import json
import logging
import traceback

from django.conf import settings
from django.http import Http404, JsonResponse
from django.utils.deprecation import MiddlewareMixin
from django.utils.translation import gettext_lazy as _

from component.utils.exceptions import BlueException

try:
    from raven.contrib.django.raven_compat.models import \
        sentry_exception_handler
# 兼容未有安装sentry的情况
except ImportError:
    sentry_exception_handler = None

logger = logging.getLogger('blueapps')


class AppExceptionMiddleware(MiddlewareMixin):

    def process_exception(self, request, exception):
        """
        app后台错误统一处理
        """

        self.exception = exception
        self.request = request

        # 用户自我感知的异常抛出
        if isinstance(exception, BlueException):
            logger.log(
                exception.LOG_LEVEL,
                (u"""捕获主动抛出异常, 具体异常堆栈->[%s] status_code->[%s] & """
                 u"""client_message->[%s] & args->[%s] """) % (
                    traceback.format_exc(),
                    exception.ERROR_CODE,
                    exception.message,
                    exception.args
                )
            )

            response = JsonResponse(exception.response_data())

            response.status_code = exception.STATUS_CODE
            return response

        # 用户未主动捕获的异常
        logger.error(
            (u"""捕获未处理异常,异常具体堆栈->[%s], 请求URL->[%s], """
             u"""请求方法->[%s] 请求参数->[%s]""") % (
                traceback.format_exc(),
                request.path,
                request.method,
                json.dumps(getattr(request, request.method, None))
            )
        )

        # 对于check开头函数进行遍历调用，如有满足条件的函数，则不屏蔽异常
        check_funtions = self.get_check_functions()
        for check_function in check_funtions:
            if check_function():
                return None

        response = JsonResponse({
            "result": False,
            'code': "50000",
            'message': _(u"系统异常,请联系管理员处理"),
            'data': None
        })
        response.status_code = 500

        # notify sentry
        if sentry_exception_handler is not None:
            sentry_exception_handler(request=request)

        return response

    def get_check_functions(self):
        """获取需要判断的函数列表"""
        return [getattr(self, func) for func in dir(self) if func.startswith('check') and callable(getattr(self, func))]

    def check_is_debug(self):
        """判断是否是开发模式"""
        return settings.DEBUG

    def check_is_http404(self):
        """判断是否基于Http404异常"""
        return isinstance(self.exception, Http404)