from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, declarative_base
from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import Session
from sqlalchemy.sql import text
from contextlib import contextmanager
from utils.rdbmsUtil.factoryRegistry import FactoryRegistry

# 数据库类


class DatabaseUtil:
    def __init__(self, url, pool_size=5, max_overflow=10, pool_recycle=1000, pool_pre_ping=True, connect_timeout=10,read_timeout=120):
        self.engine = create_engine(
            url,
            pool_size=pool_size,                # 设置最大连接池大小
            max_overflow=max_overflow,          # 设置最大溢出连接数
            pool_recycle=pool_recycle,          # 设置连接回收时间
            pool_pre_ping=pool_pre_ping,        # 检查连接的可用性
            connect_args={
                'connect_timeout': connect_timeout,  # 连接超时时间（秒）
                'read_timeout': read_timeout    # 读取超时时间（秒）
            }  # 增加连接超时设置
        )
        self.Session = sessionmaker(bind=self.engine)

    def get_session(self):
        return self.Session()

    @contextmanager
    def session_scope(self):
        """Provide a transactional scope around a series of operations."""
        session = self.get_session()
        try:
            yield session
            session.commit()
        except Exception as e:
            session.rollback()
            raise
        finally:
            session.close()

    def close_session(self, session):
        """Explicitly close a given session."""
        if session:
            session.close()

# # 事务管理
# @contextmanager
# def transaction_scope(session:Session):
#     try:
#         yield session
#         session.commit()
#     except Exception as e:
#         session.rollback()
#         raise e
#     finally:
#         session.close()

# 实现动态 SQL 和批量操作支持的装饰器


def sql_operation(sql, entity_type, batch=False):
    def decorator(func):
        def wrapper(self, session, *args, **kwargs):
            factory = FactoryRegistry.get_factory(entity_type)
            if callable(sql):  # 检查sql是否为可调用对象，即函数
                resolved_sql = sql(*args, **kwargs)  # 如果是函数，执行它以获取SQL字符串
            else:
                resolved_sql = sql  # 否则直接使用sql字符串
            print(f"Self: {self}")
            print(f"Session: {session}")
            print(f"Session type: {type(session)}")
            print(f"SQL: {resolved_sql}")
            print(f"Args: {args}")
            print(f"Kwargs: {kwargs}")
            results = []
            if batch:
                for entity in args[0]:
                    # 使用参数直接执行SQL，防止注入
                    params = {key: getattr(
                        entity, key) for key in entity.__dict__ if not key.startswith('_')}
                    r = session.execute(text(resolved_sql), params)
                    print(r)
            else:
                # 单个操作的情况
                result = session.execute(text(resolved_sql), kwargs)
                if result.returns_rows:
                    results.extend([factory(**dict(row))
                                   for row in result.mappings()])
                else:
                    # 如果不需要处理返回结果，这里可以直接pass
                    pass

            return results
        return wrapper
    return decorator