defmodule AudioSaver do
  @wav_dir "recordings/"

  def save_chunk_as_wav(ref, chunk, sample_rate \\ 48100, bits_per_sample \\ 16, channels \\ 1, type) do
    File.mkdir_p!(@wav_dir)

    data_size = byte_size(chunk)
    byte_rate = sample_rate * channels * div(bits_per_sample, 8)
    block_align = div(bits_per_sample * channels, 8)
    riff_size = 36 + data_size

    header =
      <<
        "RIFF",
        riff_size::little-size(32),
        "WAVE",
        "fmt ",
        16::little-size(32),
        1::little-size(16),
        channels::little-size(16),
        sample_rate::little-size(32),
        byte_rate::little-size(32),
        block_align::little-size(16),
        bits_per_sample::little-size(16),
        "data",
        data_size::little-size(32)
      >>

    chunk_number = Whisper.Counter.next(ref)
    
    filename = 
        case type do 
            "part" -> "#{ref}_#{chunk_number}.wav"
            "final" -> "#{ref}_final.wav"
            _ -> "#{ref}_#{chunk_number}.wav"
        end
    path = Path.join(@wav_dir, filename)
    IO.inspect(path, label: "---> ")
    File.write!(path, header <> chunk)
    {:ok, path}
  end
end