from pathlib import Path
from urllib.parse import urljoin
import uuid

from django.conf import settings
from django.contrib.auth.decorators import login_required
from django.core.files.storage import default_storage
from django.http import JsonResponse
from django.shortcuts import render
from django.views.decorators.csrf import csrf_exempt
from rest_framework import status, viewsets
from rest_framework.decorators import action
from rest_framework.permissions import AllowAny
from rest_framework.response import Response
from rest_framework.views import APIView

from menu.models import Dish, DishCategory, Order
from menu.serializers import DishSerializer, DishCategorySerializer, OrderSerializer
from menu.services import DishService, OrderService, ParserService


@login_required
def index(request):
    """首页"""
    return render(request, 'index.html')


@csrf_exempt
@login_required
def upload_image(request):
    """上传图片"""
    if request.method != 'POST':
        return JsonResponse({'error': 'Method not allowed'}, status=405)

    # Rate limit: 20 uploads per minute per user
    from django.core.cache import cache
    user_key = f'upload_throttle_{request.user.id}'
    cache.add(user_key, 0, 60)
    count = cache.get(user_key, 0)
    if count >= 20:
        return JsonResponse({'error': '上传太频繁，请稍后再试'}, status=429)
    cache.set(user_key, count + 1, 60)

    image = request.FILES.get('image')
    if not image:
        return JsonResponse({'error': 'No image provided'}, status=400)

    ext = Path(image.name).suffix.lower()
    if ext not in settings.ALLOWED_UPLOAD_IMAGE_EXTENSIONS:
        return JsonResponse({'error': 'Unsupported image extension'}, status=400)

    content_type = (image.content_type or '').lower()
    if content_type not in settings.ALLOWED_UPLOAD_IMAGE_CONTENT_TYPES:
        return JsonResponse({'error': 'Unsupported image content type'}, status=400)

    if image.size > settings.MAX_UPLOAD_IMAGE_SIZE:
        return JsonResponse({'error': 'Image file too large'}, status=400)

    filename = f"dishes/{uuid.uuid4().hex}{ext}"
    saved_path = default_storage.save(filename, image)
    media_path = str(saved_path).lstrip('/')
    media_url = urljoin(settings.MEDIA_URL, media_path)

    return JsonResponse({'url': media_url})


class DishCategoryViewSet(viewsets.ModelViewSet):
    """分类视图"""
    queryset = DishCategory.objects.all()
    serializer_class = DishCategorySerializer
    pagination_class = None


class DishViewSet(viewsets.ModelViewSet):
    """菜品视图"""
    serializer_class = DishSerializer
    pagination_class = None

    def get_queryset(self):
        category_id = self.request.query_params.get('category')
        search = self.request.query_params.get('search')
        return DishService.get_queryset(category_id, search)

    def retrieve(self, request, *args, **kwargs):
        instance = self.get_object()
        DishService.increment_view_count(instance)
        serializer = self.get_serializer(instance)
        return Response(serializer.data)


class OrderViewSet(viewsets.ModelViewSet):
    """订单视图"""
    serializer_class = OrderSerializer
    pagination_class = None

    def get_queryset(self):
        status_filter = self.request.query_params.get('status')
        return OrderService.get_queryset(status_filter)

    def create(self, request, *args, **kwargs):
        request_data = request.data.copy()
        dish_ids = request_data.pop('dish_ids', [])
        serializer = self.get_serializer(data=request_data)
        serializer.is_valid(raise_exception=True)
        order = OrderService.create_order(serializer, dish_ids)
        response_serializer = self.get_serializer(order)
        return Response(response_serializer.data, status=status.HTTP_201_CREATED)

    @action(detail=True, methods=['post'])
    def complete(self, request, pk=None):
        order = self.get_object()
        order = OrderService.complete_order(order)
        serializer = self.get_serializer(order)
        return Response(serializer.data)

    @action(detail=True, methods=['get'])
    def share(self, request, pk=None):
        order = self.get_object()
        serializer = self.get_serializer(order)
        return Response(serializer.data)


class ParseUrlView(APIView):
    """解析外部链接"""
    throttle_scope = 'parse-url'
    permission_classes = [AllowAny]

    def post(self, request):
        url = request.data.get('url', '')
        try:
            result = ParserService.parse_url(url)
            return Response(result)
        except ValueError as e:
            return Response({'error': f'解析失败: {str(e)}'}, status=status.HTTP_400_BAD_REQUEST)
        except TypeError as e:
            return Response({'error': f'解析失败: {str(e)}'}, status=status.HTTP_400_BAD_REQUEST)
        except Exception as e:
            return Response({'error': f'解析失败: {str(e)}'}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)