fix(backend): improve LoginID synchronization from custom metadata fields

- Centralize LoginID sync logic in syncLoginID helper
- Support namespaced metadata in CreateUser, UpdateUser, and BulkCreateUsers
- Ensure UpdateUser and UpdateMe always sync LoginID from configured field even if not in update request
- Add phone number normalization consistency for custom LoginIDs
- Add unit tests for namespaced metadata LoginID sync

backend/internal/handler/auth_handler.go

@@ -5272,37 +5272,30 @@ func (h *AuthHandler) UpdateMe(c *fiber.Ctx) error {
 		for k, v := range req.Metadata {
 			// Do not overwrite core fields
 			if _, isCore := map[string]bool{"email": true, "phone_number": true, "name": true, "department": true, "grade": true, "companyCode": true, "affiliationType": true, "id": true, "role": true, "tenant_id": true}[k]; !isCore {
-				traits[k] = v
+				// [Fix] Support merging namespaced metadata maps
+				if incomingMap, ok := v.(map[string]any); ok {
+					if existingMap, ok := traits[k].(map[string]interface{}); ok {
+						for subK, subV := range incomingMap {
+							existingMap[subK] = subV
+						}
+						traits[k] = existingMap
+					} else {
+						traits[k] = incomingMap
+					}
+				} else {
+					traits[k] = v
+				}
 			}
 		}
 	}
 
 	// [LoginID Sync based on Tenant Settings]
-	schemaCompCode := extractTraitString(traits, "companyCode")
-	if schemaCompCode != "" && h.TenantService != nil {
-		if tenant, err := h.TenantService.GetTenantBySlug(c.Context(), schemaCompCode); err == nil && tenant != nil {
-			if loginIDField, ok := tenant.Config["loginIdField"].(string); ok && loginIDField != "" {
-				slog.Debug("[UpdateMe] Login ID sync active", "field", loginIDField)
-				// Search in Metadata (could be flat or namespaced)
-				var newLoginID string
-				if val, exists := req.Metadata[loginIDField]; exists {
-					if s, ok := val.(string); ok {
-						newLoginID = s
-					}
-				} else if namespaced, exists := req.Metadata[tenant.ID]; exists {
-					if subMeta, ok := namespaced.(map[string]any); ok {
-						if val, exists := subMeta[loginIDField]; exists {
-							if s, ok := val.(string); ok {
-								newLoginID = s
-							}
-						}
-					}
-				}
-
-				if newLoginID != "" {
-					slog.Info("[UpdateMe] Syncing custom field to LoginID", "field", loginIDField, "value", newLoginID)
-					traits["id"] = newLoginID
-				}
+	// Perform sync AFTER metadata merge to ensure traits contains current values
+	syncCompCode := extractTraitString(traits, "companyCode")
+	if syncCompCode != "" && h.TenantService != nil {
+		if tenant, err := h.TenantService.GetTenantBySlug(c.Context(), syncCompCode); err == nil && tenant != nil {
+			if loginIdField, ok := tenant.Config["loginIdField"].(string); ok && loginIdField != "" {
+				syncLoginID(traits, req.Metadata, tenant.ID, loginIdField)
 			}
 		}
 	}

backend/internal/handler/user_handler.go

@@ -334,12 +334,8 @@ func (h *UserHandler) CreateUser(c *fiber.Ctx) error {
 			tenantID = tenant.ID
 
 			// Sync custom field to LoginID if configured
-			if loginIDField, ok := tenant.Config["loginIdField"].(string); ok && loginIDField != "" {
-				if val, exists := req.Metadata[loginIDField]; exists {
-					if loginIDStr, ok := val.(string); ok && loginIDStr != "" {
-						attributes["id"] = loginIDStr
-					}
-				}
+			if loginIdField, ok := tenant.Config["loginIdField"].(string); ok && loginIdField != "" {
+				syncLoginID(attributes, req.Metadata, tenantID, loginIdField)
 			}
 		}
 	}
@@ -565,11 +561,7 @@ func (h *UserHandler) BulkCreateUsers(c *fiber.Ctx) error {
 
 		// Sync LoginID from configured custom field (overrides explicit LoginID)
 		if tItem.LoginIDField != "" {
-			if val, exists := item.Metadata[tItem.LoginIDField]; exists {
-				if loginIDStr, ok := val.(string); ok && loginIDStr != "" {
-					attributes["id"] = loginIDStr
-				}
-			}
+			syncLoginID(attributes, item.Metadata, tItem.ID, tItem.LoginIDField)
 		}
 
