import os
import shutil
import subprocess

def ffmpeg_suitability(path):
    try:
        version = subprocess.run([path, "-version"], check=True,
                                 capture_output=True).stdout.decode("utf-8")
    except:
        return 0
    score = 0
    #rough layout of the importance of various features
    simple_criterion = [("libvpx", 20),("264",10), ("265",3),
                        ("svtav1",5),("libopus", 1)]
    for criterion in simple_criterion:
        if version.find(criterion[0]) >= 0:
            score += criterion[1]
    #obtain rough compile year from copyright information
    copyright_index = version.find('2000-2')
    if copyright_index >= 0:
        copyright_year = version[copyright_index+6:copyright_index+9]
        if copyright_year.isnumeric():
            score += int(copyright_year)
    return score

if "VHS_FORCE_FFMPEG_PATH" in os.environ:
    ffmpeg_path = os.environ.get("VHS_FORCE_FFMPEG_PATH")
else:
    ffmpeg_paths = []
    try:
        from imageio_ffmpeg import get_ffmpeg_exe
        imageio_ffmpeg_path = get_ffmpeg_exe()
        ffmpeg_paths.append(imageio_ffmpeg_path)
    except:
        if "VHS_USE_IMAGEIO_FFMPEG" in os.environ:
            raise
        # logger.warn("Failed to import imageio_ffmpeg")
    if "VHS_USE_IMAGEIO_FFMPEG" in os.environ:
        ffmpeg_path = imageio_ffmpeg_path
    else:
        system_ffmpeg = shutil.which("ffmpeg")
        if system_ffmpeg is not None:
            ffmpeg_paths.append(system_ffmpeg)
        if os.path.isfile("ffmpeg"):
            ffmpeg_paths.append(os.path.abspath("ffmpeg"))
        if os.path.isfile("ffmpeg.exe"):
            ffmpeg_paths.append(os.path.abspath("ffmpeg.exe"))
        if len(ffmpeg_paths) == 0:
            # logger.error("No valid ffmpeg found.")
            ffmpeg_path = None
        elif len(ffmpeg_paths) == 1:
            #Evaluation of suitability isn't required, can take sole option
            #to reduce startup time
            ffmpeg_path = ffmpeg_paths[0]
        else:
            ffmpeg_path = max(ffmpeg_paths, key=ffmpeg_suitability)