billing details for a service booking in the Vehicle Service Management System.
+             Each invoice includes booking information, labor cost, parts used, discount percentage, total amount, payment details, and status.
+Author: Trenser
+Date: 19-May-2026
+*/
+
+
 #pragma once
 #include <string>
 #include "Map.h"

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

@@ -12,10 +12,12 @@ int JobCard::m_uid = 0;
 
 /*
 Function: JobCard
-Description: Default constructor that initializes a new job card with
-             a unique ID and default values.
-Parameter: None
-Return type: Constructor
+Description: Default constructor that initializes a new job card with a unique ID,
+             null booking, null service, null technician, and default job status.
+Parameters:
+    - None
+Returns:
+    - A new JobCard object.
 */
 JobCard::JobCard()
     : m_id("JC" + std::to_string(++m_uid)),
@@ -62,9 +64,9 @@ JobCard::JobCard(const std::string& bookingId,
 
 /*
 Function: getId
-Description: Retrieves the unique identifier of the job card.
-Parameter: None
-Return type: const std::string&
+Description: Retrieves the unique ID of the job card.
+Returns:
+    - const std::string& representing the job card ID.
 */
 const std::string& JobCard::getId() const
 {
@@ -74,8 +76,8 @@ const std::string& JobCard::getId() const
 /*
 Function: getBookingId
 Description: Retrieves the booking ID associated with the job card.
-Parameter: None
-Return type: const std::string&
+Returns:
+    - const std::string& representing the booking ID.
 */
 const std::string& JobCard::getBookingId() const
 {
@@ -84,9 +86,9 @@ const std::string& JobCard::getBookingId() const
 
 /*
 Function: getBooking
-Description: Retrieves the booking object associated with the job card.
-Parameter: None
-Return type: ServiceBooking*
+Description: Retrieves the pointer to the associated ServiceBooking.
+Returns:
+    - ServiceBooking* representing the booking.
 */
 ServiceBooking* JobCard::getBooking() const
 {
@@ -95,9 +97,9 @@ ServiceBooking* JobCard::getBooking() const
 
 /*
 Function: getService
-Description: Retrieves the service object associated with the job card.
-Parameter: None
-Return type: Service*
+Description: Retrieves the pointer to the associated Service.
+Returns:
+    - Service* representing the service.
 */
 Service* JobCard::getService() const
 {
@@ -107,8 +109,8 @@ Service* JobCard::getService() const
 /*
 Function: getServiceId
 Description: Retrieves the service ID associated with the job card.
-Parameter: None
-Return type: const std::string&
+Returns:
+    - const std::string& representing the service ID.
 */
 const std::string& JobCard::getServiceId() const
 {
@@ -117,9 +119,9 @@ const std::string& JobCard::getServiceId() const
 
 /*
 Function: getTechnicianId
-Description: Retrieves the technician ID assigned to the job card.
-Parameter: None
-Return type: const std::string&
+Description: Retrieves the technician ID associated with the job card.
+Returns:
+    - const std::string& representing the technician ID.
 */
 const std::string& JobCard::getTechnicianId() const
 {
@@ -128,9 +130,9 @@ const std::string& JobCard::getTechnicianId() const
 
 /*
 Function: getTechnician
-Description: Retrieves the technician object assigned to the job card.
-Parameter: None
-Return type: User*
+Description: Retrieves the pointer to the assigned technician.
+Returns:
+    - User* representing the technician.
 */
 User* JobCard::getTechnician() const
 {
@@ -139,9 +141,9 @@ User* JobCard::getTechnician() const
 
 /*
 Function: getAssignedDate
-Description: Retrieves the date when the job was assigned.
-Parameter: None
-Return type: const util::Timestamp&
+Description: Retrieves the timestamp of when the job was assigned.
+Returns:
+    - const util::Timestamp& representing the assigned date.
 */
 const util::Timestamp& JobCard::getAssignedDate() const
 {
@@ -161,9 +163,9 @@ util::ServiceJobStatus JobCard::getStatus() const
 
 /*
 Function: getCompletionDate
-Description: Retrieves the completion date of the job card.
-Parameter: None
-Return type: const util::Timestamp&
+Description: Retrieves the timestamp of when the job was completed.
+Returns:
+    - const util::Timestamp& representing the completion date.
 */
 const util::Timestamp& JobCard::getCompletionDate() const
 {
@@ -172,9 +174,11 @@ const util::Timestamp& JobCard::getCompletionDate() const
 
 /*
 Function: setId
-Description: Sets the unique identifier of the job card.
-Parameter: const std::string& id - new job card ID
-Return type: void
+Description: Sets the unique ID of the job card.
+Parameters:
+    - id: New job card ID string.
+Returns:
+    - void
 */
 void JobCard::setId(const std::string& id)
 {
@@ -183,9 +187,11 @@ void JobCard::setId(const std::string& id)
 
 /*
 Function: setBookingId
-Description: Sets the booking ID for the job card.
-Parameter: const std::string& bookingId - new booking ID
-Return type: void
+Description: Sets the booking ID associated with the job card.
+Parameters:
+    - bookingId: New booking ID string.
+Returns:
+    - void
 */
 void JobCard::setBookingId(const std::string& bookingId)
 {
@@ -194,9 +200,11 @@ void JobCard::setBookingId(const std::string& bookingId)
 
 /*
 Function: setBooking
-Description: Sets the booking object for the job card.
-Parameter: ServiceBooking* booking - pointer to the booking object
-Return type: void
+Description: Sets the associated ServiceBooking pointer.
+Parameters:
+    - booking: Pointer to the ServiceBooking object.
+Returns:
+    - void
 */
 void JobCard::setBooking(ServiceBooking* booking)
 {
@@ -205,9 +213,11 @@ void JobCard::setBooking(ServiceBooking* booking)
 
 /*
 Function: setService
-Description: Sets the service object for the job card.
-Parameter: Service* service - pointer to the service object
-Return type: void
+Description: Sets the associated Service pointer.
+Parameters:
+    - service: Pointer to the Service object.
+Returns:
+    - void
 */
 void JobCard::setService(Service* service)
 {
@@ -216,9 +226,11 @@ void JobCard::setService(Service* service)
 
 /*
 Function: setServiceId
-Description: Sets the service ID for the job card.
-Parameter: const std::string& serviceId - new service ID
-Return type: void
+Description: Sets the service ID associated with the job card.
+Parameters:
+    - serviceId: New service ID string.
+Returns:
+    - void
 */
 void JobCard::setServiceId(const std::string& serviceId)
 {
@@ -227,9 +239,11 @@ void JobCard::setServiceId(const std::string& serviceId)
 
 /*
 Function: setTechnicianId
-Description: Sets the technician ID for the job card.
-Parameter: const std::string& technicianId - new technician ID
-Return type: void
+Description: Sets the technician ID associated with the job card.
+Parameters:
+    - technicianId: New technician ID string.
+Returns:
+    - void
 */
 void JobCard::setTechnicianId(const std::string& technicianId)
 {
@@ -238,9 +252,11 @@ void JobCard::setTechnicianId(const std::string& technicianId)
 
 /*
 Function: setTechnician
-Description: Sets the technician object for the job card.
-Parameter: User* technician - pointer to the technician object
-Return type: void
+Description: Sets the pointer to the assigned technician.
+Parameters:
+    - technician: Pointer to the User object.
+Returns:
+    - void
 */
 void JobCard::setTechnician(User* technician)
 {
@@ -249,9 +265,11 @@ void JobCard::setTechnician(User* technician)
 
 /*
 Function: setAssignedDate
-Description: Sets the assigned date for the job card.
-Parameter: const util::Timestamp& assignedDate - new assigned date
-Return type: void
+Description: Sets the timestamp of when the job was assigned.
+Parameters:
+    - assignedDate: New timestamp for the assigned date.
+Returns:
+    - void
 */
 void JobCard::setAssignedDate(const util::Timestamp& assignedDate)
 {
@@ -271,9 +289,11 @@ void JobCard::setStatus(util::ServiceJobStatus status)
 
 /*
 Function: setCompletionDate
-Description: Sets the completion date for the job card.
-Parameter: const util::Timestamp& completionDate - new completion date
-Return type: void
+Description: Sets the timestamp of when the job was completed.
+Parameters:
+    - completionDate: New timestamp for the completion date.
+Returns:
+    - void
 */
 void JobCard::setCompletionDate(const util::Timestamp& completionDate)
 {

