defmodule RemoteControlCar do
  @enforce_keys [:nickname]
  defstruct [:nickname, battery_percentage: 100, distance_driven_in_meters: 0]

  def new(nickname \\ "none") do
    %RemoteControlCar{nickname: nickname}
  end

  def display_distance(%RemoteControlCar{} = remote_car) do
    "#{remote_car.distance_driven_in_meters} meters"
  end

  def display_battery(%RemoteControlCar{} = car) do
    if car.battery_percentage > 0 do
      "Battery at #{car.battery_percentage}%"
    else
      "Battery empty"
    end
  end

  def drive(%RemoteControlCar{} = remote_car) when remote_car.battery_percentage > 0 do
    %{remote_car | battery_percentage: remote_car.battery_percentage - 1, distance_driven_in_meters: remote_car.distance_driven_in_meters + 20}
  end
  def drive(%RemoteControlCar{} = car), do: car
end