Adding deletemessages command

cogs/generalcog.py

+from datetime import datetime, timedelta
+from discord import Member, Message
 from discord.ext import commands
+import re
+
 from cogs.basecog import BaseCog, BotMessage
+from config import CONFIG
+from rbutils import parse_timedelta, describe_timedelta
 from storage import ConfigKey, Storage
 
 class GeneralCog(BaseCog):
 	@commands.guild_only()
 	async def shutdown(self, context):
 		await self.bot.close()
+
+	@commands.command(
+		brief='Mass deletes messages',
+		description='Deletes recent messages by the given user. The age is ' +
+			'a duration, such as "30s", "5m", "1h30m". Messages far back in ' +
+			'the scrollback might not be deleted by this command.',
+		usage='<user> <age>'
+	)
+	@commands.has_permissions(manage_messages=True)
+	@commands.guild_only()
+	async def deletemessages(self, context, user: str, age: str) -> None:
+		member_id = self.__parse_member_id(user)
+		if member_id is None:
+			await context.message.reply(
+				f'{CONFIG["failure_emoji"]} user must be a mention or numeric user id',
+				mention_author=False)
+			return
+		try:
+			age_delta: timedelta = parse_timedelta(age)
+		except ValueError:
+			await context.message.reply(
+				f'{CONFIG["failure_emoji"]} age must be a timespan, like "30s", "10m", "1h30m"',
+				mention_author=False)
+			return
+		cutoff: datetime = datetime.utcnow() - age_delta
+		def predicate(message: Message) -> bool:
+			return str(message.author.id) == member_id and message.created_at >= cutoff
+		deleted_messages = []
+		for channel in context.guild.text_channels:
+			try:
+				deleted_messages += await channel.purge(limit=100, check=predicate)
+			except:
+				# XXX: Sloppily glossing over access errors instead of checking access
+				pass
+		await context.message.reply(
+			f'{CONFIG["success_emoji"]} Deleted {len(deleted_messages)} ' + \
+			f'messages by <@!{member_id}> from the past {describe_timedelta(age_delta)}.',
+			mention_author=False)
+
+	def __parse_member_id(self, arg: str) -> str:
+		p = re.compile('^<@!?([0-9]+)>$')
+		m = p.match(arg)
+		if m:
+			return m.group(1)
+		p = re.compile('^([0-9]+)$')
+		m = p.match(arg)
+		if m:
+			return m.group(1)
+		return None

cogs/patterncog.py

 
 from cogs.basecog import BaseCog, BotMessage, BotMessageReaction
 from config import CONFIG
+from rbutils import parse_timedelta
 from storage import Storage
 
 class PatternAction:
 		for cmd in command_chain:
 			if pattern_str.startswith(cmd):
 				pattern_str = pattern_str[len(cmd):].lstrip()
+			elif pattern_str.startswith(f'"{cmd}"'):
+				pattern_str = pattern_str[len(cmd) + 2:].lstrip()
 		return pattern_str
 
 	@classmethod
 		if type == cls.TYPE_FLOAT:
 			return float(value)
 		if type == cls.TYPE_TIMESPAN:
-			p = re.compile('^(?:[0-9]+[dhms])+$')
-			if p.match(value) is None:
-				raise RuntimeError("Illegal timespan value \"{value}\". Must be like \"100d\", \"5m30s\", etc.")
-			p = re.compile('([0-9]+)([dhms])')
-			days = 0
-			hours = 0
-			minutes = 0
-			seconds = 0
-			for m in p.finditer(value):
-				scalar = int(m.group(1))
-				unit = m.group(2)
-				if unit == 'd':
-					days = scalar
-				elif unit == 'h':
-					hours = scalar
-				elif unit == 'm':
-					minutes = scalar
-				elif unit == 's':
-					seconds = scalar
-			return timedelta(days=days, hours=hours, minutes=minutes, seconds=seconds)
+			return parse_timedelta(value)
 		raise ValueError(f'Unhandled datatype {datatype}')

patterns.md

 reply "You can't say that word!", delete if message contains "heck"
 ```
 
-This statement has two actions: replying, then deleting the original message. It will match any word that contains the word "heck".
+This statement has two actions: replying, then deleting the original message. It will match any message that contains the word "heck".
 
 The list of actions and the matching expression are separated by the word "if", which must be present in every statement.
 

rbutils.py

+from datetime import timedelta
+import re
+
+def parse_timedelta(s: str) -> timedelta:
+	"""
+	Parses a timespan. Format examples:
+	"30m"
+	"10s"
+	"90d"
+	"1h30m"
+	"73d18h22m52s"
+	"""
+	p = re.compile('^(?:[0-9]+[dhms])+$')
+	if p.match(s) is None:
+		raise ValueError("Illegal timespan value '{s}'.")
+	p = re.compile('([0-9]+)([dhms])')
+	days = 0
+	hours = 0
+	minutes = 0
+	seconds = 0
+	for m in p.finditer(s):
+		scalar = int(m.group(1))
+		unit = m.group(2)
+		if unit == 'd':
+			days = scalar
+		elif unit == 'h':
+			hours = scalar
+		elif unit == 'm':
+			minutes = scalar
+		elif unit == 's':
+			seconds = scalar
+	return timedelta(days=days, hours=hours, minutes=minutes, seconds=seconds)
+
+def describe_timedelta(td: timedelta, max_components: int = 2) -> str:
+	values = [
+		td.days,
+		td.seconds // 3600,
+		(td.seconds // 60) % 60,
+		td.seconds % 60,
+	]
+	units = [
+		'day' if values[0] == 1 else 'days',
+		'hour' if values[1] == 1 else 'hours',
+		'minute' if values[2] == 1 else 'minutes',
+		'second' if values[3] == 1 else 'seconds',
+	]
+	while len(values) > 1 and values[0] == 0:
+		values.pop(0)
+		units.pop(0)
+	if len(values) > max_components:
+		values = values[0:max_components]
+		units = units[0:max_components]
+	while len(values) > 1 and values[-1] == 0:
+		values.pop(-1)
+		units.pop(-1)
+	tokens = []
+	for i in range(len(values)):
+		tokens.append(f'{values[i]} {units[i]}')
+	return ' '.join(tokens)