from sqlalchemy import create_engine, event
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, Session
from app.config import get_settings

settings = get_settings()

# 创建引擎
engine = create_engine(
    settings.DATABASE_URL,
    connect_args={"check_same_thread": False} if settings.DATABASE_URL.startswith("sqlite") else {},
    echo=settings.DEBUG
)

# 会话工厂
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# 模型基类
Base = declarative_base()


def get_db() -> Session:
    """获取数据库会话"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def init_db():
    """初始化数据库"""
    Base.metadata.create_all(bind=engine)