Redoing all Music Code, seeing if it works

cogs/music.py

@@ -1,15 +1,31 @@
+"""
+Please understand Music bots are complex, and that even this basic example can be daunting to a beginner.
+For this reason it's highly advised you familiarize yourself with discord.py, python and asyncio, BEFORE
+you attempt to write a music bot.
+This example makes use of: Python 3.6
+For a more basic voice example please read:
+    https://github.com/Rapptz/discord.py/blob/rewrite/examples/basic_voice.py
+This is a very basic playlist example, which allows per guild playback of unique queues.
+The commands implement very basic logic for basic usage. But allow for expansion. It would be advisable to implement
+your own permissions and usage logic for commands.
+e.g You might like to implement a vote before skipping the song or only allow admins to stop the player.
+Music bots require lots of work, and tuning. Goodluck.
+If you find any bugs feel free to ping me on discord. @Eviee#0666
+"""
 import asyncio
+import itertools
+import sys
+import traceback
+from functools import partial
 
 import discord
-import youtube_dl
+from async_timeout import timeout
 from discord.ext import commands
+from youtube_dl import YoutubeDL
 
-# Suppress noise about console usage from errors
+ytdlopts = {
-youtube_dl.utils.bug_reports_message = lambda: ''
-
-ytdl_format_options = {
     'format': 'bestaudio/best',
-    'outtmpl': '%(extractor)s-%(id)s-%(title)s.%(ext)s',
+    'outtmpl': 'downloads/%(extractor)s-%(id)s-%(title)s.%(ext)s',
     'restrictfilenames': True,
     'noplaylist': True,
     'nocheckcertificate': True,
@@ -18,107 +34,375 @@ ytdl_format_options = {
     'quiet': True,
     'no_warnings': True,
     'default_search': 'auto',
-    'source_address': '0.0.0.0'  # bind to ipv4 since ipv6 addresses cause issues sometimes
+    'source_address': '0.0.0.0'  # ipv6 addresses cause issues sometimes
 }
 
-ffmpeg_options = {
+ffmpegopts = {
+    'before_options': '-nostdin',
     'options': '-vn'
 }
 
-ytdl = youtube_dl.YoutubeDL(ytdl_format_options)
+ytdl = YoutubeDL(ytdlopts)
+
+
+class VoiceConnectionError(commands.CommandError):
+    """Custom Exception class for connection errors."""
+
+
+class InvalidVoiceChannel(VoiceConnectionError):
+    """Exception for cases of invalid Voice Channels."""
 
 
 class YTDLSource(discord.PCMVolumeTransformer):
-    def __init__(self, source, *, data, volume=0.5):
-        super().__init__(source, volume)
 
-        self.data = data
+    def __init__(self, source, *, data, requester):
+        super().__init__(source)
+        self.requester = requester
 
         self.title = data.get('title')
-        self.url = data.get('url')
+        self.web_url = data.get('webpage_url')
+
+        # YTDL info dicts (data) have other useful information you might want
+        # https://github.com/rg3/youtube-dl/blob/master/README.md
+
+    def __getitem__(self, item: str):
+        """Allows us to access attributes similar to a dict.
+        This is only useful when you are NOT downloading.
+        """
+        return self.__getattribute__(item)
 
     @classmethod
-    async def from_url(cls, url, *, loop=None, stream=False):
+    async def create_source(cls, ctx, search: str, *, loop, download=False):
         loop = loop or asyncio.get_event_loop()
-        data = await loop.run_in_executor(None, lambda: ytdl.extract_info(url, download=not stream))
+
+        to_run = partial(ytdl.extract_info, url=search, download=download)
+        data = await loop.run_in_executor(None, to_run)
 
         if 'entries' in data:
             # take first item from a playlist
             data = data['entries'][0]
 
-        filename = data['url'] if stream else ytdl.prepare_filename(data)
+        await ctx.send(f'```ini\n[Added {data["title"]} to the Queue.]\n```', delete_after=15)
-        return cls(discord.FFmpegPCMAudio(filename, **ffmpeg_options), data=data)
+
+        if download:
+            source = ytdl.prepare_filename(data)
+        else:
+            return {'webpage_url': data['webpage_url'], 'requester': ctx.author, 'title': data['title']}
 