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

@@ -1,11 +1,39 @@
+/*
+File: Notification.cpp
+Description: Implements the Notification class which represents system notifications in the Vehicle Service Management System.
+             Provides constructors, accessors, and mutators for notification details such as ID, recipient, title, message, and timestamp.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "Notification.h"
 
 int Notification::m_uid = 0;
 
+/*
+Function: Notification
+Description: Default constructor that initializes a new notification with a unique ID and null recipient.
+Parameters:
+    - None
+Returns:
+    - A new Notification object.
+*/
 Notification::Notification()
     : m_id("NOT" + std::to_string(++m_uid)),
     m_recipient(nullptr) {}
 
+/*
+Function: Notification
+Description: Parameterized constructor that initializes a new notification with a unique ID and specified details.
+Parameters:
+    - recipientUserId: ID of the recipient user.
+    - recipient: Pointer to the User object representing the recipient.
+    - title: Title of the notification.
+    - message: Message content of the notification.
+    - createdAt: Timestamp of when the notification was created.
+Returns:
+    - A new Notification object.
+*/
 Notification::Notification(const std::string& recipientUserId, User* recipient, const std::string& title, const std::string& message, const util::Timestamp& createdAt)
     : m_id("NOT" + std::to_string(++m_uid)),
     m_recipientUserId(recipientUserId),
@@ -14,61 +42,145 @@ Notification::Notification(const std::string& recipientUserId, User* recipient,
     m_message(message),
     m_createdAt(createdAt) {}
 
+/*
+Function: getId
+Description: Retrieves the unique ID of the notification.
+Returns:
+    - const std::string& representing the notification ID.
+*/
 const std::string& Notification::getId() const 
 {
     return m_id;
 }
 
+/*
+Function: getRecipientUserId
+Description: Retrieves the recipient user ID associated with the notification.
+Returns:
+    - const std::string& representing the recipient user ID.
+*/
 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.
+Returns:
+    - const std::string& representing the notification title.
+*/
 const std::string& Notification::getTitle() const
 {
     return m_title;
 }
 
+/*
+Function: getMessage
+Description: Retrieves the message content of the notification.
+Returns:
+    - const std::string& representing the notification message.
+*/
 const std::string& Notification::getMessage() const
 {
     return m_message;
 }
 
+/*
+Function: getCreatedAt
+Description: Retrieves the timestamp of when the notification was created.
+Returns:
+    - const util::Timestamp& representing the creation timestamp.
+*/
 const util::Timestamp& Notification::getCreatedAt() const
 {
     return m_createdAt;
 }
 
+/*
+Function: setId
+Description: Sets the unique ID of the notification.
+Parameters:
+    - id: New notification ID string.
+Returns:
+    - void
+*/
 void Notification::setId(const std::string& id)
 {
     m_id = id;
 }
 
+/*
+Function: setRecipientUserId
+Description: Sets the recipient user ID for the notification.
+Parameters:
+    - recipientUserId: New recipient user ID string.
+Returns:
+    - void
+*/
 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.
+Parameters:
+    - title: New notification title string.
+Returns:
+    - void
+*/
 void Notification::setTitle(const std::string& title)
 {
     m_title = title;
 }
 
+/*
+Function: setMessage
+Description: Sets the message content of the notification.
+Parameters:
+    - message: New notification message string.
+Returns:
+    - void
+*/
 void Notification::setMessage(const std::string& message)
 {
     m_message = message;
 }
 
+/*
+Function: setCreatedAt
+Description: Sets the timestamp of when the notification was created.
+Parameters:
+    - createdAt: New timestamp value.
+Returns:
+    - void
+*/
 void Notification::setCreatedAt(const util::Timestamp& createdAt)
 {
     m_createdAt = createdAt;

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

@@ -1,3 +1,11 @@
+/*
+File: Notification.h
+Description: Declares the Notification class which represents system messages sent to users in the Vehicle Service Management System.
+             Each notification includes a unique ID, recipient details, title, message content, and timestamp of creation.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include <string>
 #include "Timestamp.h"

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

@@ -1,12 +1,40 @@
+/*
+File: Service.cpp
+Description: Implements the Service class which represents a vehicle service in the Vehicle Service Management System.
+             Provides constructors, accessors, and mutators for service details such as ID, name, required inventory items,
+             labor cost, and state.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "Service.h"
 
 int Service::m_uid = 0;
 
+/*
+Function: Service
+Description: Default constructor that initializes a new service with a unique ID,
+             active state, and zero labor cost.
+Parameters:
+    - None
+Returns:
+    - A new Service object.
+*/
 Service::Service()
     : m_id("SRV" + std::to_string(++m_uid)),
     m_status(util::State::ACTIVE),
     m_laborCost(0.0) {}
 
+/*
+Function: Service
+Description: Parameterized constructor that initializes a new service with a unique ID and specified details.
+Parameters:
+    - name: Name of the service.
+    - requiredInventoryItems: Map of inventory items required for the service.
+    - laborCost: Labor cost associated with the service.
+Returns:
+    - A new Service object.
+*/
 Service::Service(const std::string& name, const util::Map<std::string, InventoryItem*>& requiredInventoryItems, double laborCost)
     : m_id("SRV" + std::to_string(++m_uid)),
     m_name(name),
@@ -14,51 +42,121 @@ Service::Service(const std::string& name, const util::Map<std::string, Inventory
     m_status(util::State::ACTIVE),
     m_laborCost(laborCost) {}
 
+/*
+Function: getId
+Description: Retrieves the unique ID of the service.
+Returns:
+    - const std::string& representing the service ID.
+*/
 const std::string& Service::getId() const
 {
     return m_id;
 }
 
+/*
+Function: getName
+Description: Retrieves the name of the service.
+Returns:
+    - const std::string& representing the service name.
+*/
 const std::string& Service::getName() const
 {
     return m_name;
 }
 
+/*
+Function: getRequiredInventoryItems
+Description: Retrieves the map of inventory items required for the service.
+Returns:
+    - const util::Map<std::string, InventoryItem*>& representing the required inventory items.
+*/
 const util::Map<std::string, InventoryItem*>& Service::getRequiredInventoryItems() const
 {
     return m_requiredInventoryItems;
 }
 
+/*
+Function: getLaborCost
+Description: Retrieves the labor cost associated with the service.
+Returns:
+    - double representing the labor cost.
+*/
 double Service::getLaborCost() const
 {
     return m_laborCost;
 }
 
+/*
+Function: getState
+Description: Retrieves the current state (ACTIVE/INACTIVE) of the service.
+Returns:
+    - util::State representing the service state.
+*/
 util::State Service::getState() const
 {
     return m_status;
 }
 
+/*
+Function: setId
+Description: Sets the unique ID of the service.
+Parameters:
+    - id: New service ID string.
+Returns:
+    - void
+*/
 void Service::setId(const std::string& id)
 {
     m_id = id;
 }
 
+/*
+Function: setName
+Description: Sets the name of the service.
+Parameters:
+    - name: New service name string.
+Returns:
+    - void
+*/
 void Service::setName(const std::string& name)
 {
     m_name = name;
 }
 
+/*
+Function: setRequiredInventoryItems
+Description: Sets the inventory items required for the service.
+Parameters:
+    - requiredInventoryItems: Map of inventory items.
+Returns:
+    - void
+*/
 void Service::setRequiredInventoryItems(const util::Map<std::string, InventoryItem*>& requiredInventoryItems)
 {
     m_requiredInventoryItems = requiredInventoryItems;
 }
 
+/*
+Function: setLaborCost
+Description: Sets the labor cost for the service.
+Parameters:
+    - laborCost: New labor cost value.
+Returns:
+    - void
+*/
 void Service::setLaborCost(double laborCost)
 {
     m_laborCost = laborCost;
 }
 
+/*
+Function: setState
+Description: Sets the state (ACTIVE/INACTIVE) of the service.
+Parameters:
+    - status: New state value.
+Returns:
+    - void
+*/
 void Service::setState(util::State status)
 {
     m_status = status;

