defmodule PerfAgent do
  @moduledoc """
  Entry point for Perf Agent
  """

  use Application

  @doc """
  Application callback to start Perf Agent
  """
  @spec start(Application.app, Application.start_type) :: :ok | {:error, term}
  def start(_type \\ :normal, _args \\ []) do
    import Supervisor.Spec, warn: false

    children = []

    opts = [strategy: :one_for_one, name: PerfAgent.Supervisor]
    result = Supervisor.start_link(children, opts)

    if api_key = Application.get_env(:perf_agent, :api_key) do
      # Queue is the shared agent between the recorder and the poller
      {:ok, queue} = PerfAgent.TransactionQueue.start_link()
      {:ok, _} = PerfAgent.Poller.start_link(queue)
      {:ok, recorder} = PerfAgent.Recorder.start_link(queue)
      # Put recorder in application config to access from plug
      Application.put_env(:perf_agent, :recorder, recorder)
    end

    result
  end

  @doc """
  Checks if the required configuration params are set.
  Application will take no action if not set.
  """
  @spec configured? :: boolean
  def configured? do
    Application.get_env(:perf_agent, :api_key) != nil
  end
end