309 lines
16 KiB
Python

import ciso8601
import logging
import re
import time
from typing import List, Optional
import aiohttp
import discord
from pluralkit import db, stats
from pluralkit.bot import channel_logger, utils
logger = logging.getLogger("pluralkit.bot.proxy")
def extract_leading_mentions(message_text):
# This regex matches one or more mentions at the start of a message, separated by any amount of spaces
match = re.match(r"^(<(@|@!|#|@&|a?:\w+:)\d+>\s*)+", message_text)
if not match:
return message_text, ""
# Return the text after the mentions, and the mentions themselves
return message_text[match.span(0)[1]:].strip(), match.group(0)
def match_member_proxy_tags(member: db.ProxyMember, message_text: str):
# Skip members with no defined proxy tags
if not member.prefix and not member.suffix:
return None
# DB defines empty prefix/suffixes as None, replace with empty strings to prevent errors
prefix = member.prefix or ""
suffix = member.suffix or ""
# Ignore mentions at the very start of the message, and match proxy tags after those
message_text, leading_mentions = extract_leading_mentions(message_text)
logger.debug("Matching text '{}' and leading mentions '{}' to proxy tags {}text{}".format(message_text, leading_mentions, prefix, suffix))
if message_text.startswith(member.prefix or "") and message_text.endswith(member.suffix or ""):
prefix_length = len(prefix)
suffix_length = len(suffix)
# If suffix_length is 0, the last bit of the slice will be "-0", and the slice will fail
if suffix_length > 0:
inner_string = message_text[prefix_length:-suffix_length]
else:
inner_string = message_text[prefix_length:]
# Add the mentions we stripped back
inner_string = leading_mentions + inner_string
return inner_string
def match_proxy_tags(members: List[db.ProxyMember], message_text: str):
# Sort by specificity (members with both prefix and suffix go higher)
# This will make sure more "precise" proxy tags get tried first
members: List[db.ProxyMember] = sorted(members, key=lambda x: int(
bool(x.prefix)) + int(bool(x.suffix)), reverse=True)
for member in members:
match = match_member_proxy_tags(member, message_text)
if match is not None: # Using "is not None" because an empty string is OK here too
logger.debug("Matched member {} with inner text '{}'".format(member.hid, match))
return member, match
def get_message_attachment_url(message: discord.Message):
if not message.attachments:
return None
attachment = message.attachments[0]
if "proxy_url" in attachment:
return attachment["proxy_url"]
if "url" in attachment:
return attachment["url"]
# TODO: possibly move this to bot __init__ so commands can access it too
class WebhookPermissionError(Exception):
pass
class DeletionPermissionError(Exception):
pass
class Proxy:
def __init__(self, client: discord.Client, token: str, logger: channel_logger.ChannelLogger):
self.logger = logging.getLogger("pluralkit.bot.proxy")
self.session = aiohttp.ClientSession()
self.client = client
self.token = token
self.channel_logger = logger
async def save_channel_webhook(self, conn, channel: discord.Channel, id: str, token: str) -> (str, str):
await db.add_webhook(conn, channel.id, id, token)
return id, token
async def create_and_add_channel_webhook(self, conn, channel: discord.Channel) -> (str, str):
# This method is only called if there's no webhook found in the DB (and hopefully within a transaction)
# No need to worry about error handling if there's a DB conflict (which will throw an exception because DB constraints)
req_headers = {"Authorization": "Bot {}".format(self.token)}
# First, check if there's already a webhook belonging to the bot
async with self.session.get("https://discordapp.com/api/v6/channels/{}/webhooks".format(channel.id),
headers=req_headers) as resp:
if resp.status == 200:
webhooks = await resp.json()
for webhook in webhooks:
if webhook["user"]["id"] == self.client.user.id:
# This webhook belongs to us, we can use that, return it and save it
return await self.save_channel_webhook(conn, channel, webhook["id"], webhook["token"])
elif resp.status == 403:
self.logger.warning(
"Did not have permission to fetch webhook list (server={}, channel={})".format(channel.server.id,
channel.id))
raise WebhookPermissionError()
else:
raise discord.HTTPException(resp, await resp.text())
# Then, try submitting a new one
req_data = {"name": "PluralKit Proxy Webhook"}
async with self.session.post("https://discordapp.com/api/v6/channels/{}/webhooks".format(channel.id),
json=req_data, headers=req_headers) as resp:
if resp.status == 200:
webhook = await resp.json()
return await self.save_channel_webhook(conn, channel, webhook["id"], webhook["token"])
elif resp.status == 403:
self.logger.warning(
"Did not have permission to create webhook (server={}, channel={})".format(channel.server.id,
channel.id))
raise WebhookPermissionError()
else:
raise discord.HTTPException(resp, await resp.text())
# Should not be reached without an exception being thrown
async def get_webhook_for_channel(self, conn, channel: discord.Channel):
async with conn.transaction():
hook_match = await db.get_webhook(conn, channel.id)
if not hook_match:
# We don't have a webhook, create/add one
return await self.create_and_add_channel_webhook(conn, channel)
else:
return hook_match
async def do_proxy_message(self, conn, member: db.ProxyMember, original_message: discord.Message, text: str,
attachment_url: str, has_already_retried=False):
hook_id, hook_token = await self.get_webhook_for_channel(conn, original_message.channel)
form_data = aiohttp.FormData()
form_data.add_field("username", "{} {}".format(member.name, member.tag or "").strip())
if text:
form_data.add_field("content", text)
if attachment_url:
attachment_resp = await self.session.get(attachment_url)
form_data.add_field("file", attachment_resp.content, content_type=attachment_resp.content_type,
filename=attachment_resp.url.name)
if member.avatar_url:
