"""Sessions collection."""

from datetime import datetime
from typing import cast

from pymongo.database import Database
import bottle

from server_utilities.type import SessionId


def upsert(
        database: Database, username: str, email: str, session_id: SessionId,
        session_expiration_datetime: datetime) -> None:
    """Update the existing session for the user or insert a new session."""
    database.sessions.update(
        dict(user=username),
        dict(user=username, email=email, session_id=session_id,
             session_expiration_datetime=session_expiration_datetime),
        upsert=True)


def delete(database: Database, session_id: SessionId) -> None:
    """Remove the session."""
    database.sessions.delete_one(dict(session_id=session_id))


def valid(database: Database, session_id: SessionId) -> bool:
    """Return whether the session is present in the database and has not expired."""
    session = find_one(database, session_id)
    return bool(session.get("session_expiration_datetime", datetime.min) > datetime.now()) if session else False


def find_one(database: Database, session_id: SessionId):
    """Return the session."""
    return database.sessions.find_one(dict(session_id=session_id))


def user(database: Database):
    """Return the user sending the request."""
    session_id = cast(SessionId, bottle.request.get_cookie("session_id"))
    return find_one(database, session_id)
