Fix PR review comments and refactor menu helper logic

Changes:
- Added name parameter to createTechnician for consistency
- Added function headers for notification-related methods in InventoryManagementService
- Used variables for notification title and message instead of passing strings directly
- Fixed payment reminder notification message formatting
- Moved common helper functions to MenuHelper.h
- Updated CustomerMenu to use shared helper functions instead of duplicate code
- Added missing includes in MenuHelper.h
- Removed redundant helper code from CustomerMenu.cpp
- Minor formatting and comment cleanup

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

@@ -1,7 +1,24 @@
+/*
+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;
 	userInterface.run();
-}
+}

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

@@ -185,6 +185,7 @@
     <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

@@ -248,5 +248,8 @@
     <ClInclude Include="utilities\Utility.h">
       <Filter>Header Files\Utilities</Filter>
     </ClInclude>
+    <ClInclude Include="views\MenuHelper.h">
+      <Filter>Header Files\Views</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

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

@@ -1,33 +1,96 @@
+/*
+File: Controller.cpp
+Description: Implementation file containing the method definitions of the
+             Controller class, including authentication, user creation,
+             service purchasing, and system checks.
+Author: Trenser
+Date:19-May-2026
+*/
+#include <stdexcept>
 #include "Controller.h"
+#include "Enums.h"
+#include "User.h"
 
+/*
+Function: login
+Description: Authenticates a user by delegating to the authentication management service.
+Parameter: const std::string& username - user’s username
+           const std::string& password - user’s password
+Return type: bool - true if login successful, false otherwise
+*/
 bool Controller::login(const std::string& username, const std::string& password)
 {
-    return false;
+    return m_authenticationManagementService.login(username, password);
 }
 
+/*
+Function: logout
+Description: Logs out the currently authenticated user.
+Parameter: None
+Return type: void
+*/
 void Controller::logout()
 {
+    m_authenticationManagementService.logout();
 }
 
+/*
+Function: changePassword
+Description: Changes the password of the currently authenticated user.
+Parameter: const std::string& newPassword - new password to set
+Return type: void
+*/
 void Controller::changePassword(const std::string& newPassword)
 {
+    m_authenticationManagementService.changePassword(newPassword);
 }
 
-void Controller::createCustomer(const std::string& username, const std::string& password, const std::string& email, const std::string& phone)
+/*
+Function: createCustomer
+Description: Creates a new customer account with the provided details.
+Parameter: const std::string& username - customer’s username
+           const std::string& name - customer’s name
+           const std::string& password - customer’s password
+           const std::string& email - customer’s email
+           const std::string& phone - customer’s phone number
+Return type: void
+*/
+
+void Controller::createCustomer(const std::string& username, const std::string& name, const std::string& password, const std::string& email, const std::string& phone)
 {
+    m_userManagementService.createUser(username, name, password, email, phone, util::UserType::CUSTOMER);
 }
 
+/*
+Function: getAuthenticatedUser
+Description: Retrieves the currently authenticated user.
+Parameter: None
+Return type: const User* - pointer to the authenticated user
+*/
 const User* Controller::getAuthenticatedUser()
 {
-    return nullptr;
+    return m_authenticationManagementService.getAuthenticatedUser();
 }
 
-void Controller::createTechnician(const std::string& username, const std::string& password, const std::string& email, const std::string& phone)
+void Controller::createTechnician(const std::string& username, const std::string& name, const std::string& password, const std::string& email, const std::string& phone)
 {
 }
 
+/*
+Function: updateUserDetails
+Description: Updates the email and phone details of the currently authenticated user.
+Parameter: const std::string& email - new email address
+           const std::string& phone - new phone number
+Return type: void
+*/
 void Controller::updateUserDetails(const std::string& email, const std::string& phone)
 {
+    User* authenticatedUser = m_authenticationManagementService.getAuthenticatedUser();
+    if (authenticatedUser == nullptr)
+    {
+        throw std::runtime_error("No user currently logged in!");
+    }
+    m_userManagementService.updateUserDetails(authenticatedUser->getId(), email, phone);
 }
 
 util::Map<std::string, const Service*> Controller::getServices()
@@ -40,12 +103,32 @@ util::Map<std::string, const ComboPackage*> Controller::getComboPackages()
     return util::Map<std::string, const ComboPackage*>();
 }
 
+/*
+Function: purchaseService
+Description: Purchases one or more services for a vehicle by delegating to the service management service.
+Parameter: const util::Vector<std::string>& serviceIDs - IDs of services to purchase
+           const std::string& vehicleNumber - vehicle registration number
+           const std::string& vehicleBrand - brand of the vehicle
+           const std::string& vehicleModel - model of the vehicle
+Return type: void
+*/
 void Controller::purchaseService(const util::Vector<std::string>& serviceIDs, const std::string& vehicleNumber, const std::string& vehicleBrand, const std::string& vehicleModel)
 {
+    m_serviceManagementService.purchaseService(serviceIDs, vehicleNumber, vehicleBrand, vehicleModel);
 }
 
+/*
+Function: purchaseComboPackage
+Description: Purchases a combo package for a vehicle by delegating to the service management service.
+Parameter: const std::string& comboPackageID - ID of the combo package
+           const std::string& vehicleNumber - vehicle registration number
+           const std::string& vehicleBrand - brand of the vehicle
+           const std::string& vehicleModel - model of the vehicle
+Return type: void
+*/
 void Controller::purchaseComboPackage(const std::string& comboPackageID, const std::string& vehicleNumber, const std::string& vehicleBrand, const std::string& vehicleModel)
 {
+    m_serviceManagementService.purchaseComboPackage(comboPackageID, vehicleNumber, vehicleBrand, vehicleModel);
 }
 
 util::Map<std::string, const InventoryItem*> Controller::getInventoryItems()
@@ -128,17 +211,82 @@ void Controller::completePayment(const std::string& invoiceID, util::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!");
+    }
 }
 
 /*
@@ -189,7 +337,16 @@ void Controller::saveSystemData()
     m_inventoryManagementService.saveObservers();
 }
 
+/*
+Function: runSystemChecks
+Description: Runs system checks to ensure critical configurations, such as verifying admin existence.
+Parameter: None
+Return type: void
+*/
 void Controller::runSystemChecks()
 {
+    m_userManagementService.ensureAdminExists();
+    m_inventoryManagementService.sendLowStockAlerts();
+    m_paymentManagementService.sendPaymentReminders();
 }
 

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

@@ -1,8 +1,21 @@
+/*
+File: Controller.h
+Description: Header file declaring the Controller class, which coordinates
+             authentication, user management, service management, inventory,
+             and notifications across the Vehicle Service System.
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
-#include "Map.h"
 #include <string>
+#include "AuthenticationManagementService.h"
 #include "Enums.h"
 #include "InventoryManagementService.h"
+#include "Map.h"
+#include "PaymentManagementService.h"
+#include "ServiceManagementService.h"
+#include "UserManagementService.h"
+#include "InventoryManagementService.h"
 #include "UserManagementService.h"
 #include "ServiceManagementService.h"
 #include "PaymentManagementService.h"
@@ -19,17 +32,18 @@ class Notification;
 class Controller
 {
 private:
+    AuthenticationManagementService m_authenticationManagementService;
     UserManagementService m_userManagementService;
-    InventoryManagementService m_inventoryManagementService;
     ServiceManagementService m_serviceManagementService;
+    InventoryManagementService m_inventoryManagementService;
     PaymentManagementService m_paymentManagementService;
 public:
     bool login(const std::string& username, const std::string& password);
     void logout();
     void changePassword(const std::string& newPassword);
-    void createCustomer(const std::string& username, const std::string& password, const std::string& email, const std::string& phone);
+    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& phone);
+    void createTechnician(const std::string& username, const std::string& name, const std::string& password, const std::string& email, const std::string& phone);
     void updateUserDetails(const std::string& email, const std::string& phone);
     util::Map<std::string, const Service*> getServices();
     util::Map<std::string, const ComboPackage*> getComboPackages();
@@ -55,7 +69,7 @@ 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 configureNotifications(bool paymentNotifications, bool serviceNotifications);
     void loadSystemData();
     void saveSystemData();
     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

@@ -1,3 +1,12 @@
+/*
+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 <sstream>
 #include <stdexcept>
 #include "ComboPackage.h"
@@ -7,11 +16,31 @@
 
 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),
@@ -54,21 +83,53 @@ ComboPackage::ComboPackage(const std::string& id, const std::string& packageName
     }
 }
 
