Implement review fixes

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

@@ -140,6 +140,7 @@
     <ClCompile Include="models\User.cpp" />
     <ClCompile Include="services\AuthenticationManagementService.cpp" />
     <ClCompile Include="services\InventoryManagementService.cpp" />
+    <ClCompile Include="services\NotificationManagementService.cpp" />
     <ClCompile Include="services\PaymentManagementService.cpp" />
     <ClCompile Include="services\ServiceManagementService.cpp" />
     <ClCompile Include="services\UserManagementService.cpp" />

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

@@ -114,6 +114,9 @@
     <ClCompile Include="datastores\DataStore.cpp">
       <Filter>Source Files\DataStores</Filter>
     </ClCompile>
+    <ClCompile Include="services\NotificationManagementService.cpp">
+      <Filter>Source Files\Services</Filter>
+    </ClCompile>
     <ClCompile Include="core\patterns\Observer.cpp">
       <Filter>Source Files\Core\Patterns</Filter>
     </ClCompile>
@@ -275,8 +278,5 @@
     <ClInclude Include="datastores\sharedmemory\SharedMemory.h">
       <Filter>Header Files\DataStores\SharedMemory</Filter>
     </ClInclude>
-    <ClInclude Include="datastores\DataStoreLockGuard.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
   </ItemGroup>
 </Project>

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

@@ -13,4 +13,5 @@ class Observer
 {
 public:
     virtual ~Observer() = default;
+    virtual void addNotification(Notification* notification) = 0;
 };

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

@@ -230,6 +230,20 @@ util::Map<std::string, TrackedRecord<User>>& DataStore::getUsers()
 {
     auto users = loadRecords<User, SerializedUser>(m_users);
     refreshCache(m_userCache, users);
+    auto& notifications = getNotifications();
+    int numberOfNotifications = m_notificationCache.getSize();
+    for (int index = 0; index < numberOfNotifications; index++)
+    {
+        Notification* notification = notifications.getValueAt(index).data;
+        const std::string& recipientUserId = notification->getRecipientUserId();
+        int userIndex = m_userCache.find(recipientUserId);
+        if (userIndex == -1)
+        {
+            throw std::runtime_error("Invalid recipient user ID");
+        }
+        User* user = m_userCache.getValueAt(userIndex).data;
+        user->addNotification(notification);
+    }
     return m_userCache;
 }
 
@@ -326,37 +340,6 @@ util::Map<std::string, TrackedRecord<Invoice>>& DataStore::getInvoices()
     return m_invoiceCache;
 }
 
-/*
-Function: getObservers
-Description: Retrieves observer records from the specified observer mapping
-             and resolves them to User objects.
-Parameters:
-    - mapping: Observer mapping to read from
-Returns:
-    - util::Map<std::string, User*>: Collection of observer records
-Throws:
-    - std::runtime_error if an observer references an invalid user ID
-*/
-util::Map<std::string, User*> DataStore::getObservers(MappingInfo& mapping)
-{
-    auto& users = getUsers();
-    util::Map<std::string, User*> observers;
-    SharedMemory::ensureLatestMapping(mapping);
-    size_t recordCount = SharedMemory::getRecordCount(mapping);
-    for (size_t index = 0; index < recordCount; index++)
-    {
-        const SerializedObserver* observer = static_cast<SerializedObserver*>(SharedMemory::getRecordAddress(mapping, index));
-        int userIndex = users.find(observer->id);
-        if (userIndex == -1)
-        {
-            throw std::runtime_error("Invalid observer user ID");
-        }
-        User* user = users.getValueAt(userIndex).data;
-        observers.insert(user->getId(), user);
-    }
-    return observers;
-}
-
 /*
 Function: getServiceManagementObservers
 Description: Retrieves all service management observer records from the datastore.
@@ -367,7 +350,7 @@ Returns:
 */
 util::Map<std::string, User*> DataStore::getServiceManagementObservers()
 {
-    return getObservers(m_serviceManagementObservers);
+    return util::Map<std::string, User*>();
 }
 
