bot-skel.py

#!./.venv/bin/python

import discord      # base discord module
import code         # code.interact
import os           # environment variables
import inspect      # call stack inspection
import random
import os
from discord.channel import VoiceChannel
from discord.ext import commands	# Bot class and utils

################################################################################
############################### HELPER FUNCTIONS ###############################
################################################################################

# log_msg - fancy print
#   @msg   : string to print
#   @level : log level from {'debug', 'info', 'warning', 'error'}
def log_msg(msg: str, level: str):
    # user selectable display config (prompt symbol, color)
    dsp_sel = {
        'debug'   : ('\033[34m', '-'),
        'info'    : ('\033[32m', '*'),
        'warning' : ('\033[33m', '?'),
        'error'   : ('\033[31m', '!'),
    }

    # internal ansi codes
    _extra_ansi = {
        'critical' : '\033[35m',
        'bold'     : '\033[1m',
        'unbold'   : '\033[2m',
        'clear'    : '\033[0m',
    }

    # get information about call site
    caller = inspect.stack()[1]

    # input sanity check
    if level not in dsp_sel:
        print('%s%s[@] %s:%d %sBad log level: "%s"%s' % \
            (_extra_ansi['critical'], _extra_ansi['bold'],
             caller.function, caller.lineno,
             _extra_ansi['unbold'], level, _extra_ansi['clear']))
        return

    # print the damn message already
    print('%s%s[%s] %s:%d %s%s%s' % \
        (_extra_ansi['bold'], *dsp_sel[level],
         caller.function, caller.lineno,
         _extra_ansi['unbold'], msg, _extra_ansi['clear']))

################################################################################
############################## BOT IMPLEMENTATION ##############################
################################################################################

song_list = {
    'song1.mp3' : '1',
    'song2.mp3' : '2',
    'song3.mp3' : '3'
}

# bot instantiation
bot = commands.Bot(command_prefix='*')

# on_ready - called after connection to server is established
@bot.event
async def on_ready():
    log_msg('logged on as <%s>' % bot.user, 'info')

# on_message - called when a new message is posted to the server
#   @msg : discord.message.Message
@bot.event
async def on_message(msg):
    # filter out our own messages
    if msg.author == bot.user:
        return

    log_msg('message from <%s>: "%s"' % (msg.author, msg.content), 'debug')

    # overriding the default on_message handler blocks commands from executing
    # manually call the bot's command processor on given message
    await bot.process_commands(msg)
    #code.interact(local=dict(globals(), **locals()))

@bot.event
async def on_voice_state_update(member, before, after):
    voice_state = member.guild.voice_client
    if voice_state is None:
        return
    if len(voice_state.channel.members) == 1:
        await voice_state.disconnect()

@bot.command(brief='Play a song.')
# play - play music
async def play(ctx, song):
    if not ctx.message.author.voice:
        await ctx.send("You're not in any voice channel :(".format(ctx.message.author.name))
        return
    else:
        channel = ctx.message.author.voice.channel
        await ctx.send("Here I am.")
        await channel.connect()
        try :
            server = ctx.message.guild
            voice_channel = server.voice_client
            if song in song_list:
                async with ctx.typing():
                    voice_channel.play(discord.FFmpegPCMAudio(song))
                await ctx.send('Current song: ' + song)
            else :
                await ctx.send("I don't know that song.")
        except :
            await ctx.send("Not playing anything right now.")

@bot.command()
async def list(ctx):
    await ctx.send("Song list: ")
    for key in song_list:
        await ctx.send(song_list[key] + '. ' + key)


@bot.command(brief='The bot will leave the voice channel.')
async def scram(ctx):
    voice_client = ctx.message.guild.voice_client
    if voice_client.is_connected():
        await voice_client.disconnect()
        await ctx.send("Ok, bye...")
    else:
        await ctx.send("The bot is not connected to a voice channel.")


@bot.command(brief='Pause the song.')
async def pause(ctx):
    voice = discord.utils.get(bot.voice_clients, guild= ctx.guild)
    if voice.is_playing():
        voice.pause()
        await ctx.send("Paused song.")
    else:
        await ctx.send("Not playing anything at the moment.")

@bot.command()
async def resume(ctx):
    voice = discord.utils.get(bot.voice_clients, guild= ctx.guild)
    if voice.is_paused():
        voice.resume()
        await ctx.send("Let's resume :)")
    else:
        await ctx.send("I'm already playing something.")

@bot.command()
async def stop(ctx):
    voice = discord.utils.get(bot.voice_clients, guild= ctx.guild)
    voice.stop();

# roll - rng chat command
#   @ctx     : command invocation context
#   @max_val : upper bound for number generation (must be at least 1)
@bot.command(brief='Generate random number between 1 and <arg>')
async def roll(ctx, max_val: int):
    # argument sanity check
    if max_val < 1:
        raise Exception('argument <max_val> must be at least 1')

    await ctx.send(random.randint(1, max_val))

# roll_error - error handler for the <roll> command
#   @ctx     : command that crashed invocation context
#   @error   : ...
@roll.error
async def roll_error(ctx, error):
    await ctx.send(str(error))


################################################################################
############################# PROGRAM ENTRY POINT ##############################################################################################################

if __name__ == '__main__':
    # check that token exists in environment
    if 'BOT_TOKEN' not in os.environ:
        log_msg('save your token in the BOT_TOKEN env variable!', 'error')
        exit(-1)

    # launch bot (blocking operation)
    bot.run(os.environ['BOT_TOKEN'])