from pathlib import Path
import subprocess
import numpy as np
from scipy.signal import correlate
import tempfile
import soundfile as sf
import matplotlib.pyplot as plt

def extract_audio(file: Path, duration: float):
    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)
    return data, sr


def get_audio_offset(file1: Path, file2: Path, important_time: 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 = lag / sr1
    return offset_seconds

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

    if sr1 != sr2:
        raise ValueError("Sample rates differ")

    sig1 = sig1 - np.mean(sig1)
    sig2 = sig2 - np.mean(sig2)

    corr = correlate(sig1, sig2, mode="full")

    lags = np.arange(-len(sig2)+1, len(sig1))
    lag_seconds = lags / sr1

    offset_index = np.argmax(corr)
    offset_seconds = lag_seconds[offset_index]

    plt.figure(figsize=(10,5))
    plt.plot(lag_seconds, corr)
    plt.axvline(offset_seconds, linestyle="--")
    plt.title(f"Audio Cross-Correlation (offset ≈ {offset_seconds:.3f}s)")
    plt.xlabel("Lag (seconds)")
    plt.ylabel("Correlation")
    plt.show()

    return offset_seconds

ger = "/home/honney/mount/Media/tmp/serien/Maid Sama All/Maid Sama/S01/07.mkv"
jap = "/home/honney/mount/Media/tmp/serien/Maid Sama All/Kaichou wa Maid-sama!/S01/07.mkv"

offset = view_audio_correlation(Path(ger), Path(jap), 90)
print(offset)