Worked on #13 and #4. There are some caching issues left, though. Introduced abstract class Cacheable. Replaced async_pymongo with pymongo

modules/utils/autocomplete_utils.py

@@ -49,31 +49,41 @@ async def autocomplete_user_available_events(ctx: AutocompleteContext) -> List[O
 async def autocomplete_user_registered_events(ctx: AutocompleteContext) -> List[OptionChoice]:
     """Return list of active events user is registered in"""
 
+    utc_now: datetime = datetime.now(tz=ZoneInfo("UTC"))
+
     pipeline: List[Dict[str, Any]] = [
         {"$match": {"id": ctx.interaction.user.id}},
         {
             "$lookup": {
                 "from": "events",
-                "localField": "registered_event_ids",
-                "foreignField": "_id",
+                "let": {"event_ids": "$registered_event_ids"},
+                "pipeline": [
+                    {
+                        "$match": {
+                            "$expr": {
+                                "$and": [
+                                    {"$in": ["$_id", "$$event_ids"]},
+                                    {"$eq": ["$ended", None]},
+                                    {"$gt": ["$ends", utc_now]},
+                                    {"$gt": ["$starts", utc_now]},
+                                    {"$eq": ["$is_cancelled", False]},
+                                ]
+                            }
+                        }
+                    }
+                ],
                 "as": "registered_events",
             }
         },
-        {
-            "$match": {
-                "registered_events.ended": None,
-                "registered_events.ends": {"$gt": datetime.now(tz=ZoneInfo("UTC"))},
-                "registered_events.starts": {"$gt": datetime.now(tz=ZoneInfo("UTC"))},
-                "registered_events.is_cancelled": False,
-            }
-        },
+        {"$match": {"registered_events.0": {"$exists": True}}},
     ]
 
     event_names: List[OptionChoice] = []
 
-    async for result in col_users.aggregate(pipeline):
-        for registered_event in result["registered_events"]:
-            event_names.append(OptionChoice(registered_event["name"], str(registered_event["_id"])))
+    async with await col_users.aggregate(pipeline) as cursor:
+        async for result in cursor:
+            for registered_event in result["registered_events"]:
+                event_names.append(OptionChoice(registered_event["name"], str(registered_event["_id"])))
 
     return event_names