action_wrapper_helpers.ex

defmodule AshEvents.Events.ActionWrapperHelpers do
  @moduledoc """
  Helper functions used by the action wrappers.
  """

  def dump_value(nil, _attribute), do: nil

  def dump_value(values, %{type: {:array, attr_type}} = attribute) do
    item_constraints = attribute.constraints[:items]

    # This is a work around for a bug in Ash.Type.dump_to_embedded/3
    Enum.map(values, fn value ->
      {:ok, dumped_value} = Ash.Type.dump_to_embedded(attr_type, value, item_constraints)
      dumped_value
    end)
  end

  def dump_value(value, attribute) do
    {:ok, dumped_value} = Ash.Type.dump_to_embedded(attribute.type, value, attribute.constraints)
    dumped_value
  end

  defp cast_and_dump_value(value, attr_or_arg) do
    case Ash.Type.cast_input(attr_or_arg.type, value, attr_or_arg.constraints) do
      {:ok, cast_value} ->
        dump_value(cast_value, attr_or_arg)

      {:error, _} ->
        dump_value(value, attr_or_arg)
    end
  end

  def create_event!(changeset, original_params, module_opts, opts) do
    pg_repo = AshPostgres.DataLayer.Info.repo(changeset.resource)

    if pg_repo do
      lock_key =
        module_opts[:advisory_lock_key_generator].generate_key!(
          changeset,
          module_opts[:advisory_lock_key_default]
        )

      if is_list(lock_key) do
        [key1, key2] = lock_key
        Ecto.Adapters.SQL.query(pg_repo, "SELECT pg_advisory_xact_lock($1, $2)", [key1, key2])
      else
        Ecto.Adapters.SQL.query(pg_repo, "SELECT pg_advisory_xact_lock($1)", [lock_key])
      end
    end

    params =
      original_params
      |> Enum.reduce(%{}, fn {key, value}, acc ->
        cond do
          attr = Ash.Resource.Info.attribute(changeset.resource, key) ->
            Map.put(acc, key, cast_and_dump_value(value, attr))

          arg = Enum.find(changeset.action.arguments, &(&1.name == key)) ->
            Map.put(acc, key, cast_and_dump_value(value, arg))

          true ->
            acc
        end
      end)

    event_log_resource = module_opts[:event_log]
    [primary_key] = Ash.Resource.Info.primary_key(changeset.resource)
    persist_actor_primary_keys = AshEvents.EventLog.Info.event_log(event_log_resource)
    actor = opts[:actor]

    record_id =
      if changeset.action_type == :create do
        Map.get(changeset.attributes, primary_key)
      else
        Map.get(changeset.data, primary_key)
      end

    metadata = Map.get(changeset.context, :ash_events_metadata, %{})

    event_params =
      %{
        data: params,
        record_id: record_id,
        resource: changeset.resource,
        action: module_opts[:action],
        action_type: changeset.action_type,
        metadata: metadata,
        version: module_opts[:version]
      }

    event_params =
      Enum.reduce(persist_actor_primary_keys, event_params, fn persist_actor_primary_key, input ->
        if is_struct(actor) and actor.__struct__ == persist_actor_primary_key.destination do
          primary_key = Map.get(actor, hd(Ash.Resource.Info.primary_key(actor.__struct__)))
          Map.put(input, persist_actor_primary_key.name, primary_key)
        else
          input
        end
      end)

    has_atomics? = not Enum.empty?(changeset.atomics)

    event_log_resource
    |> Ash.Changeset.for_create(:create, event_params, opts)
    |> then(fn cs ->
      if has_atomics? do
        Ash.Changeset.add_error(
          cs,
          Ash.Error.Changes.InvalidChanges.exception(
            message: "atomic changes are not compatible with ash_events"
          )
        )
      else
        cs
      end
    end)
    |> Ash.create!()
  end
end