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

@@ -1,3 +1,12 @@
+/*
+File: Service.h
+Description: Declares the Service class which represents a vehicle service in the Vehicle Service Management System.
+             Each service includes a unique ID, name, required inventory items, labor cost, and status.
+Author: Trenser
+Date: 19-May-2026
+*/
+
+
 #pragma once
 #include <string>
 #include "Map.h"

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

@@ -12,10 +12,12 @@ int ServiceBooking::m_uid = 0;
 
 /*
 Function: ServiceBooking
-Description: Default constructor that initializes a new service booking
-             with a unique ID, no customer, and zero discount.
-Parameter: None
-Return type: Constructor
+Description: Default constructor that initializes a new service booking with a unique ID,
+             null customer, and zero discount percentage.
+Parameters:
+    - None
+Returns:
+    - A new ServiceBooking object.
 */
 ServiceBooking::ServiceBooking()
     : m_id("SRV" + std::to_string(++m_uid)),
@@ -49,8 +51,6 @@ ServiceBooking::ServiceBooking(
     const std::string& vehicleNumber,
     const std::string& vehicleBrand,
     const std::string& vehicleModel,
-    const std::string& assignedTechnicianId,
-    User* assignedTechnician,
     double discountPercentage
 )
     : m_id("SRV" + std::to_string(++m_uid)),
@@ -69,9 +69,9 @@ ServiceBooking::ServiceBooking(
 
 /*
 Function: getId
-Description: Retrieves the unique identifier of the service booking.
-Parameter: None
-Return type: const std::string&
+Description: Retrieves the unique ID of the service booking.
+Returns:
+    - const std::string& representing the booking ID.
 */
 const std::string& ServiceBooking::getId() const
 {
@@ -81,8 +81,8 @@ const std::string& ServiceBooking::getId() const
 /*
 Function: getStatus
 Description: Retrieves the current status of the service booking.
-Parameter: None
-Return type: util::ServiceJobStatus
+Returns:
+    - util::ServiceJobStatus representing the booking status.
 */
 util::ServiceJobStatus ServiceBooking::getStatus() const
 {
@@ -91,9 +91,9 @@ util::ServiceJobStatus ServiceBooking::getStatus() const
 
 /*
 Function: getServices
-Description: Retrieves the services associated with the booking.
-Parameter: None
-Return type: const util::Map<std::string, Service*>&
+Description: Retrieves the map of services included in the booking.
+Returns:
+    - const util::Map<std::string, Service*>& representing the services.
 */
 const util::Map<std::string, Service*>& ServiceBooking::getServices() const
 {
@@ -103,8 +103,8 @@ const util::Map<std::string, Service*>& ServiceBooking::getServices() const
 /*
 Function: getCustomerId
 Description: Retrieves the customer ID associated with the booking.
-Parameter: None
-Return type: const std::string&
+Returns:
+    - const std::string& representing the customer ID.
 */
 const std::string& ServiceBooking::getCustomerId() const
 {
@@ -113,9 +113,9 @@ const std::string& ServiceBooking::getCustomerId() const
 
 /*
 Function: getCustomer
-Description: Retrieves the customer object associated with the booking.
-Parameter: None
-Return type: User*
+Description: Retrieves the pointer to the associated customer.
+Returns:
+    - User* representing the customer.
 */
 User* ServiceBooking::getCustomer() const
 {
@@ -124,9 +124,9 @@ User* ServiceBooking::getCustomer() const
 
 /*
 Function: getVehicleNumber
-Description: Retrieves the vehicle registration number for the booking.
-Parameter: None
-Return type: const std::string&
+Description: Retrieves the vehicle registration number.
+Returns:
+    - const std::string& representing the vehicle number.
 */
 const std::string& ServiceBooking::getVehicleNumber() const
 {
@@ -135,9 +135,9 @@ const std::string& ServiceBooking::getVehicleNumber() const
 
 /*
 Function: getVehicleBrand
-Description: Retrieves the brand of the vehicle for the booking.
-Parameter: None
-Return type: const std::string&
+Description: Retrieves the brand of the vehicle.
+Returns:
+    - const std::string& representing the vehicle brand.
 */
 const std::string& ServiceBooking::getVehicleBrand() const
 {
@@ -146,9 +146,9 @@ const std::string& ServiceBooking::getVehicleBrand() const
 
 /*
 Function: getVehicleModel
-Description: Retrieves the model of the vehicle for the booking.
-Parameter: None
-Return type: const std::string&
+Description: Retrieves the model of the vehicle.
+Returns:
+    - const std::string& representing the vehicle model.
 */
 const std::string& ServiceBooking::getVehicleModel() const
 {
@@ -157,9 +157,9 @@ const std::string& ServiceBooking::getVehicleModel() const
 
 /*
 Function: getAssignedTechnicianId
-Description: Retrieves the ID of the technician assigned to the booking.
-Parameter: None
-Return type: const std::string&
+Description: Retrieves the ID of the assigned technician.
+Returns:
+    - const std::string& representing the technician ID.
 */
 const std::string& ServiceBooking::getAssignedTechnicianId() const
 {
@@ -180,8 +180,8 @@ User* ServiceBooking::getAssignedTechnician() const
 /*
 Function: getDiscountPercentage
 Description: Retrieves the discount percentage applied to the booking.
-Parameter: None
-Return type: double
+Returns:
+    - double representing the discount percentage.
 */
 double ServiceBooking::getDiscountPercentage() const
 {
@@ -190,9 +190,11 @@ double ServiceBooking::getDiscountPercentage() const
 
 /*
 Function: setId
-Description: Sets the unique identifier of the service booking.
-Parameter: const std::string& id - new booking ID
-Return type: void
+Description: Sets the unique ID of the service booking.
+Parameters:
+    - id: New booking ID string.
+Returns:
+    - void
 */
 void ServiceBooking::setId(const std::string& id)
 {
@@ -202,8 +204,10 @@ void ServiceBooking::setId(const std::string& id)
 /*
 Function: setStatus
 Description: Sets the current status of the service booking.
-Parameter: const util::ServiceJobStatus& status - new booking status
-Return type: void
+Parameters:
+    - status: New booking status value.
+Returns:
+    - void
 */
 void ServiceBooking::setStatus(const util::ServiceJobStatus& status)
 {
@@ -212,9 +216,11 @@ void ServiceBooking::setStatus(const util::ServiceJobStatus& status)
 
 /*
 Function: setServices
-Description: Sets the services associated with the booking.
-Parameter: const util::Map<std::string, Service*>& services - new services map
-Return type: void
+Description: Sets the services included in the booking.
+Parameters:
+    - services: Map of services.
+Returns:
+    - void
 */
 void ServiceBooking::setServices(const util::Map<std::string, Service*>& services)
 {
@@ -223,9 +229,11 @@ void ServiceBooking::setServices(const util::Map<std::string, Service*>& service
 
 /*
 Function: setCustomerId
-Description: Sets the customer ID for the booking.
-Parameter: const std::string& customerId - new customer ID
-Return type: void
+Description: Sets the customer ID associated with the booking.
+Parameters:
+    - customerId: New customer ID string.
+Returns:
+    - void
 */
 void ServiceBooking::setCustomerId(const std::string& customerId)
 {
@@ -234,9 +242,11 @@ void ServiceBooking::setCustomerId(const std::string& customerId)
 
 /*
 Function: setCustomer
-Description: Sets the customer object for the booking.
-Parameter: User* customer - pointer to the customer object
-Return type: void
+Description: Sets the pointer to the associated customer.
+Parameters:
+    - customer: Pointer to the User object.
+Returns:
+    - void
 */
 void ServiceBooking::setCustomer(User* customer)
 {
@@ -245,9 +255,11 @@ void ServiceBooking::setCustomer(User* customer)
 
 /*
 Function: setVehicleNumber
-Description: Sets the vehicle registration number for the booking.
-Parameter: const std::string& vehicleNumber - new vehicle number
-Return type: void
+Description: Sets the vehicle registration number.
+Parameters:
+    - vehicleNumber: New vehicle number string.
+Returns:
+    - void
 */
 void ServiceBooking::setVehicleNumber(const std::string& vehicleNumber)
 {
@@ -256,9 +268,11 @@ void ServiceBooking::setVehicleNumber(const std::string& vehicleNumber)
 
