import math
import glob
import subprocess
from mutagen.mp3 import MP3


class Chapters:

    def __init__(self, title, artist):
        self.title = title
        self.artist = artist
        self.file_names = sorted(glob.glob("*.mp3"))
        self.FFMETADATAFILE = f""";FFMETADATA1
title={self.title}
artist={self.artist}
encoder=libfdk_aac

"""
        self.file_list = ""

    def generate_metadata(self):
        start = 1

        for f in self.file_names:
            self.file_list += f"file '{f}'\n"
            mp3 = MP3(f)
            l = int(mp3.info.length * 1000)
            title = f[:-4]

            self.FFMETADATAFILE += f"""[CHAPTER]
TIMEBASE=1/1000
START={start}
END={start+l}
title={title}

"""
            start = start+l

    def convert(self):
        commands = [
            'ffmpeg',
            '-f', 'concat',
            '-safe', '0',
            '-i', 'file_list.txt',
            '-i', 'FFMETADATAFILE.txt',
            '-map_metadata', '1',
            '-c:a', 'libfdk_aac',
            '-b:a', '128k',
            '-f', 'mp4', f'{self.title}.m4b',
        ]
        if subprocess.run(commands).returncode == 0:
            print("FFmpeg Script Ran Successfully")
        else:
            print("There was an error running your FFmpeg script")


def main():
    title = input("Title: ")
    artist = input("Artist: ")
    ch = Chapters(title=title, artist=artist)
    ch.generate_metadata()
    with open("FFMETADATAFILE.txt", "w") as f:
        print(ch.FFMETADATAFILE, file=f)
    with open("file_list.txt", "w") as f:
        print(ch.file_list, file=f)

    ch.convert()


if __name__ == "__main__":
    main()