Chat: add minimalistic chat session tracking and fix shadow user spy problem (#121)

Kindly,

Not sure if this is too dramaphobic. I also went with the just enough (TM) approach

The issue this PR intends to fix:
1. user has no chat tabs open
2. user opens two chat tabs
3. user closes second chat tab
4. user disappears from sidebar and user count (because was removed from online py list)
5. user (became shadow user) can now spy on the chat without being listed

Thanks,
granny

Reviewed-on: #121
Co-authored-by: mummified-corroding-granny <mummified-corroding-granny@noreply.fsdfsd.net>
Co-committed-by: mummified-corroding-granny <mummified-corroding-granny@noreply.fsdfsd.net>

files/routes/chat.py

@@ -3,6 +3,7 @@ import time
 import uuid
 
 from flask_socketio import SocketIO, emit
+from flask import request
 
 from files.helpers.actions import *
 from files.helpers.alerts import *
@@ -22,6 +23,7 @@ socketio = SocketIO(
 
 typing = []
 online =  []
+sessions = []
 cache.set(CHAT_ONLINE_CACHE_KEY, len(online), timeout=0)
 muted = cache.get(f'muted') or {}
 messages = cache.get(f'messages') or {}
@@ -132,6 +134,7 @@ def refresh_online():
 @admin_level_required(PERMS['CHAT'])
 def connect(v):
 
+	sessions.append([v.id, request.sid])
 	if [v.username, v.id, v.name_color] not in online:
 		online.append([v.username, v.id, v.name_color])
 
@@ -143,13 +146,19 @@ def connect(v):
 @socketio.on('disconnect')
 @admin_level_required(PERMS['CHAT'])
 def disconnect(v):
+	if ([v.id, request.sid]) in sessions:
+		sessions.remove([v.id, request.sid])
+		if any(v.id in i for i in sessions):
+			# user has other running sessions
+			return '', 204
+
 	if [v.username, v.id, v.name_color] in online:
 		online.remove([v.username, v.id, v.name_color])
 		refresh_online()
 
 	if v.username in typing:
 		typing.remove(v.username)
-	
+
 	return '', 204
 
 @socketio.on('typing')