 /*
 Function: setVehicleBrand
-Description: Sets the brand of the vehicle for the booking.
-Parameter: const std::string& vehicleBrand - new vehicle brand
-Return type: void
+Description: Sets the brand of the vehicle.
+Parameters:
+    - vehicleBrand: New vehicle brand string.
+Returns:
+    - void
 */
 void ServiceBooking::setVehicleBrand(const std::string& vehicleBrand)
 {
@@ -267,9 +281,11 @@ void ServiceBooking::setVehicleBrand(const std::string& vehicleBrand)
 
 /*
 Function: setVehicleModel
-Description: Sets the model of the vehicle for the booking.
-Parameter: const std::string& vehicleModel - new vehicle model
-Return type: void
+Description: Sets the model of the vehicle.
+Parameters:
+    - vehicleModel: New vehicle model string.
+Returns:
+    - void
 */
 void ServiceBooking::setVehicleModel(const std::string& vehicleModel)
 {
@@ -278,9 +294,11 @@ void ServiceBooking::setVehicleModel(const std::string& vehicleModel)
 
 /*
 Function: setAssignedTechnicianId
-Description: Sets the ID of the technician assigned to the booking.
-Parameter: const std::string& assignedTechnicianId - new technician ID
-Return type: void
+Description: Sets the ID of the assigned technician.
+Parameters:
+    - assignedTechnicianId: New technician ID string.
+Returns:
+    - void
 */
 void ServiceBooking::setAssignedTechnicianId(const std::string& assignedTechnicianId)
 {
@@ -300,9 +318,11 @@ void ServiceBooking::setAssignedTechnician(User* assignedTechnician)
 
 /*
 Function: setDiscountPercentage
-Description: Sets the discount percentage for the booking.
-Parameter: double discountPercentage - new discount percentage
-Return type: void
+Description: Sets the discount percentage applied to the booking.
+Parameters:
+    - discountPercentage: New discount percentage value.
+Returns:
+    - void
 */
 void ServiceBooking::setDiscountPercentage(double discountPercentage)
 {

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

@@ -40,8 +40,6 @@ public:
         const std::string& vehicleNumber,
         const std::string& vehicleBrand,
         const std::string& vehicleModel,
-        const std::string& assignedTechnicianId,
-        User* assignedTechnician,
         double discountPercentage
     );
     const std::string& getId() const;

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

@@ -1,14 +1,45 @@
+/*
+File: User.cpp
+Description: Implements the User class which represents system users in the Vehicle Service Management System.
+             Provides constructors, destructor, accessors, and mutators for user details such as ID, username,
+             password, name, phone, email, role, state, and notifications.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "User.h"
 #include "Notification.h"
 #include "Enums.h"
 
 int User::m_uid = 0;
 
+/*
+Function: User
+Description: Default constructor that initializes a new user with a unique ID,
+             default role as CUSTOMER, and active state.
+Parameters:
+    - None
+Returns:
+    - A new User object.
+*/
 User::User()
     : m_id("USR" + std::to_string(++m_uid)),
     m_type(util::UserType::CUSTOMER),
     m_status(util::State::ACTIVE) {}
 
+/*
+Function: User
+Description: Parameterized constructor that initializes a new user with a unique ID and specified details.
+Parameters:
+    - userName: Username for login.
+    - password: Password for authentication.
+    - name: Full name of the user.
+    - phone: Phone number of the user.
+    - email: Email address of the user.
+    - role: Role of the user (CUSTOMER, ADMIN, TECHNICIAN, etc.).
+Returns:
+    - A new User object.
+*/
 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)
     : m_id("USR" + std::to_string(++m_uid)),
     m_userName(userName),
@@ -19,6 +50,14 @@ User::User(const std::string& userName, const std::string& password, const std::
     m_type(role),
     m_status(util::State::ACTIVE) {}
 
+/*
+Function: ~User
+Description: Destructor that cleans up dynamically allocated notifications associated with the user.
+Parameters:
+    - None
+Returns:
+    - void
+*/
 User::~User()
 {
     for (int index = 0; index < m_notifications.getSize(); index++)
@@ -27,96 +66,221 @@ User::~User()
     }
 }
 
+/*
+Function: getId
+Description: Retrieves the unique ID of the user.
+Returns:
+    - const std::string& representing the user ID.
+*/
 const std::string& User::getId() const
 {
     return m_id;
 }
 
+/*
+Function: getUserName
+Description: Retrieves the username of the user.
+Returns:
+    - const std::string& representing the username.
+*/
 const std::string& User::getUserName() const
 {
     return m_userName;
 }
 
+/*
+Function: getPassword
+Description: Retrieves the password of the user.
+Returns:
+    - const std::string& representing the password.
+*/
 const std::string& User::getPassword() const
 {
     return m_password;
 }
 
+/*
+Function: getName
+Description: Retrieves the full name of the user.
+Returns:
+    - const std::string& representing the name.
+*/
 const std::string& User::getName() const
 {
     return m_name;
 }
 
+/*
+Function: getPhone
+Description: Retrieves the phone number of the user.
+Returns:
+    - const std::string& representing the phone number.
+*/
 const std::string& User::getPhone() const
 {
     return m_phone;
 }
 
+/*
+Function: getEmail
+Description: Retrieves the email address of the user.
+Returns:
+    - const std::string& representing the email.
+*/
 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.
+Returns:
+    - util::UserType representing the user role.
+*/
 util::UserType User::getUserType() const
 {
     return m_type;
 }
 
+/*
+Function: getState
+Description: Retrieves the current state (ACTIVE/INACTIVE) of the user.
+Returns:
+    - util::State representing the user state.
+*/
 util::State User::getState() const
 {
     return m_status;
 }
 
+/*
+Function: setId
+Description: Sets the unique ID of the user.
+Parameters:
+    - id: New user ID string.
+Returns:
+    - void
+*/
 void User::setId(const std::string& id)
 {
     m_id = id;
 }
 
+/*
+Function: setUserName
+Description: Sets the username of the user.
+Parameters:
+    - userName: New username string.
+Returns:
+    - void
+*/
 void User::setUserName(const std::string& userName)
 {
     m_userName = userName;
 }
 
+/*
+Function: setPassword
+Description: Sets the password of the user.
+Parameters:
+    - password: New password string.
+Returns:
+    - void
+*/
 void User::setPassword(const std::string& password)
 {
     m_password = password;
 }
 
+/*
+Function: setName
+Description: Sets the full name of the user.
+Parameters:
+    - name: New name string.
+Returns:
+    - void
+*/
 void User::setName(const std::string& name)
 {
     m_name = name;
 }
 
+/*
+Function: setPhone
+Description: Sets the phone number of the user.
+Parameters:
+    - phone: New phone number string.
+Returns:
+    - void
+*/
 void User::setPhone(const std::string& phone)
 {
     m_phone = phone;
 }
 
+/*
+Function: setEmail
+Description: Sets the email address of the user.
+Parameters:
+    - email: New email string.
+Returns:
+    - void
+*/
 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.
+Parameters:
+    - role: New user role value.
+Returns:
+    - void
+*/
 void User::setRole(util::UserType role)
 {
     m_type = role;
 }
 
+/*
+Function: setState
+Description: Sets the state (ACTIVE/INACTIVE) of the user.
+Parameters:
+    - status: New state value.
+Returns:
+    - void
+*/
 void User::setState(util::State status)
 {
     m_status = status;
 }
-
-void User::update(Notification* notification)
-{
-}

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

@@ -1,3 +1,12 @@
+/*
+File: User.h
+Description: Declares the User class which represents system users in the Vehicle Service Management System.
+             Each user has a unique ID, credentials, personal details, notifications, role type, and status.
+             The User class also implements the Observer interface to handle notifications.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include <string>
 #include "Map.h"
@@ -38,8 +47,7 @@ public:
     void setName(const std::string& name);
     void setPhone(const std::string& phone);
     void setEmail(const std::string& email);
-    void addNotification(Notification* notification);
+    void addNotification(Notification* notification) override;
     void setRole(util::UserType role);
     void setState(util::State status);
-    void update(Notification* notification) override;
 };