+/*
+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;
@@ -79,26 +140,66 @@ const util::Vector<std::string>& ComboPackage::getServiceIDs() const
     return m_serviceIDs;
 }
 
+/*
+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;
@@ -111,6 +212,14 @@ void ComboPackage::setServices(const util::Map<std::string, Service*>& 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

@@ -1,3 +1,11 @@
+/*
+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 <sstream>
 #include <stdexcept>
 #include "Factory.h"
@@ -6,12 +14,32 @@
 
 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),
@@ -46,51 +74,131 @@ InventoryItem::InventoryItem(const std::string& id, const std::string& partName,
     }
 }
 
+/*
+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

@@ -1,3 +1,12 @@
+/*
+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 <sstream>
 #include <stdexcept>
 #include "Invoice.h"
@@ -7,6 +16,16 @@
 
 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),
@@ -17,6 +36,24 @@ 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,
@@ -84,26 +121,56 @@ Invoice::Invoice(
     }
 }
 
+/*
+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;
@@ -122,66 +189,156 @@ const util::Vector<std::string>& Invoice::getPartIDs() const
     return m_partIDs;
 }
 
+/*
+Function: getParts
+Description: Retrieves the map of inventory items used in the service.
+Returns:
+    - const util::Map<int, 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;
@@ -194,31 +351,79 @@ void Invoice::setParts(const util::Map<std::string, InventoryItem*>& 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

@@ -1,3 +1,12 @@
+/*
+File: JobCard.cpp
+Description: Implements the JobCard class which represents a technician’s job assignment in the Vehicle Service Management System.
+             Provides constructors, accessors, and mutators for job details such as ID, booking, service, technician,
+             assigned date, completion date, and job status.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include <sstream>
 #include <stdexcept>
 #include "JobCard.h"
@@ -7,6 +16,15 @@
 
 int JobCard::m_uid = 0;
 
+/*
+Function: JobCard
+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)),
     m_booking(nullptr),
@@ -14,6 +32,22 @@ JobCard::JobCard()
     m_technician(nullptr),
     m_status(util::ServiceJobStatus()) {}
 
+/*
+Function: JobCard
+Description: Parameterized constructor that initializes a new job card with a unique ID and specified details.
+Parameters:
+    - bookingId: ID of the associated service booking.
+    - booking: Pointer to the ServiceBooking object.
+    - service: Pointer to the Service object.
+    - serviceId: ID of the associated service.
+    - technicianId: ID of the assigned technician.
+    - technician: Pointer to the User object representing the technician.
+    - assignedDate: Timestamp of when the job was assigned.
+    - status: Current status of the job (STARTED/COMPLETED).
+    - completionDate: Timestamp of when the job was completed.
+Returns:
+    - A new JobCard object.
+*/
 JobCard::JobCard(const std::string& bookingId,
     ServiceBooking* booking,
     Service* service,
@@ -77,101 +111,241 @@ JobCard::JobCard(const std::string& id,
     }
 }
 
+/*
+Function: getId
+Description: Retrieves the unique ID of the job card.
+Returns:
+    - const std::string& representing the job card ID.
+*/
 const std::string& JobCard::getId() const
 {
     return m_id;
 }
 
+/*
+Function: getBookingId
+Description: Retrieves the booking ID associated with the job card.
+Returns:
+    - const std::string& representing the booking ID.
+*/
 const std::string& JobCard::getBookingId() const
 {
     return m_bookingId;
 }
 
+/*
+Function: getBooking
+Description: Retrieves the pointer to the associated ServiceBooking.
+Returns:
+    - ServiceBooking* representing the booking.
+*/
 ServiceBooking* JobCard::getBooking() const
 {
     return m_booking;
 }
 
+/*
+Function: getService
+Description: Retrieves the pointer to the associated Service.
+Returns:
+    - Service* representing the service.
+*/
 Service* JobCard::getService() const
 {
     return m_service;
 }
 
+/*
+Function: getServiceId
+Description: Retrieves the service ID associated with the job card.
+Returns:
+    - const std::string& representing the service ID.
+*/
 const std::string& JobCard::getServiceId() const
 {
     return m_serviceId;
 }
 
+/*
+Function: getTechnicianId
+Description: Retrieves the technician ID associated with the job card.
+Returns:
+    - const std::string& representing the technician ID.
+*/
 const std::string& JobCard::getTechnicianId() const
 {
     return m_technicianId;
 }
 
+/*
+Function: getTechnician
+Description: Retrieves the pointer to the assigned technician.
+Returns:
+    - User* representing the technician.
+*/
 User* JobCard::getTechnician() const
 {
     return m_technician;
 }
 
+/*
+Function: getAssignedDate
+Description: Retrieves the timestamp of when the job was assigned.
+Returns:
+    - const util::Timestamp& representing the assigned date.
+*/
 const util::Timestamp& JobCard::getAssignedDate() const
 {
     return m_assignedDate;
 }
 
+/*
+Function: getStatus
+Description: Retrieves the current status of the job.
+Returns:
+    - ServiceJobStatus representing the job status.
+*/
 util::ServiceJobStatus JobCard::getStatus() const
 {
     return m_status;
 }
 
+/*
+Function: getCompletionDate
+Description: Retrieves the timestamp of when the job was completed.
+Returns:
+    - const util::Timestamp& representing the completion date.
+*/
 const util::Timestamp& JobCard::getCompletionDate() const
 {
     return m_completionDate;
 }
 
+/*
+Function: setId
+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)
 {
     m_id = id;
 }
 
+/*
+Function: setBookingId
+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)
 {
     m_bookingId = bookingId;
 }
 
+/*
+Function: setBooking
+Description: Sets the associated ServiceBooking pointer.
+Parameters:
+    - booking: Pointer to the ServiceBooking object.
+Returns:
+    - void
+*/
 void JobCard::setBooking(ServiceBooking* booking)
 {
     m_booking = booking;
 }
 
+/*
+Function: setService
+Description: Sets the associated Service pointer.
+Parameters:
+    - service: Pointer to the Service object.
+Returns:
+    - void
+*/
 void JobCard::setService(Service* service)
 {
     m_service = service;
 }
 
+/*
+Function: setServiceId
+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)
 {
     m_serviceId = serviceId;
 }
 
+/*
+Function: setTechnicianId
+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)
 {
     m_technicianId = technicianId;
 }
 
+/*
+Function: setTechnician
+Description: Sets the pointer to the assigned technician.
+Parameters:
+    - technician: Pointer to the User object.
+Returns:
+    - void
+*/
 void JobCard::setTechnician(User* technician)
 {
     m_technician = technician;
 }
 
+/*
+Function: setAssignedDate
+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)
 {
     m_assignedDate = assignedDate;
 }
 
+/*
+Function: setStatus
+Description: Sets the current status of the job.
+Parameters:
+    - status: New job status value.
+Returns:
+    - void
+*/
 void JobCard::setStatus(util::ServiceJobStatus status)
 {
     m_status = status;
 }
 
+/*
+Function: setCompletionDate
+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)
 {
     m_completionDate = completionDate;

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

@@ -1,3 +1,11 @@
+/*
+File: JobCard.h
+Description: Declares the JobCard class which represents a technician’s job assignment in the Vehicle Service Management System.
+             Each job card includes booking details, associated service, technician information, assigned and completion dates, and job status.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include <string>
 #include "Timestamp.h"

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

@@ -1,3 +1,11 @@
+/*
+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 <sstream>
 #include "Notification.h"
 #include "StringHelper.h"
@@ -5,10 +13,30 @@
 
 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),
@@ -45,61 +73,145 @@ Notification::Notification(const std::string& id, const std::string& recipientUs
     }
 }
 
+/*
+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

@@ -1,3 +1,12 @@
+/*
+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 <sstream>
 #include "Service.h"
 #include "InventoryItem.h"
@@ -6,11 +15,30 @@
 
 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),
@@ -53,11 +81,23 @@ Service::Service(const std::string& id, const std::string& name, const util::Vec
     }
 }
 
+/*
+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;
@@ -76,31 +116,73 @@ const util::Vector<std::string>& Service::getRequiredInventoryItemIDs() const
     return m_requiredInventoryItemIDs;
 }
 
+/*
+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;
@@ -113,11 +195,27 @@ void Service::setRequiredInventoryItems(const util::Map<std::string, InventoryIt
     }
 }
 
