# for import needed
import sys
from pathlib import Path

sys.path.append(str(Path(__file__).resolve().parent.parent))

from utils import run
### Normal Imports:
import tempfile
import subprocess
import soundfile as sf
import numpy as np
from scipy.signal import correlate

def extract_audio(file: Path, duration: float) -> tuple[np.ndarray, int]:
    tmp = tempfile.NamedTemporaryFile(suffix=".wav", delete=False)

    subprocess.run([
        "ffmpeg",
        "-y",
        "-i", str(file),
        "-map", "0:a:0",        # first audio stream
        "-ac", "1",             # mono
        "-ar", "44100",         # fixed sample rate
        "-t", str(duration),    # limit duration
        tmp.name
    ], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)

    data, sr = sf.read(tmp.name)
    if not isinstance(data, np.ndarray):
        raise ChildProcessError(f"Could not get signal from {file}")
    if not isinstance(sr, int):
        try:
            sr = int(sr)
        except:
            ValueError(f"sr could not be read from {file}")
    return data, sr

def get_audio_offset(file1: Path, file2: Path, important_time: float) -> float:
    sig1, sr1 = extract_audio(file1, important_time)
    sig2, sr2 = extract_audio(file2, important_time)

    if sr1 != sr2:
        raise ValueError("Sample rates do not match")

    # normalize signals
    sig1 = sig1 - np.mean(sig1)
    sig2 = sig2 - np.mean(sig2)

    corr = correlate(sig1, sig2, mode="full")
    lag = np.argmax(corr) - (len(sig2) - 1)

    offset_seconds = float(lag / sr1)
    return offset_seconds