import logging
from datetime import datetime
from django.conf import settings
from django.utils import timezone
from django import forms
from django.shortcuts import render, reverse, redirect, get_object_or_404
from django.http import HttpResponseRedirect
from django.urls import reverse, reverse_lazy
from django.views.generic.base import RedirectView, TemplateView
from django.views.generic.edit import (
    FormView, CreateView, UpdateView, DeleteView, FormMixin
)
from django.views.generic.detail import DetailView, SingleObjectMixin
from django.views.generic.list import ListView
from django.contrib.auth.decorators import login_required
from django.contrib.auth.mixins import (
    LoginRequiredMixin, PermissionRequiredMixin
)
from django.forms import inlineformset_factory
from django.contrib import messages
from django.contrib.messages.views import SuccessMessageMixin

from django.db.models import (
    Exists, OuterRef, Prefetch, Subquery, Count, Sum, Avg, F, Q, Value,
    ExpressionWrapper, IntegerField
)
from django.db.models.functions import Coalesce

from accounts.models import User
from accounts.utils import get_or_create_customer
from accounts.forms import AddressForm
from core.models import (
    ProductCategory,
    Product,
    ProductPhoto,
    ProductVariant,
    ProductOption,
    Order,
    OrderLine,
    ShippingRate,
    Transaction,
    TrackingNumber,
    Coupon,
    SiteSettings
)

from core import (
    DiscountValueType,
    VoucherType,
    OrderStatus
)
from .forms import (
    ProductVariantUpdateForm,
    OrderLineFulfillForm,
    OrderLineFormset,
    OrderCancelForm,
    OrderTrackingFormset,
    CouponForm,
    ProductPhotoForm
)

logger = logging.getLogger(__name__)


class DashboardHomeView(LoginRequiredMixin, TemplateView):
    template_name = 'dashboard/home.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        today = timezone.localtime(timezone.now()).date()
        context['order_count'] = Order.objects.exclude(
            status=OrderStatus.DRAFT
        ).filter(
            created_at__date=today
        ).count()
        context['orders_unfulfilled'] = Order.objects.filter(
            status=OrderStatus.UNFULFILLED
        ).count()
        context['todays_sales'] = Order.objects.exclude(
            status=OrderStatus.DRAFT
        ).filter(
            created_at__date=today
        ).aggregate(total=Sum('total_amount'))['total']
        return context


class DashboardConfigView(LoginRequiredMixin, TemplateView):
    template_name = 'dashboard/config.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['shipping_rate_list'] = ShippingRate.objects.all()
        return context


class SiteSettingsUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, UpdateView
):
    permission_required = 'core.change_sitesettings'
    model = SiteSettings
    context_object_name = 'settings'
    template_name = 'dashboard/settings_form.html'
    fields = '__all__'
    success_url = reverse_lazy('dashboard:config')
    success_message = 'Settings saved.'


class CatalogView(LoginRequiredMixin, ListView):
    model = ProductCategory
    context_object_name = 'category_list'
    template_name = 'dashboard/catalog.html'

    def get_context_data(self, *args, **kwargs):
        context = super().get_context_data(*args, **kwargs)
        context['uncategorized_products'] = Product.objects.filter(
            category=None
        )
        context['option_list'] = ProductOption.objects.all()
        return context


class StockView(LoginRequiredMixin, ListView):
    model = ProductVariant
    context_object_name = 'variant_list'
    template_name = 'dashboard/stock.html'

    def get_queryset(self):
        object_list = ProductVariant.objects.filter(
            track_inventory=True
        ).prefetch_related('order_lines', 'product').annotate(
            total_in_warehouse=F('stock') + Coalesce(Sum('order_lines__quantity', filter=Q(
                order_lines__order__status=OrderStatus.UNFULFILLED) | Q(
                order_lines__order__status=OrderStatus.PARTIALLY_FULFILLED)
                ) - Sum('order_lines__quantity_fulfilled', filter=Q(
                    order_lines__order__status=OrderStatus.UNFULFILLED) | Q(
                    order_lines__order__status=OrderStatus.PARTIALLY_FULFILLED)), 0)
        ).order_by('product')
        return object_list


class ShippingRateDetailView(LoginRequiredMixin, DetailView):
    model = ShippingRate
    context_object_name = 'rate'
    template_name = 'dashboard/rate/detail.html'


class ShippingRateCreateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, CreateView
):
    permission_required = 'core.add_shippingrate'
    model = ShippingRate
    context_object_name = 'rate'
    template_name = 'dashboard/rate/create_form.html'
    fields = '__all__'
    success_message = '%(name)s created.'


class ShippingRateUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, UpdateView
):
    permission_required = 'core.change_shippingrate'
    model = ShippingRate
    context_object_name = 'rate'
    template_name = 'dashboard/rate/form.html'
    success_message = 'ShippingRate saved.'
    fields = '__all__'


class ShippingRateDeleteView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, DeleteView
):
    permission_required = 'core.delete_shippingrate'
    model = ShippingRate
    context_object_name = 'rate'
    template_name = 'dashboard/rate/confirm_delete.html'
    success_message = 'ShippingRate deleted.'
    success_url = reverse_lazy('dashboard:config')


class CouponListView(LoginRequiredMixin, ListView):
    model = Coupon
    template_name = 'dashboard/coupon/list.html'


class CouponCreateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, CreateView
):
    permission_required = 'core.add_coupon'
    model = Coupon
    template_name = 'dashboard/coupon/create_form.html'
    form_class = CouponForm
    success_message = '%(name)s created.'


class CouponDetailView(LoginRequiredMixin, DetailView):
    model = Coupon
    template_name = 'dashboard/coupon/detail.html'


class CouponUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, UpdateView
):
    permission_required = 'core.change_coupon'
    model = Coupon
    template_name = 'dashboard/coupon/form.html'
    success_message = '%(name)s saved.'
    form_class = CouponForm


class CouponDeleteView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, DeleteView
):
    permission_required = 'core.delete_coupon'
    model = Coupon
    template_name = 'dashboard/coupon/confirm_delete.html'
    success_url = reverse_lazy('dashboard:coupon-list')
    success_message = 'Coupon deleted.'


class OrderListView(LoginRequiredMixin, ListView):
    model = Order
    template_name = 'dashboard/order/list.html'
    paginate_by = 50

    def get_queryset(self):
        query = self.request.GET.get('status')
        if query == 'unfulfilled':
            object_list = Order.objects.filter(
                Q(status=OrderStatus.UNFULFILLED) |
                Q(status=OrderStatus.PARTIALLY_FULFILLED)
            ).order_by('-created_at').select_related('customer')

        else:
            object_list = Order.objects.order_by(
                '-created_at'
            ).select_related('customer')

        return object_list


class OrderDetailView(LoginRequiredMixin, DetailView):
    model = Order
    template_name = 'dashboard/order/detail.html'

    def get_object(self):
        queryset = Order.objects.with_fulfillment_and_filter(
            self.kwargs.get(self.pk_url_kwarg)
        ).select_related(
            'customer',
            'billing_address',
            'shipping_address'
        ).prefetch_related(
            'lines__variant__product__productphoto_set'
        )
        obj = queryset.get()
        return obj

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        return context


class OrderFulfillView(LoginRequiredMixin, SuccessMessageMixin, UpdateView):
    model = Order
    template_name = 'dashboard/order/fulfill.html'
    form_class = OrderLineFormset
    success_message = 'Order saved.'

    def form_valid(self, form):
        form.save()
        return HttpResponseRedirect(self.get_success_url())

    def get_success_url(self):
        return reverse('dashboard:order-detail', kwargs={'pk': self.object.pk})


class OrderCancelView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, UpdateView
):
    permission_required = 'core.cancel_order'
    model = Order
    template_name = 'dashboard/order/cancel_form.html'
    form_class = OrderCancelForm
    success_message = 'Order canceled.'
    initial = {
        'status': OrderStatus.CANCELED
    }

    def form_valid(self, form):
        form.instance.add_stock()
        form.instance.save()
        return super().form_valid(form)

    def get_success_url(self):
        return reverse('dashboard:order-detail', kwargs={'pk': self.object.pk})


class OrderTrackingView(LoginRequiredMixin, SuccessMessageMixin, UpdateView):
    model = Order
    template_name = 'dashboard/order/tracking_form.html'
    form_class = OrderTrackingFormset
    success_message = 'Order saved.'

