Identify DeletionContext by members, not channels

Since the anti-spam now works cross-channels, it makes no sense to identify it by the channel in which it was invoked.
The DeletionContext class was changed to accept a frozenset of members, and the message_deletion_queue dict uses the frozensets as keys.
DeletionContext still accepts a channel on creation, because while it might get added more channels, there's only one channel in which the mute message will be sent.

Using members as the key can run into the issue of one member becoming irrelevant to the filter while others still are, resulting in another log message being sent, but it's an unlikely edge case since the users should be muted almost immediately, and we're currently not using any multi-member filters in the first place.

1 files changed, 14 insertions, 17 deletions

diff --git a/bot/exts/filters/antispam.py b/bot/exts/filters/antispam.py
index 2df93a867..987060779 100644
--- a/bot/exts/filters/antispam.py
+++ b/bot/exts/filters/antispam.py
@@ -47,20 +47,18 @@ RULE_FUNCTION_MAPPING = {
 class DeletionContext:
     """Represents a Deletion Context for a single spam event."""
 
+    members: frozenset[Member]
     triggered_in: TextChannel
-    channels: set[TextChannel]
-    members: Dict[int, Member] = field(default_factory=dict)
+    channels: set[TextChannel] = field(default_factory=set)
     rules: Set[str] = field(default_factory=set)
     messages: Dict[int, Message] = field(default_factory=dict)
     attachments: List[List[str]] = field(default_factory=list)
 
-    async def add(self, rule_name: str, members: Iterable[Member], messages: Iterable[Message]) -> None:
+    async def add(self, rule_name: str, channels: Iterable[TextChannel], messages: Iterable[Message]) -> None:
         """Adds new rule violation events to the deletion context."""
         self.rules.add(rule_name)
 
-        for member in members:
-            if member.id not in self.members:
-                self.members[member.id] = member
+        self.channels.update(channels)
 
         for message in messages:
             if message.id not in self.messages:
@@ -73,7 +71,7 @@ class DeletionContext:
 
     async def upload_messages(self, actor_id: int, modlog: ModLog) -> None:
         """Method that takes care of uploading the queue and posting modlog alert."""
-        triggered_by_users = ", ".join(format_user(m) for m in self.members.values())
+        triggered_by_users = ", ".join(format_user(m) for m in self.members)
         triggered_in_channel = f"**Triggered in:** {self.triggered_in.mention}\n" if len(self.channels) > 1 else ""
         channels_description = ", ".join(channel.mention for channel in self.channels)
 
@@ -197,20 +195,19 @@ class AntiSpam(Cog):
                 full_reason = f"`{rule_name}` rule: {reason}"
 
                 # If there's no spam event going on for this channel, start a new Message Deletion Context
-                channel = message.channel
-                if channel.id not in self.message_deletion_queue:
-                    log.trace(f"Creating queue for channel `{channel.id}`")
-                    affected_channels = set(message.channel for message in messages_for_rule)
-                    self.message_deletion_queue[message.channel.id] = DeletionContext(channel, affected_channels)
+                authors_set = frozenset(members)
+                if authors_set not in self.message_deletion_queue:
+                    log.trace(f"Creating queue for members `{authors_set}`")
+                    self.message_deletion_queue[authors_set] = DeletionContext(authors_set, message.channel)
                     scheduling.create_task(
-                        self._process_deletion_context(message.channel.id),
-                        name=f"AntiSpam._process_deletion_context({message.channel.id})"
+                        self._process_deletion_context(authors_set),
+                        name=f"AntiSpam._process_deletion_context({authors_set})"
                     )
 
                 # Add the relevant of this trigger to the Deletion Context
-                await self.message_deletion_queue[message.channel.id].add(
+                await self.message_deletion_queue[authors_set].add(
                     rule_name=rule_name,
-                    members=members,
+                    channels=set(message.channel for message in messages_for_rule),
                     messages=relevant_messages
                 )
 
@@ -264,7 +261,7 @@ class AntiSpam(Cog):
                 except NotFound:
                     log.info(f"Tried to delete message `{messages[0].id}`, but message could not be found.")
 
-    async def _process_deletion_context(self, context_id: int) -> None:
+    async def _process_deletion_context(self, context_id: frozenset) -> None:
         """Processes the Deletion Context queue."""
         log.trace("Sleeping before processing message deletion queue.")
         await asyncio.sleep(10)