import os
import sys
import re
import subprocess

from datetime import datetime, timedelta

EACH_SEC = 6000
OVERFLOW_SEC = 4


def get_video_real_duration(filename):
    ffmpeg_process = subprocess.Popen([
        "ffmpeg", "-hide_banner", "-i", filename, "-c", "copy", "-f", "null", "-"
    ], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    result = "0:0:0.0"
    for line in ffmpeg_process.stderr.readlines():
        match_result = re.findall("(?<= time=).+?(?= )", line.decode())
        if len(match_result) == 0:
            continue
        result = match_result.pop()
    return result


if __name__ == '__main__':
    if len(sys.argv) < 2:
        print("请输入文件")
        exit(1)
    input_file = sys.argv[1]
    if not os.path.isfile(input_file):
        raise FileNotFoundError(input_file)
    file_name = os.path.split(input_file)[-1]
    _create_dt = os.path.splitext(file_name)[0]
    create_dt = datetime.strptime(_create_dt, "%Y%m%d_%H%M")
    print(create_dt)
    _duration_str = get_video_real_duration(input_file)
    _duration = datetime.strptime(_duration_str, "%H:%M:%S.%f") - datetime(1900, 1, 1)
    duration = _duration.total_seconds()
    print(duration)
    current_sec = 0
    while current_sec < duration:
        current_dt = (create_dt + timedelta(seconds=current_sec)).strftime("%Y%m%d_%H%M")
        print("CUR_DT", current_dt)
        print("BIAS_T", current_sec)
        split_process = subprocess.Popen([
            "ffmpeg", "-y", "-hide_banner", "-progress", "-", "-v", "0",
            "-ss", str(current_sec),
            "-i", input_file, "-c", "copy", "-f", "mp4",
            "-t", str(EACH_SEC + OVERFLOW_SEC),
            "-shortest",
            "{}.mp4".format(current_dt)
        ])
        split_process.wait()
        current_sec += EACH_SEC