+/*
+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

@@ -1,3 +1,11 @@
+/*
+File: ServiceBooking.cpp
+Description: Implementation file containing the method definitions of the
+             ServiceBooking class, including constructors, getters, and setters
+             for booking attributes.
+Author: Trenser
+Date:19-May-2026
+*/
 #include <stdexcept>
 #include <sstream>
 #include "ServiceBooking.h"
@@ -8,12 +16,37 @@
 
 int ServiceBooking::m_uid = 0;
 
+/*
+Function: ServiceBooking
+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)),
     m_customer(nullptr),
     m_assignedTechnician(nullptr),
     m_discountPercentage(0.0) {}
 
+/*
+Function: ServiceBooking
+Description: Parameterized constructor that initializes a new service booking with a unique ID and specified details.
+Parameters:
+    - id: Booking ID string.
+    - status: Current status of the booking (e.g., PENDING, COMPLETED).
+    - services: Map of services included in the booking.
+    - customerId: ID of the customer.
+    - customer: Pointer to the User object representing the customer.
+    - vehicleNumber: Vehicle registration number.
+    - vehicleBrand: Brand of the vehicle.
+    - vehicleModel: Model of the vehicle.
+    - assignedTechnicianId: ID of the assigned technician.
+    - assignedTechnician: Name of the assigned technician.
+    - discountPercentage: Discount applied to the booking.
+Returns:
+    - A new ServiceBooking object.
+*/
 ServiceBooking::ServiceBooking(
     util::ServiceJobStatus status,
     const util::Map<std::string,
@@ -23,8 +56,6 @@ 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)),
@@ -35,8 +66,8 @@ ServiceBooking::ServiceBooking(
     m_vehicleNumber(vehicleNumber),
     m_vehicleBrand(vehicleBrand),
     m_vehicleModel(vehicleModel),
-    m_assignedTechnicianId(assignedTechnicianId),
-    m_assignedTechnician(assignedTechnician),
+    m_assignedTechnicianId(""),
+    m_assignedTechnician(nullptr),
     m_discountPercentage(discountPercentage)
 {
     int numberOfServices = m_services.getSize();
@@ -95,11 +126,23 @@ ServiceBooking::ServiceBooking(
     }
 }
 
+/*
+Function: getId
+Description: Retrieves the unique identifier of the service booking.
+Parameter: None
+Return type: const std::string&
+*/
 const std::string& ServiceBooking::getId() const
 {
     return m_id;
 }
 
+/*
+Function: getStatus
+Description: Retrieves the current status of the service booking.
+Parameter: None
+Return type: util::ServiceJobStatus
+*/
 util::ServiceJobStatus ServiceBooking::getStatus() const
 {
     return m_status;
@@ -118,61 +161,132 @@ const util::Vector<std::string>& ServiceBooking::getServiceIDs() const
     return m_serviceIDs;
 }
 
+/*
+Function: getServices
+Description: Retrieves the services associated with the booking.
+Parameter: None
+Return type: const util::Map<std::string, Service*>&
+*/
 const util::Map<std::string, Service*>& ServiceBooking::getServices() const
 {
     return m_services;
 }
 
+/*
+Function: getCustomerId
+Description: Retrieves the customer ID associated with the booking.
+Parameter: None
+Return type: const std::string&
+*/
 const std::string& ServiceBooking::getCustomerId() const
 {
     return m_customerId;
 }
 
+/*
+Function: getCustomer
+Description: Retrieves the customer object associated with the booking.
+Parameter: None
+Return type: User*
+*/
 User* ServiceBooking::getCustomer() const
 {
     return m_customer;
 }
 
+/*
+Function: getVehicleNumber
+Description: Retrieves the vehicle registration number for the booking.
+Parameter: None
+Return type: const std::string&
+*/
 const std::string& ServiceBooking::getVehicleNumber() const
 {
     return m_vehicleNumber;
 }
 
+/*
+Function: getVehicleBrand
+Description: Retrieves the brand of the vehicle for the booking.
+Parameter: None
+Return type: const std::string&
+*/
 const std::string& ServiceBooking::getVehicleBrand() const
 {
     return m_vehicleBrand;
 }
 
+/*
+Function: getVehicleModel
+Description: Retrieves the model of the vehicle for the booking.
+Parameter: None
+Return type: const std::string&
+*/
 const std::string& ServiceBooking::getVehicleModel() const
 {
     return m_vehicleModel;
 }
 
+/*
+Function: getAssignedTechnicianId
+Description: Retrieves the ID of the technician assigned to the booking.
+Parameter: None
+Return type: const std::string&
+*/
 const std::string& ServiceBooking::getAssignedTechnicianId() const
 {
     return m_assignedTechnicianId;
 }
 
-const User* ServiceBooking::getAssignedTechnician() const
+/*
+Function: getAssignedTechnician
+Description: Retrieves the technician object assigned to the booking.
+Parameter: None
+Return type: User*
+*/
+User* ServiceBooking::getAssignedTechnician() const
 {
     return m_assignedTechnician;
 }
-
+/*
+Function: getDiscountPercentage
+Description: Retrieves the discount percentage applied to the booking.
+Parameter: None
+Return type: double
+*/
 double ServiceBooking::getDiscountPercentage() const
 {
     return m_discountPercentage;
 }
 
+/*
+Function: setId
+Description: Sets the unique identifier of the service booking.
+Parameter: const std::string& id - new booking ID
+Return type: void
+*/
 void ServiceBooking::setId(const std::string& id)
 {
     m_id = id;
 }
 
+/*
+Function: setStatus
+Description: Sets the current status of the service booking.
+Parameter: const util::ServiceJobStatus& status - new booking status
+Return type: void
+*/
 void ServiceBooking::setStatus(const util::ServiceJobStatus& status)
 {
     m_status = 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
+*/
 void ServiceBooking::setServices(const util::Map<std::string, Service*>& services)
 {
     m_services = services;
@@ -185,41 +299,89 @@ 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
+*/
 void ServiceBooking::setCustomerId(const std::string& customerId)
 {
     m_customerId = customerId;
 }
 
+/*
+Function: setCustomer
+Description: Sets the customer object for the booking.
+Parameter: User* customer - pointer to the customer object
+Return type: void
+*/
 void ServiceBooking::setCustomer(User* customer)
 {
     m_customer = customer;
 }
 
+/*
+Function: setVehicleNumber
+Description: Sets the vehicle registration number for the booking.
+Parameter: const std::string& vehicleNumber - new vehicle number
+Return type: void
+*/
 void ServiceBooking::setVehicleNumber(const std::string& vehicleNumber)
 {
     m_vehicleNumber = vehicleNumber;
 }
 
+/*
+Function: setVehicleBrand
+Description: Sets the brand of the vehicle for the booking.
+Parameter: const std::string& vehicleBrand - new vehicle brand
+Return type: void
+*/
 void ServiceBooking::setVehicleBrand(const std::string& vehicleBrand)
 {
     m_vehicleBrand = vehicleBrand;
 }
 
+/*
+Function: setVehicleModel
+Description: Sets the model of the vehicle for the booking.
+Parameter: const std::string& vehicleModel - new vehicle model
+Return type: void
+*/
 void ServiceBooking::setVehicleModel(const std::string& vehicleModel)
 {
     m_vehicleModel = 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
+*/
 void ServiceBooking::setAssignedTechnicianId(const std::string& assignedTechnicianId)
 {
     m_assignedTechnicianId = assignedTechnicianId;
 }
 
+/*
+Function: setAssignedTechnician
+Description: Sets the technician object assigned to the booking.
+Parameter: User* assignedTechnician - pointer to the technician object
+Return type: void
+*/
 void ServiceBooking::setAssignedTechnician(User* assignedTechnician)
 {
     m_assignedTechnician = assignedTechnician;
 }
 
+/*
+Function: setDiscountPercentage
+Description: Sets the discount percentage for the booking.
+Parameter: double discountPercentage - new discount percentage
+Return type: void
+*/
 void ServiceBooking::setDiscountPercentage(double discountPercentage)
 {
     m_discountPercentage = discountPercentage;

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

@@ -1,3 +1,11 @@
+/*
+File: ServiceBooking.h
+Description: Header file declaring the ServiceBooking class, which represents
+             a booking of services by a customer, including vehicle details,
+             assigned technician, and discount information.
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
 #include <string>
 #include "Map.h"
@@ -34,8 +42,6 @@ public:
         const std::string& vehicleNumber,
         const std::string& vehicleBrand,
         const std::string& vehicleModel,
-        const std::string& assignedTechnicianId,
-        User* assignedTechnician,
         double discountPercentage
     );
     ServiceBooking(
@@ -59,7 +65,7 @@ public:
     const std::string& getVehicleBrand() const;
     const std::string& getVehicleModel() const;
     const std::string& getAssignedTechnicianId() const;
-    const User* getAssignedTechnician() const;
+    User* getAssignedTechnician() const;
     double getDiscountPercentage() const;
     void setId(const std::string& id);
     void setStatus(const util::ServiceJobStatus& status);

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

@@ -1,3 +1,12 @@
+/*
+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 <sstream>
 #include "User.h"
 #include "Notification.h"
@@ -7,11 +16,33 @@
 
 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),
@@ -55,6 +86,14 @@ User::User(const std::string& userId, const std::string& userName, const std::st
     }
 }
 
+/*
+Function: ~User
+Description: Destructor that cleans up dynamically allocated notifications associated with the user.
+Parameters:
+    - None
+Returns:
+    - void
+*/
 User::~User()
 {
     auto values = m_notifications.getValues();
@@ -64,100 +103,225 @@ 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)
 {
-    m_notifications.insert(notification->getId(), 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)
-{
-}
-
 /*
 Function: serialize
 Description: Serializes the user into a CSV-formatted string.

