import io
import shlex
import subprocess

import discord
from discord.opus import Encoder


# Huge thanks to https://github.com/Rapptz/discord.py/issues/5192#issuecomment-669515571


class FFmpegPCMAudio(discord.AudioSource):
    def __init__(self, source, *, executable='ffmpeg', pipe=False, stderr=None, before_options=None, options=None):
        stdin = None if not pipe else source
        args = [executable]
        if isinstance(before_options, str):
            args.extend(shlex.split(before_options))
        args.append('-i')
        args.append('-' if pipe else source)
        args.extend(('-f', 's16le', '-ar', '48000', '-ac', '2', '-loglevel', 'warning'))
        if isinstance(options, str):
            args.extend(shlex.split(options))
        args.append('pipe:1')
        self._process = None
        try:
            self._process = subprocess.Popen(args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=stderr)
            self._stdout = io.BytesIO(
                self._process.communicate(input=stdin)[0]
            )
        except FileNotFoundError:
            raise discord.ClientException(executable + ' was not found.') from None
        except subprocess.SubprocessError as exc:
            raise discord.ClientException('Popen failed: {0.__class__.__name__}: {0}'.format(exc)) from exc

    def read(self):
        ret = self._stdout.read(Encoder.FRAME_SIZE)
        if len(ret) != Encoder.FRAME_SIZE:
            return b''
        return ret

    def cleanup(self):
        proc = self._process
        if proc is None:
            return
        proc.kill()
        if proc.poll() is None:
            proc.communicate()

        self._process = None