from django.shortcuts import render
from rest_framework.generics import ListAPIView, GenericAPIView
from rest_framework.filters import OrderingFilter
from drf_haystack.viewsets import HaystackViewSet
from rest_framework.response import Response

from .models import SKU, GoodsCategory
from .serializers import SKUSerializer, SKUIndexSerializer, ChannelSerializer, CategorySerializer
# Create your views here.
class CategoryView(GenericAPIView):
    """
    类别
    """
    queryset = GoodsCategory.objects.all()

    def get(self, request, pk=None):
        ret = dict(
            cat1='',
            cat2='',
            cat3=''
        )
        category = self.get_object()
        if category.parent is None:
            # 当前类别为一级类别
            ret['cat1'] = ChannelSerializer(category.goodschannel_set.all()[0]).data
        elif category.goodscategory_set.count() == 0:
            # 当前类别为三级
            ret['cat3'] = CategorySerializer(category).data
            cat2 = category.parent
            ret['cat2'] = CategorySerializer(cat2).data
            ret['cat1'] = ChannelSerializer(cat2.parent.goodschannel_set.all()[0]).data
        else:
            # 当前类别为二级
            ret['cat2'] = CategorySerializer(category).data
            ret['cat1'] = ChannelSerializer(category.parent.goodschannel_set.all()[0]).data

        return Response(ret)


class SKUSearchViewSet(HaystackViewSet):
    """
    SKU搜索
    """
    index_models = [SKU]

    serializer_class = SKUIndexSerializer


# /categories/(?P<category_id>\d+)/skus?page=xxx&page_size=xxx&ordering=xxx
class SKUListView(ListAPIView):
    """商品列表页：分页和排序"""

    # 指定查询集：需要展示的列表数据，需要根绝条件过滤,category_id需要对应，还有必须是未下架的商品
    # queryset = SKU.objects.all()

    # 指定序列化器
    serializer_class = SKUSerializer

    # 这种写法，只对这个视图的分页有效
    # pagination_class = '自定义的分页类，自己制定分页规则'

    # 指定排序和过滤的后端:ordering=price(根据价格小到大) ordering=-price(根据价格大到小)
    filter_backends = [OrderingFilter]
    # 指定排序和过滤的字段:create_time=根据记录的时间排序，price=根据价格排序，sales=根据销量排序
    ordering_fields = ('create_time', 'price', 'sales')

    def get_queryset(self):
        """根据条件刷选出需要展示在列表界面的数据"""
        category_id = self.kwargs.get('category_id')
        return SKU.objects.filter(category_id=category_id, is_launched=True)

#-------------------------------------------------------------------------------

from rest_framework import serializers
from drf_haystack.serializers import HaystackSerializer

from .models import SKU, GoodsCategory, GoodsChannel
from .search_indexes import SKUIndex


class SKUSerializer(serializers.ModelSerializer):
    """序列化器序列化商品SKU信息"""

    class Meta:
        model = SKU
        # 指定序列化的字段
        fields = ('id', 'name', 'price', 'default_image_url', 'comments')


class SKUIndexSerializer(HaystackSerializer):
    """
    SKU索引结果数据序列化器
    """
    class Meta:
        index_classes = [SKUIndex]
        fields = ('text', 'id', 'name', 'price', 'default_image_url', 'comments')


class CategorySerializer(serializers.ModelSerializer):
    """
    类别序列化器
    """
    class Meta:
        model = GoodsCategory
        fields = ('id', 'name')


class ChannelSerializer(serializers.ModelSerializer):
    """
    频道序列化器
    """
    category = CategorySerializer()

    class Meta:
        model = GoodsChannel
        fields = ('category', 'url')

#utils-------------------------------------------------------
from collections import OrderedDict

from .models import GoodsChannel


def get_categories():
    """
    获取商城商品分类菜单
    :return 菜单字典
    """
    # 商品频道及分类菜单
    # 使用有序字典保存类别的顺序
    # categories = {
    #     1: { # 组1
    #         'channels': [{'id':, 'name':, 'url':},{}, {}...],
    #         'sub_cats': [{'id':, 'name':, 'sub_cats':[{},{}]}, {}, {}, ..]
    #     },
    #     2: { # 组2
    #
    #     }
    # }
    categories = OrderedDict()
    channels = GoodsChannel.objects.order_by('group_id', 'sequence')
    for channel in channels:
        group_id = channel.group_id  # 当前组

        if group_id not in categories:
            categories[group_id] = {'channels': [], 'sub_cats': []}

        cat1 = channel.category  # 当前频道的类别

        # 追加当前频道
        categories[group_id]['channels'].append({
            'id': cat1.id,
            'name': cat1.name,
            'url': channel.url
        })
        # 构建当前类别的子类别
        for cat2 in cat1.goodscategory_set.all():
            cat2.sub_cats = []
            for cat3 in cat2.goodscategory_set.all():
                cat2.sub_cats.append(cat3)
            categories[group_id]['sub_cats'].append(cat2)
    return categories