garuda

defmodule Garuda.RoomManager.Records do
  @moduledoc false

  # A wrapper around Registry, (cause registry can be replaced by swarm if we want)

  # Why we use Registry?
  # If we want to communicate with a genserver, we need its process id.
  # Since this becomes unintuitive, we can name it, But catch here is
  # genserver names can only be atoms!! 😕. Atoms are not garbage
  # collected in erlang VM. And since we are spawning say 100's of genserver at
  # a time, this will cause pain to us in long run. In order to solve this
  # there is `Registry`. Under the hood registry is an genserver which owns an ETS.
  # So basically we map our genserver name with its pid in the ETS. So whenever
  # we need a genserver pid, we use our name as key and fetch the correct pid from ETS.
  # Registry abstracts this. And we abstract Registry with Records (for standards
  # across codebase and replacing registry, if we want to) ☮.

  @doc """
  Registering and accessing named process.

  Accepts `process_name`
  """
  def via_tuple(process_name) do
    {:via, Registry, {GarudaRegistry, process_name}}
  end

  @doc """
  Returns if a process is still in Registry

  Accepts `process_name`
  Returns `boolean`
  """
  def is_process_registered(process_name) do
    case Registry.lookup(GarudaRegistry, process_name) do
      [] -> false
      _ -> true
    end
  end
end