#!/usr/bin/env python
# coding=utf-8
'''
Description  :  
Author       : chenxl
Date         : 2024-06-12 09:12:58
Version      : 1.0.0
LastEditors  : chenxl 
LastEditTime : 2024-07-27 01:56:04
'''

from urllib.parse import urlparse
import os
from contextlib import contextmanager
from sqlalchemy import create_engine
from sqlalchemy.orm import Session, sessionmaker, declarative_base

from ktransformers.server.config.config import Config
from ktransformers.server.config.singleton import Singleton
from ktransformers.server.config.log import logger
from ktransformers.server.exceptions import db_exception


Base = declarative_base()


class SQLUtil(metaclass=Singleton):
    """
    database connections init and management
    """
    sqlalchemy_engine = None
    session_local = None

    def __init__(self) -> None:
        self.cfg: Config = Config()
        if not self.sqlalchemy_engine:
            SQLUtil.init_engine(self.cfg)

    @contextmanager
    def get_db(self):
        """
        After you finish using the session, it's crucial to close it.
        """
        if not SQLUtil.sqlalchemy_engine:
            SQLUtil.init_engine(self.cfg)
        session = self.session_local()  # type: ignore pylint: disable=not-callable
        try:
            yield session
        finally:
            session.close()

    @staticmethod
    def init_engine(cfg: Config):
        """
        initial engine and session maker Factory
        """
        pool_size = cfg.db_pool_size
        if SQLUtil.sqlalchemy_engine is None:
            if cfg.db_type == "sqllite":
                db_url = SQLUtil.create_sqllite_url(cfg)
            else:
                logger.error("Unsupported database type %s", cfg.db_type)
                exit(-1)
            SQLUtil.sqlalchemy_engine = create_engine(
                db_url, connect_args={"check_same_thread": False}, pool_size=pool_size)
            SQLUtil.session_local = sessionmaker(
                autocommit=False, autoflush=False, bind=SQLUtil.sqlalchemy_engine)

    @staticmethod
    def create_sqllite_url(cfg):
        """
        create and validate SQLLite url
        """
        path: str = cfg.db_host
        database: str = cfg.db_database
        absolute_path: str = os.path.join(path, database)
        url = 'sqlite:///' + absolute_path
        try:
            result = urlparse(url)
            if all([result.scheme, result.path, result.scheme == 'sqlite']):
                return url
            else:
                logger.error("invalid sqllite url: %s", url)
                exit(-1)
        except ValueError:
            logger.error("invalid sqllite url: %s", url)
            exit(-1)

    def db_add_commit_refresh(self, session: Session, what):
        """
        add data to database
        """
        try:
            session.add(what)
            session.commit()
            session.refresh(what)
        except Exception as e:
            logger.exception("db commit error with data %s", str(what.__dict__))
            ex = db_exception()
            ex.detail = str(e)
            session.rollback()
            raise ex from e

    def db_merge_commit(self, session: Session, what):
        try:
            session.merge(what)
            session.commit()
        except Exception as e:
            ex = db_exception()
            ex.detail = str(e)
            logger.exception("db merge commit error with data %s", str(what.__dict__))
            session.rollback()
            raise ex from e

    def db_update_commit_refresh(self, session: Session, existing, what):
        what = what.model_dump(mode="json")
        try:
            for key in what.keys():
                if what[key] is not None:  # 检查b中的字段是否为None
                    setattr(existing, key, what[key])  # 更新a的字段
            session.commit()
            session.refresh(existing)
        except Exception as e:
            ex = db_exception()
            ex.detail = str(e)
            logger.exception("db update commit refresh error with data %s", str(what.__dict__))
            session.rollback()
            raise ex from e