import subprocess
import os
from logzero import logger as log


"""What are the differences and similarities between ffmpeg, libav, and avconv?
https://stackoverflow.com/questions/9477115

ffmeg encoders high to lower quality
libopus > libvorbis >= libfdk_aac > aac > libmp3lame

libfdk_aac due to copyrights needs to be compiled by end user
on MacOS brew install ffmpeg --with-fdk-aac will do just that. Other OS?
https://trac.ffmpeg.org/wiki/Encode/AAC
"""


def song(input_song, output_song, folder, avconv=False, trim_silence=False):
    """ Do the audio format conversion. """
    convert = Converter(input_song, output_song, folder, trim_silence)
    if not input_song == output_song:
        log.info("Converting {0} to {1}".format(input_song, output_song.split(".")[-1]))
    elif input_song.endswith(".m4a"):
        log.info("Correcting container in {}".format(input_song))
    else:
        return 0
    if avconv:
        exit_code = convert.with_avconv()
    else:
        exit_code = convert.with_ffmpeg()
    return exit_code


class Converter:
    def __init__(self, input_song, output_song, folder, trim_silence=False):
        self.input_file = os.path.join(folder, input_song)
        self.output_file = os.path.join(folder, output_song)
        self.trim_silence = trim_silence

    def with_avconv(self):
        if log.level == 10:
            level = "debug"
        else:
            level = "0"

        command = [
            "avconv",
            "-loglevel",
            level,
            "-i",
            self.input_file,
            "-ab",
            "192k",
            self.output_file,
            "-y",
        ]

        if self.trim_silence:
            log.warning("--trim-silence not supported with avconv")

        log.debug(command)
        return subprocess.call(command)

    def with_ffmpeg(self):
        ffmpeg_pre = "ffmpeg -y "

        if not log.level == 10:
            ffmpeg_pre += "-hide_banner -nostats -v panic "

        _, input_ext = os.path.splitext(self.input_file)
        _, output_ext = os.path.splitext(self.output_file)

        ffmpeg_params = ""

        if input_ext == ".m4a":
            if output_ext == ".mp3":
                ffmpeg_params = "-codec:v copy -codec:a libmp3lame -ar 44100 "
            elif output_ext == ".webm":
                ffmpeg_params = "-codec:a libopus -vbr on "
            elif output_ext == ".m4a":
                ffmpeg_params = "-vn -acodec copy "

        elif input_ext == ".webm":
            if output_ext == ".mp3":
                ffmpeg_params = "-codec:a libmp3lame -ar 44100 "
            elif output_ext == ".m4a":
                ffmpeg_params = "-cutoff 20000 -codec:a libfdk_aac -ar 44100 "

        if output_ext == ".flac":
            ffmpeg_params = "-codec:a flac -ar 44100 "

        # add common params for any of the above combination
        ffmpeg_params += "-b:a 192k -vn "
        ffmpeg_pre += " -i"

        if self.trim_silence:
            ffmpeg_params += "-af silenceremove=start_periods=1 "

        command = (
            ffmpeg_pre.split()
            + [self.input_file]
            + ffmpeg_params.split()
            + [self.output_file]
        )

        log.debug(command)
        return subprocess.call(command)