Implement Service Refactoring

<UserStory> 1952: Service Refactoring </UserStory>
UserStory #1952
<Changes>

1. Enhanced DataStore::getUsers to load SerializedUser records, refresh cache,
   and attach notifications to recipient users with validation for recipient IDs.

2. Updated DataStore::saveUsers to persist SerializedUser records and save
   notifications alongside user data.

3. Refactored AuthenticationManagementService::login to use DataStoreLockGuard
   and tracked user map with SerializedUser-backed records.

4. Modified AuthenticationManagementService::changePassword to ensure thread-safe
   updates, mark user record as MODIFIED, and persist changes via DataStore::saveUsers.

5. Added dependencies for Utility.h and DataStoreLockGuard.h in
   AuthenticationManagementService.cpp to support safe record handling.

</Changes>

<Test>

N/A

</Test>

<Review>

Sreeja Reghukumar

</Review>

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

@@ -278,5 +278,8 @@
     <ClInclude Include="datastores\sharedmemory\SharedMemory.h">
       <Filter>Header Files\DataStores\SharedMemory</Filter>
     </ClInclude>
+    <ClInclude Include="datastores\DataStoreLockGuard.h">
+      <Filter>Header Files\DataStores</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

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

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

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

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

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

@@ -257,8 +257,6 @@ Returns:
 */
 util::Map<std::string, TrackedRecord<Notification>>& DataStore::getNotifications()
 {
-    auto notifications = loadRecords<Notification, SerializedNotification>(m_notifications);
-    refreshCache(m_notificationCache, notifications);
     return m_notificationCache;
 }
 
@@ -403,7 +401,6 @@ Returns:
 */
 void DataStore::saveNotifications()
 {
-    saveRecords<Notification, SerializedNotification>(m_notifications, m_notificationCache);
 }
 
 /*

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

@@ -10,7 +10,6 @@ Created: 11-June-2026
 */
 
 #include "SharedMemory.h"
-#include "Windows.h"
 #include "Config.h"
 
 /*

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

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

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

@@ -20,9 +20,6 @@ Date:19-May-2026
 #include "UserManagementService.h"
 #include "Vector.h"
 #include "Validator.h"
-#include "Utility.h"
-#include "TrackedRecord.h"
-#include "DataStoreLockGuard.h"
 
 /*
 Function: ensureAdminExists
@@ -34,13 +31,12 @@ Return type: void
 */
 void UserManagementService::ensureAdminExists()
 {
-	DataStoreLockGuard lock(m_dataStore);
 	auto& usersMap = m_dataStore.getUsers();
 	int usersMapSize = usersMap.getSize();
 	bool isAdminFound = false;
 	for (int index = 0; index < usersMapSize; index++)
 	{
-		User* user = usersMap.getValueAt(index).data;
+		User* user = usersMap.getValueAt(index);
 		if (user && user->getUserType() == util::UserType::ADMIN)
 		{
 			isAdminFound = true;
@@ -77,9 +73,7 @@ void UserManagementService::createUser(const std::string& username, const std::s
 	InventoryManagementService inventoryManagementService;
 	PaymentManagementService paymentManagementService;
 	ServiceManagementService serviceManagementService;
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	auto usersMap = util::getObjects(trackedUsersMap);
+	auto& usersMap = m_dataStore.getUsers();
 	if (util::isUsernameDuplicate(username, usersMap))
 	{
 		throw std::runtime_error("Username already exists");
@@ -93,14 +87,13 @@ void UserManagementService::createUser(const std::string& username, const std::s
 		throw std::runtime_error("Phone already exists");
 	}
 	User* newUser = Factory::getObject<User>(username, password, name, phone, email, type);
-	trackedUsersMap.insert(newUser->getId(), util::createNewRecord(newUser));
+	usersMap.insert(newUser->getId(), newUser);
 	paymentManagementService.attach(newUser);
 	serviceManagementService.attach(newUser);
 	if (newUser->getUserType() == util::UserType::ADMIN)
 	{
 		inventoryManagementService.attach(newUser);
 	}
-	m_dataStore.saveUsers();
 }
 
