from .models import Equipment, EquipmentCategory
from django.contrib.auth.models import Group
from django.db.models import Sum
from django.views.generic import DetailView, ListView
from django.contrib.auth.mixins import LoginRequiredMixin

from django_filters.views import FilterView
from django_tables2.views import SingleTableMixin

from .tables import EquipmentTable, EquipmentFilter


class EquipmentHome(LoginRequiredMixin, ListView):
    template_name = 'equipment/home.html'
    context_object_name = 'categories'
    model = EquipmentCategory

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        # TODO remplacer par les vrais owners
        context['owners'] = Group.objects.all()
        categories = (EquipmentCategory.objects.order_by('name')
                      .prefetch_related('children'))
        context['root_cat'] = categories.filter(parent=None)
        queryset = Equipment.objects.all()
        context['stock'] = queryset.aggregate(Sum('stock'))['stock__sum']
        context['nb_type'] = queryset.count()
        return context


class EquipmentListAbstract(LoginRequiredMixin, SingleTableMixin,FilterView):
    table_class = EquipmentTable
    filterset_class = EquipmentFilter
    template_name = 'equipment/list.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['stock'] = self.queryset.aggregate(Sum('stock'))['stock__sum']
        context['nb_type'] = self.queryset.count()
        return context


class EquipmentList(EquipmentListAbstract):
    def get_queryset(self):
        self.queryset = Equipment.objects.all()
        return self.queryset


class EquipmentListByCategory(EquipmentListAbstract):
    def get_category(self):
        try:
            pk = self.kwargs.get('pk')
        except KeyError:
            raise AttributeError(
                "View %s must be called with an object "
                "pk in the URLconf." % self.__class__.__name__
            )
        return EquipmentCategory.objects.get(id=pk)

    def get_queryset(self):
        cat = self.get_category()
        self.queryset = Equipment.objects.all().in_category(cat)
        return self.queryset

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        cat = self.get_category()
        context['subtitle'] = "Dans {cat}".format(cat=cat.full_name())
        return context


class EquipmentListByOwner(EquipmentListAbstract):
    def get_owner(self):
        try:
            pk = self.kwargs.get('pk')
        except KeyError:
            raise AttributeError(
                "View %s must be called with an object "
                "pk in the URLconf." % self.__class__.__name__
            )
        return Group.objects.get(id=pk)

    def get_queryset(self):
        owner = self.get_owner()
        self.queryset = Equipment.objects.filter(owner=owner)
        return self.queryset

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        owner = self.get_owner()
        context['subtitle'] = "Matériel de {owner}".format(owner=owner)
        return context


class EquipmentView(LoginRequiredMixin, DetailView):
    model = Equipment
    template_name = 'equipment/detail.html'