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"
@@ -39,10 +48,9 @@ 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;
     std::string serialize() const;
     static User* deserialize(const std::string&);
     static std::string getHeaders();

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

@@ -1,3 +1,81 @@
+/*
+File: AuthenticationManagementService.cpp
+Description: Implementation file containing the method definitions of the
+			 AuthenticationManagementService class, including login, logout,
+			 password change, and retrieval of the authenticated user.
+Author: Trenser
+Date:19-May-2026
+*/
+#include <stdexcept>
 #include "AuthenticationManagementService.h"
+#include "User.h"
 
 User* AuthenticationManagementService::m_authenticatedUser = nullptr;
+
+/*
+Function: login
+Description: Authenticates a user by checking the provided username and password
+			 against the stored users in the DataStore. If successful, sets the
+			 authenticated user.
+Parameter: const std::string& username - user’s username
+		   const std::string& password - user’s password
+Return type: bool - true if login successful, false otherwise
+*/
+bool AuthenticationManagementService::login(const std::string& username, const std::string& password)
+{
+	util::Map<std::string, User*> users = m_dataStore.getUsers();
+	int usersMapSize = users.getSize();
+	for (int index = 0; index < usersMapSize; index++)
+	{
+		User* user = users.getValueAt(index);
+		if (username == user->getUserName())
+		{
+			if (password == user->getPassword())
+			{
+				m_authenticatedUser = user;
+				return true;
+			}
+			return false;
+		}
+	}
+	return false;
+}
+
+/*
+Function: getAuthenticatedUser
+Description: Retrieves the currently authenticated user.
+Parameter: None
+Return type: User* - pointer to the authenticated user
+*/
+User* AuthenticationManagementService::getAuthenticatedUser()
+{
+	return m_authenticatedUser;
+}
+
+/*
+Function: logout
+Description: Logs out the currently authenticated user by clearing the
+			 static authenticated user pointer.
+Parameter: None
+Return type: void
+*/
+void AuthenticationManagementService::logout()
+{
+	m_authenticatedUser = nullptr;
+}
+
+/*
+Function: changePassword
+Description: Changes the password of the currently authenticated user.
+			 Throws an exception if no user is logged in.
+Parameter: const std::string& newPassword - new password to set
+Return type: void
+*/
+void AuthenticationManagementService::changePassword(const std::string& newPassword)
+{
+	if (m_authenticatedUser == nullptr)
+	{
+		throw std::runtime_error("There is no user currently logged in!");
+	}
+	m_authenticatedUser->setPassword(newPassword);
+}

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

@@ -1,3 +1,11 @@
+/*
+File: AuthenticationManagementService.h
+Description: Header file declaring the AuthenticationManagementService class, which manages
+             user authentication, login, logout, password changes, and retrieval of the
+             authenticated user.
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
 #include <string>
 #include "DataStore.h"

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

@@ -8,11 +8,160 @@ Author: Trenser
 Date: 22-May-2026
 */
 
-#include "InventoryManagementService.h"
+#include <stdexcept>
+#include "Config.h"
+#include "Enums.h"
+#include "Factory.h"
 #include "FileManager.h"
 #include "InventoryItem.h"
+#include "InventoryManagementService.h"
+#include "Timestamp.h"
+#include "User.h"
 #include "Utility.h"
-#include "Config.h"
+#include "Vector.h"
+
+util::Map<std::string, User*> InventoryManagementService::m_observers{};
+
+/*
+Function: attach
+Description: Adds a user to the observer list for receiving inventory notifications.
+Parameters:
+	- user: User*, pointer to the user to be attached as an observer
+Returns:
+	- None
+*/
+void InventoryManagementService::attach(User* user)
+{
+	if (user)
+	{
+		const std::string& userID = user->getId();
+		if (m_observers.find(userID) == -1)
+		{
+			m_observers[userID] = user;
+		}
+	}
+}
+
+/*
+Function: detach
+Description: Removes a user from the observer list so they no longer receive inventory notifications.
+Parameters:
+	- user: User*, pointer to the user to be detached from the observer list
+Returns:
+	- None
+*/
+void InventoryManagementService::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 subscribed as an observer.
+Parameters:
+	- user: User*, pointer to the user receiving the notification
+	- title: std::string, title of the notification
+	- message: std::string, body/content of the notification
+Returns:
+	- None
+Throws:
+	- std::runtime_error if notification creation fails
+*/
+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");
+			}
+		}
+	}
+}
+
+/*
+Function: sendLowStockAlertsToAdmins (static helper)
+Description: Sends low stock alert notifications to all admin users for a given inventory item.
+Parameters:
+	- inventoryManagementService: InventoryManagementService&, service used to send notifications
+	- inventoryItem: const InventoryItem*, pointer to the low-stock inventory item
+	- adminUsers: const util::Vector<User*>&, list of admin users to notify
+Returns:
+	- None
+*/
+static void sendLowStockAlertsToAdmins(InventoryManagementService& inventoryManagementService, const InventoryItem* inventoryItem, const util::Vector<User*>& adminUsers)
+{
+	int adminUsersSize = adminUsers.getSize();
+	for (int index = 0; index < adminUsersSize; index++)
+	{
+		std::string title = "Low Stock Alert";
+		std::string message = "The inventory item with ID " + inventoryItem->getId() + " has very low quantity in the inventory";
+		inventoryManagementService.sendNotification(
+			adminUsers[index],
+			title,
+			message
+		);
+	}
+}
+
+/*
+Function: sendLowStockAlerts
+Description: Sends alerts to user for inventory items with low stock
+Parameters:
+	- None
+Returns:
+	- None
+*/
+void InventoryManagementService::sendLowStockAlerts()
+{
+	auto& inventoryItems = m_dataStore.getInventoryItems();
+	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);
+		}
+	}
+}
 
 /*
 Function: getObserverIDs

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

@@ -1,3 +1,11 @@
+/*
+File: InventoryManagementService.h
+Description: Declares the InventoryManagementService class which manages inventory operations in the Vehicle Service Management System.
+             Provides functionality to retrieve, add, and remove inventory items, send low stock alerts, 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/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

@@ -1,9 +1,141 @@
+/*
+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 <stdexcept>
-#include "PaymentManagementService.h"
-#include "Invoice.h"
-#include "FileManager.h"
-#include "Utility.h"
 #include "Config.h"
+#include "Enums.h"
+#include "Factory.h"
+#include "FileManager.h"
+#include "Invoice.h"
+#include "PaymentManagementService.h"
+#include "ServiceBooking.h"
+#include "Timestamp.h"
+#include "User.h"
+#include "Utility.h"
+
+util::Map<std::string, User*> PaymentManagementService::m_observers{};
+
+/*
+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)
+					{
+						std::string title = "Payment Reminder";
+						std::string message = "Your payment for Invoice ID " + invoice->getId() + " is still pending. Please complete the payment.";
+						sendNotification(customer, title, message);
+					}
+				}
+			}
+		}
+	}
+}
 
 /*
 Function: getObserverIDs

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

@@ -1,13 +1,189 @@
+/*
+File: ServiceManagementService.cpp
+Description: Implementation file containing the method definitions of the
+			 ServiceManagementService class, including service and combo package
+			 purchasing logic, booking creation, and notification handling.
+Author: Trenser
+Date:19-May-2026
+*/
+
 #include <stdexcept>
-#include "ServiceManagementService.h"
-#include "FileManager.h"
-#include "Service.h"
+#include "AuthenticationManagementService.h"
 #include "ComboPackage.h"
-#include "ServiceBooking.h"
-#include "JobCard.h"
 #include "Config.h"
+#include "Factory.h"
+#include "FileManager.h"
+#include "JobCard.h"
+#include "Service.h"
+#include "ServiceBooking.h"
+#include "ServiceManagementService.h"
+#include "Timestamp.h"
+#include "User.h"
 #include "Utility.h"
 
