ModLog: log voice state updates

* Add corresponding event to the Event enum so the event can be ignored

2 files changed, 51 insertions, 0 deletions

diff --git a/bot/cogs/moderation/modlog.py b/bot/cogs/moderation/modlog.py
index 0df752a97..ac45782c9 100644
--- a/bot/cogs/moderation/modlog.py
+++ b/bot/cogs/moderation/modlog.py
@@ -25,6 +25,8 @@ CHANNEL_CHANGES_SUPPRESSED = ("_overwrites", "position")
 MEMBER_CHANGES_SUPPRESSED = ("status", "activities", "_client_status", "nick")
 ROLE_CHANGES_UNSUPPORTED = ("colour", "permissions")
 
+VOICE_STATE_ATTRIBUTES = {"self_video": "Broadcasting", "afk": "AFK"}
+
 
 class ModLog(Cog, name="ModLog"):
     """Logging for server events and staff actions."""
@@ -748,3 +750,50 @@ class ModLog(Cog, name="ModLog"):
             Icons.message_edit, Colour.blurple(), "Message edited (After)",
             after_response, channel_id=Channels.message_log
         )
+
+    @Cog.listener()
+    async def on_voice_state_update(
+        self,
+        member: discord.Member,
+        before: discord.VoiceState,
+        after: discord.VoiceState
+    ) -> None:
+        """Log member voice state changes to the voice log channel."""
+        if member.guild.id != GuildConstant.id:
+            return
+
+        if member.id in self._ignored[Event.voice_state_update]:
+            self._ignored[Event.voice_state_update].remove(member.id)
+            return
+
+        diff = DeepDiff(before, after, exclude_paths="root.session_id")
+
+        # A type change seems to always take precedent over a value change. Furthermore, it will
+        # include the value change along with the type change anyway. Therefore, it's OK to
+        # "overwrite" values_changed; in practice there will never even be anything to overwrite.
+        diff_values = {**diff.get("values_changed", {}), **diff.get("type_changes", {})}
+
+        changes = []
+        for attr, values in diff_values.items():
+            if not attr:  # Not sure why, but it happens
+                continue
+
+            attr = attr[5:]  # Remove "root." prefix
+            attr = VOICE_STATE_ATTRIBUTES.get(attr, attr.replace("_", " ").capitalize())
+
+            changes.append(f"**{attr}:** `{values['old_value']}` **->** `{values['new_value']}`")
+
+        if not changes:
+            return
+
+        message = "\n".join(f"{Emojis.bullet} {item}" for item in sorted(changes))
+        message = f"**{member}** (`{member.id}`)\n{message}"
+
+        await self.send_log_message(
+            icon_url=Icons.user_update,
+            colour=Colour.blurple(),
+            title="Voice state updated",
+            text=message,
+            thumbnail=member.avatar_url_as(static_format="png"),
+            channel_id=Channels.voice_log
+        )
diff --git a/bot/constants.py b/bot/constants.py
index 389326edd..b96f23f83 100644
--- a/bot/constants.py
+++ b/bot/constants.py
@@ -544,6 +544,8 @@ class Event(Enum):
     message_delete = "message_delete"
     message_edit = "message_edit"
 
+    voice_state_update = "voice_state_update"
+
 
 # Debug mode
 DEBUG_MODE = True if 'local' in os.environ.get("SITE_URL", "local") else False