defmodule Mv.Membership.Member.Changes.SyncEmailToUser do
  @moduledoc """
  Synchronizes member email changes to the linked user.
  Uses `around_transaction` for atomicity - both updates in the same transaction.
  """
  use Ash.Resource.Change
  alias Mv.EmailSync.{Helpers, Loader}

  @impl true
  def change(changeset, _opts, context) do
    cond do
      Map.get(context, :syncing_email, false) -> changeset
      not Ash.Changeset.changing_attribute?(changeset, :email) -> changeset
      true -> sync_email(changeset)
    end
  end

  defp sync_email(changeset) do
    new_email = Ash.Changeset.get_attribute(changeset, :email)

    Ash.Changeset.around_transaction(changeset, fn cs, callback ->
      result = callback.(cs)

      with {:ok, member} <- Helpers.extract_record(result),
           linked_user <- Loader.get_linked_user(member) do
        Helpers.sync_email_to_linked_record(result, linked_user, new_email)
      else
        _ -> result
      end
    end)
  end
end