import io
import wave


DEFAULT_SAMPLE_RATE = 16000
DEFAULT_CHANNELS = 1
DEFAULT_SAMPLE_WIDTH = 2


def detect_audio_format(audio_data: bytes) -> str:
    if len(audio_data) >= 12 and audio_data[:4] == b"RIFF" and audio_data[8:12] == b"WAVE":
        return "wav"
    if audio_data.startswith(b"ID3"):
        return "mp3"
    if len(audio_data) >= 2 and audio_data[0] == 0xFF and (audio_data[1] & 0xE0) == 0xE0:
        return "mp3"
    return "pcm_s16le_16k_mono"


def wrap_pcm_as_wav(
    audio_data: bytes,
    *,
    sample_rate: int = DEFAULT_SAMPLE_RATE,
    channels: int = DEFAULT_CHANNELS,
    sample_width: int = DEFAULT_SAMPLE_WIDTH,
) -> bytes:
    wav_buffer = io.BytesIO()
    with wave.open(wav_buffer, "wb") as wav_file:
        wav_file.setnchannels(channels)
        wav_file.setsampwidth(sample_width)
        wav_file.setframerate(sample_rate)
        wav_file.writeframes(audio_data)
    return wav_buffer.getvalue()