defmodule Metrex do
  @moduledoc """
  Metrex application
  """

  use Application

  @counters Application.get_env(:metrex, :counters) || []
  @meters Application.get_env(:metrex, :meters) || []

  @doc """
  Starts `Metrex.Counter, Metrex.Meter` agents when app starts
  """
  def start(_type, _args) do
    import Supervisor.Spec, warn: false

    counters = Enum.map(@counters, fn(counter) ->
      worker(Metrex.Counter, [counter], id: make_ref) end
    )

    meters = Enum.map(@meters, fn(meter) ->
      worker(Metrex.Meter, [meter], id: make_ref) end
    )

    children = [
      worker(Metrex.Scheduler.Cleaner, [])
    ]

    opts = [strategy: :one_for_one, name: Metrex.Supervisor]
    Supervisor.start_link(children ++ counters ++ meters, opts)
  end

  @doc """
  Starts `Metrex.Counter` child
  """
  def start_counter(metric, val \\ 0) do
    import Supervisor.Spec, warn: false
    Supervisor.start_child(
      Metrex.Supervisor, worker(Metrex.Counter, [metric, val], id: make_ref))
  end

  @doc """
  Starts `Metrex.Meter` child
  """
  def start_meter(metric, val \\ []) do
    import Supervisor.Spec, warn: false
    Supervisor.start_child(
      Metrex.Supervisor, worker(Metrex.Meter, [metric, val], id: make_ref))
  end
end