Backfill user accounts

backend/src/main/java/com/petshop/backend/service/CustomerService.java

@@ -4,23 +4,31 @@ import com.petshop.backend.dto.common.BulkDeleteRequest;
 import com.petshop.backend.dto.customer.CustomerRequest;
 import com.petshop.backend.dto.customer.CustomerResponse;
 import com.petshop.backend.entity.Customer;
+import com.petshop.backend.entity.User;
 import com.petshop.backend.exception.ResourceNotFoundException;
 import com.petshop.backend.repository.CustomerRepository;
 import com.petshop.backend.repository.UserRepository;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
+import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 @Service
 public class CustomerService {
 
+    private static final String TEMP_PASSWORD = "TempPass123!";
+
     private final CustomerRepository customerRepository;
     private final UserRepository userRepository;
+    private final PasswordEncoder passwordEncoder;
+    private final UserBusinessLinkageService userBusinessLinkageService;
 
-    public CustomerService(CustomerRepository customerRepository, UserRepository userRepository) {
+    public CustomerService(CustomerRepository customerRepository, UserRepository userRepository, PasswordEncoder passwordEncoder, UserBusinessLinkageService userBusinessLinkageService) {
         this.customerRepository = customerRepository;
         this.userRepository = userRepository;
+        this.passwordEncoder = passwordEncoder;
+        this.userBusinessLinkageService = userBusinessLinkageService;
     }
 
     public Page<CustomerResponse> getAllCustomers(String query, Pageable pageable) {
@@ -47,8 +55,13 @@ public class CustomerService {
         customer.setEmail(request.getEmail());
 
         customer = customerRepository.save(customer);
-        syncLinkedUser(customer);
-        return mapToResponse(customer);
+        Customer savedCustomer = customer;
+        User user = userRepository.findByEmail(savedCustomer.getEmail())
+                .orElseGet(() -> createLinkedUser(savedCustomer));
+
+        Customer linkedCustomer = userBusinessLinkageService.ensureLinkedCustomer(user);
+        syncLinkedUser(linkedCustomer);
+        return mapToResponse(linkedCustomer);
     }
 
     @Transactional
@@ -99,4 +112,25 @@ public class CustomerService {
             userRepository.save(user);
         });
     }
+
+    private User createLinkedUser(Customer customer) {
+        User user = new User();
+        user.setUsername(generateUsername(customer));
+        user.setPassword(passwordEncoder.encode(TEMP_PASSWORD));
+        user.setEmail(customer.getEmail());
+        user.setFullName((customer.getFirstName() + " " + customer.getLastName()).trim());
+        user.setPhone(generatePhone(customer));
+        user.setRole(User.Role.CUSTOMER);
+        user.setActive(true);
+        user.setTokenVersion(0);
+        return userRepository.save(user);
+    }
+
+    private String generateUsername(Customer customer) {
+        return "customer_" + customer.getCustomerId();
+    }
+
+    private String generatePhone(Customer customer) {
+        return String.format("200-000-%04d", customer.getCustomerId());
+    }
 }