"""Audio preparation — silence prepend, format conversion."""

from pydub import AudioSegment


def prepare_audio(
    audio_path: str,
    output_path: str,
    silence_duration_sec: float = 3.0,
    output_format: str = "ogg",
) -> None:
    """Prepend silence to audio and export in the target format."""
    audio = AudioSegment.from_file(audio_path)
    silence = AudioSegment.silent(duration=int(silence_duration_sec * 1000))
    prepared = silence + audio
    prepared.export(output_path, format=output_format)