"""
CRUD представления для товаров (Product).
"""
from django.contrib import messages
from django.contrib.auth.mixins import LoginRequiredMixin, PermissionRequiredMixin
from django.views.generic import ListView, CreateView, DetailView, UpdateView, DeleteView
from django.urls import reverse_lazy
from django.db.models import Q
from itertools import chain

from ..models import Product, ProductCategory, ProductTag, ProductKit
from ..forms import ProductForm
from .utils import handle_photos
from ..models import ProductPhoto


class ProductListView(LoginRequiredMixin, PermissionRequiredMixin, ListView):
    model = Product
    template_name = 'products/product_list.html'
    context_object_name = 'products'
    permission_required = 'products.view_product'
    paginate_by = 10

    def get_queryset(self):
        queryset = super().get_queryset()
        # Добавляем prefetch_related для оптимизации запросов к категориям
        queryset = queryset.prefetch_related('categories', 'photos', 'tags')

        # Улучшенный поиск по нескольким полям
        search_query = self.request.GET.get('search')
        if search_query:
            # Ищем по названию, артикулу, описанию, категориям и ключевым словам
            queryset = queryset.filter(
                Q(name__icontains=search_query) |
                Q(sku__icontains=search_query) |
                Q(description__icontains=search_query) |
                Q(categories__name__icontains=search_query) |
                Q(search_keywords__icontains=search_query)
            ).distinct()

        # Фильтр по категории
        category_id = self.request.GET.get('category')
        if category_id:
            queryset = queryset.filter(categories__id=category_id)

        # Фильтр по статусу
        is_active = self.request.GET.get('is_active')
        if is_active == '1':
            queryset = queryset.filter(is_active=True)
        elif is_active == '0':
            queryset = queryset.filter(is_active=False)

        # Фильтр по тегам
        tags = self.request.GET.getlist('tags')
        if tags:
            queryset = queryset.filter(tags__id__in=tags).distinct()

        return queryset.order_by('-created_at')

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

        # Данные для фильтров
        context['filters'] = {
            'categories': ProductCategory.objects.filter(is_active=True),
            'tags': ProductTag.objects.all(),
            'current': {
                'search': self.request.GET.get('search', ''),
                'category': self.request.GET.get('category', ''),
                'is_active': self.request.GET.get('is_active', ''),
                'tags': self.request.GET.getlist('tags'),
            }
        }

        # Кнопки действий
        action_buttons = []

        if self.request.user.has_perm('products.add_product'):
            action_buttons.append({
                'url': reverse_lazy('products:product-create'),
                'text': 'Создать товар',
                'class': 'btn-primary',
                'icon': 'plus-circle'
            })

        if self.request.user.has_perm('products.add_productkit'):
            action_buttons.append({
                'url': reverse_lazy('products:productkit-create'),
                'text': 'Создать комплект',
                'class': 'btn-outline-primary',
                'icon': 'box-seam'
            })

        action_buttons.append({
            'url': reverse_lazy('products:productkit-list'),
            'text': 'К списку комплектов',
            'class': 'btn-outline-secondary',
            'icon': 'list'
        })

        context['action_buttons'] = action_buttons

        return context


class ProductCreateView(LoginRequiredMixin, PermissionRequiredMixin, CreateView):
    model = Product
    form_class = ProductForm
    template_name = 'products/product_form.html'
    permission_required = 'products.add_product'

    def get_success_url(self):
        return reverse_lazy('products:product-list')

    def form_valid(self, form):
        response = super().form_valid(form)

        # Handle photo uploads
        photo_errors = handle_photos(self.request, self.object, ProductPhoto, 'product')
        if photo_errors:
            for error in photo_errors:
                messages.error(self.request, error)

        messages.success(self.request, f'Товар "{form.instance.name}" успешно создан!')
        return response


class ProductDetailView(LoginRequiredMixin, PermissionRequiredMixin, DetailView):
    model = Product
    template_name = 'products/product_detail.html'
    context_object_name = 'product'
    permission_required = 'products.view_product'

    def get_queryset(self):
        # Prefetch photos to avoid N+1 queries
        return super().get_queryset().prefetch_related('photos')

