from collections.abc import Generator

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

from app.config import get_settings


class Base(DeclarativeBase):
    pass


def _create_engine():
    settings = get_settings()
    url = settings.database_url
    connect_args = {}
    if url.startswith("sqlite"):
        connect_args["check_same_thread"] = False
    return create_engine(url, connect_args=connect_args, pool_pre_ping=True)


engine = _create_engine()
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


def get_db() -> Generator[Session, None, None]:
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def init_db() -> None:
    from app import models  # noqa: F401

    Base.metadata.create_all(bind=engine)