+        return cls(discord.FFmpegPCMAudio(source), data=data, requester=ctx.author)
+
+    @classmethod
+    async def regather_stream(cls, data, *, loop):
+        """Used for preparing a stream, instead of downloading.
+        Since Youtube Streaming links expire."""
+        loop = loop or asyncio.get_event_loop()
+        requester = data['requester']
+
+        to_run = partial(ytdl.extract_info, url=data['webpage_url'], download=False)
+        data = await loop.run_in_executor(None, to_run)
+
+        return cls(discord.FFmpegPCMAudio(data['url']), data=data, requester=requester)
+
+
+class MusicPlayer:
+    """A class which is assigned to each guild using the bot for Music.
+    This class implements a queue and loop, which allows for different guilds to listen to different playlists
+    simultaneously.
+    When the bot disconnects from the Voice it's instance will be destroyed.
+    """
+
+    __slots__ = ('bot', '_guild', '_channel', '_cog', 'queue', 'next', 'current', 'np', 'volume')
+
+    def __init__(self, ctx):
+        self.bot = ctx.bot
+        self._guild = ctx.guild
+        self._channel = ctx.channel
+        self._cog = ctx.cog
+
+        self.queue = asyncio.Queue()
+        self.next = asyncio.Event()
+
+        self.np = None  # Now playing message
+        self.volume = .5
+        self.current = None
+
+        ctx.bot.loop.create_task(self.player_loop())
+
+    async def player_loop(self):
+        """Our main player loop."""
+        await self.bot.wait_until_ready()
+
+        while not self.bot.is_closed():
+            self.next.clear()
+
+            try:
+                # Wait for the next song. If we timeout cancel the player and disconnect...
+                async with timeout(300):  # 5 minutes...
+                    source = await self.queue.get()
+            except asyncio.TimeoutError:
+                return self.destroy(self._guild)
+
+            if not isinstance(source, YTDLSource):
+                # Source was probably a stream (not downloaded)
+                # So we should regather to prevent stream expiration
+                try:
+                    source = await YTDLSource.regather_stream(source, loop=self.bot.loop)
+                except Exception as e:
+                    await self._channel.send(f'There was an error processing your song.\n'
+                                             f'```css\n[{e}]\n```')
+                    continue
+
+            source.volume = self.volume
+            self.current = source
+
+            self._guild.voice_client.play(source, after=lambda _: self.bot.loop.call_soon_threadsafe(self.next.set))
+            self.np = await self._channel.send(f'**Now Playing:** `{source.title}` requested by '
+                                               f'`{source.requester}`')
+            await self.next.wait()
+
+            # Make sure the FFmpeg process is cleaned up.
+            source.cleanup()
+            self.current = None
+
+            try:
+                # We are no longer playing this song...
+                await self.np.delete()
+            except discord.HTTPException:
+                pass
+
+    def destroy(self, guild):
+        """Disconnect and cleanup the player."""
+        return self.bot.loop.create_task(self._cog.cleanup(guild))
+
+
+class Music:
+    """Music related commands."""
+
+    __slots__ = ('bot', 'players')
 
-class Music(commands.Cog):
     def __init__(self, bot):
         self.bot = bot
+        self.players = {}
 
-    @commands.command()
+    async def cleanup(self, guild):
-    async def join(self, ctx, *, channel: discord.VoiceChannel):
+        try:
-        """Joins a voice channel"""
+            await guild.voice_client.disconnect()
+        except AttributeError:
+            pass
 
-        if ctx.voice_client is not None:
+        try:
-            return await ctx.voice_client.move_to(channel)
+            del self.players[guild.id]
+        except KeyError:
+            pass
 
-        await channel.connect()
+    async def __local_check(self, ctx):
+        """A local check which applies to all commands in this cog."""
+        if not ctx.guild:
+            raise commands.NoPrivateMessage
+        return True
 
-    """@commands.command()
+    async def __error(self, ctx, error):
-    async def play(self, ctx, *, query):
+        """A local error handler for all errors arising from commands in this cog."""
-        """"""Plays a file from the local filesystem""""""
+        if isinstance(error, commands.NoPrivateMessage):
+            try:
+                return await ctx.send('This command can not be used in Private Messages.')
+            except discord.HTTPException:
+                pass
+        elif isinstance(error, InvalidVoiceChannel):
+            await ctx.send('Error connecting to Voice Channel. '
+                           'Please make sure you are in a valid channel or provide me with one')
 
