import subprocess
import os
import json


def isMkvpropeditAvailable():
    if subprocess.run("mkvpropedit"):
        print("mkvpropedit exists.")


def getListOfSubtitles(filename):
    if not os.path.exists(filename):
        raise FileNotFoundError
    result = subprocess.run(
        ["mkvmerge", "-i", filename, "-F", "json"], capture_output=True
    )
    if result.returncode == 0:
        info = json.loads(result.stdout)
        return {
            track["id"]: track["properties"]["language"]
            for track in info["tracks"]
            if track["type"] == "subtitles"
        }


if __name__ == "__main__":
    getListOfSubtitles("/home/lukas/Downloads/test5.mkv")