Merge branch 'main' into 565-add-poll-ban

config/settings.yml.example

@@ -40,3 +40,14 @@ EMBED_ICONS:
   KICK: "https://github.com/allthingslinux/tux/blob/main/assets/emojis/kick.png?raw=true"
   TIMEOUT: "https://github.com/allthingslinux/tux/blob/main/assets/emojis/timeout.png?raw=true"
   WARN: "https://github.com/allthingslinux/tux/blob/main/assets/emojis/warn.png?raw=true"
+
+GIF_LIMITER:
+  RECENT_GIF_AGE: 60
+
+  GIF_LIMIT_EXCLUDE:
+    - 123456789012345
+
+  GIF_LIMITS_USER:
+    "123456789012345": 2
+  GIF_LIMITS_CHANNEL:
+    "123456789012345": 3

tux/cogs/services/gif_limiter.py

@@ -0,0 +1,114 @@
+import asyncio
+from collections import defaultdict
+from time import time
+
+import discord
+from discord.ext import commands, tasks
+
+from tux.bot import Tux
+from tux.utils.constants import CONST
+
+
+class GifLimiter(commands.Cog):
+    """
+    This class is a handler for GIF ratelimiting.
+    It keeps a list of GIF send times and routinely removes old times.
+    It will prevent people from posting GIFs if the quotas are exceeded.
+    """
+
+    def __init__(self, bot: Tux) -> None:
+        self.bot = bot
+
+        # Max age for a GIF to be considered a recent post
+        self.recent_gif_age: int = CONST.RECENT_GIF_AGE
+
+        # Max number of GIFs sent recently in a channel
+        self.channelwide_gif_limits: dict[int, int] = CONST.GIF_LIMITS_CHANNEL
+        # Max number of GIFs sent recently by a user to be able to post one in specified channels
+        self.user_gif_limits: dict[int, int] = CONST.GIF_LIMITS
+
+        # list of channels in which not to count GIFs
+        self.gif_limit_exclude: list[int] = CONST.GIF_LIMIT_EXCLUDE
+
+        # Timestamps for recently-sent GIFs for the server, and channels
+
+        # UID, list of timestamps
+        self.recent_gifs_by_user: defaultdict[int, list[int]] = defaultdict(list)
+        # Channel ID, list of timestamps
+        self.recent_gifs_by_channel: defaultdict[int, list[int]] = defaultdict(list)
+
+        # Lock to prevent race conditions
+        self.gif_lock = asyncio.Lock()
+
+        self.old_gif_remover.start()
+
+    async def _should_process_message(self, message: discord.Message) -> bool:
+        """Checks if a message contains a GIF and was not sent in a blacklisted channel"""
+        return not (
+            len(message.embeds) == 0
+            or "gif" not in message.content.lower()
+            or message.channel.id in self.gif_limit_exclude
+        )
+
+    async def _handle_gif_message(self, message: discord.Message) -> None:
+        """Checks for ratelimit infringements"""
+        async with self.gif_lock:
+            channel: int = message.channel.id
+            user: int = message.author.id
+
+            if (
+                channel in self.channelwide_gif_limits
+                and channel in self.recent_gifs_by_channel
+                and len(self.recent_gifs_by_channel[channel]) >= self.channelwide_gif_limits[channel]
+            ):
+                await self._delete_message(message, "for channel")
+                return
+
+            if (
+                user in self.recent_gifs_by_user
+                and channel in self.user_gif_limits
+                and len(self.recent_gifs_by_user[user]) >= self.user_gif_limits[channel]
+            ):
+                await self._delete_message(message, "for user")
+                return
+
+            # Add message to recent GIFs if it doesn't infringe on ratelimits
+            current_time: int = int(time())
+            self.recent_gifs_by_channel[channel].append(current_time)
+            self.recent_gifs_by_user[user].append(current_time)
+
+    async def _delete_message(self, message: discord.Message, epilogue: str) -> None:
+        """
+        Deletes the message passed as an argument, and sends a self-deleting message with the reason
+        """
+        await message.delete()
+        await message.channel.send(f"-# GIF ratelimit exceeded {epilogue}", delete_after=3)
+
+    @commands.Cog.listener()
+    async def on_message(self, message: discord.Message) -> None:
+        """Checks for GIFs in every sent message"""
+
+        if await self._should_process_message(message):
+            await self._handle_gif_message(message)
+
+    @tasks.loop(seconds=20)
+    async def old_gif_remover(self) -> None:
+        """Regularly cleans old GIF timestamps"""
+        current_time: int = int(time())
+
+        async with self.gif_lock:
+            for channel_id, timestamps in self.recent_gifs_by_channel.items():
+                self.recent_gifs_by_channel[channel_id] = [
+                    t for t in timestamps if current_time - t < self.recent_gif_age
+                ]
+
+            for user_id, timestamps in self.recent_gifs_by_user.items():
+                self.recent_gifs_by_user[user_id] = [t for t in timestamps if current_time - t < self.recent_gif_age]
+
+                # Delete user key if no GIF has recently been sent by them
+                if len(self.recent_gifs_by_user[user_id]) == 0:
+                    del self.recent_gifs_by_user[user_id]
+
+
+async def setup(bot: Tux) -> None:
+    await bot.add_cog(GifLimiter(bot))