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        # Добавляем фотографии товара в контекст
        context['product_photos'] = self.object.photos.all().order_by('order', 'created_at')
        context['photos_count'] = self.object.photos.count()
        return context


class ProductUpdateView(LoginRequiredMixin, PermissionRequiredMixin, UpdateView):
    model = Product
    form_class = ProductForm
    template_name = 'products/product_form.html'
    permission_required = 'products.change_product'

    def get_success_url(self):
        return reverse_lazy('products:product-list')

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        # Добавляем фотографии товара в контекст
        context['product_photos'] = self.object.photos.all().order_by('order', 'created_at')
        context['photos_count'] = self.object.photos.count()
        return context

    def form_valid(self, form):
        response = super().form_valid(form)

        # Handle photo uploads
        photo_errors = handle_photos(self.request, self.object, ProductPhoto, 'product')
        if photo_errors:
            for error in photo_errors:
                messages.error(self.request, error)

        messages.success(self.request, f'Товар "{form.instance.name}" успешно обновлен!')
        return response


class ProductDeleteView(LoginRequiredMixin, PermissionRequiredMixin, DeleteView):
    model = Product
    template_name = 'products/product_confirm_delete.html'
    context_object_name = 'product'
    permission_required = 'products.delete_product'

    def get_success_url(self):
        messages.success(self.request, f'Товар "{self.object.name}" успешно удален!')
        return reverse_lazy('products:product-list')


class CombinedProductListView(LoginRequiredMixin, PermissionRequiredMixin, ListView):
    """
    Объединенное представление для товаров и комплектов.
    Показывает оба типа продуктов в одном списке.
    """
    template_name = 'products/all_products_list.html'
    context_object_name = 'items'
    permission_required = 'products.view_product'
    paginate_by = 20

    def get_queryset(self):
        # Получаем товары и комплекты (только постоянные комплекты)
        products = Product.objects.prefetch_related('categories', 'photos', 'tags')
        kits = ProductKit.objects.filter(is_temporary=False).prefetch_related('categories', 'photos')

        # Применяем фильтры
        search_query = self.request.GET.get('search')
        category_id = self.request.GET.get('category')
        is_active = self.request.GET.get('is_active')

        # Фильтрация по поиску
        if search_query:
            products = products.filter(
                Q(name__icontains=search_query) |
                Q(sku__icontains=search_query) |
                Q(description__icontains=search_query) |
                Q(categories__name__icontains=search_query) |
                Q(search_keywords__icontains=search_query)
            ).distinct()

            kits = kits.filter(
                Q(name__icontains=search_query) |
                Q(sku__icontains=search_query) |
                Q(description__icontains=search_query) |
                Q(categories__name__icontains=search_query)
            ).distinct()

        # Фильтрация по категории
        if category_id:
            products = products.filter(categories__id=category_id)
            kits = kits.filter(categories__id=category_id)

        # Фильтрация по статусу
        if is_active == '1':
            products = products.filter(is_active=True)
            kits = kits.filter(is_active=True)
        elif is_active == '0':
            products = products.filter(is_active=False)
            kits = kits.filter(is_active=False)

        # Добавляем type для различения в шаблоне
        products_list = list(products.order_by('-created_at'))
        for p in products_list:
            p.item_type = 'product'

        kits_list = list(kits.order_by('-created_at'))
        for k in kits_list:
            k.item_type = 'kit'

        # Объединяем и сортируем по дате создания
        combined = sorted(
            chain(products_list, kits_list),
            key=lambda x: x.created_at,
            reverse=True
        )

        return combined

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

        # Данные для фильтров
        context['filters'] = {
            'categories': ProductCategory.objects.filter(is_active=True),
            'tags': ProductTag.objects.all(),
            'current': {
                'search': self.request.GET.get('search', ''),
                'category': self.request.GET.get('category', ''),
                'is_active': self.request.GET.get('is_active', ''),
            }
        }

        # Кнопки действий
        action_buttons = []

        if self.request.user.has_perm('products.add_product'):
            action_buttons.append({
                'url': reverse_lazy('products:product-create'),
                'text': 'Создать товар',
                'class': 'btn-primary',
                'icon': 'plus-circle'
            })

        if self.request.user.has_perm('products.add_productkit'):
            action_buttons.append({
                'url': reverse_lazy('products:productkit-create'),
                'text': 'Создать комплект',
                'class': 'btn-outline-primary',
                'icon': 'box-seam'
            })

        context['action_buttons'] = action_buttons

        return context