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

@@ -7,8 +7,15 @@ Author: Trenser
 Date:19-May-2026
 */
 #include "InventoryManagementService.h"
+#include "Vector.h"
+#include "Enums.h"
 #include "InventoryItem.h"
+#include "Config.h"
+#include "User.h"
 #include "Factory.h"
+#include "Timestamp.h"
+
+util::Map<std::string, User*> InventoryManagementService::m_observers{};
 
 /*
 Function: addInventoryItem
@@ -91,3 +98,101 @@ InventoryItem* InventoryManagementService::getInventoryItem(const std::string& i
 	}
 	return nullptr;
 }
+
+void InventoryManagementService::attach(User* user)
+{
+	if (user)
+	{
+		const std::string& userID = user->getId();
+		if (m_observers.find(userID) == -1)
+		{
+			m_observers[userID] = user;
+		}
+	}
+}
+
+void InventoryManagementService::detach(User* user)
+{
+	if (user)
+	{
+		const std::string& userID = user->getId();
+		if (m_observers.find(userID) != -1)
+		{
+			m_observers.remove(userID);
+		}
+	}
+}
+
+void InventoryManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
+{
+	if (user)
+	{
+		if (m_observers.find(user->getId()) != -1)
+		{
+			Notification* notification =
+				Factory::getObject<Notification>(
+					user->getId(),
+					user,
+					"InventoryManagementService: " + title,
+					message,
+					util::Timestamp()
+				);
+			if (notification)
+			{
+				user->addNotification(notification);
+			}
+			else
+			{
+				throw std::runtime_error("Failed to create notification");
+			}
+		}
+	}
+}
+
+static void sendLowStockAlertsToAdmins(InventoryManagementService& inventoryManagementService, const InventoryItem* inventoryItem, const util::Vector<User*>& adminUsers)
+{
+	int adminUsersSize = adminUsers.getSize();
+	for (int index = 0; index < adminUsersSize; index++)
+	{
+		inventoryManagementService.sendNotification(
+			adminUsers[index],
+			"Low Stock Alert",
+			"The inventory item with ID " + inventoryItem->getId() +
+			" has very low quantity in the inventory"
+			);
+	}
+}
+
+void InventoryManagementService::sendLowStockAlerts()
+{
+	auto& inventoryItems = m_dataStore.getInventoryItems();
+	if (inventoryItems.isEmpty())
+	{
+		return;
+	}
+	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 = usersMap.getValueAt(index);
+		if (user->getUserType() == util::UserType::ADMIN)
+		{
+			adminUsers.push_back(user);
+		}
+	}
+	int adminUsersSize = adminUsers.getSize();
+	if (adminUsersSize < 1)
+	{
+		throw std::runtime_error("The system has no admins present!");
+	}
+	for (int index = 0; index <= inventoryItemsSize; index++)
+	{
+		InventoryItem* inventoryItem = inventoryItems.getValueAt(index);
+		if (inventoryItem && inventoryItem->getQuantity() < config::threshold::INVENTORY_LOW_STOCK_THRESHOLD)
+		{
+			sendLowStockAlertsToAdmins(*this, inventoryItem, adminUsers);
+		}
+	}
+}

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

@@ -1,6 +1,15 @@
+/*
+File: NotificationManagementService.h
+Description: Declares the NotificationManagementService abstract class which defines the contract for managing notifications in the Vehicle Service Management System.
+			 Implements the Subject interface and provides pure virtual methods for sending notifications and managing user subscriptions (attach/detach).
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include <string>
 #include "Subject.h"
+#include "Notification.h"
 #include "User.h"
 
 class NotificationManagementService : public Subject

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

@@ -1,13 +1,28 @@
-#include "PaymentManagementService.h"
-#include "ServiceBooking.h"
-#include "Service.h"
-#include "InventoryItem.h"
-#include "Utility.h"
+/*
+File: PaymentManagementService.cpp
+Description: Implements the PaymentManagementService class which manages payment-related operations
+			 in the Vehicle Service Management System. Provides functionality for attaching/detaching observers,
+			 sending notifications, and issuing payment reminders based on invoice status and thresholds.
+Author: Trenser
+Date: 20-May-2026
+*/
+
+#include "Config.h"
+#include "Enums.h"
+#include <stdexcept>
+#include "Enums.h"
 #include "Factory.h"
-#include "Timestamp.h"
+#include "InventoryItem.h"
 #include "Invoice.h"
 #include "JobCard.h"
-#include "Enums.h"
+#include "PaymentManagementService.h"
+#include "Service.h"
+#include "ServiceBooking.h"
+#include "Timestamp.h"
+#include "User.h"
+#include "Utility.h"
+
+util::Map<std::string, User*> PaymentManagementService::m_observers{};
 
 static void createInventoryItemsMap(util::Map<std::string, InventoryItem*>& completeInventoryItemMapOfBooking, const Service* currentService)
 {
@@ -92,3 +107,119 @@ void PaymentManagementService::completePayment(const std::string& invoiceID, uti
 		throw std::runtime_error("Payment failed: invalid invoice ID.");
 	}
 }
+
+/*
+Function: attach
+Description: Attaches a user as an observer to the PaymentManagementService for receiving notifications.
+Parameters:
+	- user: Pointer to the User object to be attached.
+Returns:
+	- void
+*/
+void PaymentManagementService::attach(User* user)
+{
+	if (user)
+	{
+		const std::string& userID = user->getId();
+		if (m_observers.find(userID) == -1)
+		{
+			m_observers[userID] = user;
+		}
+	}
+}
+
+/*
+Function: detach
+Description: Detaches a user from the observer list of the PaymentManagementService.
+Parameters:
+	- user: Pointer to the User object to be detached.
+Returns:
+	- void
+*/
+void PaymentManagementService::detach(User* user)
+{
+	if (user)
+	{
+		const std::string& userID = user->getId();
+		if (m_observers.find(userID) != -1)
+		{
+			m_observers.remove(userID);
+		}
+	}
+}
+
+/*
+Function: sendNotification
+Description: Sends a notification to a user if they are registered as an observer.
+Parameters:
+	- user: Pointer to the User object to receive the notification.
+	- title: Title of the notification.
+	- message: Message content of the notification.
+Returns:
+	- void
+Throws:
+	- std::runtime_error if notification creation fails.
+*/
+void PaymentManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
+{
+	if (user)
+	{
+		if (m_observers.find(user->getId()) != -1)
+		{
+			Notification* notification =
+				Factory::getObject<Notification>(
+					user->getId(),
+					user,
+					"PaymentManagementService: " + title,
+					message,
+					util::Timestamp()
+				);
+			if (notification)
+			{
+				user->addNotification(notification);
+			}
+			else
+			{
+				throw std::runtime_error("Failed to create notification");
+			}
+		}
+	}
+}
+
+/*
+Function: sendPaymentReminders
+Description: Iterates through all invoices in the datastore and sends payment reminders to customers
+			 whose invoices are pending beyond the configured threshold duration.
+Parameters:
+	- None
+Returns:
+	- void
+*/
+void PaymentManagementService::sendPaymentReminders()
+{
+	auto& invoicesMap = m_dataStore.getInvoices();
+	int invoicesMapSize = invoicesMap.getSize();
+	for (int index = 0; index < invoicesMapSize; index++)
+	{
+		const Invoice* invoice = invoicesMap.getValueAt(index);
+		if (invoice && invoice->getStatus() == util::PaymentStatus::PENDING)
+		{
+			util::Timestamp invoiceCreationTimestamp = invoice->getInvoiceDate();
+			util::Timestamp currentTimestamp;
+			if (util::Timestamp::getDurationInHours(invoiceCreationTimestamp, currentTimestamp) >= config::threshold::PAYMENT_REMINDER_THRESHOLD_HOURS)
+			{
+				const ServiceBooking* serviceBooking = invoice->getBooking();
+				if (serviceBooking)
+				{
+					User* customer = serviceBooking->getCustomer();
+					if (customer)
+					{
+						sendNotification(customer,
+							"Payment Reminder",
+							"Your payment for Invoice ID " + invoice->getId() + " is still pending.Please complete the payment." + invoice->getId());
+					}
+				}
+			}
+		}
+	}
+}

