Update main.cpp

[Chinh-2006]

void pauseScreen() {
cout << "\nPress ENTER to continue...";
cin.ignore(numeric_limits::max(), '\n');
}

int main() {
PhoneBook pb;
pb.load();
const string ADMIN_PASSWORD = "Admin";
int choice;

while (true) {
    cout << "\n=== PHONE BOOK MANAGEMENT SYSTEM ===\n1. Admin Login\n2. Guest Access (User)\n3. Exit System\nChoose role: ";
    if (!(cin >> choice)) { cin.clear(); cin.ignore(numeric_limits<streamsize>::max(), '\n'); continue; }
    if (choice == 1) {
        string pwd;
        cout << "Enter security password: ";
        cin >> pwd;
        if (pwd == ADMIN_PASSWORD) {
            while (true) {
                cout << "\n=== ADMIN MENU ===\n1. Add Contact\n2. Update Contact\n3. Delete Contact\n4. Delete All Contact\n5. Display Contact\n6. Search By Name\n7. Search By Phone\n8. Search By City\n9. Logout\n10. Exit\nChoice: ";
                cin >> choice;
                if (choice == 10) { pb.save(); return 0; }
                if (choice == 9) break;
                switch (choice) {
                    case 1: pb.addContact(); break;
                    case 2: pb.updateContact(); break;
                    case 3: pb.deleteContact(); break;
                    case 4: pb.deleteAll(); break;
                    case 5: pb.displayContacts(); break;
                    case 6: pb.searchByName(); break;
                    case 7: pb.searchByPhone(); break;
                    case 8: pb.searchByCity(); break;
                    default: cout << "Invalid.\n";
                }
                pauseScreen();
            }
        } else cout << "[Error] Wrong password!\n";
    } else if (choice == 2) {
        while (true) {
            cout << "\n=== USER MENU ===\n1. Display\n2. Search Name\n3. Search Phone\n4. Search City\n5. Logout\n6. Exit\nChoice: ";
            cin >> choice;
            if (choice == 6) { pb.save(); return 0; }
            if (choice == 5) break;
            switch (choice) {
                case 1: pb.displayContacts(); break;
                case 2: pb.searchByName(); break;
                case 3: pb.searchByPhone(); break;
                case 4: pb.searchByCity(); break;
                default: cout << "Invalid.\n";
            }
            pauseScreen();
        }
    } else if (choice == 3) break;
}
pb.save();
return 0;

}