 /*
@@ -380,7 +363,7 @@ Returns:
 */
 util::Map<std::string, User*> DataStore::getPaymentManagementObservers()
 {
-    return getObservers(m_paymentManagementObservers);
+    return util::Map<std::string, User*>();
 }
 
 /*
@@ -393,7 +376,7 @@ Returns:
 */
 util::Map<std::string, User*> DataStore::getInventoryManagementObservers()
 {
-    return getObservers(m_inventoryManagementObservers);
+    return util::Map<std::string, User*>();
 }
 
 /*
@@ -407,6 +390,7 @@ Returns:
 void DataStore::saveUsers()
 {
     saveRecords<User, SerializedUser>(m_users, m_userCache);
+    saveNotifications();
 }
 
 /*
@@ -494,49 +478,16 @@ void DataStore::saveInvoices()
 {
 }
 
-/*
-Function: saveObservers
-Description: Persists observer records to the specified observer mapping.
-Parameters:
-    - mapping: MappingInfo&, observer mapping to save to
-    - observers: util::Map<std::string, User*>&, collection of observer records
-Returns:
-    - None
-*/
-void DataStore::saveObservers(MappingInfo& mapping, util::Map<std::string, User*>& observers)
-{
-    size_t observerCount = static_cast<size_t>(observers.getSize());
-    size_t capacity = config::file::INITIAL_CAPACITY;
-    while (capacity < observerCount)
-    {
-        capacity *= config::file::GROWTH_FACTOR;
-    }
-    if (!SharedMemory::resizeMapping(mapping, capacity))
-    {
-        throw std::runtime_error("Failed to resize observer mapping");
-    }
-    SharedMemory::setRecordCount(mapping, observerCount);
-    for (size_t index = 0; index < observerCount; index++)
-    {
-        SerializedObserver serializedObserver;
-        User* user = observers.getValueAt(static_cast<int>(index));
-        strcpy_s(serializedObserver.id, user->getId().c_str());
-        SerializedObserver* destination = static_cast<SerializedObserver*>(SharedMemory::getRecordAddress(mapping, index));
-        *destination = serializedObserver;
-    }
-}
-
 /*
 Function: saveServiceManagementObservers
 Description: Persists all service management observer records to the datastore.
 Parameters:
-    - observers: util::Map<std::string, User*>&, collection of observer records
+    - observers: util::Map<std::string, TrackedRecord<std::string>>&, collection of observer records
 Returns:
     - None
 */
 void DataStore::saveServiceManagementObservers(util::Map<std::string, User*>& observers)
 {
-    saveObservers(m_serviceManagementObservers, observers);
 }
 
 /*
@@ -549,7 +500,6 @@ Returns:
 */
 void DataStore::savePaymentManagementObservers(util::Map<std::string, User*>& observers)
 {
-    saveObservers(m_paymentManagementObservers, observers);
 }
 
 /*
@@ -562,7 +512,6 @@ Returns:
 */
 void DataStore::saveInventoryManagementObservers(util::Map<std::string, User*>& observers)
 {
-    saveObservers(m_inventoryManagementObservers, observers);
 }
 
 /*

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

@@ -86,8 +86,6 @@ private:
     void saveRecords(MappingInfo& mapping, util::Map<std::string, TrackedRecord<TObject>>& records);
     template<typename TObject> void clearCache(util::Map<std::string, TrackedRecord<TObject>>&cache);
     template<typename TObject> void refreshCache(util::Map<std::string, TrackedRecord<TObject>>&cache, util::Map<std::string, TrackedRecord<TObject>>&refreshedCache);
-    util::Map<std::string, User*> getObservers(MappingInfo& mapping);
-    void saveObservers(MappingInfo& mapping, util::Map<std::string, User*>& observers);
 };
 
 /*

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

@@ -320,7 +320,7 @@ bool SharedMemory::ensureCapacityForInsert(MappingInfo& mapping)
     {
         return true;
     }
-    return resizeMapping(mapping, capacity * config::file::GROWTH_FACTOR);
+    return resizeMapping(mapping, capacity * 2);
 }
 