+/*
+Function: purchaseService
+Description: Creates a new service booking for the authenticated user. Validates
+			 service IDs, retrieves services from the DataStore, and generates a
+			 booking. Sends a notification upon successful booking.
+Parameter: const util::Vector<std::string>& serviceIDs - IDs of services to purchase
+		   const std::string& vehicleNumber - vehicle registration number
+		   const std::string& vehicleBrand - brand of the vehicle
+		   const std::string& vehicleModel - model of the vehicle
+Return type: void
+*/
+void ServiceManagementService::purchaseService(const util::Vector<std::string>& serviceIDs, const std::string& vehicleNumber, const std::string& vehicleBrand, const std::string& vehicleModel)
+{
+	AuthenticationManagementService m_authenticationManagementService;
+	auto authenticatedUser = m_authenticationManagementService.getAuthenticatedUser();
+	if (authenticatedUser == nullptr)
+	{
+		throw std::runtime_error("No user is currently logged in!");
+	}
+	auto& servicesMap = m_dataStore.getServices();
+	auto& serviceBookingMap = m_dataStore.getServiceBookings();
+	util::Map<std::string, Service*> selectedServices;
+	int selectedServicesCount = serviceIDs.getSize();
+	for (int index = 0; index < selectedServicesCount; index++)
+	{
+		int serviceIndex = servicesMap.find(serviceIDs[index]);
+		if (serviceIndex == -1)
+		{
+			throw std::runtime_error("Service not found!");
+		}
+		Service* service = servicesMap.getValueAt(serviceIndex);
+		selectedServices[service->getId()] = service;
+	}
+	ServiceBooking* serviceBooking = Factory::getObject<ServiceBooking>(util::ServiceJobStatus::STARTED, selectedServices, authenticatedUser->getId(), authenticatedUser, vehicleNumber, vehicleBrand, vehicleModel, 0);
+	if (serviceBooking == nullptr)
+	{
+		throw std::runtime_error("Failed to create service booking");
+	}
+	serviceBookingMap[serviceBooking->getId()] = serviceBooking;
+    std::string title = "Service Booking succeeded";
+    std::string message = "Your service booking has been successfully placed with ID " + serviceBooking->getId();
+    sendNotification(authenticatedUser, title, message);
+}
+
+/*
+Function: purchaseComboPackage
+Description: Creates a new service booking for a combo package. Validates the combo
+			 package ID, retrieves services from the package, and generates a booking
+			 with the applicable discount. Sends a notification upon successful booking.
+Parameter: const std::string& comboPackageID - ID of the combo package
+		   const std::string& vehicleNumber - vehicle registration number
+		   const std::string& vehicleBrand - brand of the vehicle
+		   const std::string& vehicleModel - model of the vehicle
+Return type: void
+*/
+void ServiceManagementService::purchaseComboPackage(const std::string& comboPackageID, const std::string& vehicleNumber, const std::string& vehicleBrand, const std::string& vehicleModel)
+{
+	AuthenticationManagementService m_authenticationManagementService;
+	auto authenticatedUser = m_authenticationManagementService.getAuthenticatedUser();
+	if (authenticatedUser == nullptr)
+	{
+		throw std::runtime_error("No user is currently logged in!");
+	}
+	auto& comboPackagesMap = m_dataStore.getComboPackages();
+	auto& serviceBookingMap = m_dataStore.getServiceBookings();
+	int comboPackageIndex = comboPackagesMap.find(comboPackageID);
+	if (comboPackageIndex == -1)
+	{
+		throw std::runtime_error("Combo Package not found!");
+	}
+	const ComboPackage* comboPackage = comboPackagesMap[comboPackageID];
+	util::Map<std::string, Service*> selectedServices = comboPackage->getServices();
+	ServiceBooking* serviceBooking = Factory::getObject<ServiceBooking>(util::ServiceJobStatus::STARTED, selectedServices, authenticatedUser->getId(), authenticatedUser, vehicleNumber, vehicleBrand, vehicleModel, comboPackage->getDiscountPercentage());
+	if (serviceBooking == nullptr)
+	{
+		throw std::runtime_error("Failed to create combo package service booking");
+	}
+	serviceBookingMap[serviceBooking->getId()] = serviceBooking;
+    std::string title = "Combo Package Service Booking succeeded";
+    std::string message = "Your service booking for the combo package has been successfully placed with ID " + serviceBooking->getId();
+    sendNotification(authenticatedUser, title, message);
+}
+
+util::Map<std::string, User*> ServiceManagementService::m_observers{};
+
+/*
+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");
+			}
+		}
+	}
+}
+
 /*
 Function: getObserverIDs
 Description: Retrieves the IDs of all observers currently attached to the

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

@@ -1,3 +1,11 @@
+/*
+File: ServiceManagementService.h
+Description: Header file declaring the ServiceManagementService class, which manages
+             services, combo packages, job cards, and service bookings. Inherits from
+             NotificationManagementService to handle notifications.
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
 #include <string>
 #include "Map.h"

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

@@ -1,8 +1,181 @@
-#include "UserManagementService.h"
-#include "FileManager.h"
-#include "User.h"
-#include "Notification.h"
+/*
+File: UserManagementService.cpp
+Description: Implementation file containing the method definitions of the
+			 UserManagementService class, including user creation, updates,
+			 and ensuring an admin account exists.
+Author: Trenser
+Date:19-May-2026
+*/
+#include <stdexcept>
 #include "Config.h"
+#include "Enums.h"
+#include "Factory.h"
+#include "FileManager.h"
+#include "InventoryManagementService.h"
+#include "Notification.h"
+#include "PaymentManagementService.h"
+#include "ServiceManagementService.h"
+#include "User.h"
+#include "UserManagementService.h"
+#include "Vector.h"
+
+
+/*
+Function: ensureAdminExists
+Description: Ensures that at least one admin user exists in the system.
+			 If no admin is found, creates a default admin user using
+			 configuration constants.
+Parameter: None
+Return type: void
+*/
+void UserManagementService::ensureAdminExists()
+{
+	auto& usersMap = m_dataStore.getUsers();
+	int usersMapSize = usersMap.getSize();
+	bool isAdminFound = false;
+	for (int index = 0; index < usersMapSize; index++)
+	{
+		User* user = usersMap.getValueAt(index);
+		if (user && user->getUserType() == util::UserType::ADMIN)
+		{
+			isAdminFound = true;
+			break;
+		}
+	}
+	if (!isAdminFound)
+	{
+		createUser(
+			config::admin::DEFAULT_ADMIN_USERNAME,
+			config::admin::DEFAULT_ADMIN_NAME,
+			config::admin::DEFAULT_ADMIN_PASSWORD,
+			config::admin::DEFAULT_ADMIN_EMAIL,
+			config::admin::DEFAULT_ADMIN_PHONE, 
+			util::UserType::ADMIN);
+	}
+}
+
+/*
+Function: createUser
+Description: Creates a new user with the provided details. Validates that
+			 the username is unique, then attaches the user to relevant
+			 management services (payment, service, inventory).
+Parameter: const std::string& username - user’s username
+		   const std::string& name - user’s name
+		   const std::string& password - user’s password
+		   const std::string& email - user’s email address
+		   const std::string& phone - user’s phone number
+		   util::UserType type - type of user (ADMIN, CUSTOMER, TECHNICIAN)
+Return type: void
+*/
+void UserManagementService::createUser(const std::string& username, const std::string& name, const std::string& password, const std::string& email, const std::string& phone, util::UserType type)
+{
+	InventoryManagementService inventoryManagementService;
+	PaymentManagementService paymentManagementService;
+	ServiceManagementService serviceManagementService;
+	auto& usersMap = m_dataStore.getUsers();
+	int index = usersMap.findIf(
+		[&](const std::string&, User* user)
+		{
+			return user->getUserName() == username;
+		}
+	);
+	if (index != -1)
+	{
+		throw std::runtime_error("Username already exists");
+	}
+	User* newUser = Factory::getObject<User>(username, password, name, phone, email, type);
+	usersMap.insert(newUser->getId(), newUser);
+	paymentManagementService.attach(newUser);
+	serviceManagementService.attach(newUser);
+	if (newUser->getUserType() == util::UserType::ADMIN)
+	{
+		inventoryManagementService.attach(newUser);
+	}
+}
+
+/*
+Function: updateUserDetails
+Description: Updates the email and phone details of an existing user.
+			 Throws an exception if the user does not exist.
+Parameter: const std::string& userID - ID of the user to update
+		   const std::string& email - new email address
+		   const std::string& phone - new phone number
+Return type: void
+*/
+void UserManagementService::updateUserDetails(const std::string& userID, const std::string& email, const std::string& phone)
+{
+	auto& usersMap = m_dataStore.getUsers();
+	int index = usersMap.find(userID);
+	if (index == -1)
+	{
+		throw std::runtime_error("User does not exist!");
+	}
+	User* user = usersMap.getValueAt(index);
+	user->setEmail(email);
+	user->setPhone(phone);
+}
+
+/*
+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);
+}
 