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

@@ -1,3 +1,12 @@
+/*
+File: PaymentManagementService.h
+Description: Declares the PaymentManagementService class which manages payment operations in the Vehicle Service Management System.
+             Provides functionality to generate invoices, retrieve customer invoices, complete payments, send payment reminders,
+             and handle notifications using the Observer pattern.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include <string>
 #include "Map.h"

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

@@ -8,23 +8,21 @@ Date:19-May-2026
 */
 #include <stdexcept>
 #include "AuthenticationManagementService.h"
-#include "AuthenticationManagementService.h"
-#include "Service.h"
-#include "ServiceBooking.h"
 #include "ComboPackage.h"
-#include "Factory.h"
-#include "UserManagementService.h"
-#include "ServiceBooking.h"
-#include "Factory.h"
-#include "JobCard.h"
-#include "Timestamp.h"
-#include "Service.h"
 #include "Enums.h"
+#include "Factory.h"
 #include "InventoryItem.h"
-#include "AuthenticationManagementService.h"
-#include "PaymentManagementService.h"
+#include "JobCard.h"
 #include "NotificationManagementService.h"
+#include "PaymentManagementService.h"
+#include "Service.h"
+#include "ServiceBooking.h"
+#include "ServiceManagementService.h"
+#include "Timestamp.h"
 #include "User.h"
+#include "UserManagementService.h"
+
+util::Map<std::string, User*> ServiceManagementService::m_observers{};
 
 util::Map<std::string, ServiceBooking*> ServiceManagementService::getServiceBookings()
 {
@@ -514,3 +512,81 @@ void ServiceManagementService::removeComboPackage(const std::string& comboPackag
         throw std::runtime_error("Combo package with ID '" + comboPackageID + "' not found.");
     }
 }
+
+/*
+Function: attach
+Description: Attaches a user as an observer to the ServiceManagementService for receiving notifications.
+Parameters:
+	- user: Pointer to the User object to be attached.
+Returns:
+	- void
+*/
+void ServiceManagementService::attach(User* user)
+{
+	if (user)
+	{
+		const std::string& userID = user->getId();
+		if (m_observers.find(userID) == -1)
+		{
+			m_observers[userID] = user;
+		}
+	}
+}
+
+/*
+Function: detach
+Description: Detaches a user from the observer list of the ServiceManagementService.
+Parameters:
+	- user: Pointer to the User object to be detached.
+Returns:
+	- void
+*/
+void ServiceManagementService::detach(User* user)
+{
+	if (user)
+	{
+		const std::string& userID = user->getId();
+		if (m_observers.find(userID) != -1)
+		{
+			m_observers.remove(userID);
+		}
+	}
+}
+
+/*
+Function: sendNotification
+Description: Sends a notification to a user if they are registered as an observer.
+Parameters:
+	- user: Pointer to the User object to receive the notification.
+	- title: Title of the notification.
+	- message: Message content of the notification.
+Returns:
+	- void
+Throws:
+	- std::runtime_error if notification creation fails.
+*/
+void ServiceManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
+{
+	if (user)
+	{
+		if (m_observers.find(user->getId()) != -1)
+		{
+			Notification* notification =
+				Factory::getObject<Notification>(
+					user->getId(),
+					user,
+					"ServiceManagementService: " + title,
+					message,
+					util::Timestamp()
+				);
+			if (notification)
+			{
+				user->addNotification(notification);
+			}
+			else
+			{
+				throw std::runtime_error("Failed to create notification");
+			}
+		}
+	}
+}

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

@@ -5,6 +5,7 @@ Description: Implementation file containing the method definitions of the
 Author: Trenser
 Date:19-May-2026
 */
+#include "UserManagementService.h"
 #include "Config.h"
 #include "Enums.h"
 #include "Factory.h"
@@ -12,7 +13,7 @@ Date:19-May-2026
 #include "PaymentManagementService.h"
 #include "ServiceManagementService.h"
 #include "User.h"
-#include "UserManagementService.h"
+#include "Vector.h"
 #include <stdexcept>
 
 void UserManagementService::ensureAdminExists()
@@ -140,3 +141,65 @@ void UserManagementService::removeUser(const std::string& userID)
 		}
 	}
 }
+
+/*
+Function: getUserNotifications
+Description: Retrieves all notifications associated with a given user ID.
+Parameters:
+	- userID: The unique ID of the user whose notifications are to be retrieved.
+Returns:
+	- util::Vector<Notification*> containing all notifications for the user.
+Throws:
+	- std::runtime_error if no user is found with the given UserID or if the User object is invalid.
+*/
+util::Vector<Notification*> UserManagementService::getUserNotifications(const std::string& userID)
+{
+	auto& usersMap = m_dataStore.getUsers();
+	if (usersMap.find(userID) == -1)
+	{
+		throw std::runtime_error("No user found with given UserID");
+	}
+	User* user = usersMap[userID];
+	if (user)
+	{
+		auto& notifications = user->getNotifications();
+		int numberOfNotifications = notifications.getSize();
+		util::Vector<Notification*> notificationsVector;
+		for (int index = 0; index < numberOfNotifications; index++)
+		{
+			notificationsVector.push_back(notifications.getValueAt(index));
+		}
+		return notificationsVector;
+	}
+	else
+	{
+		throw std::runtime_error("Invalid User object");
+	}
+}
+
+/*
+Function: deleteNotification
+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.
+*/
+void UserManagementService::deleteNotification(const std::string& notificationID, const std::string& userID)
+{
+	auto& usersMap = m_dataStore.getUsers();
+	if (usersMap.find(userID) == -1)
+	{
+		throw std::runtime_error("No user found with given UserID");
+	}
+	User* user = usersMap[userID];
+	auto& notifications = user->getNotifications();
+	if (notifications.find(notificationID) == -1)
+	{
+		throw std::runtime_error("No notification found with given NotificationID");
+	}
+	notifications.remove(notificationID);
+}

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

@@ -24,7 +24,7 @@ public:
     void updateUserDetails(const std::string& userID, const std::string& email, const std::string& phone);
     util::Map<std::string, User*> getUsers();
     util::Map<std::string, User*> getUsers(util::UserType type);
-    User* getUser(const std::string& userID);
+    User* getUser (const std::string& userID);
     void removeUser(const std::string& userID);
     util::Vector<Notification*> getUserNotifications(const std::string& userID);
     void deleteNotification(const std::string& notificationID, const std::string& userID);

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

@@ -1,3 +1,11 @@
+/*
+File: Config.h
+Description: Defines configuration constants for system thresholds in the Vehicle Service Management System.
+			 Includes limits for inventory stock alerts and payment reminder intervals.
+Author: Trenser
+Date: 21-May-2026
+*/
+
 #pragma once
 
 namespace config
@@ -6,8 +14,14 @@ namespace config
 	{
 		constexpr const char* DEFAULT_ADMIN_USERNAME = "admin";
 		constexpr const char* DEFAULT_ADMIN_NAME = "admin";
-		constexpr const char* DEFAULT_ADMIN_PASSWORD = "";
+		constexpr const char* DEFAULT_ADMIN_PASSWORD = "admin";
 		constexpr const char* DEFAULT_ADMIN_EMAIL = "admin@vss";
 		constexpr const char* DEFAULT_ADMIN_PHONE = "0000000000";
 	}
+
+	namespace threshold
+	{
+		constexpr int INVENTORY_LOW_STOCK_THRESHOLD = 5;
+		constexpr int PAYMENT_REMINDER_THRESHOLD_HOURS = 168;
+	}
 }

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

@@ -1,3 +1,12 @@
+/*
+File: Enums.h
+Description: Declares enumerations and utility functions for user types, payment modes, payment status,
+             service job status, and state management in the Vehicle Service Management System.
+             Provides string conversion and parsing functions for each enum type.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include <stdexcept>
 
@@ -37,6 +46,14 @@ namespace util
         INACTIVE
     };
 
+    /*
+    Function: getUserTypeString
+    Description: Converts a UserType enum value to its corresponding string representation.
+    Parameters:
+        - type: UserType enum value.
+    Returns:
+        - std::string representing the UserType.
+    */
     inline std::string getUserTypeString(UserType type)
     {
         switch (type)
@@ -51,6 +68,16 @@ namespace util
         throw std::invalid_argument("Invalid UserType");
     }
 
