from rest_framework import status
from adrf.views import APIView
from rest_framework.permissions import IsAuthenticated
from asgiref.sync import sync_to_async
from drf_yasg.utils import swagger_auto_schema
from drf_yasg import openapi
import logging
from chunyu_project.common_schemas import success_response, error_response, unauthorized_response, not_found_response

from utils.response_codes import (
    ResponseCode,
    create_standardized_response,
    create_standardized_error_response
)
from utils.email_utils import validate_email_mx
from ..serializers.user_serializers import (
    SendEmailCodeSerializer,
    ChangeEmailSerializer,
    UserSerializer,
)

logger = logging.getLogger(__name__)


class SendChangeEmailCodeAPIView(APIView):
    permission_classes = [IsAuthenticated]

    @swagger_auto_schema(
        tags=['用户'],
        operation_summary='发送修改邮箱验证码',
        operation_description='向新邮箱发送验证码用于修改邮箱',
        request_body=openapi.Schema(
            type=openapi.TYPE_OBJECT,
            properties={
                'email': openapi.Schema(type=openapi.TYPE_STRING, description='新邮箱地址'),
                'captcha_key': openapi.Schema(type=openapi.TYPE_STRING, description='图形验证码 key'),
                'captcha_code': openapi.Schema(type=openapi.TYPE_STRING, description='图形验证码'),
            },
        ),
        responses={200: success_response, 400: error_response, 401: unauthorized_response, 500: error_response},
    )
    async def post(self, request):
        from utils.captcha import check_captcha_required, verify_captcha, record_failure, reset_failures

        identifier = str(request.user.id)
        operation = 'change_email'
        captcha_required = await sync_to_async(check_captcha_required)(operation, identifier)

        if captcha_required:
            captcha_key = request.data.get('captcha_key', None)
            captcha_code = request.data.get('captcha_code', None)

            if not captcha_key or not captcha_code:
                return create_standardized_error_response(
                    code=ResponseCode.CAPTCHA_REQUIRED,
                    status_code=status.HTTP_400_BAD_REQUEST
                )

            captcha_result = await sync_to_async(verify_captcha)(captcha_key, captcha_code)
            if captcha_result == 'expired':
                return create_standardized_error_response(
                    code=ResponseCode.CAPTCHA_EXPIRED,
                    status_code=status.HTTP_400_BAD_REQUEST
                )
            elif captcha_result == 'wrong':
                await sync_to_async(record_failure)(operation, identifier)
                return create_standardized_error_response(
                    code=ResponseCode.CAPTCHA_ERROR,
                    status_code=status.HTTP_400_BAD_REQUEST
                )

        serializer = SendEmailCodeSerializer(
            data=request.data,
            context={'request': request}
        )

        # 校验器内含同步 ORM（validate_email 查重）与 cache 写入，线程池兜底
        if not await sync_to_async(serializer.is_valid)():
            errors = serializer.errors
            first_error = ''
            for field, msgs in errors.items():
                if isinstance(msgs, list) and msgs:
                    first_error = str(msgs[0])
                    break

            await sync_to_async(record_failure)(operation, identifier)
            return create_standardized_error_response(
                data=errors,
                code=ResponseCode.PARAMETER_ERROR,
                message=first_error or '参数异常',
                status_code=status.HTTP_400_BAD_REQUEST
            )

        email = serializer.validated_data.get('email')
        if email and not await sync_to_async(validate_email_mx)(email):
            logger.warning(f'[ChangeEmail] Domain MX check failed: email={email}')
            await sync_to_async(record_failure)(operation, identifier)
            return create_standardized_error_response(
                code=ResponseCode.EMAIL_DOMAIN_INVALID,
                status_code=status.HTTP_400_BAD_REQUEST
            )

        try:
            # save() 内部触发验证码邮件发送（Celery/cache/SMTP 链路），线程池兜底
            email = await serializer.asave()
            await sync_to_async(reset_failures)(operation, identifier)
            return create_standardized_response(
                data={'email_sent': True},
                code=ResponseCode.EMAIL_CHANGE_CODE_SENT,
                status_code=status.HTTP_200_OK
            )
        except Exception as e:
            await sync_to_async(record_failure)(operation, identifier)
            return create_standardized_error_response(
                message=f'邮件发送失败: {str(e)}',
                code=ResponseCode.EMAIL_SEND_FAILED,
                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR
            )


class ChangeEmailAPIView(APIView):
    permission_classes = [IsAuthenticated]

    @swagger_auto_schema(
        tags=['用户'],
        operation_summary='修改邮箱',
        operation_description='使用邮箱验证码修改用户邮箱',
        request_body=openapi.Schema(
            type=openapi.TYPE_OBJECT,
            properties={
                'email': openapi.Schema(type=openapi.TYPE_STRING, description='新邮箱地址'),
                'email_code': openapi.Schema(type=openapi.TYPE_STRING, description='邮箱验证码'),
            },
        ),
        responses={200: success_response, 400: error_response, 401: unauthorized_response, 500: error_response},
    )
    async def post(self, request):
        serializer = ChangeEmailSerializer(
            data=request.data,
            context={'request': request}
        )

        # 校验器内含同步 ORM 查询，线程池兜底
        if not await sync_to_async(serializer.is_valid)():
            errors = serializer.errors
            first_error = ''
            for field, msgs in errors.items():
                if isinstance(msgs, list) and msgs:
                    first_error = str(msgs[0])
                    break

            return create_standardized_error_response(
                data=errors,
                code=ResponseCode.PARAMETER_ERROR,
                message=first_error or '参数异常',
                status_code=status.HTTP_400_BAD_REQUEST
            )

        try:
            updated_user = await serializer.asave()
            user_serializer = UserSerializer(updated_user)

            return create_standardized_response(
                data={'user': await user_serializer.adata},
                code=ResponseCode.EMAIL_CHANGED,
                status_code=status.HTTP_200_OK
            )
        except Exception as e:
            return create_standardized_error_response(
                message=f'邮箱修改失败: {str(e)}',
                code=ResponseCode.SERVER_INTERNAL_ERROR,
                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR
            )