#!/usr/bin/python3
"""
mkvmerge required (python-pymkv)
ffmpeg required
TODO:
DONE make encoding queue with limiting by workers
DONE make concatenating videos after encoding
DONE make passing your arguments for encoding,
make separate audio and encode it separately,
"""

import os
import subprocess
import argparse
import time
import shutil
import pathlib
from multiprocessing import Pool
try:
    import scenedetect
except:
    print('ERROR: No PyScenedetect installed, try: sudo pip install scenedetect')


def arg_parsing():
    """
    Command line parser
    """

    parser = argparse.ArgumentParser()
    parser.add_argument('--encoding_params', type=str,
                        default=' -an -c:v libaom-av1 -strict -2 -row-mt 1 -tiles 2x2 -cpu-used 8 -crf 60 ',
                        help='FFmpeg settings')
    parser.add_argument('--input_file', '-i', type=str, default='bruh.mp4', help='input video file')
    parser.add_argument('--num_worker', '-t', type=int, default=8, help='number of encode running at a time')
    return parser.parse_args()


def get_cpu_count():
    return os.cpu_count()


def get_ram():
    return round((os.sysconf('SC_PAGE_SIZE') * os.sysconf('SC_PHYS_PAGES')) / (1024. ** 3), 3)


def extract_audio(input_vid):
    """
    Extracting audio from video file
    """
    cmd = f'ffmpeg -i {os.getcwd()}/{input_vid} -vn -acodec libopus {os.getcwd()}/temp/audio.opus'
    subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE).wait()


def split_video(input_vid):
    cmd2 = f'scenedetect -i {input_vid} --output temp/split detect-content split-video -c'
    subprocess.call(cmd2, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    print(f'Video {input_vid} splitted')


def get_video_queue(source_path):
    videos = []
    for root, dirs, files in os.walk(source_path):
        for file in files:
            f = os.path.getsize(os.path.join(root, file))
            videos.append([file, f])

    videos = sorted(videos, key=lambda x: -x[1])
    return videos


def encode(commands):
    """
    Passing encoding params to ffmpeg for encoding
    TODO:
    Replace ffmpeg with aomenc because ffmpeg libaom doen't work with parameters properly
    """
    cmd = f'ffmpeg {commands}'
    print('Started encode process...')
    subprocess.Popen(cmd, shell=True).wait()
    print('Finished encode process')


def concat():
    """
    Using FFMPEG to concatenate all encoded videos to 1 file.
    Reading all files in A-Z order and saving it to concat.txt
    """
    with open(f'{os.getcwd()}/temp/concat.txt', 'w') as f:

        for root, firs, files in os.walk(f'{os.getcwd()}/temp/encode'):
            for file in sorted(files):
                f.write(f"file '{os.path.join(root, file)}'\n")

    cmd = f'ffmpeg -f concat -safe 0 -i {os.getcwd()}/temp/concat.txt -i {os.getcwd()}/temp/audio.opus -c copy output.webm'
    subprocess.Popen(cmd, shell=True).wait()
    print('File finished')


def main(input_video, encoding_params, num_worker):

    # Make temporal directories, and remove them if already presented
    if os.path.isdir(f'{os.getcwd()}/temp/'):
        shutil.rmtree(f'{os.getcwd()}/temp')

    os.makedirs(f'{os.getcwd()}/temp/split')
    os.makedirs(f'{os.getcwd()}/temp/encode')

    # Extracting audio
    extract_audio(input_video)

    # Spliting video and sorting big-first
    split_video(input_video)
    vid_queue = get_video_queue('temp')
    files = [i[0] for i in vid_queue[:-1]]

    # Making list of commands for encoding
    commands = [f'-i {os.getcwd()}/temp/split/{file} {encoding_params} {os.getcwd()}/temp/encode/{file}' for file in files]

    # Creating threading pool to encode fixed amount of files at the same time
    pool = Pool(num_worker)
    pool.map(encode, commands)

    # Merging all encoded videos to 1
    concat()


if __name__ == '__main__':

    # Command line parser
    parser = argparse.ArgumentParser()
    parser.add_argument('--encoding_params', type=str, default=' -an -c:v libaom-av1 -strict -2 -row-mt 1 -tiles 2x2 -cpu-used 8 -crf 60 ', help='FFmpeg settings')
    parser.add_argument('--input_file', '-i', type=str, default='bruh.mp4', help='input video file')
    parser.add_argument('--num_worker', '-t', type=int, default=8, help='number of encode running at a time')

    args = arg_parsing()

    # Main thread
    start = time.time()
    main(args.input_file, args.encoding_params, args.num_worker)
    print(f'Encoding completed in {round(time.time()-start)}ces')

    # Delete temp folders
    shutil.rmtree(f'{os.getcwd()}/temp')