ctrl.rb

  def update
    if (criteria_to_remove = params[:delete])
      model = criteria_to_remove.keys.first
      field = criteria_to_remove.values.first

      feed.update(criteria: feed.criteria.except(model).deep_merge({ model => feed.criteria[model].except(field) }) )

      redirect_to edit_admin_feed_path(feed), notice: 'Критерии фида отредактированы успешно'

    elsif params[:criteria].present?

      permitted_criteria_params
      criteria = params[:criteria]

      additional_criteria =
        criteria.keys.map do |model|
          { model.to_sym => criteria[model].to_h.map { |key, value| Hash[key.to_sym, Hash[value['operator'].to_sym, value['value']]] }.inject(:merge) }
        end
        .inject(:merge)

      feed.update(criteria: feed.criteria.deep_merge(additional_criteria))

      redirect_to edit_admin_feed_path(feed), notice: 'Критерии фида отредактированы успешно'
    else
      if feed.update(permitted_params)
        redirect_to edit_admin_feed_path(feed), notice: 'Фид отредактирован успешно'
      else
        render :edit
      end
    end
  end