Refactor notification service abstraction

- Removed observer map from Subject base class
- Removed notify() from Subject interface
- Made NotificationManagementService abstract with pure virtual methods
- Added static observer maps to notification service implementations
- Added attach() and detach() overrides in inventory, payment, and service management services
- Added update() override in User model for observer pattern support
- Updated notification method declarations with override specifiers

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

@@ -7,11 +7,8 @@ class Notification;
 
 class Subject
 {
-protected:
-    util::Map<std::string, User*> m_observers;
 public:
     virtual ~Subject() = default;
     virtual void attach(User* user) = 0;
     virtual void detach(User* user) = 0;
-    virtual void notify(Notification* notification) = 0;
 };

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

@@ -116,3 +116,7 @@ void User::setState(util::State status)
 {
     m_status = status;
 }
+
+void User::update(Notification* notification)
+{
+}

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

@@ -41,4 +41,5 @@ public:
     void addNotification(Notification* notification);
     void setRole(util::UserType role);
     void setState(util::State status);
+    void update(Notification* notification) override;
 };

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

@@ -10,6 +10,7 @@ class InventoryManagementService : public NotificationManagementService
 {
 private:
     DataStore& m_dataStore;
+    static util::Map<std::string, User*> m_observers;
 public:
     InventoryManagementService() : m_dataStore(DataStore::getInstance()) {}
     util::Map<std::string, InventoryItem*> getInventoryItems();
@@ -17,5 +18,7 @@ public:
     void addInventoryItem(const std::string& partName, int quantity, double price);
     void removeInventoryItem(const std::string& inventoryItemID);
     void sendLowStockAlerts();
-    void sendNotification(User* user, const std::string& title, const std::string& message);
+    void sendNotification(User* user, const std::string& title, const std::string& message) override;
+    void attach(User* user) override;
+    void detach(User* user) override;
 };

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

@@ -6,8 +6,8 @@
 class NotificationManagementService : public Subject
 {
 public:
-	void sendNotification(User* recipient, const std::string& title, const std::string& message);
-	void attach(User* user) override;
-	void detach(User* user) override;
-	void notify(Notification* notification) override;
+	virtual ~NotificationManagementService() = default;
+	virtual void sendNotification(User* recipient, const std::string& title, const std::string& message) = 0;
+	virtual void attach(User* user) = 0;
+	virtual void detach(User* user) = 0;
 };

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

@@ -12,11 +12,14 @@ class PaymentManagementService : public NotificationManagementService
 {
 private:
     DataStore& m_dataStore;
+    static util::Map<std::string, User*> m_observers;
 public:
     PaymentManagementService() : m_dataStore(DataStore::getInstance()) {}
     void generateInvoice(ServiceBooking* booking);
     util::Map<std::string, Invoice*> getInvoices(const std::string& customerID);
     void completePayment(const std::string& invoiceID, util::PaymentMode paymentMode);
     void sendPaymentReminders();
-    void sendNotification(User* user, const std::string& title, const std::string& message);
+    void sendNotification(User* user, const std::string& title, const std::string& message) override;
+    void attach(User* user) override;
+    void detach(User* user) override;
 };

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

@@ -13,6 +13,7 @@ class ServiceManagementService : public NotificationManagementService
 {
 private:
     DataStore& m_dataStore;
+    static util::Map<std::string, User*> m_observers;
 public:
     ServiceManagementService() : m_dataStore(DataStore::getInstance()) {}
     util::Map<std::string, Service*> getServices();
@@ -30,5 +31,7 @@ public:
     void cancelTechnicianJobs(const std::string& technicianID);
     void createComboPackage(const std::string& name, const util::Vector<std::string>& serviceIDs, double discountPercentage);
     void removeComboPackage(const std::string& comboPackageID);
-    void sendNotification(User* user, const std::string& title, const std::string& message);
+    void sendNotification(User* user, const std::string& title, const std::string& message) override;
+    void attach(User* user) override;
+    void detach(User* user) override;
 };