import numpy as np
import noisereduce as nr
import soundfile as sf
from pydub import AudioSegment
import io

def preprocess_audio(file_bytes):
    # Charger l'audio
    audio = AudioSegment.from_file(io.BytesIO(file_bytes))
    # Convertir en mono, 16kHz
    audio = audio.set_channels(1).set_frame_rate(16000)
    # Exporter en wav bytes
    wav_io = io.BytesIO()
    audio.export(wav_io, format='wav')
    wav_io.seek(0)
    # Charger en numpy
    y, sr = sf.read(wav_io)
    # Réduction de bruit
    y_denoised = nr.reduce_noise(y=y, sr=sr)
    # Sauvegarder en wav bytes
    out_io = io.BytesIO()
    sf.write(out_io, y_denoised, sr, format='WAV')
    out_io.seek(0)
    return out_io