from __future__ import annotations

from collections.abc import Generator
from functools import lru_cache

from sqlalchemy import create_engine
from sqlalchemy.orm import DeclarativeBase, Session, sessionmaker

from gitea_codex_bot.config import get_settings


class Base(DeclarativeBase):
    pass


@lru_cache(maxsize=1)
def get_engine():
    settings = get_settings()
    return create_engine(settings.sqlalchemy_url, pool_pre_ping=True, future=True)


@lru_cache(maxsize=1)
def get_session_factory():
    return sessionmaker(bind=get_engine(), class_=Session, autoflush=False, autocommit=False, expire_on_commit=False)


def get_session() -> Generator[Session, None, None]:
    session = get_session_factory()()
    try:
        yield session
    finally:
        session.close()