 /*
@@ -114,24 +107,19 @@ Return type: void
 */
 void UserManagementService::updateUserDetails(const std::string& userID, const std::string& email, const std::string& phone)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	auto usersMap = util::getObjects(trackedUsersMap);
-	int index = trackedUsersMap.find(userID);
+	auto& usersMap = m_dataStore.getUsers();
+	int index = usersMap.find(userID);
 	if (index == -1)
 	{
 		throw std::runtime_error("User does not exist!\n");
 	}
-	User* user = trackedUsersMap.getValueAt(index).data;
-	bool isModified = false;
+	User* user = usersMap.getValueAt(index);
 	if (email != user->getEmail())
 	{
 		if (util::isEmailDuplicate(email, usersMap))
 		{
 			throw std::runtime_error("Email already exists!\n");
 		}
-		user->setEmail(email);
-		isModified = true;
 	}
 	if (phone != user->getPhone())
 	{
@@ -139,14 +127,9 @@ void UserManagementService::updateUserDetails(const std::string& userID, const s
 		{
 			throw std::runtime_error("Phone number already exists!\n");
 		}
+	}
+	user->setEmail(email);
 	user->setPhone(phone);
-		isModified = true;
-	}
-	if (isModified)
-	{
-		trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
-		m_dataStore.saveUsers();
-	}
 }
 
 /*
@@ -161,13 +144,12 @@ Throws:
 */
 util::Vector<Notification*> UserManagementService::getUserNotifications(const std::string& userID)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers(); 
-	if (trackedUsersMap.find(userID) == -1)
+	auto& usersMap = m_dataStore.getUsers();
+	if (usersMap.find(userID) == -1)
 	{
 		throw std::runtime_error("No user found with given UserID");
 	}
-	User* user = trackedUsersMap[userID].data;
+	User* user = usersMap[userID];
 	if (user)
 	{
 		auto& notifications = user->getNotifications();
@@ -187,41 +169,97 @@ util::Vector<Notification*> UserManagementService::getUserNotifications(const st
 
 /*
 Function: deleteNotification
-Description: Marks a specific notification associated with a given user
-			 as inactive.
+Description: Deletes a specific notification associated with a given user ID.
 Parameters:
 	- notificationID: The unique ID of the notification to be deleted.
 	- userID: The unique ID of the user whose notification is to be deleted.
 Returns:
 	- void
 Throws:
-	- std::runtime_error if no user is found with the given UserID or
-	  if no notification is found with the given NotificationID.
+	- std::runtime_error if no user is found with the given UserID or if no notification is found with the given NotificationID.
 */
 void UserManagementService::deleteNotification(const std::string& notificationID, const std::string& userID)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	auto& trackedNotificationsMap = m_dataStore.getNotifications();
-	int userIndex = trackedUsersMap.find(userID);
-	if (userIndex == -1)
+	auto& usersMap = m_dataStore.getUsers();
+	if (usersMap.find(userID) == -1)
 	{
 		throw std::runtime_error("No user found with given UserID");
 	}
-	User* user = trackedUsersMap.getValueAt(userIndex).data;
+	User* user = usersMap[userID];
 	auto& notifications = user->getNotifications();
 	if (notifications.find(notificationID) == -1)
 	{
 		throw std::runtime_error("No notification found with given NotificationID");
 	}
-	int notificationIndex = trackedNotificationsMap.find(notificationID);
-	if (notificationIndex == -1)
+	notifications.remove(notificationID);
+}
+
+/*
+Function: loadUsers
+Description: Loads users and notifications from persistent storage into the datastore.
+             Validates that each notification’s recipient exists and attaches the
+             notification to the corresponding user.
+Parameters:
+    - None
+Returns:
+    - void
+Throws:
+    - std::runtime_error if a notification recipient user ID is invalid
+*/
+void UserManagementService::loadUsers()
+{
+    util::FileManager<User> userFileManager(config::file::USER_FILE);
+    util::FileManager<Notification> notificationFileManager(config::file::NOTIFICATION_FILE);
+    auto& users = m_dataStore.getUsers();
+    auto usersMap = userFileManager.load();
+    auto notificationsMap = notificationFileManager.load();
+    int numberOfUsers = usersMap.getSize();
+    int numberOfNotifications = notificationsMap.getSize();
+    for (int index = 0; index < numberOfUsers; index++)
     {
-		throw std::runtime_error("No notification found with given NotificationID");
+        users[usersMap.getKeyAt(index)] = usersMap.getValueAt(index);
     }
-	notifications[notificationID]->setState(util::State::INACTIVE);
-	trackedNotificationsMap.getValueAt(notificationIndex).state = RecordState::MODIFIED;
-	m_dataStore.saveNotifications();
+    for (int index = 0; index < numberOfNotifications; index++)
+    {
+        Notification* notification = notificationsMap.getValueAt(index);
+        const std::string& recipientUserId = notification->getRecipientUserId();
+        int userIndex = users.find(recipientUserId);
+        if (userIndex == -1)
+        {
+            throw std::runtime_error("Invalid recipient user ID");
+        }
+        User* user = users.getValueAt(userIndex);
+        user->addNotification(notification);
+    }
+}
+
+/*
+Function: saveUsers
+Description: Saves users and their notifications from the datastore to persistent storage.
+             Collects notifications from all users into a single map before saving.
+Parameters:
+    - None
+Returns:
+    - void
+*/
+void UserManagementService::saveUsers()
+{
+    util::FileManager<User> userFileManager(config::file::USER_FILE);
+    util::FileManager<Notification> notificationFileManager(config::file::NOTIFICATION_FILE);
+    auto& users = m_dataStore.getUsers();
+    util::Map<std::string, Notification*> notifications;
+    for (int userIndex = 0; userIndex < users.getSize(); userIndex++)
+    {
+        User* user = users.getValueAt(userIndex);
+        auto& userNotifications = user->getNotifications();
+        for (int notificationIndex = 0; notificationIndex < userNotifications.getSize(); notificationIndex++)
+        {
+            notifications[userNotifications.getKeyAt(notificationIndex)] =
+                userNotifications.getValueAt(notificationIndex);
+        }
+    }
+    userFileManager.save(users);
+    notificationFileManager.save(notifications);
 }
 
