# -*- coding: utf-8 -*-

import json
from pathlib import Path
from typing import Dict, List
from sqlalchemy import select, func
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.logger import logger
from app.core.database import AsyncSessionLocal, async_engine
from app.core.base_model import MappedBase
from app.config.setting import settings

from app.api.v1.module_system.user.model import UserModel, UserRolesModel, UserPositionsModel
from app.api.v1.module_system.role.model import RoleModel, RoleDeptsModel, RoleMenusModel
from app.api.v1.module_system.position.model import PositionModel
from app.api.v1.module_system.dept.model import DeptModel
from app.api.v1.module_system.menu.model import MenuModel
from app.api.v1.module_system.params.model import ParamsModel
from app.api.v1.module_system.dict.model import DictTypeModel, DictDataModel
from app.api.v1.module_system.notice.model import NoticeModel


class InitializeData:
    """
    初始化数据库和基础数据
    """

    def __init__(self) -> None:
        # 按照依赖关系排序：先创建基础表，再创建关联表
        self.prepare_init_models = [
            # 部门表（自引用，需要先创建）
            DeptModel,
            # 菜单表（自引用，需要先创建）
            MenuModel,
            # 用户表（依赖部门和角色）
            UserModel,
            # 角色表（依赖菜单和部门）
            RoleModel,
            # 岗位表（无外键依赖）
            PositionModel,
            # 基础表（无外键依赖）
            ParamsModel,
            DictTypeModel,
            DictDataModel,
            # 关联表（依赖基础表）
            UserPositionsModel,
            UserRolesModel,
            RoleDeptsModel,
            RoleMenusModel,
            # 通知表（无外键依赖）
            NoticeModel,
        ]
    
    async def __init_create_table(self) -> None:
        """初始化表结构（第一阶段）"""
        try:
            # 使用引擎创建所有表
            async with async_engine.begin() as conn:
                await conn.run_sync(MappedBase.metadata.create_all)
            logger.info("✅️ 数据库表结构初始化完成")
        except Exception as e:
            logger.error(f"❌️ 数据库表结构初始化失败: {str(e)}")
            raise

    async def __init_data(self, db: AsyncSession) -> None:
        """初始化基础数据"""
        for model in self.prepare_init_models:
            table_name = model.__tablename__
            
            # 检查表中是否已经有数据
            count_result = await db.execute(select(func.count()).select_from(model))
            existing_count = count_result.scalar()
            if existing_count and existing_count > 0:
                logger.warning(f"⚠️  跳过 {table_name} 表数据初始化（表已存在 {existing_count} 条记录）")
                continue

            data = await self.__get_data(table_name)
            if not data:
                logger.warning(f"⚠️  跳过 {table_name} 表，无初始化数据")
                continue
            
            try:
                # 特殊处理具有嵌套 children 数据的表
                if table_name in ["system_dept", "system_menu"]:
                    # 获取对应的模型类
                    model_class = DeptModel if table_name == "system_dept" else MenuModel
                    objs = self.__create_objects_with_children(data, model_class)
                else:
                    # 表为空，直接插入全部数据
                    objs = [model(**item) for item in data]
                db.add_all(objs)
                await db.flush()
                logger.info(f"✅️ 已向 {table_name} 表写入初始化数据")

            except Exception as e:
                logger.error(f"❌️ 初始化 {table_name} 表数据失败: {str(e)}")
                raise

    def __create_objects_with_children(self, data: List[Dict], model_class) -> List:
        """通用递归创建对象函数，处理嵌套的 children 数据"""
        objs = []
        
        def create_object(obj_data: Dict):
            # 分离 children 数据
            children_data = obj_data.pop('children', [])
            
            # 创建当前对象
            obj = model_class(**obj_data)
            
            # 递归处理子对象
            if children_data:
                obj.children = [create_object(child) for child in children_data]
                
            return obj
        
        for item in data:
            objs.append(create_object(item))
            
        return objs

    async def __get_data(self, filename: str) -> List[Dict]:
        """读取初始化数据文件"""
        json_path = Path.joinpath(settings.SCRIPT_DIR, f'{filename}.json')
        if not json_path.exists():
            return []

        try:
            with open(json_path, 'r', encoding='utf-8') as f:
                return json.loads(f.read())
        except json.JSONDecodeError as e:
            logger.error(f"❌️ 解析 {json_path} 失败: {str(e)}")
            raise
        except Exception as e:
            logger.error(f"❌️ 读取 {json_path} 失败: {str(e)}")
            raise

    async def init_db(self) -> None:
        """
        执行完整初始化流程
        """
        # 先创建表结构
        await self.__init_create_table()
        
        # 再初始化数据
        async with AsyncSessionLocal() as session:
            async with session.begin():
                await self.__init_data(session)