Fix: add duplicate user validation and update register customer UI

- add username duplicate validation
- add email duplicate validation
- add phone duplicate validation
- move duplicate checks to Validator utility
- add Register Customer header
- update registration success message

Fixes #1737

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

@@ -19,7 +19,7 @@ Date:19-May-2026
 #include "User.h"
 #include "UserManagementService.h"
 #include "Vector.h"
-
+#include "Validator.h"
 
 /*
 Function: ensureAdminExists
@@ -74,16 +74,18 @@ void UserManagementService::createUser(const std::string& username, const std::s
 	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)
+	if (util::isUsernameDuplicate(username, usersMap))
 	{
 		throw std::runtime_error("Username already exists");
 	}
+	if (util::isEmailDuplicate(email, usersMap))
+	{
+		throw std::runtime_error("Email already exists");
+	}
+	if (util::isPhoneDuplicate(phone, usersMap))
+	{
+		throw std::runtime_error("Phone already exists");
+	}
 	User* newUser = Factory::getObject<User>(username, password, name, phone, email, type);
 	usersMap.insert(newUser->getId(), newUser);
 	paymentManagementService.attach(newUser);

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/utilities/Validator.cpp

@@ -106,4 +106,37 @@ bool util::isPasswordValid(const std::string& password)
     }
 
     return hasUpper && hasLower && hasDigit && hasSpecial;
-}
+}
+
+bool util::isUsernameDuplicate(const std::string& username, const util::Map<std::string, User*>& usersMap)
+{
+    int index = usersMap.findIf(
+        [&](const std::string&, User* user)
+        {
+            return (user->getUserName() == username && user->getState() == util::State::ACTIVE);
+        }
+    );
+    return index != -1;
+}
+
+bool util::isPhoneDuplicate(const std::string& phone, const util::Map<std::string, User*>& usersMap)
+{
+    int index = usersMap.findIf(
+        [&](const std::string&, User* user)
+        {
+            return (user->getPhone() == phone && user->getState() == util::State::ACTIVE);
+        }
+    );
+    return index != -1;
+}
+
+bool util::isEmailDuplicate(const std::string& email, const util::Map<std::string, User*>& usersMap)
+{
+    int index = usersMap.findIf(
+        [&](const std::string&, User* user)
+        {
+            return (user->getEmail() == email && user->getState() == util::State::ACTIVE);
+        }
+    );
+    return index != -1;
+}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/utilities/Validator.h

@@ -9,10 +9,15 @@
 #include<string>
 #include<algorithm>
 #include<cctype>
+#include "Map.h"
+#include "User.h"
 
 namespace util
 {
 	bool isPhoneNumberValid(const std::string&);
 	bool isEmailValid(const std::string&);
 	bool isPasswordValid(const std::string&);
+	bool isUsernameDuplicate(const std::string&, const util::Map<std::string, User*>&);
+	bool isPhoneDuplicate(const std::string&, const util::Map<std::string, User*>&);
+	bool isEmailDuplicate(const std::string&, const util::Map<std::string, User*>&);
 }

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

@@ -136,6 +136,7 @@ void UserInterface::registerCustomer()
 {
 	std::string username, name, email, phone, password;
 	util::clear();
+	std::cout << "Register Customer\n";
 	std::cout << "Enter username: ";
 	util::read(username);
 	std::cout << "Enter name: ";
@@ -165,6 +166,6 @@ void UserInterface::registerCustomer()
 		return;
 	}
 	m_controller.createCustomer(username, name, password, email, phone);
-	std::cout << "Registration is successful";
+	std::cout << "Registration is successfull";
 	util::pressEnter();
 }