 /*
 Function: loadUsers

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

@@ -1,3 +1,11 @@
+/*
+File: UserManagementService.h
+Description: Header file declaring the UserManagementService class, which manages
+             user creation, updates, retrieval, removal, notifications, and ensures
+             the existence of an admin account.
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
 #include <string>
 #include "Map.h"
@@ -13,14 +21,15 @@ private:
     DataStore& m_dataStore;
 public:
     UserManagementService() : m_dataStore(DataStore::getInstance()) {}
-    void createUser(const std::string& username, const std::string& password, const std::string& email, const std::string& phone, util::UserType type);
+    void createUser(const std::string& username, const std::string& name, const std::string& password, const std::string& email, const std::string& phone, util::UserType type);
     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);
+    void ensureAdminExists();
     void loadUsers();
     void saveUsers();
 };

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

@@ -1,7 +1,31 @@
+/*
+File: Config.h
+Description: Header file declaring configuration constants for the Vehicle Service System.
+			 Includes default admin account details such as username, name, password,
+			 email, and phone number.
+Author: Trenser
+Date: 21-May-2026
+*/
+
 #pragma once
 
 namespace config
 {
+	namespace admin
+	{
+		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_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;
+	}
+
 	namespace file
 	{
 		constexpr const char* INVENTORYITEM_FILE = "files/InventoryItem.csv";

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>
 
@@ -34,6 +43,14 @@ 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)
@@ -48,6 +65,16 @@ 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")
@@ -65,6 +92,14 @@ 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)
@@ -77,6 +112,16 @@ 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")
@@ -90,6 +135,14 @@ 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)
@@ -102,6 +155,16 @@ 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")
@@ -117,6 +180,14 @@ 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)
@@ -129,6 +200,16 @@ namespace util
         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")
@@ -142,6 +223,14 @@ 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)
@@ -154,6 +243,16 @@ 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/FileManager.h

@@ -11,6 +11,7 @@ Date: 22-May-2026
 
 #pragma once
 #include <stdexcept>
+#include <string>
 #include <fstream>
 #include "Vector.h"
 #include "Map.h"

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

@@ -1,20 +1,60 @@
 /*
-File: ObserversHelper.h
-Description: Provides utility functions for loading and saving observers
-             in the notification management system. Ensures that observer
-             IDs are validated against existing users in the datastore
-             before attaching them to the notification service.
+File: Utility.h
+Description: Header file declaring utility functions used across the system,
+             including cost calculation for services and combo packages.
 Author: Trenser
-Date: 22-May-2026
+Date:19-May-2026
 */
 
 #pragma once
-#include "NotificationManagementService.h"
-#include "FileHelper.h"
 #include "DataStore.h"
+#include "FileHelper.h"
+#include "InventoryItem.h"
+#include "NotificationManagementService.h"
+#include "Service.h"
+#include "ComboPackage.h"
 
 namespace util
 {
+    /*
+    Function: calculatePartsCost
+    Description: Calculates the total cost of parts required for a given service
+                 by summing the prices of all associated inventory items.
+    Parameter: const Service* service - pointer to the service object
+    Return type: double - total cost of required parts
+    */
+    inline double calculatePartsCost(const Service* service)
+    {
+        double cost = 0;
+        auto& requiredInventoryItems = service->getRequiredInventoryItems();
+        int requiredInventoryItemsSize = requiredInventoryItems.getSize();
+        for (int index = 0; index < requiredInventoryItemsSize; index++)
+        {
+            cost += requiredInventoryItems.getValueAt(index)->getPrice();
+        }
+        return cost;
+    }
+
+    /*
+    Function: calculateComboServiceEstimatedCost
+    Description: Calculates the estimated total cost of a combo package by summing
+                  the labor and parts costs of all services included in the package.
+    Parameter: const ComboPackage* comboPackage - pointer to the combo package object
+    Return type: double - estimated total cost of the combo package
+    */
+    inline double calculateComboServiceEstimatedCost(const ComboPackage* comboPackage)
+    {
+        double cost = 0;
+        auto& services = comboPackage->getServices();
+        int servicesSize = services.getSize();
+        for (int index = 0; index < servicesSize; index++)
+        {
+            const Service* service = services.getValueAt(index);
+            cost += calculatePartsCost(service) + service->getLaborCost();
+        }
+        return cost;
+    }
+
     /*
     Function: loadObservers
     Description: Loads observer IDs from a file and attaches the corresponding users

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

@@ -1,7 +1,27 @@
+/*
+File: AdminMenu.cpp
+Description: Implements the AdminMenu class which provides the administrator’s console interface
+			 in the Vehicle Service Management System. Handles menu display, user input, and
+			 admin-specific operations such as inventory management, technician management,
+			 service creation, combo package management, job assignment, and notifications.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "AdminMenu.h"
 #include "InputHelper.h"
 #include "OutputHelper.h"
+#include "MenuHelper.h"
 
+/*
+Function: showMenu
+Description: Displays the admin menu in a loop until the user chooses to logout.
+			 Handles exceptions and ensures smooth user interaction.
+Parameters:
+	- None
+Returns:
+	- void
+*/
 void AdminMenu::showMenu()
 {
 	bool isMenuActive = true;
@@ -84,6 +104,15 @@ void AdminMenu::removeComboPackage()
 {
 }
 
+/*
+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/AdminMenu.h

@@ -1,3 +1,12 @@
+/*
+File: AdminMenu.h
+Description: Declares the AdminMenu class which provides the administrative console menu in the Vehicle Service Management System.
+             Supports operations such as inventory management, job assignment, service creation/removal, technician management,
+             combo package handling, notification viewing, and account management functions like logout and password change.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include "Controller.h"
 

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

@@ -1,54 +1,226 @@
+/*
+File: CustomerMenu.cpp
+Description: Implementation file containing the method definitions of the
+             CustomerMenu class, including menu handling, service selection,
+             combo package booking, profile updates, and password management.
+Author: Trenser
+Date:19-May-2026
+*/
+#include <iomanip>
+#include "ComboPackage.h"
 #include "CustomerMenu.h"
 #include "InputHelper.h"
+#include "InventoryItem.h"
+#include "Map.h"
+#include "MenuHelper.h"
 #include "OutputHelper.h"
+#include "Service.h"
+#include "Validator.h"
+#include "Vector.h"
+
+/*
+Function: showMenu
+Description: Displays the customer menu and handles user input until logout is selected.
+Parameter: None
+Return type: void
+*/
 
 void CustomerMenu::showMenu()
 {
-	bool isMenuActive = true;
-	while (isMenuActive)
-	{
-		try
-		{
-			int choice;
-			util::clear();
-			std::cout << "" << std::endl;
-			util::read(choice);
-			if (!handleOperation(choice))
-			{
-				isMenuActive = false;
-			}
-		}
-		catch (const std::exception& e)
-		{
-			std::cout << "Exception: " << e.what() << std::endl;
-			util::pressEnter();
-		}
-	}
+    while (true)
+    {
+        try
+        {
+            int choice;
+            util::clear();
+            std::cout << "Customer Menu"
+                << "\n1. Select a service"
+                << "\n2. Select a combo package"
+                << "\n3. Update Profile"
+                << "\n4. Change Password"
+                << "\n5. View Service History"
+                << "\n6. Complete Payments"
+                << "\n7. View Invoices"
+                << "\n8. View Notifications"
+                << "\n9. Configure Notifications"
+                << "\n10. Logout"
+                << "\nEnter a choice: ";
+            util::read(choice);
+            if (!handleOperation(choice))
+            {
+                break;
+            }
+        }
+        catch (const std::exception& e)
+        {
+            std::cout << "Exception: " << e.what() << std::endl;
+            util::pressEnter();
+        }
+    }
 }
 