-        source = discord.PCMVolumeTransformer(discord.FFmpegPCMAudio(query))
+        print('Ignoring exception in command {}:'.format(ctx.command), file=sys.stderr)
-        ctx.voice_client.play(source, after=lambda e: print('Player error: %s' % e) if e else None)
+        traceback.print_exception(type(error), error, error.__traceback__, file=sys.stderr)
 
-        await ctx.send('Now playing: {}'.format(query))"""
+    def get_player(self, ctx):
+        """Retrieve the guild player, or generate one."""
+        try:
+            player = self.players[ctx.guild.id]
+        except KeyError:
+            player = MusicPlayer(ctx)
+            self.players[ctx.guild.id] = player
+
+        return player
+
+    @commands.command(name='connect', aliases=['join'])
+    async def connect_(self, ctx, *, channel: discord.VoiceChannel = None):
+        """Connect to voice.
+        Parameters
+        ------------
+        channel: discord.VoiceChannel [Optional]
+            The channel to connect to. If a channel is not specified, an attempt to join the voice channel you are in
+            will be made.
+        This command also handles moving the bot to different channels.
+        """
+        if not channel:
+            try:
+                channel = ctx.author.voice.channel
+            except AttributeError:
+                raise InvalidVoiceChannel('No channel to join. Please either specify a valid channel or join one.')
 
-    @commands.command(name="play", aliases=["p", "Play", "P"])
+        vc = ctx.voice_client
-    async def play(self, ctx, *, url):
-        """Plays from a url (almost anything youtube_dl supports)"""
 
-        async with ctx.typing():
+        if vc:
-            player = await YTDLSource.from_url(url, loop=self.bot.loop, stream=True)
+            if vc.channel.id == channel.id:
-            ctx.voice_client.play(player, after=lambda e: print('Player error: %s' % e) if e else None)
+                return
+            try:
+                await vc.move_to(channel)
+            except asyncio.TimeoutError:
+                raise VoiceConnectionError(f'Moving to channel: <{channel}> timed out.')
+        else:
+            try:
+                await channel.connect()
+            except asyncio.TimeoutError:
+                raise VoiceConnectionError(f'Connecting to channel: <{channel}> timed out.')
 
-        await ctx.send('Now playing: **{}**'.format(player.title))
+        await ctx.send(f'Connected to: **{channel}**', delete_after=20)
 
-    @commands.command()
+    @commands.command(name='play', aliases=['sing'])
-    async def stream(self, ctx, *, url):
+    async def play_(self, ctx, *, search: str):
-        """Streams from a url (same as yt, but doesn't predownload)"""
+        """Request a song and add it to the queue.
+        This command attempts to join a valid voice channel if the bot is not already in one.
+        Uses YTDL to automatically search and retrieve a song.
+        Parameters
+        ------------
+        search: str [Required]
+            The song to search and retrieve using YTDL. This could be a simple search, an ID or URL.
+        """
+        await ctx.trigger_typing()
 
-        async with ctx.typing():
+        vc = ctx.voice_client
-            player = await YTDLSource.from_url(url, loop=self.bot.loop)
-            ctx.voice_client.play(player, after=lambda e: print('Player error: %s' % e) if e else None)
 
+        if not vc:
+            await ctx.invoke(self.connect_)
+
+        player = self.get_player(ctx)
+
+        # If download is False, source will be a dict which will be used later to regather the stream.
+        # If download is True, source will be a discord.FFmpegPCMAudio with a VolumeTransformer.
+        source = await YTDLSource.create_source(ctx, search, loop=self.bot.loop, download=False)
         await ctx.send('Now playing: {}'.format(player.title))
 
-    @commands.command()
+        await player.queue.put(source)
-    async def volume(self, ctx, volume: int):
-        """Changes the player's volume"""
 
-        if ctx.voice_client is None:
+    @commands.command(name='pause')
-            return await ctx.send("Not connected to a voice channel.")
+    async def pause_(self, ctx):
+        """Pause the currently playing song."""
+        vc = ctx.voice_client
 
-        ctx.voice_client.source.volume = volume / 100
+        if not vc or not vc.is_playing():
-        await ctx.send("Changed volume to {}%".format(volume))
+            return await ctx.send('I am not currently playing anything!', delete_after=20)
+        elif vc.is_paused():
+            return
 
