Create database/connection.py

utils/database/connection.py

@@ -0,0 +1,58 @@
+# filename: database/connection.py
+
+import logging
+from motor.motor_asyncio import AsyncIOMotorClient
+import config
+
+logger = logging.getLogger(__name__)
+
+class Database:
+    """
+    Manages connections to one or more MongoDB databases.
+    """
+    def __init__(self, uris: list[str]):
+        if not uris:
+            raise ValueError("At least one MongoDB URI is required.")
+            
+        self.clients = [AsyncIOMotorClient(uri) for uri in uris]
+        self.databases = [client.get_default_database() for client in self.clients]
+        
+        # For data that should not be split (like cache), we use the first DB as the primary.
+        self.primary_db = self.databases[0]
+        
+        # For distributing new users, we'll cycle through the available databases.
+        self._user_db_round_robin_counter = 0
+        
+        logger.info(f"Successfully connected to {len(self.clients)} MongoDB database(s).")
+
+    async def get_user_db(self, user_id: int):
+        """
+        Gets the database assigned to a specific user.
+        This ensures a user's data always stays in the same database.
+        We use a simple hashing method to distribute users.
+        """
+        db_index = user_id % len(self.databases)
+        return self.databases[db_index]
+        
+    async def find_user_db(self, user_id: int):
+        """
+        Searches across all databases to find which one contains the user.
+        Returns the database object if found, otherwise None.
+        """
+        for db in self.databases:
+            if await db.users.find_one({"user_id": user_id}):
+                return db
+        return None
+
+    def get_next_db_for_new_user(self):
+        """
+        Picks a database for a new user using a round-robin strategy.
+        This helps distribute new users evenly.
+        """
+        db = self.databases[self._user_db_round_robin_counter]
+        self._user_db_round_robin_counter = (self._user_db_round_robin_counter + 1) % len(self.databases)
+        return db
+
+# --- Initialize the Database Connection ---
+# This single `db` object will be imported and used by the rest of the application.
+db = Database(config.MONGODB_URIS)