 /*

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

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

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

@@ -9,10 +9,8 @@ Date: 19-May-2026
 #pragma once
 #include <string>
 #include "Timestamp.h"
-#include "Enums.h"
 
 class User;
-struct SerializedNotification;
 
 class Notification
 {
@@ -20,26 +18,27 @@ private:
     static int m_uid;
     std::string m_id;
     std::string m_recipientUserId;
+    User* m_recipient;
     std::string m_title;
     std::string m_message;
     util::Timestamp m_createdAt;
-    util::State m_state;
 public:
     Notification();
-    Notification(const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt);
-    Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt, const util::State& state);
+    Notification(const std::string& recipientUserId, User* recipient, const std::string& title, const std::string& message, const util::Timestamp& createdAt);
+    Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt);
     const std::string& getId() const;
     const std::string& getRecipientUserId() const;
+    User* getRecipient() const;
     const std::string& getTitle() const;
     const std::string& getMessage() const;
     const util::Timestamp& getCreatedAt() const;
     void setId(const std::string& id);
     void setRecipientUserId(const std::string& recipientUserId);
+    void setRecipient(User* recipient);
     void setTitle(const std::string& title);
     void setMessage(const std::string& message);
     void setCreatedAt(const util::Timestamp& createdAt);
-    util::State getState() const;
-    void setState(util::State state);
-    SerializedNotification serialize() const;
-    static Notification* deserialize(const SerializedNotification&);
+    std::string serialize() const;
+    static Notification* deserialize(const std::string&);
+    static std::string getHeaders();
 };

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

@@ -89,6 +89,23 @@ User::User(const std::string& userId, const std::string& userName, const std::st
     }
 }
 
+/*
+Function: ~User
+Description: Destructor that cleans up dynamically allocated notifications associated with the user.
+Parameters:
+    - None
+Returns:
+    - void
+*/
+User::~User()
+{
+    auto values = m_notifications.getValues();
+    for (int index = 0; index < values.getSize(); index++)
+    {
+        delete values[index];
+    }
+}
+
 /*
 Function: getId
 Description: Retrieves the unique ID of the user.
@@ -155,6 +172,17 @@ const std::string& User::getEmail() const
     return m_email;
 }
 
+/*
+Function: getNotifications
+Description: Retrieves the map of notifications associated with the user.
+Returns:
+    - util::Map<std::string, Notification*>& representing the notifications.
+*/
+util::Map<std::string, Notification*>& User::getNotifications()
+{
+    return m_notifications;
+}
+
 /*
 Function: getUserType
 Description: Retrieves the role of the user.
@@ -255,6 +283,22 @@ void User::setEmail(const std::string& email)
     m_email = email;
 }
 
+/*
+Function: addNotification
+Description: Adds a new notification to the user’s notification map.
+Parameters:
+    - notification: Pointer to the Notification object.
+Returns:
+    - void
+*/
+void User::addNotification(Notification* notification)
+{
+    if (notification)
+    {
+        m_notifications.insert(notification->getId(), notification);
+    }
+}
+
 /*
 Function: setRole
 Description: Sets the role of the user.

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

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

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

@@ -19,7 +19,7 @@ Date: 22-May-2026
 #include "User.h"
 #include "Utility.h"
 #include "Vector.h"
-#include "DataStoreLockGuard.h"
+
 
 util::Map<std::string, User*> InventoryManagementService::m_observers{};
 
@@ -271,9 +271,6 @@ Returns:
 */
 void InventoryManagementService::attach(User* user)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	m_observers.clear();
-	m_observers = m_dataStore.getInventoryManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -282,7 +279,6 @@ void InventoryManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
-	m_dataStore.saveInventoryManagementObservers(m_observers);
 }
 
 /*
@@ -295,9 +291,6 @@ Returns:
 */
 void InventoryManagementService::detach(User* user)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	m_observers.clear();
-	m_observers = m_dataStore.getInventoryManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -306,7 +299,6 @@ void InventoryManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
-	m_dataStore.saveInventoryManagementObservers(m_observers);
 }
 
 /*
@@ -323,27 +315,27 @@ Throws:
 */
 void InventoryManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (!user)
+	if (user)
 	{
-		return;
+		if (m_observers.find(user->getId()) != -1)
+		{
+			Notification* notification =
+				Factory::getObject<Notification>(
+					user->getId(),
+					user,
+					title,
+					message,
+					util::Timestamp()
+				);
+			if (notification)
+			{
+				user->addNotification(notification);
+			}
+			else
+			{
+				throw std::runtime_error("Failed to create notification");
+			}
+		}
 	}
-	DataStoreLockGuard lock(m_dataStore);
-	m_observers = m_dataStore.getInventoryManagementObservers();
-	if (m_observers.find(user->getId()) == -1)
-	{
-		return;
-	}
-	Notification* notification = Factory::getObject<Notification>(
-		user->getId(),
-		title,
-		message,
-		util::Timestamp());
-	if (!notification)
-	{
-		throw std::runtime_error("Failed to create notification");
-	}
-	auto& trackedNotificationsMap = m_dataStore.getNotifications();
-	trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
-	m_dataStore.saveNotifications();
 }
 

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

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

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

@@ -21,7 +21,6 @@ Date: 20-May-2026
 #include "Timestamp.h"
 #include "User.h"
 #include "Utility.h"
-#include "DataStoreLockGuard.h"
 
 util::Map<std::string, User*> PaymentManagementService::m_observers{};
 
@@ -35,9 +34,6 @@ Returns:
 */
 void PaymentManagementService::attach(User* user)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	m_observers.clear();
-	m_observers = m_dataStore.getPaymentManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -46,7 +42,6 @@ void PaymentManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
-	m_dataStore.savePaymentManagementObservers(m_observers);
 }
 
 /*
@@ -59,9 +54,6 @@ Returns:
 */
 void PaymentManagementService::detach(User* user)
 {
-	DataStoreLockGuard lock(m_dataStore);
-	m_observers.clear();
-	m_observers = m_dataStore.getPaymentManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -70,7 +62,6 @@ void PaymentManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
-	m_dataStore.savePaymentManagementObservers(m_observers);
 }
 
 /*
@@ -87,28 +78,28 @@ Throws:
 */
 void PaymentManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (!user)
+	if (user)
 	{
-		return;
+		if (m_observers.find(user->getId()) != -1)
+		{
+			Notification* notification =
+				Factory::getObject<Notification>(
+					user->getId(),
+					user,
+					title,
+					message,
+					util::Timestamp()
+				);
+			if (notification)
+			{
+				user->addNotification(notification);
+			}
+			else
+			{
+				throw std::runtime_error("Failed to create notification");
+			}
+		}
 	}
-	DataStoreLockGuard lock(m_dataStore);
-	m_observers = m_dataStore.getPaymentManagementObservers();
-	if (m_observers.find(user->getId()) == -1)
-	{
-		return;
-	}
-	Notification* notification = Factory::getObject<Notification>(
-		user->getId(),
-		title,
-		message,
-		util::Timestamp());
-	if (!notification)
-	{
-		throw std::runtime_error("Failed to create notification");
-	}
-	auto& trackedNotificationsMap = m_dataStore.getNotifications();
-	trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
-	m_dataStore.saveNotifications();
 }
 
 /*

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

@@ -26,7 +26,6 @@ Date:19-May-2026
 #include "User.h"
 #include "UserManagementService.h"
 #include "Utility.h"
-#include "DataStoreLockGuard.h"
 
 /*
 Function: purchaseService
@@ -123,9 +122,6 @@ Returns:
 */
 void ServiceManagementService::attach(User* user)
 {
-    DataStoreLockGuard lock(m_dataStore);
-    m_observers.clear();
-    m_observers = m_dataStore.getServiceManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -134,7 +130,6 @@ void ServiceManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
-    m_dataStore.saveServiceManagementObservers(m_observers);
 }
 
