feat: add LDAP sync (#106)

Co-authored-by: Elias Schneider <login@eliasschneider.com>

backend/internal/service/user_service.go

@@ -46,6 +46,10 @@ func (s *UserService) DeleteUser(userID string) error {
 		return err
 	}
 
+	if user.LdapID != nil {
+		return &common.LdapUserUpdateError{}
+	}
+
 	return s.db.Delete(&user).Error
 }
 
@@ -56,6 +60,7 @@ func (s *UserService) CreateUser(input dto.UserCreateDto) (model.User, error) {
 		Email:     input.Email,
 		Username:  input.Username,
 		IsAdmin:   input.IsAdmin,
+		LdapID:    &input.LdapID,
 	}
 	if err := s.db.Create(&user).Error; err != nil {
 		if errors.Is(err, gorm.ErrDuplicatedKey) {
@@ -66,11 +71,16 @@ func (s *UserService) CreateUser(input dto.UserCreateDto) (model.User, error) {
 	return user, nil
 }
 
-func (s *UserService) UpdateUser(userID string, updatedUser dto.UserCreateDto, updateOwnUser bool) (model.User, error) {
+func (s *UserService) UpdateUser(userID string, updatedUser dto.UserCreateDto, updateOwnUser bool, allowLdapUpdate bool) (model.User, error) {
 	var user model.User
 	if err := s.db.Where("id = ?", userID).First(&user).Error; err != nil {
 		return model.User{}, err
 	}
+
+	if user.LdapID != nil && !allowLdapUpdate {
+		return model.User{}, &common.LdapUserUpdateError{}
+	}
+
 	user.FirstName = updatedUser.FirstName
 	user.LastName = updatedUser.LastName
 	user.Email = updatedUser.Email