 /*
@@ -232,9 +270,7 @@ Return type: util::Map<std::string, User*>
 */
 util::Map<std::string, User*> UserManagementService::getUsers()
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto users = util::getObjects(m_dataStore.getUsers());
-	return users;
+	return m_dataStore.getUsers();
 }
 
 /*
@@ -245,12 +281,10 @@ Return type: User*
 */
 User* UserManagementService::getUser(const std::string& userID)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	int index = trackedUsersMap.find(userID);
+	int index = m_dataStore.getUsers().find(userID);
 	if (index != -1)
 	{
-		return trackedUsersMap.getValueAt(index).data;
+		return m_dataStore.getUsers().getValueAt(index);
 	}
 	return nullptr;
 }
@@ -266,12 +300,10 @@ void UserManagementService::removeUser(const std::string& userID)
 	InventoryManagementService inventoryManagementService;
 	PaymentManagementService paymentManagementService;
 	ServiceManagementService serviceManagementService;
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	int index = trackedUsersMap.find(userID);
+	int index = m_dataStore.getUsers().find(userID);
 	if (index != -1)
 	{
-		User* user = trackedUsersMap.getValueAt(index).data;
+		User* user = m_dataStore.getUsers().getValueAt(index);
 		if (user != nullptr)
 		{
 			if (user->getUserType() == util::UserType::CUSTOMER)
@@ -282,37 +314,21 @@ void UserManagementService::removeUser(const std::string& userID)
 			{
 				serviceManagementService.cancelTechnicianJobs(userID);
 			}
+			user->setState(util::State::INACTIVE);
 			inventoryManagementService.detach(user);
 			paymentManagementService.detach(user);
 			serviceManagementService.detach(user);
-			user->setState(util::State::INACTIVE);
-			trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
-			m_dataStore.saveUsers();
 		}
 	}
 }
 
-/*
-Function: getUsers
-Description: Retrieves all active users of the specified type from
-			 the DataStore.
-Parameters:
-	- type: The user type to filter by
-			(ADMIN, CUSTOMER, or TECHNICIAN).
-Returns:
-	- util::Map<std::string, User*>:
-	  Collection of active users matching the specified type,
-	  keyed by user ID.
-*/
 util::Map<std::string, User*> UserManagementService::getUsers(util::UserType type)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	auto& trackedUsersMap = m_dataStore.getUsers();
-	util::Map<std::string, User*> currentUsers = util::getObjects(trackedUsersMap);
+	util::Map<std::string, User*>& currentUsers = m_dataStore.getUsers();
 	util::Map<std::string, User*> filteredUsersMap;
-	for (int index = 0; index < currentUsers.getSize(); index++)
+	for (int iterator = 0; iterator < currentUsers.getSize(); iterator++)
 	{
-		User* currentUser = currentUsers.getValueAt(index);
+		User* currentUser = currentUsers.getValueAt(iterator);
 		if (currentUser && currentUser->getState() == util::State::ACTIVE && currentUser->getUserType() == type)
 		{
 			filteredUsersMap.insert(currentUser->getId(), currentUser);

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

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

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

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