    def form_valid(self, form):
        form.save()
        return HttpResponseRedirect(self.get_success_url())

    def get_success_url(self):
        return reverse('dashboard:order-detail', kwargs={'pk': self.object.pk})


class CategoryListView(LoginRequiredMixin, ListView):
    model = ProductCategory
    context_object_name = 'category_list'
    template_name = 'dashboard/category/list.html'


class CategoryCreateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, CreateView
):
    permission_required = 'core.add_productcategory'
    model = ProductCategory
    context_object_name = 'category'
    success_message = 'Category created.'
    template_name = 'dashboard/category/create_form.html'
    fields = '__all__'


class CategoryDetailView(LoginRequiredMixin, DetailView):
    model = ProductCategory
    context_object_name = 'category'
    template_name = 'dashboard/category/detail.html'


class CategoryUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, UpdateView
):
    permission_required = 'core.change_productcategory'
    model = ProductCategory
    context_object_name = 'category'
    success_message = 'Category saved.'
    template_name = 'dashboard/category/form.html'
    fields = '__all__'


class CategoryDeleteView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, DeleteView
):
    permission_required = 'core.delete_productcategory'
    model = ProductCategory
    context_object_name = 'category'
    success_message = 'Category deleted.'
    template_name = 'dashboard/category/confirm_delete.html'
    success_url = reverse_lazy('dashboard:catalog')


class ProductListView(LoginRequiredMixin, ListView):
    model = Product
    template_name = 'dashboard/product/list.html'
    ordering = 'sorting'

    # def get_queryset(self):
    #     object_list = Product.objects.filter(
    #         status=OrderStatus.UNFULFILLED
    #     ).select_related(
    #         'customer'
    #     )
    #     return object_list


class ProductDetailView(LoginRequiredMixin, DetailView):
    model = Product
    template_name = 'dashboard/product/detail.html'

    def get_object(self):
        pk = self.kwargs.get(self.pk_url_kwarg)
        queryset = Product.objects.filter(
            pk=pk
        ).select_related(
            'category',
        ).prefetch_related(
            'options',
            'productphoto_set',
            Prefetch(
                'variants',
                queryset=ProductVariant.objects.all().order_by('sorting')
            )
        )
        obj = queryset.get()
        return obj


class ProductCreateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, CreateView
):
    permission_required = 'core.add_product'
    model = Product
    template_name = 'dashboard/product/create_form.html'
    fields = '__all__'
    success_message = '%(name)s created.'


class ProductUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, UpdateView
):
    permission_required = 'core.change_product'
    model = Product
    template_name = 'dashboard/product/form.html'
    fields = '__all__'
    success_message = '%(name)s saved.'


class ProductDeleteView(
    LoginRequiredMixin,
    PermissionRequiredMixin,
    SuccessMessageMixin,
    DeleteView
):
    permission_required = 'core.delete_product'
    model = Product
    template_name = 'dashboard/product/confirm_delete.html'
    success_url = reverse_lazy('dashboard:catalog')
    success_message = 'Product deleted.'


class ProductPhotoCreateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, CreateView
):
    permission_required = 'core.add_productphoto'
    model = ProductPhoto
    pk_url_kwarg = 'photo_pk'
    template_name = 'dashboard/product/photo_create_form.html'
    form_class = ProductPhotoForm
    success_message = 'Photo added.'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['product'] = Product.objects.get(pk=self.kwargs['pk'])
        return context

    def form_valid(self, form):
        form.instance.product = Product.objects.get(pk=self.kwargs['pk'])
        return super().form_valid(form)

    def get_success_url(self):
        return reverse('dashboard:product-detail', kwargs={'pk': self.kwargs['pk']})


class ProductPhotoDeleteView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, DeleteView
):
    permission_required = 'core.delete_productphoto'
    model = ProductPhoto
    pk_url_kwarg = 'photo_pk'
    template_name = 'dashboard/prodphoto_confirm_delete.html'
    success_message = 'Photo deleted.'

    def get_success_url(self):
        return reverse('dashboard:product-detail', kwargs={'pk': self.kwargs['pk']})


class ProductVariantCreateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, CreateView
):
    permission_required = 'core.add_productvariant'
    model = ProductVariant
    success_message = 'Variant created.'
    template_name = 'dashboard/variant/create_form.html'
    fields = [
        'name',
        'sku',
        'price',
        'weight',
        'visible_in_listings',
        'track_inventory',
        'stock',
    ]