+    /*
+    Function: getUserType
+    Description: Converts a string value to its corresponding UserType enum.
+    Parameters:
+        - value: std::string representing the UserType.
+    Returns:
+        - UserType enum value.
+    Throws:
+        - std::invalid_argument if the string does not match a valid UserType.
+    */
     inline UserType getUserType(const std::string& value)
     {
         if (value == "ADMIN")
@@ -68,6 +95,14 @@ namespace util
         throw std::invalid_argument("Invalid UserType string");
     }
 
+    /*
+    Function: getPaymentModeString
+    Description: Converts a PaymentMode enum value to its corresponding string representation.
+    Parameters:
+        - mode: PaymentMode enum value.
+    Returns:
+        - std::string representing the PaymentMode.
+    */
     inline std::string getPaymentModeString(PaymentMode mode)
     {
         switch (mode)
@@ -82,6 +117,16 @@ namespace util
         throw std::invalid_argument("Invalid PaymentMode");
     }
 
+    /*
+    Function: getPaymentMode
+    Description: Converts a string value to its corresponding PaymentMode enum.
+    Parameters:
+        - value: std::string representing the PaymentMode.
+    Returns:
+        - PaymentMode enum value.
+    Throws:
+        - std::invalid_argument if the string does not match a valid PaymentMode.
+    */
     inline PaymentMode getPaymentMode(const std::string& value)
     {
         if (value == "ONLINE")
@@ -95,6 +140,14 @@ namespace util
         throw std::invalid_argument("Invalid PaymentMode string");
     }
 
+    /*
+    Function: getPaymentStatusString
+    Description: Converts a PaymentStatus enum value to its corresponding string representation.
+    Parameters:
+        - status: PaymentStatus enum value.
+    Returns:
+        - std::string representing the PaymentStatus.
+    */
     inline std::string getPaymentStatusString(PaymentStatus status)
     {
         switch (status)
@@ -107,6 +160,16 @@ namespace util
         throw std::invalid_argument("Invalid PaymentStatus");
     }
 
+    /*
+    Function: getPaymentStatus
+    Description: Converts a string value to its corresponding PaymentStatus enum.
+    Parameters:
+        - value: std::string representing the PaymentStatus.
+    Returns:
+        - PaymentStatus enum value.
+    Throws:
+        - std::invalid_argument if the string does not match a valid PaymentStatus.
+    */
     inline PaymentStatus getPaymentStatus(const std::string& value)
     {
         if (value == "PENDING")
@@ -122,6 +185,14 @@ namespace util
         throw std::invalid_argument("Invalid PaymentStatus string");
     }
 
+    /*
+    Function: getServiceJobStatusString
+    Description: Converts a ServiceJobStatus enum value to its corresponding string representation.
+    Parameters:
+        - status: ServiceJobStatus enum value.
+    Returns:
+        - std::string representing the ServiceJobStatus.
+    */
     inline std::string getServiceJobStatusString(ServiceJobStatus status)
     {
         switch (status)
@@ -132,14 +203,22 @@ namespace util
             return "STARTED";
         case ServiceJobStatus::COMPLETED:
             return "COMPLETED";
-        case ServiceJobStatus::PENDING:
-            return "STARTED";
         case ServiceJobStatus::CANCELLED:
             return "CANCELLED";
         }
         throw std::invalid_argument("Invalid ServiceJobStatus");
     }
 
+    /*
+    Function: getServiceJobStatus
+    Description: Converts a string value to its corresponding ServiceJobStatus enum.
+    Parameters:
+        - value: std::string representing the ServiceJobStatus.
+    Returns:
+        - ServiceJobStatus enum value.
+    Throws:
+        - std::invalid_argument if the string does not match a valid ServiceJobStatus.
+    */
     inline ServiceJobStatus getServiceJobStatus(const std::string& value)
     {
         if (value == "STARTED")
@@ -161,6 +240,14 @@ namespace util
         throw std::invalid_argument("Invalid ServiceJobStatus string");
     }
 
+    /*
+    Function: getStateString
+    Description: Converts a State enum value to its corresponding string representation.
+    Parameters:
+        - status: State enum value.
+    Returns:
+        - std::string representing the State.
+    */
     inline std::string getStateString(State status)
     {
         switch (status)
@@ -173,6 +260,16 @@ namespace util
         throw std::invalid_argument("Invalid State");
     }
 
+    /*
+    Function: getState
+    Description: Converts a string value to its corresponding State enum.
+    Parameters:
+        - value: std::string representing the State.
+    Returns:
+        - State enum value.
+    Throws:
+        - std::invalid_argument if the string does not match a valid State.
+    */
     inline State getState(const std::string& value)
     {
         if (value == "ACTIVE")

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

@@ -7,6 +7,7 @@ Date:19-May-2026
 */
 #pragma once
 #include "Service.h"
+#include "ComboPackage.h"
 #include "InventoryItem.h"
 
 /*
@@ -28,6 +29,15 @@ inline double calculatePartsCost(const Service* service)
     return cost;
 }
 
+/*
+Function: calculateComboServiceEstimatedCost
+Description: Calculates the estimated total cost of a combo package by summing
+             the labor cost and parts cost of all services included in the package.
+Parameters:
+    - comboPackage: const ComboPackage*, pointer to the combo package whose cost is to be estimated
+Returns:
+    - double: The estimated total cost of the combo package
+*/
 inline double calculateComboServiceEstimatedCost(const ComboPackage* comboPackage)
 {
     double cost = 0;

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

@@ -13,6 +13,7 @@ Date:19-May-2026
 #include "Enums.h"
 #include "InputHelper.h"
 #include "InventoryItem.h"
+#include "MenuHelper.h"
 #include "OutputHelper.h"
 #include "Service.h"
 #include "ServiceBooking.h"
@@ -704,7 +705,7 @@ Return type: void
 void AdminMenu::addTechnician()
 {
 	util::clear();
-	std::string username, password, email, phoneNumber;
+	std::string username, name, password, email, phoneNumber;
 	std::cout << std::left << std::setw(25) << "Enter Technician Username:";
 	util::read(username);
 	std::cout << std::setw(25) << "Enter Technician Password:";
@@ -715,6 +716,8 @@ void AdminMenu::addTechnician()
 		util::pressEnter();
 		return;
 	}
+	std::cout << std::left << std::setw(25) << "Enter Technician Name:";
+	util::read(name);
 	std::cout << std::setw(25) << "Enter Technician Email:";
 	util::read(email);
 	if(!util::isEmailValid(email))
@@ -731,7 +734,7 @@ void AdminMenu::addTechnician()
 		util::pressEnter();
 		return;
 	}
-	m_controller.createTechnician(username, password, email, phoneNumber);
+	m_controller.createTechnician(username, name, password, email, phoneNumber);
 	std::cout << "\nTechnician Added Successfully.\n";
 	util::pressEnter();
 }
@@ -1018,6 +1021,15 @@ void AdminMenu::removeComboPackage()
 	util::pressEnter();
 }
 
+/*
+Function: viewNotifications
+Description: Displays notifications for the admin and allows deletion of notifications.
+Parameters:
+	- None
+Returns:
+	- void
+*/
 void AdminMenu::viewNotifications()
 {
+	viewAndDeleteNotification(m_controller);
 }

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

@@ -1,3 +1,13 @@
+/*
+File: CustomerMenu.cpp
+Description: Implements the CustomerMenu class which provides the customer’s console interface
+             in the Vehicle Service Management System. Handles menu display, user input, and
+             customer-specific operations such as booking services, viewing history, managing payments,
+             invoices, and notifications.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include <iomanip>
 #include <iostream>
 #include "ComboPackage.h"
@@ -7,6 +17,7 @@
 #include "InventoryItem.h"
 #include "Invoice.h"
 #include "Map.h"
+#include "MenuHelper.h"
 #include "OutputHelper.h"
 #include "Service.h"
 #include "ServiceBooking.h"
@@ -16,6 +27,15 @@
 #include "Validator.h"
 #include "Vector.h"
 
+/*
+Function: showMenu
+Description: Displays the customer menu in a loop until the user chooses to logout.
+             Handles exceptions and ensures smooth user interaction.
+Parameters:
+    - None
+Returns:
+    - void
+*/
 void CustomerMenu::showMenu()
 {
     while (true)
@@ -464,10 +484,66 @@ void CustomerMenu::viewInvoices()
 	displayInvoices(currentUserInvoices);
 }
 