form_data.add_field("avatar_url", member.avatar_url)
time_before = time.perf_counter()
async with self.session.post(
"https://discordapp.com/api/v6/webhooks/{}/{}?wait=true".format(hook_id, hook_token),
data=form_data) as resp:
if resp.status == 200:
message = await resp.json()
# Report webhook stats to Influx
stats.report_webhook(time.perf_counter() - time_before, True)
await db.add_message(conn, message["id"], message["channel_id"], member.id, original_message.author.id,
text or "")
try:
await self.client.delete_message(original_message)
except discord.Forbidden:
self.logger.warning(
"Did not have permission to delete original message (server={}, channel={})".format(
original_message.server.id, original_message.channel.id))
raise DeletionPermissionError()
except discord.NotFound:
self.logger.warning("Tried to delete message when proxying, but message was already gone (server={}, channel={})".format(original_message.server.id, original_message.channel.id))
message_image = None
if message["attachments"]:
first_attachment = message["attachments"][0]
if "width" in first_attachment and "height" in first_attachment:
# Only log attachments that are actually images
message_image = first_attachment["url"]
await self.channel_logger.log_message_proxied(conn,
server_id=original_message.server.id,
channel_name=original_message.channel.name,
channel_id=original_message.channel.id,
sender_name=original_message.author.name,
sender_disc=original_message.author.discriminator,
member_name=member.name,
member_hid=member.hid,
member_avatar_url=member.avatar_url,
system_name=member.system_name,
system_hid=member.system_hid,
message_text=text,
message_image=message_image,
message_timestamp=ciso8601.parse_datetime(
message["timestamp"]),
message_id=message["id"])
elif resp.status == 404 and not has_already_retried:
# Report webhook stats to Influx
stats.report_webhook(time.perf_counter() - time_before, False)
# Webhook doesn't exist. Delete it from the DB, create, and add a new one
self.logger.warning("Webhook registered in DB doesn't exist, deleting hook from DB, re-adding, and trying again (channel={}, hook={})".format(original_message.channel.id, hook_id))
await db.delete_webhook(conn, original_message.channel.id)
await self.create_and_add_channel_webhook(conn, original_message.channel)
# Then try again all over, making sure to not retry again and go in a loop should it continually fail
return await self.do_proxy_message(conn, member, original_message, text, attachment_url, has_already_retried=True)
else:
# Report webhook stats to Influx
stats.report_webhook(time.perf_counter() - time_before, False)
raise discord.HTTPException(resp, await resp.text())
async def try_proxy_message(self, conn, message: discord.Message):
# Can't proxy in DMs, webhook creation will explode
if message.channel.is_private:
return False
# Big fat query to find every member associated with this account
# Returned member object has a few more keys (system tag, for example)
members = await db.get_members_by_account(conn, account_id=message.author.id)
match = match_proxy_tags(members, message.content)
if not match:
return False
member, text = match
attachment_url = get_message_attachment_url(message)
# Can't proxy a message with no text AND no attachment
if not text and not attachment_url:
self.logger.debug("Skipping message because of no text and no attachment")
return False
try:
async with conn.transaction():
await self.do_proxy_message(conn, member, message, text=text, attachment_url=attachment_url)
except WebhookPermissionError:
embed = utils.make_error_embed("PluralKit does not have permission to manage webhooks for this channel. Contact your local server administrator to fix this.")
await self.client.send_message(message.channel, embed=embed)
except DeletionPermissionError:
embed = utils.make_error_embed("PluralKit does not have permission to delete messages in this channel. Contact your local server administrator to fix this.")
await self.client.send_message(message.channel, embed=embed)
return True
async def try_delete_message(self, conn, message_id: str, check_user_id: Optional[str], delete_message: bool, deleted_by_moderator: bool):
async with conn.transaction():
# Find the message in the DB, and make sure it's sent by the user (if we need to check)
if check_user_id:
db_message = await db.get_message_by_sender_and_id(conn, message_id=message_id, sender_id=check_user_id)
else:
db_message = await db.get_message(conn, message_id=message_id)
if db_message:
self.logger.debug("Deleting message {}".format(message_id))
channel = self.client.get_channel(str(db_message.channel))
# If we should also delete the actual message, do that
if delete_message:
message = await self.client.get_message(channel, message_id)
try:
await self.client.delete_message(message)
except discord.Forbidden:
self.logger.warning(
"Did not have permission to remove message, aborting deletion (server={}, channel={})".format(
channel.server.id, channel.id))
return
# Remove it from the DB
await db.delete_message(conn, message_id)
# Then log deletion to logging channel
await self.channel_logger.log_message_deleted(conn,
server_id=channel.server.id,
channel_name=channel.name,
member_name=db_message.name,
member_hid=db_message.hid,
member_avatar_url=db_message.avatar_url,
system_name=db_message.system_name,
system_hid=db_message.system_hid,
message_text=db_message.content,
message_id=message_id,
deleted_by_moderator=deleted_by_moderator)
async def handle_reaction(self, conn, user_id: str, message_id: str, emoji: str):
if emoji == "":
await self.try_delete_message(conn, message_id, check_user_id=user_id, delete_message=True, deleted_by_moderator=False)
async def handle_deletion(self, conn, message_id: str):
# Don't delete the message, it's already gone at this point, just handle DB deletion and logging
await self.try_delete_message(conn, message_id, check_user_id=None, delete_message=False, deleted_by_moderator=True)