defmodule Unleash.Strategy.GradualRolloutRandom do
  @moduledoc """
  Does not require anything in `t:Unleash.context/0`

  Based on the
  [`gradualRollourRandom`](https://unleash.github.io/docs/activation_strategy#gradualrolloutrandom)
  strategy.
  """

  use Unleash.Strategy, name: "GradualRolloutRandom"

  @impl Strategy
  def enabled?(%{"percentage" => per}, _context) when is_binary(per) do
    case Integer.parse(per, 10) do
      {percentage, _} -> enabled?(percentage)
      :error -> false
    end
  end

  def enabled?(%{"percentage" => percentage}, _context) when is_number(percentage) do
    enabled?(percentage)
  end

  def enabled?(_, _), do: false

  defp enabled?(percentage) do
    rand = :rand.uniform(100)

    {percentage >= rand, %{percentage: percentage, random: rand}}
  end
end