from typing import Optional, Any, List, Union
from pydantic import BaseModel, ConfigDict


class PageData(BaseModel):
    """分页数据"""
    model_config = ConfigDict(from_attributes=True)
    
    items: List[Any]
    total: int
    skip: int
    limit: int


class ApiResponse(BaseModel):
    """统一 API 响应格式"""
    model_config = ConfigDict(from_attributes=True)
    
    code: int = 0
    msg: str = "success"
    data: Optional[Any] = None

    @classmethod
    def success(cls, data: Any = None, msg: str = "success"):
        """成功响应"""
        return cls(code=1, msg=msg, data=data)

    @classmethod
    def error(cls, msg: str = "error", code: int = 0):
        """错误响应"""
        return cls(code=code, msg=msg, data=None)

    @classmethod
    def no_data(cls, msg: str = "no data"):
        """无数据响应"""
        return cls(code=2, msg=msg, data=None)