import os
import re
import subprocess
from datetime import datetime, timedelta
from typing import IO

from config import FFMPEG_EXEC, VIDEO_BITRATE, FFMPEG_USE_GPU, VIDEO_CLIP_EACH_SEC, VIDEO_CLIP_OVERFLOW_SEC, PROD_ENV


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


def encode_video_with_subtitles(orig_filename: str, subtitles: list[str], new_filename: str):
    encode_process = subprocess.Popen([
        FFMPEG_EXEC, "-hide_banner", "-progress", "-", "-v", "0", "-y",
        "-i", orig_filename, "-vf",
        ",".join("subtitles=%s" % i for i in subtitles) + (",hwupload_cuda" if FFMPEG_USE_GPU else ""),
        "-c:a", "copy", "-c:v", "h264_nvenc" if FFMPEG_USE_GPU else "h264", "-f", "mp4",
        "-preset:v", "fast", "-profile:v", "high", "-level", "4.1",
        "-b:v", VIDEO_BITRATE, "-rc:v", "vbr", *(["-tune:v", "hq"] if FFMPEG_USE_GPU else []),
        "-qmin", "10", "-qmax", "32", "-crf", "16",
        # "-t", "10",
        new_filename
    ], stdout=subprocess.PIPE)
    handle_ffmpeg_output(encode_process.stdout)
    return encode_process.wait()


def handle_ffmpeg_output(stderr: IO[bytes]) -> None:
    while True:
        line = stderr.readline()
        if line == b"":
            break
        if PROD_ENV:
            # 正式环境不要输出一大堆的东西了
            continue
        if line.startswith(b"out_time="):
            cur_time = line.replace(b"out_time=", b"").decode()
            print("CurTime", cur_time.strip())
        if line.startswith(b"speed="):
            speed = line.replace(b"speed=", b"").decode()
            print("Speed", speed.strip())


def quick_split_video(file):
    if not os.path.isfile(file):
        raise FileNotFoundError(file)
    file_name = os.path.split(file)[-1]
    _create_dt = os.path.splitext(file_name)[0]
    create_dt = datetime.strptime(_create_dt, "%Y%m%d_%H%M")
    _duration_str = get_video_real_duration(file)
    _duration = datetime.strptime(_duration_str, "%H:%M:%S.%f") - datetime(1900, 1, 1)
    duration = _duration.total_seconds()
    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", file_name, "-c", "copy", "-f", "mp4",
            "-t", str(VIDEO_CLIP_EACH_SEC + VIDEO_CLIP_OVERFLOW_SEC),
            "{}.mp4".format(current_dt)
        ], stdout=subprocess.PIPE)
        handle_ffmpeg_output(split_process.stdout)
        current_sec += VIDEO_CLIP_EACH_SEC