import traceback
from rest_framework.renderers import JSONRenderer
from rest_framework.views import exception_handler
from rest_framework.response import Response
from rest_framework import status as drf_status
import logging

logger = logging.getLogger('log')

def custome_exception_hander(exc, context):
    """
    自定义异常处理
    """
    res = exception_handler(exc, context)
    if res:
        return res
    else:
        """
        日志记录
        """
        logger.error(traceback.format_exc())
    return None

class FitJSONRenderer(JSONRenderer):
    """
    自行封装的渲染器
    """

    def render(self, data, accepted_media_type=None, renderer_context=None):
        """
        如果使用这个render，
        普通的response将会被包装成：
            {"code":200000,"data":"X","msg":"X"}
        这样的结果
        使用方法：
            - 全局
                REST_FRAMEWORK = {
                'DEFAULT_RENDERER_CLASSES': ('utils.response.FitJSONRenderer', ),
                }
            - 局部
                class UserCountView(APIView):
                    renderer_classes = [FitJSONRenderer]

        :param data:
        :param accepted_media_type:
        :param renderer_context:
        :return: {"code":200,"data":"X","msg":"X"}
        """
        response_body = dict(success=True, code=200000, msg='请求成功', data=None)
        response = renderer_context.get("response")
        status_code = response.status_code
        if isinstance(data, dict) and data.keys() == response_body.keys():
            response_body = data
        else:
            # 处理drf格式的返回数据
            if status_code >= 400:  # 如果http响应异常
                response_body = dict(success=False, code=400000, msg='请求失败', data=None)
                response_body['data'] = data  # data里是详细异常信息
                response_body['code'] = status_code*1000
                prefix = ""
                if isinstance(data, dict):
                    prefix = list(data.keys())[0]
                    data = data[prefix]
                if isinstance(data, list):
                    data = data[0]
                
                if prefix != 'detail':
                    response_body['msg'] = prefix + str(data) # 取一部分放入msg,方便前端alert
            else:
                response_body['data'] = data
        renderer_context.get("response").status_code = 200  # 统一成200响应, 可用body里code区分业务异常
        return super(FitJSONRenderer, self).render(response_body, accepted_media_type, renderer_context)


class SuccessResponse(Response):
    def __init__(self, data=None, msg='请求成功', code=200000, status=None, template_name=None, headers=None, exception=False, content_type=None):
        std_data = dict(success=True, code=code, msg=msg, data=data)
        super().__init__(std_data, status, template_name, headers, exception, content_type)

class FailResponse(Response):
    def __init__(self, msg='请求失败', data=None, code=400000, status=400, template_name=None, headers=None, exception=False, content_type=None):
        std_data = dict(success=False, code=code, msg=msg, data=data)
        super().__init__(std_data, status, template_name, headers, exception, content_type)