Implement queue

src/bot.py

@@ -1,26 +1,70 @@
 import os
 import sys
+import asyncio
 
-from discord.ext import commands
+import discord
+from discord.ext import commands, tasks
 from dotenv import load_dotenv
+import youtube_dl
 
-from yt import YTDLSource
 from error import ErrorHandler
 
 load_dotenv()
 
+# Suppress noise about console usage from errors
+youtube_dl.utils.bug_reports_message = lambda: ''
+
 
 class Music(commands.Cog):
   def __init__(self, bot):
     self.bot = bot
+    self.queue = asyncio.Queue()
+    self.queue_lock = asyncio.Lock()
+    self._ytdl_format_options = {
+        'format': 'bestaudio/best',
+        'outtmpl': '%(extractor)s-%(id)s-%(title)s.%(ext)s',
+        'restrictfilenames': True,
+        'noplaylist': True,
+        'nocheckcertificate': True,
+        'ignoreerrors': False,
+        'logtostderr': False,
+        'quiet': True,
+        'no_warnings': True,
+        'default_search': 'auto',
+        'source_address': '0.0.0.0'  # bind to ipv4 since ipv6 addresses cause issues sometimes
+    }
+    self._ffmpeg_options = {
+        'options': '-vn'
+    }
+    self.ytdl = youtube_dl.YoutubeDL(self._ytdl_format_options)
+    # pylint: disable=no-member
+    self.handle_playback.start()
+
+  @tasks.loop()
+  async def handle_playback(self):
+    while True:
+      await self.queue_lock.acquire()
+      ctx, url, title = await self.queue.get()
+      audio = discord.FFmpegPCMAudio(url, **self._ffmpeg_options)
+
+      def after(err):
+        if err:
+          print(f"Player error: {err}")
+        self.queue.task_done()
+        self.queue_lock.release()
+      ctx.voice_client.play(audio, after=after)
+      await ctx.send(f"Now playing: {title}")
 
   @commands.command()
   async def play(self, ctx, *, url):
     async with ctx.typing():
-      player = await YTDLSource.from_url(url, loop=self.bot.loop, stream=True)
-      ctx.voice_client.play(player, after=lambda e: print(f"Player error: {e}") if e else None)
-
-    await ctx.send(f"Now playing: {player.title}")
+      data = self.ytdl.extract_info(url, download=False)
+      if 'entries' in data:
+        data = data['entries'][0]
+        title = data.get('title')
+        url = data.get('url')
+        await self.queue.put((ctx, url, title))
+        await ctx.send(f"Queued: {title}")
 
   @commands.command()
   async def stop(self, ctx):
@@ -33,8 +77,6 @@ class Music(commands.Cog):
         await ctx.author.voice.channel.connect()
       else:
         raise commands.CommandError("Author not connected to a voice channel.")
-    elif ctx.voice_client.is_playing():
-      ctx.voice_client.stop()
 
 
 if __name__ == "__main__":

src/yt.py

@@ -1,50 +0,0 @@
-import asyncio
-
-import discord
-import youtube_dl
-
-# Suppress noise about console usage from errors
-youtube_dl.utils.bug_reports_message = lambda: ''
-
-
-ytdl_format_options = {
-    'format': 'bestaudio/best',
-    'outtmpl': '%(extractor)s-%(id)s-%(title)s.%(ext)s',
-    'restrictfilenames': True,
-    'noplaylist': True,
-    'nocheckcertificate': True,
-    'ignoreerrors': False,
-    'logtostderr': False,
-    'quiet': True,
-    'no_warnings': True,
-    'default_search': 'auto',
-    'source_address': '0.0.0.0'  # bind to ipv4 since ipv6 addresses cause issues sometimes
-}
-
-ffmpeg_options = {
-    'options': '-vn'
-}
-
-ytdl = youtube_dl.YoutubeDL(ytdl_format_options)
-
-
-class YTDLSource(discord.PCMVolumeTransformer):
-  def __init__(self, source, *, data, volume=0.5):
-    super().__init__(source, volume)
-
-    self.data = data
-
-    self.title = data.get('title')
-    self.url = data.get('url')
-
-  @classmethod
-  async def from_url(cls, url, *, loop=None, stream=False):
-    loop = loop or asyncio.get_event_loop()
-    data = await loop.run_in_executor(None, lambda: ytdl.extract_info(url, download=not stream))
-
-    if 'entries' in data:
-      # take first item from a playlist
-      data = data['entries'][0]
-
-    filename = data['url'] if stream else ytdl.prepare_filename(data)
-    return cls(discord.FFmpegPCMAudio(filename, **ffmpeg_options), data=data)