 		// Merge metadata
@@ -1159,32 +1151,6 @@ func (h *UserHandler) UpdateUser(c *fiber.Ctx) error {
 		traits["id"] = *req.LoginID
 	}
 
-	// [LoginID Sync based on Tenant Settings]
-	schemaCompCode := extractTraitString(traits, "companyCode")
-	if req.CompanyCode != nil {
-		schemaCompCode = *req.CompanyCode
-	}
-	if schemaCompCode != "" && h.TenantService != nil {
-		if tenant, err := h.TenantService.GetTenantBySlug(c.Context(), schemaCompCode); err == nil && tenant != nil {
-			if loginIDField, ok := tenant.Config["loginIdField"].(string); ok && loginIDField != "" {
-				// Search in Metadata (could be flat or namespaced)
-				if val, exists := req.Metadata[loginIDField]; exists {
-					if loginIDStr, ok := val.(string); ok && loginIDStr != "" {
-						traits["id"] = loginIDStr
-					}
-				} else if namespaced, exists := req.Metadata[tenant.ID]; exists {
-					if subMeta, ok := namespaced.(map[string]any); ok {
-						if val, exists := subMeta[loginIDField]; exists {
-							if loginIDStr, ok := val.(string); ok && loginIDStr != "" {
-								traits["id"] = loginIDStr
-							}
-						}
-					}
-				}
-			}
-		}
-	}
-
 	// [Namespaced Metadata Sync]
 	coreTraits := map[string]bool{
 		"email": true, "name": true, "phone_number": true,
@@ -1212,6 +1178,17 @@ func (h *UserHandler) UpdateUser(c *fiber.Ctx) error {
 		}
 	}
 
+	// [LoginID Sync based on Tenant Settings]
+	// Perform sync AFTER metadata merge to ensure traits contains current values
+	syncCompCode := extractTraitString(traits, "companyCode")
+	if syncCompCode != "" && h.TenantService != nil {
+		if tenant, err := h.TenantService.GetTenantBySlug(c.Context(), syncCompCode); err == nil && tenant != nil {
+			if loginIdField, ok := tenant.Config["loginIdField"].(string); ok && loginIdField != "" {
+				syncLoginID(traits, req.Metadata, tenant.ID, loginIdField)
+			}
+		}
+	}
+
 	state := normalizeKratosState(req.Status)
 
 	slog.Info("[UpdateUser] Calling Kratos UpdateIdentity", "userID", userID, "traits", traits, "state", state)
@@ -1510,6 +1487,63 @@ func extractTraitString(traits map[string]interface{}, key string) string {
 	return ""
 }
 
+// syncLoginID ensures that the 'id' trait (used as Kratos identifier) is in sync with the configured custom field.
+func syncLoginID(traits map[string]interface{}, metadata map[string]any, tenantID string, loginIDField string) {
+	if loginIDField == "" || loginIDField == "id" {
+		return
+	}
+
+	var loginID string
+
+	// 1. Check incoming metadata (flat)
+	if val, ok := metadata[loginIDField].(string); ok && val != "" {
+		loginID = val
+	}
+
+	// 2. Check incoming metadata (namespaced by tenant ID)
+	if loginID == "" && tenantID != "" {
+		if namespaced, ok := metadata[tenantID].(map[string]any); ok {
+			if val, ok := namespaced[loginIDField].(string); ok && val != "" {
+				loginID = val
+			}
+		} else if namespaced, ok := metadata[tenantID].(map[string]interface{}); ok {
+			if val, ok := namespaced[loginIDField].(string); ok && val != "" {
+				loginID = val
+			}
+		}
+	}
+
+	// 3. Check merged traits (which includes existing metadata)
+	if loginID == "" {
+		// Existing trait (flat)
+		if val, ok := traits[loginIDField].(string); ok && val != "" {
+			loginID = val
+		} else if tenantID != "" {
+			// Existing trait (namespaced)
+			if namespaced, ok := traits[tenantID].(map[string]interface{}); ok {
+				if val, ok := namespaced[loginIDField].(string); ok && val != "" {
+					loginID = val
+				}
+			} else if namespaced, ok := traits[tenantID].(map[string]any); ok {
+				if val, ok := namespaced[loginIDField].(string); ok && val != "" {
+					loginID = val
+				}
+			}
+		}
+	}
+
+	if loginID != "" {
+		// Normalize if it looks like a phone number to be consistent with other identifiers
+		normalized := normalizePhoneNumber(loginID)
+		if normalized != "" {
+			loginID = normalized
+		}
+
+		slog.Info("Syncing LoginID from custom field", "field", loginIDField, "value", loginID, "tenantID", tenantID)
+		traits["id"] = loginID
+	}
+}
+
 func formatTime(value time.Time) string {
 	if value.IsZero() {
 		return ""

backend/internal/handler/user_handler_test.go

@@ -87,6 +87,14 @@ func (m *MockTenantServiceForUser) GetTenantBySlug(ctx context.Context, slug str
 	return args.Get(0).(*domain.Tenant), args.Error(1)
 }
 
