rindle

defmodule Rindle.AV.Probe do
  @moduledoc false

  @doc """
  Synchronously checks if FFmpeg is installed and is version >= 6.0.
  Raises a RuntimeError if the requirements are not met.
  """
  def check_ffmpeg!(runner \\ &System.cmd/2) do
    case runner.("ffmpeg", ["-version"]) do
      {output, 0} -> parse_and_check_version!(output)
      _ -> raise "FFmpeg is not installed or not in PATH."
    end
  end

  defp parse_and_check_version!(output) do
    # Accept an optional leading `n` on the version: official ffmpeg release
    # builds (and BtbN's static builds) report their git tag, e.g.
    # "ffmpeg version n7.1-..." or "ffmpeg version n6.0". Distro/johnvansickle
    # builds report a bare "7.0.x". Both must parse.
    case Regex.run(~r/ffmpeg version n?(\d+\.\d+)/, output) do
      [_, version] ->
        if Version.compare(version <> ".0", "6.0.0") == :lt do
          raise "Rindle requires FFmpeg >= 6.0, found: #{version}"
        end

        :ok

      _ ->
        raise "Could not parse FFmpeg version."
    end
  end
end