doing code with cond...

cond.ex

defp validate_params(params) do
  cond do
    !validate?(params["frequency"]) ->
      {:invalid, "The parameter 'frequency' isn't valid."}
    !validate?(params["storage_duration"]) ->
      {:invalid, "The parameter 'storage_duration' isn't valid."}
    !cr_status?(params["status"]) ->
      {:invalid, "The parameter 'status' isn't valid."}
    true ->
      {:ok}
  end
end

def validate?(nil), do: false
def validate?(integer) when is_integer(integer), do: true
def validate?(integer) do
  case Integer.parse(integer) do
    {_number, ""} -> true
    _ -> false
  end
end
def cr_status?(""), do: false
def cr_status?(nil), do: false
def cr_status?("off"), do: true
def cr_status?("on"), do: true
def cr_status?("on-scheduled"), do: true
def cr_status?(status), do: false