crawly

defmodule Crawly.EngineSup do
  # Engine supervisor responsible for spider subtrees
  @moduledoc false
  use DynamicSupervisor

  def start_link do
    DynamicSupervisor.start_link(__MODULE__, :ok, name: __MODULE__)
  end

  def init(:ok) do
    DynamicSupervisor.init(strategy: :one_for_one)
  end

  def start_spider(spider_name, options) do
    result =
      case Code.ensure_loaded?(spider_name) do
        true ->
          # Given spider module exists in the namespace, we can proceed
          {:ok, _sup_pid} =
            DynamicSupervisor.start_child(
              __MODULE__,
              {Crawly.ManagerSup, [spider_name, options]}
            )

        false ->
          {:error, "Spider: #{inspect(spider_name)} was not defined"}
      end

    result
  end

  def stop_spider(pid) do
    DynamicSupervisor.terminate_child(
      __MODULE__,
      pid
    )
  end
end