ex_sorcery

defmodule Sorcery.PubSub.Registry do
  @behaviour Sorcery.PubSub.Behaviour

  @registry_name :sorcery_pubsub_registry

  @impl true
  def start(_opts \\ []) do
    case Registry.start_link(keys: :duplicate, name: @registry_name, partitions: System.schedulers_online()) do
      {:ok, pid} -> {:ok, pid}
      {:error, {:already_started, pid}} -> {:ok, pid}
      error -> error
    end
  end

  @impl true
  def subscribe() do
    Registry.register(@registry_name, "events", [])
  end

  @impl true
  def subscribe(subscription, opts \\ []) do
    Registry.register(@registry_name, subscription, opts)
  end

  @impl true
  def publish(events) do
    events
    |> List.wrap()
    |> Enum.each(fn event ->
      Registry.dispatch(@registry_name, "events", fn entries ->
        for {pid, _} <- entries do
          send(pid, {:event, event} )
        end
      end)
    end)
    :ok
  end
end