 /*
@@ -147,9 +142,6 @@ Returns:
 */
 void ServiceManagementService::detach(User* user)
 {
-    DataStoreLockGuard lock(m_dataStore);
-    m_observers.clear();
-    m_observers = m_dataStore.getServiceManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -158,7 +150,6 @@ void ServiceManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
-    m_dataStore.saveServiceManagementObservers(m_observers);
 }
 
 /*
@@ -175,28 +166,52 @@ Throws:
 */
 void ServiceManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-    if (!user)
-    {
-        return;
-    }
-    DataStoreLockGuard lock(m_dataStore);
-    m_observers = m_dataStore.getServiceManagementObservers();
-    if (m_observers.find(user->getId()) == -1)
-    {
-        return;
-    }
-    Notification* notification = Factory::getObject<Notification>(
-        user->getId(),
-        title,
-        message,
-        util::Timestamp());
-    if (!notification)
-    {
-        throw std::runtime_error("Failed to create notification");
-    }
-    auto& trackedNotificationsMap = m_dataStore.getNotifications();
-    trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
-    m_dataStore.saveNotifications();
+	if (user)
+	{
+		if (m_observers.find(user->getId()) != -1)
+		{
+			Notification* notification =
+				Factory::getObject<Notification>(
+					user->getId(),
+					user,
+					title,
+					message,
+					util::Timestamp()
+				);
+			if (notification)
+			{
+				user->addNotification(notification);
+			}
+			else
+			{
+				throw std::runtime_error("Failed to create notification");
+			}
+		}
+	}
+}
+
+/*
+Function: getObserverIDs
+Description: Retrieves the IDs of all observers currently attached to the
+             ServiceManagementService.
+Parameters:
+    - None
+Returns:
+    - util::Vector<std::string>: Vector of observer user IDs
+*/
+util::Vector<std::string> ServiceManagementService::getObserverIDs()
+{
+	util::Vector<std::string> observerIDs;
+	int numberOfObservers = m_observers.getSize();
+	for (int index = 0; index < numberOfObservers; index++)
+	{
+		User* observer = m_observers.getValueAt(index);
+		if (observer)
+		{
+			observerIDs.push_back(observer->getId());
+		}
+	}
+	return observerIDs;
 }
 
 /*

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

@@ -53,4 +53,6 @@ public:
     void saveServiceBookings();
     void loadJobCards();
     void saveJobCards();
+    void loadObservers();
+    void saveObservers();
 };

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

@@ -170,18 +170,13 @@ util::Vector<Notification*> UserManagementService::getUserNotifications(const st
 	User* user = trackedUsersMap[userID].data;
 	if (user)
 	{
-		auto& trackedNotificationMap = m_dataStore.getNotifications();
-		int numberOfNotifications = trackedNotificationMap.getSize();
+		auto& notifications = user->getNotifications();
+		int numberOfNotifications = notifications.getSize();
 		util::Vector<Notification*> notificationsVector;
 		for (int index = 0; index < numberOfNotifications; index++)
 		{
-			Notification* notification = trackedNotificationMap.getValueAt(index).data;
-			if (notification->getRecipientUserId() == userID && notification->getState() == util::State::ACTIVE)
-			{
-				notificationsVector.push_back(notification);
-			}
+		    notificationsVector.push_back(notifications.getValueAt(index));
 		}
-		m_dataStore.unlockDataStore();
 		return notificationsVector;
 	}
 	else
@@ -214,12 +209,17 @@ void UserManagementService::deleteNotification(const std::string& notificationID
 		throw std::runtime_error("No user found with given UserID");
 	}
 	User* user = trackedUsersMap.getValueAt(userIndex).data;
+	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)
 	{
 		throw std::runtime_error("No notification found with given NotificationID");
 	}
-	trackedNotificationsMap.getValueAt(notificationIndex).data->setState(util::State::INACTIVE);
+	notifications[notificationID]->setState(util::State::INACTIVE);
 	trackedNotificationsMap.getValueAt(notificationIndex).state = RecordState::MODIFIED;
 	m_dataStore.saveNotifications();
 }

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

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