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

cogs/cog_utility.py

@@ -6,13 +6,13 @@ from zoneinfo import ZoneInfo
 
 from bson import ObjectId
 from bson.errors import InvalidId
-from discord import Activity, ActivityType, Cog, Member, TextChannel, File
+from discord import Activity, ActivityType, Cog, File, Member, TextChannel
 
 from classes import PycordEvent, PycordGuild, PycordUser
 from classes.errors import GuildNotFoundError
 from classes.pycord_bot import PycordBot
 from modules.database import col_users
-from modules.utils import get_logger
+from modules.utils import get_logger, get_utc_now
 
 logger: Logger = get_logger(__name__)
 
@@ -78,29 +78,39 @@ class CogUtility(Cog):
         user: PycordUser = await self.bot.find_user(member.id, member.guild.id)
         events: List[PycordEvent] = []
 
+        utc_now: datetime = get_utc_now()
+
         pipeline: List[Dict[str, Any]] = [
             {"$match": {"id": user.id}},
             {
                 "$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]},
+                                        {"$lt": ["$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": {"$lt": datetime.now(tz=ZoneInfo("UTC"))},
-                    "registered_events.is_cancelled": False,
-                }
-            },
+            {"$match": {"registered_events.0": {"$exists": True}}},
         ]
 
-        async for result in col_users.aggregate(pipeline):
-            for registered_event in result["registered_events"]:
-                events.append(PycordEvent(**registered_event))
+        async with await col_users.aggregate(pipeline) as cursor:
+            async for result in cursor:
+                for registered_event in result["registered_events"]:
+                    events.append(PycordEvent(**registered_event))
 
         for event in events:
             if user.current_event_id is not None and user.current_event_id != event._id: