from fastapi import Depends
from typing import Annotated
from sqlmodel import Session, create_engine
from core.config.settings import settings
from sqlalchemy.orm import sessionmaker

# 1.引擎配置
engine = create_engine(
    settings.mysql_url,                             # 数据库连接url
    echo=settings.DATABASE_ECHO,                    # echo=True 打印生成的SQL语句，开发调试打开，生产关闭
    pool_recycle = 3600,                            # 1小时回收连接，解决mysql 8小时断开问题
    pool_pre_ping=True,                             # 连接前检查
    pool_size=settings.DATABASE_POOL_SIZE,          # 连接池大小
    max_overflow=settings.DATABASE_MAX_OVERFLOW,    # 最大溢出连接
)

# 2. 创建 sessionmaker（工厂）
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# 3.依赖注入函数
def get_db():
    """FastAPI 依赖注入用"""
    db = SessionLocal() # 使用工厂创建 Session
    try:
        yield db
        db.commit() # 无异常则提交
    except Exception:
        db.rollback() # 异常则回滚
        raise
    finally:
        db.close() # 确保关闭

# 4. 定义依赖类型
SessionDep = Annotated[Session, Depends(get_db)]

# 5. 供定时任务使用的上下文管理器
from contextlib import contextmanager

@contextmanager
def get_db_session():
    """定时任务、脚本用"""
    db = SessionLocal()
    try:
        yield db
        db.commit()
    except Exception:
        db.rollback()
        raise
    finally:
        db.close()

# 使用方式
# def crawl_task():
#     data = fetch_lottery_data()
#
#     with get_db_session() as db:
#         # 检查是否存在
#         existing = db.query(LotteryResult).filter_by(draw_no=data['draw_no']).first()
#         if not existing:
#             record = LotteryResult(**data)
#             db.add(record)
#         # with 块结束时自动 commit