-    @commands.command()
+        vc.pause()
-    async def stop(self, ctx):
+        await ctx.send(f'**`{ctx.author}`**: Paused the song!')
-        """Stops and disconnects the bot from voice"""
 
-        await ctx.voice_client.disconnect()
+    @commands.command(name='resume')
+    async def resume_(self, ctx):
+        """Resume the currently paused song."""
+        vc = ctx.voice_client
 
-    @play.before_invoke
+        if not vc or not vc.is_connected():
-    @stream.before_invoke
+            return await ctx.send('I am not currently playing anything!', delete_after=20)
-    async def ensure_voice(self, ctx):
+        elif not vc.is_paused():
-        if ctx.voice_client is None:
+            return
-            if ctx.author.voice:
+
-                await ctx.author.voice.channel.connect()
+        vc.resume()
-            else:
+        await ctx.send(f'**`{ctx.author}`**: Resumed the song!')
-                await ctx.send("You are not connected to a voice channel.")
+
-                raise commands.CommandError("Author not connected to a voice channel.")
+    @commands.command(name='skip')
-        elif ctx.voice_client.is_playing():
+    async def skip_(self, ctx):
-            ctx.voice_client.stop()
+        """Skip the song."""
+        vc = ctx.voice_client
+
+        if not vc or not vc.is_connected():
+            return await ctx.send('I am not currently playing anything!', delete_after=20)
+
+        if vc.is_paused():
+            pass
+        elif not vc.is_playing():
+            return
+
+        vc.stop()
+        await ctx.send(f'**`{ctx.author}`**: Skipped the song!')
+
+    @commands.command(name='queue', aliases=['q', 'playlist'])
+    async def queue_info(self, ctx):
+        """Retrieve a basic queue of upcoming songs."""
+        vc = ctx.voice_client
+
+        if not vc or not vc.is_connected():
+            return await ctx.send('I am not currently connected to voice!', delete_after=20)
+
+        player = self.get_player(ctx)
+        if player.queue.empty():
+            return await ctx.send('There are currently no more queued songs.')
+
+        # Grab up to 5 entries from the queue...
+        upcoming = list(itertools.islice(player.queue._queue, 0, 5))
+
+        fmt = '\n'.join(f'**`{_["title"]}`**' for _ in upcoming)
+        embed = discord.Embed(title=f'Upcoming - Next {len(upcoming)}', description=fmt)
+
+        await ctx.send(embed=embed)
+
+    @commands.command(name='now_playing', aliases=['np', 'current', 'currentsong', 'playing'])
+    async def now_playing_(self, ctx):
+        """Display information about the currently playing song."""
+        vc = ctx.voice_client
+
+        if not vc or not vc.is_connected():
+            return await ctx.send('I am not currently connected to voice!', delete_after=20)
+
+        player = self.get_player(ctx)
+        if not player.current:
+            return await ctx.send('I am not currently playing anything!')
+
+        try:
+            # Remove our previous now_playing message.
+            await player.np.delete()
+        except discord.HTTPException:
+            pass
+
+        player.np = await ctx.send(f'**Now Playing:** `{vc.source.title}` '
+                                   f'requested by `{vc.source.requester}`')
+
+    @commands.command(name='volume', aliases=['vol'])
+    async def change_volume(self, ctx, *, volume: float):
+        """Change the player volume.
+        Parameters
+        ------------
+        volume: float or int [Required]
+            The volume to set the player to in percentage. This must be between 1 and 100.
+        """
+        vc = ctx.voice_client
+
+        if not vc or not vc.is_connected():
+            return await ctx.send('I am not currently connected to voice!', delete_after=20)
+
+        if not 0 < volume < 101:
+            return await ctx.send('Please enter a value between 1 and 100.')
+
+        player = self.get_player(ctx)
+
+        if vc.source:
+            vc.source.volume = volume / 100
+
+        player.volume = volume / 100
+        await ctx.send(f'**`{ctx.author}`**: Set the volume to **{volume}%**')
+
+    @commands.command(name='stop')
+    async def stop_(self, ctx):
+        """Stop the currently playing song and destroy the player.
+        !Warning!
+            This will destroy the player assigned to your guild, also deleting any queued songs and settings.
+        """
+        vc = ctx.voice_client
+
+        if not vc or not vc.is_connected():
+            return await ctx.send('I am not currently playing anything!', delete_after=20)
+
+        await self.cleanup(ctx.guild)
 
 
 def setup(bot):