notificator.ex

defmodule Notificator do
  def notify(topic, %{account_id: account_id} = event) do
    # Do some stuff with account_id

    resource_identifier = resource_for_topic(topic, event)

    with {:ok, resorce_data} = Transfers.get_resource(resource_identifier),
         {:ok, notification_params} <-
           to_notification(topic, event, resource_identifier, resource_data),
         {:ok, notification} <- Notification.save(notification_params) do
      Client.notify(notification)
    end
  end

  defp to_notification(topic, event, resource_identifier, resource_data) do
    %{
      timestamp: format_datetime(event["timestamp"]),
      webhook_sent_at: format_datetime(NaiveDateTime.utc_now()),
      env: get_env(),
      type: type_for_topic(topic),
      resource_data: resource_data
    }
    |> Map.merge(resource_identifier)
  end

  defp type_for_topic("domain.inbound_external_transfer.received"),
    do: "cash_in_external_transfer_transfer"

  defp type_for_topic("domain.internal_transfer.received"), do: "cash_in_internal_transfer"

  defp resource_for_topic("domain.inbound_external_transfer.received", %{
         "statement_entry_id" => resource_id
       }),
       do: %{resource_type: "statement_entries", resource_id: resource_id}

  defp resource_for_topic("domain.outbound_external_transfer.refunded", %{
         "transfer_id" => resource_id
       }),
       do: %{resource_type: "external_transfers", resource_id: resource_id}

  defp resource_for_topic(_), do: raise("unsupported topic")

  defp format_datetime(datetime) when is_binary(datetime) do
    datetime
    |> NaiveDateTime.from_iso8601!()
    |> format_datetime()
  end

  defp format_datetime(datetime) do
    datetime
    |> NaiveDateTime.truncate(:second)
    |> DateTime.from_naive!("Etc/UTC")
    |> DateTime.to_iso8601()
  end
end