def search_performers_in_contacts_relations(skill_id, contacts_ids) do
    Repo.get! Skill, skill_id   # 404 handle

    users_query = from(
      u in User,
      left_join: us in "users_skills", on: u.id == us.user_id,
      where: us.skill_id == ^skill_id,
      group_by: u.id,
      preload: [:skills],
      select: u
    )
    users = Repo.all users_query
    user_ids = users |> Enum.map(fn each_user -> each_user.id end)

    relations_query = from(
      r in Relation,
      where:
        r.state == @confirmed_state
        and r.skill_id == ^skill_id
        and r.performer_id in ^user_ids
    )
    relations = Repo.all(relations_query)

    newcomers = users
    |> Enum.map(
      fn each_user ->
        # учитываем contact_ids
        performer_relations_count = relations
        |> Enum.filter(
          fn each_relation ->
            each_relation.performer_id == each_user.id
            && each_relation.consumer_id in contacts_ids
          end
        )
        |> Enum.count()

        # не учитываем contact_ids
        all_relations_count = relations
        |> Enum.filter(
          fn each_relation ->
            each_relation.performer_id == each_user.id
          end
        )
        |> Enum.count()

        %{ each_user | performer_relations_count: performer_relations_count | all_relations_count: all_relations_count }
      end
    )

    newcomers
    |> Enum.sort(fn (user1, user2) -> user1.performer_relations_count > user2.performer_relations_count end)
end