tux/utils/constants.py

@@ -6,6 +6,8 @@ from typing import Final
 import yaml
 from dotenv import load_dotenv, set_key
 
+from tux.utils.functions import convert_dict_str_to_int
+
 load_dotenv(verbose=True)
 
 config_file = Path("config/settings.yml")
@@ -77,6 +79,13 @@ class Constants:
     # Icon constants
     EMBED_ICONS: Final[dict[str, str]] = config["EMBED_ICONS"]
 
+    # GIF ratelimit constants
+    RECENT_GIF_AGE: Final[int] = config["GIF_LIMITER"]["RECENT_GIF_AGE"]
+    GIF_LIMIT_EXCLUDE: Final[list[int]] = config["GIF_LIMITER"]["GIF_LIMIT_EXCLUDE"]
+
+    GIF_LIMITS: Final[dict[int, int]] = convert_dict_str_to_int(config["GIF_LIMITER"]["GIF_LIMITS_USER"])
+    GIF_LIMITS_CHANNEL: Final[dict[int, int]] = convert_dict_str_to_int(config["GIF_LIMITER"]["GIF_LIMITS_CHANNEL"])
+
     # Embed limit constants
     EMBED_MAX_NAME_LENGTH = 256
     EMBED_MAX_DESC_LENGTH = 4096

tux/utils/functions.py

@@ -3,6 +3,7 @@ from datetime import UTC, datetime, timedelta
 from typing import Any
 
 import discord
+from loguru import logger
 
 harmful_command_pattern = r"(?:sudo\s+|doas\s+|run0\s+)?rm\s+(-[frR]*|--force|--recursive|--no-preserve-root|\s+)*([/\∕~]\s*|\*|/bin|/boot|/etc|/lib|/proc|/root|/sbin|/sys|/tmp|/usr|/var|/var/log|/network.|/system)(\s+--no-preserve-root|\s+\*)*|:\(\)\{ :|:& \};:"  # noqa: RUF001
 
@@ -300,3 +301,19 @@ def extract_member_attrs(member: discord.Member) -> dict[str, Any]:
         "status": member.status,
         "activity": member.activity,
     }
+
+
+def convert_dict_str_to_int(original_dict: dict[str, int]) -> dict[int, int]:
+    """Helper function used for GIF Limiter constants.
+    Required as YAML keys are str. Channel and user IDs are int."""
+
+    converted_dict: dict[int, int] = {}
+
+    for key, value in original_dict.items():
+        try:
+            int_key: int = int(key)
+            converted_dict[int_key] = value
+        except ValueError:
+            logger.exception(f"An error occurred when loading the GIF ratelimiter configuration at key {key}")
+
+    return converted_dict