class UserRoleService
    def initialize(user, role_names)
      @user = user
      @role_names = role_names.reject(&:blank?).uniq
    end
  
    def update_roles
      @user.roles = Role.where(name: @role_names)
    end
  
    private
  
    def remove_unassigned_roles
      current_roles = @user.roles.pluck(:name)
      roles_to_remove = current_roles - @role_names
      roles_to_remove.each { |role| @user.remove_role(role) }
    end
  
    def add_new_roles
      roles_to_add = @role_names - @user.roles.pluck(:name)
      roles_to_add.each { |role| @user.add_role(role) }
    end
  end