+func (m *MockTenantServiceForUser) ListManageableTenants(ctx context.Context, userID string) ([]domain.Tenant, error) {
+	args := m.Called(ctx, userID)
+	if args.Get(0) == nil {
+		return nil, args.Error(1)
+	}
+	return args.Get(0).([]domain.Tenant), args.Error(1)
+}
+
 // --- Tests ---
 
 func TestUserHandler_BulkCreateUsers(t *testing.T) {
@@ -353,3 +361,194 @@ func TestUserHandler_UpdateUser_AdminOnlyField(t *testing.T) {
 		assert.Contains(t, result["error"].(string), "field salary is admin only")
 	})
 }
+
+func TestUserHandler_UpdateUser_LoginIDSync(t *testing.T) {
+	t.Run("Success - Sync LoginID from namespaced metadata", func(t *testing.T) {
+		app := fiber.New()
+		mockKratos := new(MockKratosAdmin)
+		mockTenant := new(MockTenantServiceForUser)
+		h := &UserHandler{
+			KratosAdmin:   mockKratos,
+			TenantService: mockTenant,
+		}
+		app.Put("/users/:id", func(c *fiber.Ctx) error {
+			c.Locals("user_profile", &domain.UserProfileResponse{Role: domain.RoleSuperAdmin})
+			return h.UpdateUser(c)
+		})
+
+		tenantID := "t-123"
+		userID := "u-1"
+		mockKratos.On("GetIdentity", mock.Anything, userID).Return(&service.KratosIdentity{
+			ID: userID,
+			Traits: map[string]interface{}{
+				"email":       "user@test.com",
+				"companyCode": "test-tenant",
+				"tenant_id":   tenantID,
+			},
+		}, nil).Once()
+
+		mockTenant.On("GetTenantBySlug", mock.Anything, "test-tenant").Return(&domain.Tenant{
+			ID:   tenantID,
+			Slug: "test-tenant",
+			Config: domain.JSONMap{
+				"loginIdField": "emp_no",
+				"userSchema": []interface{}{
+					map[string]interface{}{"key": "emp_no", "label": "Employee No"},
+				},
+			},
+		}, nil) // Allow multiple calls for validation and sync
+
+		mockTenant.On("ListManageableTenants", mock.Anything, userID).Return([]domain.Tenant{}, nil).Once()
+
+		// Expect traits to include 'id' synced from 'emp_no'
+		mockKratos.On("UpdateIdentity", mock.Anything, userID, mock.MatchedBy(func(traits map[string]interface{}) bool {
+			return traits["id"] == "E1001"
+		}), mock.Anything).Return(&service.KratosIdentity{
+			ID: userID,
+			Traits: map[string]interface{}{
+				"id":    "E1001",
+				"email": "user@test.com",
+			},
+		}, nil).Once()
+
+		payload := map[string]interface{}{
+			"metadata": map[string]interface{}{
+				tenantID: map[string]interface{}{
+					"emp_no": "E1001",
+				},
+			},
+		}
+		body, _ := json.Marshal(payload)
+		req := httptest.NewRequest("PUT", "/users/"+userID, bytes.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+
+		resp, _ := app.Test(req)
+		assert.Equal(t, 200, resp.StatusCode)
+		mockKratos.AssertExpectations(t)
+	})
+
+	t.Run("Success - Sync LoginID from existing traits when not in metadata", func(t *testing.T) {
+		app := fiber.New()
+		mockKratos := new(MockKratosAdmin)
+		mockTenant := new(MockTenantServiceForUser)
+		h := &UserHandler{
+			KratosAdmin:   mockKratos,
+			TenantService: mockTenant,
+		}
+		app.Put("/users/:id", func(c *fiber.Ctx) error {
+			c.Locals("user_profile", &domain.UserProfileResponse{Role: domain.RoleSuperAdmin})
+			return h.UpdateUser(c)
+		})
+
+		tenantID := "t-123"
+		userID := "u-2"
+		mockKratos.On("GetIdentity", mock.Anything, userID).Return(&service.KratosIdentity{
+			ID: userID,
+			Traits: map[string]interface{}{
+				"email":       "user2@test.com",
+				"companyCode": "test-tenant",
