voice.py

# -*- coding: utf-8 -*-

"""
jishaku.voice
~~~~~~~~~~~~~

Voice-related functions and classes.

:copyright: (c) 2019 Devon (Gorialis) R
:license: MIT, see LICENSE for more details.

"""

import discord.opus
import discord.voice_client
from discord.ext import commands

try:
    import youtube_dl
except ImportError:
    youtube_dl = None


async def vc_check(ctx: commands.Context):  # pylint: disable=unused-argument
    """
    Check for whether VC is available in this bot.
    """

    if not discord.voice_client.has_nacl:
        raise commands.CheckFailure("voice cannot be used because PyNaCl is not loaded")

    if not discord.opus.is_loaded():
        raise commands.CheckFailure("voice cannot be used because libopus is not loaded")

    return True


async def connected_check(ctx: commands.Context):
    """
    Check whether we are connected to VC in this guild.
    """

    voice = ctx.guild.voice_client

    if not voice or not voice.is_connected():
        raise commands.CheckFailure("Not connected to VC in this guild")

    return True


async def playing_check(ctx: commands.Context):
    """
    Checks whether we are playing audio in VC in this guild.

    This doubles up as a connection check.
    """

    if await connected_check(ctx) and not ctx.guild.voice_client.is_playing():
        raise commands.CheckFailure("The voice client in this guild is not playing anything.")

    return True


BASIC_OPTS = {
    'format': 'webm[abr>0]/bestaudio/best',
    'prefer_ffmpeg': True,
    'quiet': True
}


class BasicYouTubeDLSource(discord.FFmpegPCMAudio):
    """
    Basic audio source for youtube_dl-compatible URLs.
    """

    def __init__(self, url, download: bool = False):
        ytdl = youtube_dl.YoutubeDL(BASIC_OPTS)
        info = ytdl.extract_info(url, download=download)
        super().__init__(info['url'])