import asyncio
from datetime import datetime

import aiohttp

from rest_framework.permissions import AllowAny
from adrf.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 chunyu_project.common_schemas import success_response, error_response

GEOCODING_URL = "https://geocoding-api.open-meteo.com/v1/search"
AIR_QUALITY_URL = "https://air-quality-api.open-meteo.com/v1/air-quality"


def get_air_quality_level(pm2_5):
    """
    根据PM2.5浓度获取空气质量等级
    """
    if pm2_5 <= 10:
        return "优"
    elif pm2_5 <= 25:
        return "良"
    elif pm2_5 <= 50:
        return "轻度污染"
    elif pm2_5 <= 75:
        return "中度污染"
    else:
        return "重度污染"


class AirQualityView(APIView):
    """
    空气质量查询视图 - 基于 Open-Meteo Air Quality API（免费，无需API Key）
    """
    permission_classes = [AllowAny]

    @swagger_auto_schema(
        tags=['Air Quality'],
        operation_summary='获取空气质量信息（GET方式）',
        operation_description='通过城市名称获取实时空气质量信息，支持PM2.5、PM10、臭氧、二氧化氮等指标',
        manual_parameters=[
            openapi.Parameter(
                'city',
                openapi.IN_QUERY,
                description='城市名称（支持中文、英文，如：北京、Beijing、上海、Shanghai）',
                type=openapi.TYPE_STRING,
                required=True
            ),
            openapi.Parameter(
                'lang',
                openapi.IN_QUERY,
                description='返回语言（默认：zh_cn）',
                type=openapi.TYPE_STRING,
                required=False,
                enum=['zh_cn', 'en']
            ),
        ],
        responses={200: success_response, 400: error_response, 404: error_response, 502: error_response}
    )
    async def get(self, request):
        city = request.GET.get('city', '').strip()
        lang = request.GET.get('lang', 'zh_cn').strip()

        if not city:
            return Response(
                {"code": 400, "message": "参数错误：city不能为空", "data": None},
                status=status.HTTP_400_BAD_REQUEST
            )

        return await self._fetch_air_quality(city, lang)

    @swagger_auto_schema(
        tags=['Air Quality'],
        operation_summary='获取空气质量信息（POST方式）',
        operation_description='通过城市名称获取实时空气质量信息，支持PM2.5、PM10、臭氧、二氧化氮等指标',
        request_body=openapi.Schema(
            type=openapi.TYPE_OBJECT,
            required=['city'],
            properties={
                'city': openapi.Schema(type=openapi.TYPE_STRING, description='城市名称（支持中文、英文）'),
                'lang': openapi.Schema(type=openapi.TYPE_STRING, description='返回语言（默认：zh_cn）', enum=['zh_cn', 'en']),
            }
        ),
        responses={200: success_response, 400: error_response, 404: error_response, 502: error_response}
    )
    async def post(self, request):
        city = request.data.get('city', '').strip() if isinstance(request.data, dict) else ''
        lang = request.data.get('lang', 'zh_cn').strip() if isinstance(request.data, dict) else 'zh_cn'

        if not city:
            return Response(
                {"code": 400, "message": "参数错误：city不能为空", "data": None},
                status=status.HTTP_400_BAD_REQUEST
            )

        return await self._fetch_air_quality(city, lang)

    async def _fetch_air_quality(self, city, lang):
        """
        调用 Open-Meteo Air Quality API 获取空气质量数据（aiohttp 全异步）
        """
        timeout = aiohttp.ClientTimeout(total=10)
        try:
            async with aiohttp.ClientSession(timeout=timeout) as session:
                # 第一步：通过地理编码API获取城市坐标
                geo_params = {
                    'name': city,
                    'count': 1,
                    'language': 'zh' if lang == 'zh_cn' else 'en',
                    'format': 'json'
                }
                async with session.get(GEOCODING_URL, params=geo_params) as geo_response:
                    if geo_response.status != 200:
                        return Response(
                            {"code": 502, "message": "地理编码服务异常，请稍后重试", "data": None},
                            status=status.HTTP_502_BAD_GATEWAY
                        )
                    geo_data = await geo_response.json()

                results = geo_data.get('results', [])

                if not results:
                    return Response(
                        {"code": 404, "message": f"未找到城市：{city}，请检查城市名称是否正确", "data": None},
                        status=status.HTTP_404_NOT_FOUND
                    )

                location = results[0]
                latitude = location.get('latitude')
                longitude = location.get('longitude')
                city_name = location.get('name', city)
                country = location.get('country', '')

                # 第二步：获取空气质量数据
                air_quality_params = {
                    'latitude': latitude,
                    'longitude': longitude,
                    'current': 'pm10,pm2_5,carbon_monoxide,nitrogen_dioxide,sulphur_dioxide,ozone,us_aqi',
                    'timezone': 'auto'
                }

                async with session.get(AIR_QUALITY_URL, params=air_quality_params) as aq_response:
                    if aq_response.status != 200:
                        return Response(
                            {"code": 502, "message": "空气质量服务异常，请稍后重试", "data": None},
                            status=status.HTTP_502_BAD_GATEWAY
                        )
                    aq_data = await aq_response.json()

            current = aq_data.get('current', {})

            pm2_5 = current.get('pm2_5', 0)

            # 构建响应
            air_quality_info = {
                'city': city_name,
                'country': country,
                'pm2_5': pm2_5,
                'pm10': current.get('pm10', 0),
                'ozone': current.get('ozone', 0),
                'nitrogen_dioxide': current.get('nitrogen_dioxide', 0),
                'sulphur_dioxide': current.get('sulphur_dioxide', 0),
                'carbon_monoxide': current.get('carbon_monoxide', 0),
                'air_quality_level': get_air_quality_level(pm2_5),
                'updated_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
            }

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

        except (aiohttp.ClientError, asyncio.TimeoutError):
            return Response(
                {"code": 502, "message": "请求超时，请稍后重试", "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
            )