"""数据库连接和会话管理"""

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

from .config import settings

# 创建数据库引擎
engine = create_engine(
    settings.DATABASE_URL,
    connect_args={"check_same_thread": False} if "sqlite" in settings.DATABASE_URL else {},
    echo=settings.DEBUG
)

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

# 声明基类
Base = declarative_base()


def get_db():
    """获取数据库会话 (依赖注入)"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def init_db():
    """初始化数据库 (创建所有表)"""
    from .models import university, script, job, result  # noqa
    Base.metadata.create_all(bind=engine)