defmodule Fact.RunMetric do
  @moduledoc false

  use Instream.Series

  alias Fact.RunMetric
  import(Fact.Influx, only: [write: 2])

  alias TimeSupport

  series do
    database(Application.get_env(:helen, Fact.Influx) |> Keyword.get(:database))
    measurement("run_metric")

    tag(:module)
    tag(:application, default: "helen")
    tag(:metric)
    tag(:env, default: Application.get_env(:helen, :build_env, "dev"))
    tag(:device)

    field(:val)
  end

  def record(opts)
      when is_list(opts) do
    record = Keyword.get(opts, :record, true)

    if record do
      def_mtime = TimeSupport.unix_now(:second)
      f = %RunMetric{}

      f = set_tag(f, opts, :application)
      f = set_tag(f, opts, :module)
      f = set_tag(f, opts, :metric)
      f = set_tag(f, opts, :device)
      f = set_field(f, opts, :val)

      f = %{f | timestamp: Keyword.get(opts, :mtime, def_mtime)}
      write(f, precision: :second, async: true)
    else
      :did_not_record
    end
  end

  defp set_tag(map, opts, key)
       when is_map(map) and is_list(opts) and is_atom(key) do
    set_tag(map, key, Keyword.get(opts, key))
  end

  defp set_tag(map, _key, nil), do: map

  defp set_tag(map, key, value)
       when is_map(map) and is_atom(key) do
    %{map | tags: %{map.tags | key => value}}
  end

  defp set_field(map, opts, key)
       when is_map(map) and is_list(opts) and is_atom(key) do
    set_field(map, key, Keyword.get(opts, key))
  end

  defp set_field(map, _key, nil) when is_map(map), do: map

  defp set_field(map, key, value)
       when is_map(map) and is_atom(key) do
    %{map | fields: %{map.fields | key => value}}
  end
end