add add command

a lot of this is from Emoji Connoisseur

utils/__init__.py

@@ -0,0 +1,6 @@
+#!/usr/bin/env python3
+# encoding: utf-8
+
+from .misc import *
+from . import emote
+from . import errors

utils/emote.py

@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+# encoding: utf-8
+
+import re
+
+"""
+various utilities related to custom emotes
+"""
+
+"""Matches :foo: and ;foo; but not :foo;. Used for emotes in text."""
+RE_EMOTE = re.compile(r'(:|;)(?P<name>\w{2,32})\1|(?P<newline>\n)', re.ASCII)
+
+"""Matches only custom server emotes."""
+RE_CUSTOM_EMOTE = re.compile(r'<(?P<animated>a?):(?P<name>\w{2,32}):(?P<id>\d{17,})>', re.ASCII)
+
+def url(id, *, animated: bool = False):
+	"""Convert an emote ID to the image URL for that emote."""
+	extension = 'gif' if animated else 'png'
+	return f'https://cdn.discordapp.com/emojis/{id}.{extension}?v=1'

utils/errors.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+# encoding: utf-8
+
+from discord.ext.commands import CommandError
+
+
+class EmojiManagerError(CommandError):
+	"""Generic error with the bot. This can be used to catch all bot errors."""
+	pass
+
+
+class HTTPException(EmojiManagerError):
+	"""The server did not respond with an OK status code."""
+	def __init__(self, status):
+		super().__init__(f'URL error: server returned error code {status}')
+
+
+class EmojiNotFoundError(EmojiManagerError):
+	"""An emoji with that name was not found"""
+	def __init__(self, name):
+		super().__init__(f'An emoji called `{name}` does not exist in this server.')
+
+
+class InvalidImageError(EmojiManagerError):
+	"""The image is not a GIF, PNG, or JPG"""
+	def __init__(self):
+		super().__init__('The image supplied was not a GIF, PNG, or JPG.')
+
+
+class NoMoreSlotsError(EmojiManagerError):
+	"""Raised in case all slots of a particular type (static/animated) are full"""
+	def __init__(self):
+		super().__init__('No more backend slots available.')
+
+
+class PermissionDeniedError(EmojiManagerError):
+	"""Raised when a user tries to modify an emoji without the Manage Emojis permission"""
+	def __init__(self, name):
+		super().__init__(f"You're not authorized to modify `{name}`.")
+
+
+class DiscordError(Exception):
+	"""Usually raised when the client cache is being baka"""
+	def __init__(self):
+		super().__init__('Discord seems to be having issues right now, please try again later.')

utils/misc.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+# encoding: utf-8
+
+import discord
+
+"""various utilities for use within the bot"""
+
+"""Emotes used to indicate success/failure. You can obtain these from the discordbots.org guild,
+but I uploaded them to my test server
+so that both the staging and the stable versions of the bot can use them"""
+SUCCESS_EMOTES = ('<:error:416845770239508512>', '<:success:416845760810844160>')
+
+def format_user(bot, id, *, mention=False):
+	"""Format a user ID for human readable display."""
+	user = bot.get_user(id)
+	if user is None:
+		return f'Unknown user with ID {id}'
+	# not mention: @null byte#8191 (140516693242937345)
+	# mention: <@140516693242937345> (null byte#8191)
+	# this allows people to still see the username and discrim
+	# if they don't share a server with that user
+	if mention:
+		return f'{user.mention} (@{user})'
+	else:
+		return f'@{user} ({user.id})'
+
+def format_http_exception(exception: discord.HTTPException):
+	"""Formats a discord.HTTPException for relaying to the user.
+	Sample return value:
+
+	BAD REQUEST (status code: 400):
+	Invalid Form Body
+	In image: File cannot be larger than 256 kb.
+	"""
+	return (
+		f'{exception.response.reason} (status code: {exception.response.status}):'
+		f'\n{exception.text}')
+
+def strip_angle_brackets(string):
+	"""Strip leading < and trailing > from a string.
+	Useful if a user sends you a url like <this> to avoid embeds, or to convert emotes to reactions."""
+	if string.startswith('<') and string.endswith('>'):
+		return string[1:-1]
+	return string