backend/database.py

from pymongo import MongoClient
from pymongo.collection import Collection
from config import MONGO_URI, DB_NAME, MONGO_COLLECTION

def get_mongo_client(uri: str | None = None) -> MongoClient:
    """Return a pymongo MongoClient."""
    uri = uri or MONGO_URI
    return MongoClient(uri)

def get_mongo_collection(client: MongoClient | None = None, db_name: str | None = None, collection_name: str | None = None) -> Collection:
    """Return a MongoDB collection instance."""
    client = client or get_mongo_client()
    db_name = db_name or DB_NAME
    collection_name = collection_name or MONGO_COLLECTION
    return client[db_name][collection_name]