import requests

from rest_framework.permissions import AllowAny
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
from drf_yasg.utils import swagger_auto_schema
from drf_yasg import openapi
from django.core.cache import caches

default_cache = caches['default']

IP_API_URL = "http://ip-api.com/json/{ip}?lang=zh-CN"
IP_CACHE_TIMEOUT = 3600  # 1小时
REQUEST_TIMEOUT = 5  # 5秒超时


class GetIPDataView(APIView):
    """
    IP定位视图 - 基于 ip-api.com 免费地理定位服务
    """
    permission_classes = [AllowAny]

    @swagger_auto_schema(
        tags=['API'],
        operation_summary='获取IP地理信息',
        operation_description='通过IP地址获取地理定位信息，支持指定IP或自动获取客户端IP',
        manual_parameters=[
            openapi.Parameter(
                'ip',
                openapi.IN_QUERY,
                description='要查询的IP地址（可选，不传则自动获取客户端IP）',
                type=openapi.TYPE_STRING,
                required=False
            ),
        ],
        responses={
            200: openapi.Response(
                description="Success",
                schema=openapi.Schema(
                    type=openapi.TYPE_OBJECT,
                    properties={
                        'code': openapi.Schema(type=openapi.TYPE_INTEGER, example=200),
                        'message': openapi.Schema(type=openapi.TYPE_STRING, example='success'),
                        'data': openapi.Schema(
                            type=openapi.TYPE_OBJECT,
                            properties={
                                'ip': openapi.Schema(type=openapi.TYPE_STRING, description='IP地址'),
                                'country': openapi.Schema(type=openapi.TYPE_STRING, description='国家'),
                                'regionName': openapi.Schema(type=openapi.TYPE_STRING, description='省份/地区'),
                                'city': openapi.Schema(type=openapi.TYPE_STRING, description='城市'),
                                'isp': openapi.Schema(type=openapi.TYPE_STRING, description='ISP服务商'),
                                'lat': openapi.Schema(type=openapi.TYPE_NUMBER, description='纬度'),
                                'lon': openapi.Schema(type=openapi.TYPE_NUMBER, description='经度'),
                                'timezone': openapi.Schema(type=openapi.TYPE_STRING, description='时区'),
                            }
                        ),
                    }
                )
            ),
            400: openapi.Response(description="参数错误"),
            502: openapi.Response(description="第三方服务异常"),
        }
    )
    def get(self, request):
        # 获取要查询的IP地址
        ip = request.GET.get('ip', '').strip()
        if not ip:
            ip = self._get_client_ip(request)

        if not ip:
            return Response(
                {"code": 400, "message": "无法获取IP地址", "data": None},
                status=status.HTTP_400_BAD_REQUEST
            )

        return self._fetch_ip_location(ip)

    def _get_client_ip(self, request):
        """
        从 request.META 中获取客户端真实IP地址
        """
        x_forwarded_for = request.META.get('HTTP_X_FORWARDED_FOR')
        if x_forwarded_for:
            ip = x_forwarded_for.split(',')[0].strip()
            if ip:
                return ip

        x_real_ip = request.META.get('HTTP_X_REAL_IP')
        if x_real_ip:
            return x_real_ip.strip()

        remote_addr = request.META.get('REMOTE_ADDR')
        if remote_addr:
            return remote_addr.strip()

        return None

    def _fetch_ip_location(self, ip):
        """
        调用 ip-api.com 获取IP地理信息，支持Redis缓存
        """
        cache_key = f"ip_location:{ip}"

        # 先尝试从缓存获取
        cached_data = default_cache.get(cache_key)
        if cached_data:
            return Response(
                {"code": 200, "message": "success", "data": cached_data},
                status=status.HTTP_200_OK
            )

        try:
            url = IP_API_URL.format(ip=ip)
            response = requests.get(url, timeout=REQUEST_TIMEOUT)

            if response.status_code != 200:
                return Response(
                    {"code": 502, "message": "IP定位服务异常，请稍后重试", "data": None},
                    status=status.HTTP_502_BAD_GATEWAY
                )

            result = response.json()

            if result.get('status') != 'success':
                return Response(
                    {"code": 400, "message": f"IP查询失败：{result.get('message', '未知错误')}", "data": None},
                    status=status.HTTP_400_BAD_REQUEST
                )

            ip_info = {
                'ip': result.get('query', ip),
                'country': result.get('country', ''),
                'regionName': result.get('regionName', ''),
                'city': result.get('city', ''),
                'isp': result.get('isp', ''),
                'lat': result.get('lat', 0),
                'lon': result.get('lon', 0),
                'timezone': result.get('timezone', ''),
            }

            # 写入缓存
            default_cache.set(cache_key, ip_info, IP_CACHE_TIMEOUT)

            return Response(
                {"code": 200, "message": "success", "data": ip_info},
                status=status.HTTP_200_OK
            )

        except requests.exceptions.Timeout:
            return Response(
                {"code": 502, "message": "请求超时，请稍后重试", "data": None},
                status=status.HTTP_502_BAD_GATEWAY
            )
        except requests.exceptions.ConnectionError:
            return Response(
                {"code": 502, "message": "网络连接异常，请检查网络后重试", "data": None},
                status=status.HTTP_502_BAD_GATEWAY
            )
        except Exception as e:
            return Response(
                {"code": 500, "message": f"服务器内部错误：{str(e)}", "data": None},
                status=status.HTTP_500_INTERNAL_SERVER_ERROR
            )