session.ex

  defp ensure_sso_defaults(changeset) do
    # One of these fields needs to exist
    # for us to overwrite the email & password
    is_sso = (
      get_field(changeset, :digits_id)          ||
      get_field(changeset, :facebook_id)        ||
      get_field(changeset, :sms_verification_id)
    )

    changeset =
    if is_sso do
      # If the email or password fields aren't set,
      # then set them.
      if email = get_field(changeset, :email) == nil do
        changeset
          |> put_change(:email,
                        "#{SecureRandom.urlsafe_base64(16)}@email.com")
      else
        changeset
      end

      if password = get_field(changeset, :password) == nil do
        changeset
          |> put_change(:encrypted_password,
                        "#{SecureRandom.urlsafe_base64(16)}")
      else
        changeset
      end
    else
      changeset
    end
    changeset
  end