from typing import Any

from django.shortcuts import render
from django.views.generic import ListView, CreateView, UpdateView
from django.urls import reverse_lazy
from django.contrib.auth.views import LoginView
from django.contrib import messages
from django.db.models import Q
from django.contrib.auth.mixins import UserPassesTestMixin
from django.http import HttpResponseRedirect
from extra_views import CreateWithInlinesView, UpdateWithInlinesView
from django import forms

from .models import Product, Supplier, Order, OrderItem
from .forms import ProductForm, OrderForm, OrderItemFormSet

class UserLoginView(LoginView):
    template_name = "core/login.html"

class ProductListView(ListView):
    model = Product
    template_name = "core/product_list.html"
    context_object_name = "products"

    def get_queryset(self):
        queryset = Product.objects.all().select_related("supplier")
        search_query = self.request.GET.get("search", "")
        if search_query:
            queryset = queryset.filter(
                Q(name__icontains=search_query)
                | Q(description__icontains=search_query)
                | Q(manufacturer__icontains=search_query)
                | Q(category__icontains=search_query)
            )
        supplier_id = self.request.GET.get("supplier", "")
        if supplier_id and supplier_id != 'all':
            queryset = queryset.filter(supplier_id=supplier_id)
        sort = self.request.GET.get("sort")
        if sort == "asc":
            queryset = queryset.order_by("quantity")
        if sort == "desc":
            queryset = queryset.order_by("-quantity")
        return queryset

    def get_context_data(self, **kwargs) -> dict[str, Any]:
        context = super().get_context_data(**kwargs)
        context["suppliers"] = Supplier.objects.all()
        context["current_supplier"] = self.request.GET.get("supplier", "")
        context["current_search"] = self.request.GET.get("search", "")
        context["current_sort"] = self.request.GET.get("sort", "")

        return context


class AdminRequiredMixin(UserPassesTestMixin):
    def test_func(self):
        return (
            self.request.user.is_authenticated
            and self.request.user.role
            and self.request.user.role.name == "Администратор"
        )

class ProductCreateUpdateMixin:
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["all_suppliers"] = Supplier.objects.all()
        return context
    
class ProductCreateView(AdminRequiredMixin, ProductCreateUpdateMixin, CreateView):
    model = Product
    form_class = ProductForm
    template_name = "core/product_form.html"
    success_url = reverse_lazy("product_list")

    def form_valid(self, form):
        messages.success(self.request, "Товар успешно добавлен")
        return super().form_valid(form)

class ProductUpdateView(AdminRequiredMixin, ProductCreateUpdateMixin, UpdateView):
    model = Product
    form_class = ProductForm
    template_name = "core/product_form.html"
    success_url = reverse_lazy("product_list")

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["is_edit"] = True
        return context


class AdminManagerRequiredMixin(UserPassesTestMixin):
    def test_func(self):
        return (
            self.request.user.is_authenticated
            and self.request.user.role
            and (self.request.user.role.name == "Администратор" or self.request.user.role.name == "Менеджер")
        )

class OrderListView(AdminManagerRequiredMixin, ListView):
    model = Order
    template_name = "core/order_list.html"
    context_object_name = "orders"


class OrderCreateView(CreateWithInlinesView):
    model = Order
    form_class = OrderForm
    inlines = [OrderItemFormSet]
    success_url = reverse_lazy("order_list")

class OrderUpdateView(UpdateWithInlinesView):
    model = Order
    form_class = OrderForm
    inlines = [OrderItemFormSet]
    success_url = reverse_lazy("order_list")

# formset variant
# class OrderCreateView(CreateView):
#     model = Order
#     form_class = OrderForm
#     template_name = "core/order_form.html"
#     success_url = reverse_lazy("order_list")

#     def get_context_data(self, **kwargs):
#         context = super().get_context_data(**kwargs)
#         if self.request.POST:
#             # re-use the bound formset if post() already stashed an invalid one
#             context["formset"] = getattr(self, "formset", OrderItemFormSet(self.request.POST))
#         else:
#             context["formset"] = OrderItemFormSet()
#         return context

#     def post(self, request, *args, **kwargs):
#         self.object = None
#         form = self.get_form()
#         formset = OrderItemFormSet(request.POST)
#         if form.is_valid() and formset.is_valid():
#             self.object = form.save()
#             formset.instance = self.object
#             formset.save()
#             return HttpResponseRedirect(self.get_success_url())
#         # stash the invalid formset so get_context_data renders it with errors
#         self.formset = formset
#         return self.form_invalid(form)


# class OrderUpdateView(UpdateView):
#     model = Order
#     form_class = OrderForm
#     template_name = "core/order_form.html"
#     success_url = reverse_lazy("order_list")

#     def get_context_data(self, **kwargs):
#         context = super().get_context_data(**kwargs)
#         if self.request.POST:
#             context["formset"] = getattr(
#                 self, "formset", OrderItemFormSet(self.request.POST, instance=self.object)
#             )
#         else:
#             context["formset"] = OrderItemFormSet(instance=self.object)
#         return context

#     def post(self, request, *args, **kwargs):
#         self.object = self.get_object()
#         form = self.get_form()
#         formset = OrderItemFormSet(request.POST, instance=self.object)
#         if form.is_valid() and formset.is_valid():
#             form.save()
#             formset.save()
#             return HttpResponseRedirect(self.get_success_url())
#         self.formset = formset
#         return self.form_invalid(form)