Pleroma/lib/pleroma/digest_email_worker.ex

defmodule Pleroma.DigestEmailWorker do
  import Ecto.Query

  def run do
    config = Pleroma.Config.get([:email_notifications, :digest])
    negative_interval = -Map.fetch!(config, :interval)
    inactivity_threshold = Map.fetch!(config, :inactivity_threshold)
    inactive_users_query = Pleroma.User.list_inactive_users_query(inactivity_threshold)

    now = NaiveDateTime.truncate(NaiveDateTime.utc_now(), :second)

    from(u in inactive_users_query,
      where: fragment(~s(? #> '{"email_notifications","digest"}' @> 'true'), u.info),
      where: u.last_digest_emailed_at < datetime_add(^now, ^negative_interval, "day"),
      select: u
    )
    |> Pleroma.Repo.all()
    |> run()
  end

  def run([]), do: :ok

  def run([user | users]) do
    with %Swoosh.Email{} = email <- Pleroma.Emails.UserEmail.digest_email(user) do
      Pleroma.Emails.Mailer.deliver_async(email)
    end

    Pleroma.User.touch_last_digest_emailed_at(user)

    run(users)
  end
end