+/*
+Function: viewNotifications
+Description: Displays notifications for the customer and allows deletion of notifications.
+Parameters:
+    - None
+Returns:
+    - void
+*/
 void CustomerMenu::viewNotifications()
 {
+	viewAndDeleteNotification(m_controller);
 }
 
+/*
+Function: getNotificationPreference (static helper)
+Description: Helper function to configure notification preferences for a specific service.
+Parameters:
+    - serviceName: Name of the service for which notifications are being configured.
+Returns:
+    - bool: True if notifications are enabled, False if disabled.
+*/
+static bool getNotificationPreference(const std::string& serviceName)
+{
+    int choice;
+    while (true)
+    {
+        util::clear();
+        std::cout << "    Configure Notification Preferences\n";
+        std::cout << "\n" << serviceName << " Notifications\n";
+        std::cout << "1. Enable Notifications\n";
+        std::cout << "2. Disable Notifications\n";
+        std::cout << "Enter your choice: ";
+        util::read(choice);
+        if (choice == 1)
+        {
+            return true;
+        }
+        if (choice == 2)
+        {
+            return false;
+        }
+        std::cout << "\nInvalid choice. Please enter 1 or 2.\n";
+        util::pressEnter();
+    }
+}
+
+/*
+Function: configureNotifications
+Description: Allows the customer to configure notification preferences for payment and service management.
+Parameters:
+    - None
+Returns:
+    - void
+*/
 void CustomerMenu::configureNotifications()
 {
+    bool paymentServiceNotifications = getNotificationPreference("Payment Management Service");
+    bool serviceManagementNotifications = getNotificationPreference("Service Management Service");
+    m_controller.configureNotifications(paymentServiceNotifications, serviceManagementNotifications);
+    util::clear();
+    std::cout << "Notification preferences updated successfully.\n";
+    util::pressEnter();
 }

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

@@ -1,3 +1,12 @@
+/*
+File: CustomerMenu.h
+Description: Declares the CustomerMenu class which provides the customer-facing console menu in the Vehicle Service Management System.
+             Supports operations such as account management, service selection, combo package booking, viewing service history,
+             handling payments and invoices, and managing notifications.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include "Controller.h"
 

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

@@ -1,11 +1,32 @@
+/*
+File: MenuHelper.h
+Description: Provides inline utility functions to support menu operations in the Vehicle Service Management System.
+             Includes helper functions for selecting, displaying, and managing notifications, as well as
+             integrating with the controller for user interactions.
+Author: Trenser
+Date: 21-May-2026
+*/
+
 #pragma once
 #include <string>
 #include <iomanip>
+#include "Vector.h"
+#include "Controller.h"
 #include "Notification.h"
 #include "Map.h"
 #include "InputHelper.h"
 #include "OutputHelper.h"
 
+/*
+Function: selectNotification
+Description: Displays a list of notifications with index, ID, title, and timestamp,
+             then allows the user to select one by index.
+Parameters:
+    - notifications: Vector of Notification pointers to be displayed.
+Returns:
+    - const Notification* representing the selected notification.
+    - nullptr if no notifications are available or if the selection is invalid.
+*/
 inline const Notification* selectNotification(const util::Vector<const Notification*>& notifications)
 {
     if (notifications.getSize() == 0)
@@ -13,6 +34,7 @@ inline const Notification* selectNotification(const util::Vector<const Notificat
         std::cout << "No notifications available." << std::endl;
         return nullptr;
     }
+    util::Map<int, const Notification*> indexedNotifications;
     std::cout << std::left
         << std::setw(6) << "Index"
         << std::setw(15) << "ID"
@@ -20,9 +42,9 @@ inline const Notification* selectNotification(const util::Vector<const Notificat
         << std::setw(25) << "Timestamp"
         << std::endl;
     int currentIndex = 1;
-    for (int iterator = 0; iterator < notifications.getSize(); iterator++)
+    for (int index = 0; index < notifications.getSize(); index++)
     {
-        const Notification* currentNotification = notifications[iterator];
+        const Notification* currentNotification = notifications[index];
         if (currentNotification)
         {
             std::cout << std::left
@@ -31,16 +53,64 @@ inline const Notification* selectNotification(const util::Vector<const Notificat
                 << std::setw(30) << currentNotification->getTitle()
                 << std::setw(25) << currentNotification->getCreatedAt().toString()
                 << std::endl;
+            indexedNotifications.insert(currentIndex, currentNotification);
             currentIndex++;
         }
     }
     int selectedIndex;
     std::cout << "Select notification: ";
     util::read(selectedIndex);
-    if (selectedIndex < 1 || selectedIndex > notifications.getSize())
+    if (!indexedNotifications.containsKey(selectedIndex))
     {
         std::cout << "Invalid selection." << std::endl;
         return nullptr;
     }
-    return notifications[selectedIndex - 1];
+    return indexedNotifications[selectedIndex];
+}
+
+/*
+Function: displayNotification
+Description: Displays detailed information about a single notification, including ID, title, timestamp, and message.
+Parameters:
+    - notification: Pointer to the Notification object to be displayed.
+Returns:
+    - void
+*/
+inline void displayNotification(const Notification* notification)
+{
+    util::clear();
+    if (!notification)
+    {
+        std::cout << "Notification not found." << std::endl;
+        return;
+    }
+    std::cout << "Notification Details" << std::endl;
+    std::cout << "ID        : " << notification->getId() << std::endl;
+    std::cout << "Title     : " << notification->getTitle() << std::endl;
+    std::cout << "Timestamp : " << notification->getCreatedAt().toString() << std::endl;
+    std::cout << "Message   : " << notification->getMessage() << std::endl;
+}
+
+/*
+Function: viewAndDeleteNotification
+Description: Allows the user to view a notification and then delete it from the system using the controller.
+Parameters:
+    - controller: Reference to the Controller object used to manage notifications.
+Returns:
+    - void
+*/
+inline void viewAndDeleteNotification(Controller& controller)
+{
+    util::clear();
+	auto notifications = controller.getNotifications();
+	const Notification* selectedNotification = selectNotification(notifications);
+	if (!selectedNotification)
+	{
+		std::cout << "Failed to display notification!";
+		util::pressEnter();
+		return;
+	}
+	displayNotification(selectedNotification);
+    controller.deleteNotification(selectedNotification->getId());
+    util::pressEnter();
 }

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

@@ -6,10 +6,12 @@ Description: Implementation file containing the method definitions of the
 Author: Trenser
 Date:19-May-2026
 */
+
 #include <iomanip>
 #include "Enums.h"
 #include "InputHelper.h"
 #include "JobCard.h"
+#include "MenuHelper.h"
 #include "OutputHelper.h"
 #include "Service.h"
 #include "TechnicianMenu.h"
@@ -17,9 +19,12 @@ Date:19-May-2026
 
 /*
 Function: showMenu
-Description: Displays the technician menu and handles user input until logout is selected.
-Parameter: None
-Return type: void
+Description: Displays the technician menu in a loop until the user chooses to logout.
+			 Handles exceptions and ensures smooth user interaction.
+Parameters:
+	- None
+Returns:
+	- void
 */
 void TechnicianMenu::showMenu()
 {
@@ -143,8 +148,17 @@ void TechnicianMenu::completeJob()
 	}
 }
 
+/*
+Function: viewNotifications
+Description: Displays notifications for the technician and allows deletion of notifications.
+Parameters:
+	- None
+Returns:
+	- void
+*/
 void TechnicianMenu::viewNotifications()
 {
+	viewAndDeleteNotification(m_controller);
 }
 
 /*

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

@@ -22,6 +22,7 @@ Return type: void
 */
 void UserInterface::run()
 {
+	m_controller.runSystemChecks();
 	bool isMenuActive = true;
 	while (isMenuActive)
 	{
@@ -113,6 +114,14 @@ void UserInterface::login()
 	}
 }
 
+/*
+Function: registerCustomer
+Description: Handles the registration process for new customers.
+Parameters:
+	- None
+Returns:
+	- void
+*/
 void UserInterface::registerCustomer()
 {
 	std::string username, name, email, phone, password;