Package the edge and leave clues

# lib/cleaner/cli.ex
defmodule Cleaner.CLI do
  require Logger

  def main([path]) do
    with {:ok, text} <- File.read(path),
         {:ok, records} <- parse_lines(String.split(text, "\n")),
         {:ok, counts} <- Cleaner.run(records) do
      Logger.info("cleaned records path=#{inspect(path)} count=#{length(records)}")
      IO.inspect(counts, label: "levels")
      :ok
    else
      {:error, reason} -> fail(reason)
    end
  end

  def main(_args), do: {:error, :usage}

  defp parse_lines(lines) do
    Enum.reduce_while(lines, {:ok, []}, fn line, {:ok, records} ->
      case Cleaner.parse_line(line) do
        {:ok, record} -> {:cont, {:ok, [record | records]}}
        :skip -> {:cont, {:ok, records}}
        {:error, reason} -> {:halt, {:error, reason}}
      end
    end)
    |> then(fn
      {:ok, records} -> {:ok, Enum.reverse(records)}
      error -> error
    end)
  end

  defp fail(reason) do
    Logger.error("clean_failed reason=#{inspect(reason)}")
    {:error, reason}
  end
end