+/*
+Function: handleOperation
+Description: Executes the corresponding customer operation based on the selected menu choice.
+Parameter: int choice - selected menu option
+Return type: bool - true if menu continues, false if logout
+*/
 bool CustomerMenu::handleOperation(int choice)
 {
-	return false;
+    switch (choice)
+    {
+    case 1:
+        selectService();
+        break;
+    case 2:
+        selectComboPackage();
+        break;
+    case 3:
+        updateDetails();
+        break;
+    case 4:
+        changePassword();
+        break;
+    case 5:
+        viewServiceHistory();
+        break;
+    case 6:
+        completePayments();
+        break;
+    case 7:
+        viewInvoices();
+        break;
+    case 8:
+        viewNotifications();
+        break;
+    case 9:
+        configureNotifications();
+        break;
+    case 10:
+        logout();
+        return false;
+    default:
+        std::cout << "Enter a valid choice!" << std::endl;
+        util::pressEnter();
+    }
+    return true;
 }
 
+/*
+Function: logout
+Description: Logs out the currently authenticated customer user.
+Parameter: None
+Return type: void
+*/
 void CustomerMenu::logout()
 {
+	m_controller.logout();
 }
 
+/*
+Function: changePassword
+Description: Allows the customer to change their password after validation.
+Parameter: None
+Return type: void
+*/
 void CustomerMenu::changePassword()
 {
+    changePasswordHelper(m_controller);
 }
 
+/*
+Function: updateDetails
+Description: Allows the customer to update their email and phone number after validation.
+Parameter: None
+Return type: void
+*/
 void CustomerMenu::updateDetails()
 {
+	std::string email, phone;
+	util::clear();
+	std::cout << "Enter new email: ";
+	util::read(email);
+	if (!util::isEmailValid(email))
+	{
+		std::cout << "Error: Email is invalid!";
+		util::pressEnter();
+		return;
+	}
+	std::cout << "Enter new phone: ";
+	util::read(phone);
+	if (!util::isPhoneNumberValid(phone))
+	{
+		std::cout << "Error: Phone number is invalid!";
+		util::pressEnter();
+		return;
+	}
+	m_controller.updateUserDetails(email, phone);
+	std::cout << "Profile details updated successfully";
+	util::pressEnter();
 }
 
+/*
+Function: selectService
+Description: Allows the customer to select a service, provide vehicle details,
+             and book the service through the controller.
+Parameter: None
+Return type: void
+*/
 void CustomerMenu::selectService()
 {
+    std::string vehicleNumber, vehicleBrand, vehicleModel;
+	auto services = m_controller.getServices();
+    util::Vector<std::string> selectedServices;
+    util::clear();
+    const Service* selectedService = selectServiceFromServices(services);
+    if (selectedService == nullptr)
+    {
+        std::cout << "Failed to book service!";
+        util::pressEnter();
+        return;
+    }
+    selectedServices.push_back(selectedService->getId());
+    util::clear();
+    std::cout << "Enter vehicle number: ";
+    util::read(vehicleNumber);
+    std::cout << "Enter vehicle brand: ";
+    util::read(vehicleBrand);
+    std::cout << "Enter vehicle model: ";
+    util::read(vehicleModel);
+    m_controller.purchaseService(selectedServices, vehicleNumber, vehicleBrand, vehicleModel);
+    std::cout << "Service has been booked successfully";
+    util::pressEnter();
 }
 
+/*
+Function: selectComboPackage
+Description: Allows the customer to select a combo package, provide vehicle details,
+             and book the package through the controller.
+Parameter: None
+Return type: void
+*/
 void CustomerMenu::selectComboPackage()
 {
+    std::string vehicleNumber, vehicleBrand, vehicleModel;
+    auto comboPackages = m_controller.getComboPackages();
+    util::clear();
+    const ComboPackage* selectedComboPackage = selectComboPackageFromPackages(comboPackages);
+    if (selectedComboPackage == nullptr)
+    {
+        std::cout << "Failed to book combo package!";
+        util::pressEnter();
+        return;
+    }
+    util::clear();
+    std::cout << "Enter vehicle number: ";
+    util::read(vehicleNumber);
+    std::cout << "Enter vehicle brand: ";
+    util::read(vehicleBrand);
+    std::cout << "Enter vehicle model: ";
+    util::read(vehicleModel);
+    m_controller.purchaseComboPackage(selectedComboPackage->getId(), vehicleNumber, vehicleBrand, vehicleModel);
+    std::cout << "Combo Package has been booked successfully";
+    util::pressEnter();
 }
 
 void CustomerMenu::viewServiceHistory()
@@ -63,10 +235,34 @@ void CustomerMenu::viewInvoices()
 {
 }
 
+/*
+Function: viewNotifications
+Description: Displays notifications for the customer and allows deletion of notifications.
+Parameters:
+    - None
+Returns:
+    - void
+*/
 void CustomerMenu::viewNotifications()
 {
+	viewAndDeleteNotification(m_controller);
 }
 
+
+/*
+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 +1,13 @@
+/*
+File: CustomerMenu.h
+Description: Header file declaring the CustomerMenu class, which provides
+             customer operations such as selecting services, booking combo
+             packages, updating profile details, managing payments, viewing
+             invoices, and configuring notifications.
+Author: Trenser
+Date:19-May-2026
+*/
+
 #pragma once
 #include "Controller.h"
 

