from aiohttp import ClientSession, TCPConnector
from typing import Optional


_session: Optional[ClientSession] = None


def client_session() -> ClientSession:
    """Get client session."""

    if _session is None:
        raise AttributeError(f"Session is not initialized.")
    return _session


def init_session(**config) -> ClientSession:
    """Init and return session instance."""
    global _session
    _session = ClientSession(connector=TCPConnector(ssl=False), **config)
    return _session