"""数据库引擎、会话与建表"""
from sqlalchemy import create_engine
from sqlalchemy.orm import declarative_base, sessionmaker
from sqlalchemy.pool import StaticPool

from app.core.config import get_settings

settings = get_settings()

_engine_kwargs = {}
if settings.DATABASE_URL.startswith("sqlite"):
    _engine_kwargs["connect_args"] = {"check_same_thread": False}
    # :memory: 需 StaticPool，否则不同连接看不到同一库
    if ":memory:" in settings.DATABASE_URL:
        _engine_kwargs["poolclass"] = StaticPool

engine = create_engine(settings.DATABASE_URL, **_engine_kwargs)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()


def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def init_db() -> None:
    # Import models so metadata is registered before create_all
    import app.models  # noqa: F401

    Base.metadata.create_all(bind=engine)