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

@@ -0,0 +1,287 @@
+/*
+File: MenuHelper.h
+Description: Header file declaring the MenuHelper class, which provides
+             utility functions for menu-driven operations such as
+             notification selection and display.
+Author: Trenser
+Date: 21-May-2026
+*/
+
+#pragma once
+#include <iomanip>
+#include <string>
+#include "Controller.h"
+#include "InputHelper.h"
+#include "Map.h"
+#include "Notification.h"
+#include "OutputHelper.h"
+#include "Vector.h"
+#include "Validator.h"
+#include "Service.h"
+#include "ComboPackage.h"
+#include "Utility.h"
+
+/*
+Function: selectNotification
+Description: Displays a list of notifications with index, ID, title, and timestamp.
+             Allows the user to select a notification by index. Returns the selected
+             notification or nullptr if the selection is invalid.
+Parameter: const util::Vector<const Notification*>& notifications - list of notifications
+Return type: const Notification* - pointer to the selected notification
+*/
+inline const Notification* selectNotification(const util::Vector<const Notification*>& notifications)
+{
+    if (notifications.getSize() == 0)
+    {
+        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"
+        << std::setw(30) << "Title"
+        << std::setw(25) << "Timestamp"
+        << std::endl;
+    int currentIndex = 1;
+    for (int index = 0; index < notifications.getSize(); index++)
+    {
+        const Notification* currentNotification = notifications[index];
+        if (currentNotification)
+        {
+            std::cout << std::left
+                << std::setw(6) << currentIndex
+                << std::setw(15) << currentNotification->getId()
+                << 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 (!indexedNotifications.containsKey(selectedIndex))
+    {
+        std::cout << "Invalid selection." << std::endl;
+        return nullptr;
+    }
+    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();
+}
+
+/*
+Function: changePassword
+Description: Helper function to change password
+Parameter: controller: Reference to the Controller object used to manage notifications.
+Return type: void
+*/
+inline void changePasswordHelper(Controller& controller)
+{
+    std::string newPassword;
+    while (true)
+    {
+        util::clear();
+        std::cout << "Enter new password: ";
+        util::read(newPassword);
+        if (!util::isPasswordValid(newPassword))
+        {
+            std::cout << "Error: Password is not strong enough!\n";
+            util::pressEnter();
+            continue;
+        }
+        controller.changePassword(newPassword);
+        std::cout << "Password changed successfully\n";
+        util::pressEnter();
+        break;
+    }
+}
+
+/*
+Function: selectServiceFromServices
+Description: Displays active services and allows the customer to select one by index.
+Parameter: const util::Map<std::string, const Service*>& services - list of services
+Return type: const Service* - selected service
+*/
+inline const Service* selectServiceFromServices(const util::Map<std::string, const Service*>& services)
+{
+    util::Map<int, const Service*> activeServicesMap;
+    int currentIndex = 1;
+    int userInputIndex;
+    std::cout << std::left
+        << std::setw(10) << "Index"
+        << std::setw(15) << "Service ID"
+        << std::setw(25) << "Service Name"
+        << std::setw(15) << "Estimated Cost"
+        << std::endl;
+    for (int index = 0; index < services.getSize(); index++)
+    {
+        const Service* currentService = services.getValueAt(index);
+        if (currentService->getState() != util::State::ACTIVE)
+        {
+            continue;
+        }
+        activeServicesMap.insert(currentIndex, currentService);
+        double partsCost = util::calculatePartsCost(currentService);
+        std::cout << std::left
+            << std::setw(10) << currentIndex
+            << std::setw(15) << currentService->getId()
+            << std::setw(25) << currentService->getName()
+            << std::setw(15) << (currentService->getLaborCost() + partsCost)
+            << std::endl;
+        currentIndex++;
+    }
+    if (activeServicesMap.getSize() == 0)
+    {
+        std::cout << "No active services available." << std::endl;
+        return nullptr;
+    }
+    std::cout << "Enter service index: ";
+    util::read(userInputIndex);
+    if (activeServicesMap.find(userInputIndex) == -1)
+    {
+        std::cout << "Invalid service index." << std::endl;
+        return nullptr;
+    }
+    return activeServicesMap[userInputIndex];
+}
+
+/*
+Function: selectComboPackageFromPackages
+Description: Displays active combo packages and allows the customer to select one by index.
+Parameter: const util::Map<std::string, const ComboPackage*>& comboPackages - list of combo packages
+Return type: const ComboPackage* - selected combo package
+*/
+inline const ComboPackage* selectComboPackageFromPackages(const util::Map<std::string, const ComboPackage*>& comboPackages)
+{
+    util::Map<int, const ComboPackage*> activeComboPackages;
+    int currentIndex = 1;
+    int userInputIndex;
+    std::cout << std::left
+        << std::setw(10) << "Index"
+        << std::setw(15) << "Combo Package ID"
+        << std::setw(15) << "Combo Package Name"
+        << std::setw(15) << "Estimate Cost"
+        << std::endl;
+    for (int index = 0; index < comboPackages.getSize(); index++)
+    {
+        const ComboPackage* currentComboPackage = comboPackages.getValueAt(index);
+        if (currentComboPackage->getState() != util::State::ACTIVE)
+        {
+            continue;
+        }
+        activeComboPackages.insert(currentIndex, currentComboPackage);
+        std::cout << std::left
+            << std::setw(10) << currentIndex
+            << std::setw(15) << currentComboPackage->getId()
+            << std::setw(25) << currentComboPackage->getPackageName()
+            << std::setw(15) << util::calculateComboServiceEstimatedCost(currentComboPackage)
+            << std::endl;
+        currentIndex++;
+    }
+    if (activeComboPackages.getSize() == 0)
+    {
+        std::cout << "No active combo packages available." << std::endl;
+        return nullptr;
+    }
+    std::cout << "Enter combo package index: ";
+    util::read(userInputIndex);
+    if (activeComboPackages.find(userInputIndex) == -1)
+    {
+        std::cout << "Invalid combo package index." << std::endl;
+        return nullptr;
+    }
+    return activeComboPackages[userInputIndex];
+}
+
+/*
+Function: sendLowStockAlertsToAdmins (static helper)
+Description: Sends low stock alert notifications to all admin users for a given inventory item.
+Parameters:
+    - inventoryManagementService: InventoryManagementService&, service used to send notifications
+    - inventoryItem: const InventoryItem*, pointer to the low-stock inventory item
+    - adminUsers: const util::Vector<User*>&, list of admin users to notify
+Returns:
+    - None
+*/
+
+/*
+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.
+*/
+inline 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();
+    }
+}
+

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

@@ -1,7 +1,26 @@
+/*
+File: TechnicianMenu.cpp
+Description: Implements the TechnicianMenu class which provides the technician’s console interface
+			 in the Vehicle Service Management System. Handles menu display, user input, and
+			 technician-specific operations such as completing jobs and viewing notifications.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #include "TechnicianMenu.h"
 #include "InputHelper.h"
 #include "OutputHelper.h"
+#include "MenuHelper.h"
 
+/*
+Function: showMenu
+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()
 {
 	bool isMenuActive = true;
@@ -35,6 +54,15 @@ 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/TechnicianMenu.h

@@ -1,3 +1,11 @@
+/*
+File: TechnicianMenu.h
+Description: Declares the TechnicianMenu class which provides the technician-facing console menu in the Vehicle Service Management System.
+             Supports operations such as viewing assigned jobs, completing jobs, and managing notifications.
+Author: Trenser
+Date: 19-May-2026
+*/
+
 #pragma once
 #include "Controller.h"
 

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

@@ -1,10 +1,30 @@
+/*
+File: UserInterface.cpp
+Description: Implementation file containing the method definitions of the
+			 UserInterface class, including system run loop, login handling,
+			 and customer registration logic.
+Author: Trenser
+Date:19-May-2026
+
+*/
 #include "UserInterface.h"
 #include "InputHelper.h"
 #include "OutputHelper.h"
+#include "Enums.h"
+#include "User.h"
+#include "Validator.h"
 
+/*
+Function: run
+Description: Runs the main system loop, displaying the initial menu for login,
+			 customer registration, or exit. Handles exceptions gracefully.
+Parameter: None
+Return type: void
+*/
 void UserInterface::run()
 {
 	m_controller.loadSystemData();
+	m_controller.runSystemChecks();
 	bool isMenuActive = true;
 	while (isMenuActive)
 	{
@@ -28,6 +48,12 @@ void UserInterface::run()
 	m_controller.saveSystemData();
 }
 
+/*
+Function: handleOperation
+Description: Executes the corresponding system operation based on the selected menu choice.
+Parameter: int choice - selected menu option
+Return type: bool - true if menu continues, false if exit
+*/
 bool UserInterface::handleOperation(int choice)
 {
 	switch (choice)
@@ -48,12 +74,90 @@ bool UserInterface::handleOperation(int choice)
 	return true;
 }
 
+/*
+Function: login
+Description: Handles user login by validating credentials. Based on the authenticated
+			 user type, navigates to the appropriate menu (Admin, Technician, Customer).
+Parameter: None
+Return type: void
+*/
 void UserInterface::login()
 {
-
+	std::string username, password;
+	util::clear();
+	std::cout << "Enter username: ";
+	util::read(username);
+	std::cout << "Enter password: ";
+	util::read(password);
+	if (m_controller.login(username, password))
+	{
+		const User* authenticatedUser = m_controller.getAuthenticatedUser();
+		if (authenticatedUser != nullptr)
+		{
+			switch (authenticatedUser->getUserType())
+			{
+			case util::UserType::ADMIN:
+				m_adminMenu.showMenu();
+				break;
+			case util::UserType::TECHNICIAN:
+				m_technicianMenu.showMenu();
+				break;
+			case util::UserType::CUSTOMER:
+				m_customerMenu.showMenu();
+				break;
+			default:
+				std::cout << "\nError: Unknown user type";
+				break;
+			}
+		}
+	}
+	else
+	{
+		std::cout << "\nError: Invalid Username or Password";
+	}
 }
 
+/*
+Function: registerCustomer
+Description: Registers a new customer by collecting and validating details such as
+			 username, name, email, password, and phone number. Delegates creation
+			 to the controller.
+Parameter: None
+Return type: void
+*/
 void UserInterface::registerCustomer()
 {
-
+	std::string username, name, email, phone, password;
+	util::clear();
+	std::cout << "Enter username: ";
+	util::read(username);
+	std::cout << "Enter name: ";
+	util::read(name);
+	std::cout << "Enter email: ";
+	util::read(email);
+	if (!util::isEmailValid(email))
+	{
+		std::cout << "Error: Email is invalid!";
+		util::pressEnter();
+		return;
+	}
+	std::cout << "Enter password: ";
+	util::read(password);
+	if (!util::isPasswordValid(password))
+	{
+		std::cout << "Error: Password is invalid!";
+		util::pressEnter();
+		return;
+	}
+	std::cout << "Enter phone: ";
+	util::read(phone);
+	if (!util::isPhoneNumberValid(phone))
+	{
+		std::cout << "Error: Phone number is invalid!";
+		util::pressEnter();
+		return;
+	}
+	m_controller.createCustomer(username, name, password, email, phone);
+	std::cout << "Registration is successful";
+	util::pressEnter();
 }

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/UserInterface.h

@@ -1,3 +1,12 @@
+/*
+File: UserInterface.h
+Description: Header file declaring the UserInterface class, which provides
+             the main entry point for the Vehicle Service System. Handles
+             login, customer registration, and menu navigation for different
+             user roles (Admin, Technician, Customer).
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
 #include "Controller.h"
 #include "AdminMenu.h"