defmodule BACnet.Protocol.Services.Behaviour do
  alias BACnet.Protocol.APDU

  @doc """
  Get the service name atom.
  """
  @callback get_name() :: atom()

  @doc """
  Whether the service is of type confirmed or unconfirmed.
  """
  @callback is_confirmed() :: boolean()

  @doc """
  Get a service request APDU for this service.

  For confirmed service requests, the following keys default to specific values, if not specified:
    - `segmented_response_accepted: true`
    - `max_segments: :more_than_64`
    - `max_apdu: 1476`
    - `invoke_id: 0`

  These keys can be overriden through `request_data`. `request_data` may be ignored for unconfirmed services.

  When setting `max_segments`, do not use `:unspecified` because it makes it for the server unable to determine
  if the response is transmittable or not. Thus `:unspecified` might be as low as maximum two segments.
  For that reason, always use a specific max segments or `:more_than_64`.
  """
  @callback to_apdu(struct(), Keyword.t()) ::
              {:ok, APDU.ConfirmedServiceRequest.t() | APDU.UnconfirmedServiceRequest.t()}
              | {:error, term()}
end