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['product'] = Product.objects.get(pk=self.kwargs['pk'])
        return context

    def form_valid(self, form):
        form.instance.product = Product.objects.get(pk=self.kwargs['pk'])
        return super().form_valid(form)

    def get_success_url(self):
        return reverse('dashboard:product-detail', kwargs={'pk': self.kwargs['pk']})


class ProductVariantUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, UpdateView
):
    permission_required = 'core.change_productvariant'
    model = ProductVariant
    pk_url_kwarg = 'variant_pk'
    success_message = 'Variant saved.'
    template_name = 'dashboard/variant/form.html'
    form_class = ProductVariantUpdateForm
    context_object_name = 'variant'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['product'] = Product.objects.get(pk=self.kwargs['pk'])
        return context

    def form_valid(self, form):
        form.instance.product = Product.objects.get(pk=self.kwargs['pk'])
        return super().form_valid(form)

    def get_success_url(self):
        return reverse('dashboard:product-detail', kwargs={'pk': self.kwargs['pk']})


class ProductVariantDeleteView(
    LoginRequiredMixin,
    PermissionRequiredMixin,
    SuccessMessageMixin,
    DeleteView
):
    permission_required = 'core.delete_productvariant'
    model = ProductVariant
    pk_url_kwarg = 'variant_pk'
    success_message = 'ProductVariant deleted.'
    template_name = 'dashboard/variant/confirm_delete.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['product'] = Product.objects.get(pk=self.kwargs['pk'])
        return context

    def get_success_url(self):
        return reverse('dashboard:product-detail', kwargs={'pk': self.kwargs['pk']})


class ProductVariantStockUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, UpdateView
):
    permission_required = 'core.change_productvariant'
    model = ProductVariant
    pk_url_kwarg = 'variant_pk'
    success_message = 'ProductVariant saved.'
    success_url = reverse_lazy('dashboard:stock')
    template_name = 'dashboard/variant/restock.html'
    fields = [
        'stock',
    ]
    context_object_name = 'variant'

    def get_queryset(self):
        queryset = ProductVariant.objects.annotate(
            total_in_warehouse=F('stock') + Coalesce(Sum('order_lines__quantity', filter=Q(
                order_lines__order__status=OrderStatus.UNFULFILLED) | Q(
                order_lines__order__status=OrderStatus.PARTIALLY_FULFILLED)
                ) - Sum('order_lines__quantity_fulfilled', filter=Q(
                    order_lines__order__status=OrderStatus.UNFULFILLED) | Q(
                    order_lines__order__status=OrderStatus.PARTIALLY_FULFILLED)), 0)
        ).prefetch_related('order_lines', 'product')
        return queryset

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['product'] = Product.objects.get(pk=self.kwargs['pk'])
        return context

    def form_valid(self, form):
        form.instance.product = Product.objects.get(pk=self.kwargs['pk'])
        return super().form_valid(form)


class ProductOptionDetailView(LoginRequiredMixin, DetailView):
    model = ProductOption
    template_name = 'dashboard/option/detail.html'
    context_object_name = 'option'


class ProductOptionCreateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, CreateView
):
    permission_required = 'core.add_productoption'
    model = ProductOption
    template_name = 'dashboard/option/create_form.html'
    fields = [
        'name',
        'options',
        'products',
    ]
    success_message = '%(name)s created.'


class ProductOptionUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, UpdateView
):
    permission_required = 'core.change_productoption'
    model = ProductOption
    success_message = 'Option saved.'
    template_name = 'dashboard/option/form.html'
    fields = [
        'name',
        'options',
        'products',
    ]
    context_object_name = 'option'
    success_url = reverse_lazy('dashboard:catalog')


class ProductOptionDeleteView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, DeleteView
):
    permission_required = 'core.delete_productoption'
    model = ProductOption
    success_message = 'ProductOption deleted.'
    template_name = 'dashboard/option/confirm_delete.html'
    context_object_name = 'option'
    success_url = reverse_lazy('dashboard:catalog')


class CustomerListView(LoginRequiredMixin, ListView):
    model = User
    template_name = 'dashboard/customer/list.html'
    paginate_by = 100

    def get_queryset(self):
        object_list = User.objects.filter(
            Exists(
                Order.objects.filter(customer=OuterRef('pk'))
            ) | Q(is_staff=False)
        ).prefetch_related(
            'orders'
        ).annotate(
            num_orders=Count('orders')
        ).order_by('first_name', 'last_name')

        return object_list


class CustomerDetailView(LoginRequiredMixin, DetailView):
    model = User
    template_name = 'dashboard/customer/detail.html'
    context_object_name = 'customer'


class CustomerUpdateView(
    LoginRequiredMixin, PermissionRequiredMixin, SuccessMessageMixin, UpdateView
):
    permission_required = 'accounts.change_user'
    model = User
    template_name = 'dashboard/customer/form.html'
    context_object_name = 'customer'
    success_message = 'Customer saved.'
    fields = (
        'first_name',
        'last_name',
        'email',
        'is_staff',
        'addresses',
        'default_shipping_address'
    )

    def get_success_url(self):
        return reverse('dashboard:customer-detail', kwargs={'pk': self.object.pk})