src/logger.py: Log edited/deleted messages to #message-log

src/bot.py

@@ -114,6 +114,7 @@ class MILBot(commands.Bot):
     software_leaders_channel: discord.TextChannel
     electrical_leaders_channel: discord.TextChannel
     mechanical_leaders_channel: discord.TextChannel
+    message_log_channel: discord.TextChannel
 
     # Emojis
     loading_emoji: str
@@ -364,6 +365,13 @@ async def fetch_vars(self) -> None:
         assert isinstance(mechanical_leaders_channel, discord.TextChannel)
         self.mechanical_leaders_channel = mechanical_leaders_channel
 
+        message_log_channel = discord.utils.get(
+            self.active_guild.text_channels,
+            name="message-log",
+        )
+        assert isinstance(message_log_channel, discord.TextChannel)
+        self.message_log_channel = message_log_channel
+
         software_category_channel = discord.utils.get(
             self.active_guild.categories,
             name="Software",

src/logger.py

@@ -1,18 +1,22 @@
 from __future__ import annotations
 
+import difflib
 import logging
 import typing
 
 import discord
 from discord.ext import commands
 
+from .utils import surround
+
 if typing.TYPE_CHECKING:
     from .bot import MILBot
 
 logger = logging.getLogger(__name__)
 
 
 class Logger(commands.Cog):
+
     def __init__(self, bot: MILBot):
         self.bot = bot
 
@@ -49,6 +53,125 @@ async def on_member_remove(self, member: discord.Member):
         embed.set_thumbnail(url=member.display_avatar.url)
         await self.bot.leave_channel.send(embed=embed)
 
+    def _log_message_filter(self, message: discord.Message) -> bool:
+        return not (
+            message.author.bot
+            and not isinstance(
+                message.channel,
+                discord.DMChannel | discord.PartialMessageable,
+            )
+            and (
+                message.channel
+                in [
+                    self.bot.software_projects_channel,
+                    self.bot.member_services_channel,
+                    self.bot.message_log_channel,
+                ]
+                or "-lab-" in message.channel.name
+            )
+        )
+
+    @commands.Cog.listener()
+    async def on_raw_message_edit(self, payload: discord.RawMessageUpdateEvent):
+        """
+        When a message is edited, log the edit.
+
+        Args:
+            payload (discord.RawMessageUpdateEvent): The payload containing the message edit.
+        """
+
+        # Send a message like the following to #message-log:
+        # **Cameron Brown** edited a message in #channel ({jump_link}):
+        # **Before**: this was sentence
+        # **After**: this was **my** sentence
+        # bolded words are additions/deletions$
+        message = payload.cached_message
+        channel = self.bot.active_guild.get_channel(payload.channel_id)
+        if not channel:
+            await self.bot.message_log_channel.send(
+                f"error! Could not find channel ID of `{payload.channel_id}`.",
+            )
+            return
+
+        message_now = await channel.fetch_message(payload.message_id)  # type: ignore
+        if not message:
+            message = message_now
+
+        if not self._log_message_filter(message):
+            return
+
+        header = f"✏️ **{message.author.display_name}** edited a message in {channel.mention} ([jump!](<{message.jump_url}>)):"
+        # if cached message isn't present, we can't figure out
+        # what was there before
+        if not payload.cached_message:
+            before = f"? (message too old, from {discord.utils.format_dt(message.created_at, 'R')})"
+            after = message.content
+        else:
+            # words/phrases present in original, not in new
+            def is_junk(s: str) -> bool:
+                return s == " "
+
+            s = difflib.SequenceMatcher(
+                is_junk,
+                payload.cached_message.content,
+                message_now.content,
+            )
+            before = payload.cached_message.content
+            after = message_now.content
+            # add bolding around deleted phrases in before
+            # add bolding around new/replaced phrases in after
+            for tag, i1, i2, j1, j2 in s.get_opcodes():
+                if tag == "delete":
+                    before = surround(before, i1, i2, "**")
+                elif tag == "replace":
+                    before = surround(before, i1, i2, "**")
+                    after = surround(after, j1, j2, "**")
+                elif tag == "insert":
+                    after = surround(after, j1, j2, "**")
+
+        quoted_before = before.replace("\n", "\n> ")
+        quoted_after = after.replace("\n", "\n> ")
+        await self.bot.message_log_channel.send(
+            f"{header}\n"
+            f"> **Before**: {quoted_before}\n"
+            "> ---\n"
+            f"> **After**: {quoted_after}",
+        )
+
+    @commands.Cog.listener()
+    async def on_raw_message_delete(self, payload: discord.RawMessageDeleteEvent):
+        # Sends a message to #message-log:
+        # A message by **Cameron Brown** (sent at {date}) in #channel-name was deleted:
+        # > This was the message! (+ 1 attachment)
+        if payload.cached_message:
+            if not self._log_message_filter(payload.cached_message):
+                return
+
+            header = f"🔥 A message by **{payload.cached_message.author.display_name}** (sent {discord.utils.format_dt(payload.cached_message.created_at, 'R')}) in {payload.cached_message.channel.mention} was deleted:"
+            quoted_message = payload.cached_message.content.replace("\n", "\n> ")
+            header += f"\n> {quoted_message}"
+            if payload.cached_message.attachments:
+                header += f"\n(+ {len(payload.cached_message.attachments)} attachments)"
+            files = [
+                await attachment.to_file()
+                for attachment in payload.cached_message.attachments
+            ]
+            await self.bot.message_log_channel.send(header, files=files)
+        else:
+            # basic filter since we don't have full message
+            useless_ids = [
+                self.bot.software_projects_channel.id,
+                self.bot.member_services_channel.id,
+                self.bot.message_log_channel.id,
+            ]
+            if payload.channel_id in useless_ids:
+                return
+
+            created_at = discord.utils.snowflake_time(payload.message_id)
+            await self.bot.message_log_channel.send(
+                f"🔥 A message sent at {discord.utils.format_dt(created_at, 'F')} was deleted in <#{payload.channel_id}> (too old to retrieve).",
+            )
+
 
 async def setup(bot: MILBot):
     await bot.add_cog(Logger(bot))

src/utils.py

@@ -22,6 +22,13 @@ def make_and(iterable: Iterable) -> str:
     return f"{', '.join(iterable[:-1])}, and {iterable[-1]}"
 
 
+def surround(s: str, start: int, end: int, surround_with: str) -> str:
+    """
+    Surrounds a part of a string with some characters.
+    """
+    return s[:start] + surround_with + s[start:end] + surround_with + s[end:]
+
+
 def is_active() -> bool:
     """
     Whether the reports system is active.