+				"tenant_id":   tenantID,
+				"id":          "old-id",
+				tenantID: map[string]interface{}{
+					"emp_no": "E2002",
+				},
+			},
+		}, nil).Once()
+
+		mockTenant.On("GetTenantBySlug", mock.Anything, "test-tenant").Return(&domain.Tenant{
+			ID:   tenantID,
+			Slug: "test-tenant",
+			Config: domain.JSONMap{
+				"loginIdField": "emp_no",
+			},
+		}, nil)
+
+		mockTenant.On("ListManageableTenants", mock.Anything, userID).Return([]domain.Tenant{}, nil).Once()
+
+		// Even if metadata is empty, it should sync from existing traits
+		mockKratos.On("UpdateIdentity", mock.Anything, userID, mock.MatchedBy(func(traits map[string]interface{}) bool {
+			return traits["id"] == "E2002"
+		}), mock.Anything).Return(&service.KratosIdentity{
+			ID: userID,
+			Traits: map[string]interface{}{
+				"id": "E2002",
+			},
+		}, nil).Once()
+
+		payload := map[string]interface{}{
+			"name": "New Name",
+		}
+		body, _ := json.Marshal(payload)
+		req := httptest.NewRequest("PUT", "/users/"+userID, bytes.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+
+		resp, _ := app.Test(req)
+		assert.Equal(t, 200, resp.StatusCode)
+		mockKratos.AssertExpectations(t)
+	})
+}
+
+func TestUserHandler_CreateUser_LoginIDSync(t *testing.T) {
+	t.Run("Success - Sync LoginID from namespaced metadata", func(t *testing.T) {
+		app := fiber.New()
+		mockKratos := new(MockKratosAdmin)
+		mockOry := new(MockOryProvider)
+		mockTenant := new(MockTenantServiceForUser)
+		h := &UserHandler{
+			KratosAdmin:   mockKratos,
+			OryProvider:   mockOry,
+			TenantService: mockTenant,
+		}
+		app.Post("/users", h.CreateUser)
+
+		tenantID := "t-123"
+		mockTenant.On("GetTenantBySlug", mock.Anything, "test-tenant").Return(&domain.Tenant{
+			ID:   tenantID,
+			Slug: "test-tenant",
+			Config: domain.JSONMap{
+				"loginIdField": "emp_no",
+				"userSchema": []interface{}{
+					map[string]interface{}{"key": "emp_no", "label": "Employee No"},
+				},
+			},
+		}, nil)
+
+		mockOry.On("GetPasswordPolicy").Return(&domain.PasswordPolicy{MinLength: 8}, nil)
+
+		// Expect OryProvider.CreateUser to be called with attributes["id"] synced from metadata
+		mockOry.On("CreateUser", mock.MatchedBy(func(user *domain.BrokerUser) bool {
+			return user.LoginID == "E1001" && user.Attributes["id"] == "E1001"
+		}), mock.Anything).Return("u-1", nil).Once()
+
+		// Mock GetIdentity after creation
+		mockKratos.On("GetIdentity", mock.Anything, "u-1").Return(&service.KratosIdentity{
+			ID: "u-1",
+			Traits: map[string]interface{}{
+				"id":          "E1001",
+				"email":       "new@test.com",
+				"companyCode": "test-tenant",
+			},
+		}, nil).Once()
+
+		// Mock ListManageableTenants for mapIdentitySummary
+		mockTenant.On("ListManageableTenants", mock.Anything, "u-1").Return([]domain.Tenant{}, nil).Once()
+
+		payload := map[string]interface{}{
+			"email":       "new@test.com",
+			"name":        "New User",
+			"companyCode": "test-tenant",
+			"metadata": map[string]interface{}{
+				tenantID: map[string]interface{}{
+					"emp_no": "E1001",
+				},
+			},
+		}
+		body, _ := json.Marshal(payload)
+		req := httptest.NewRequest("POST", "/users", bytes.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+
+		resp, _ := app.Test(req)
+		assert.Equal(t, 201, resp.StatusCode)
+		mockOry.AssertExpectations(t)
+	})
+}