feat(discounts, orders): рефакторинг системы скидок - единый источник правды

- Добавлен combine_mode в форму создания/редактирования скидок - Добавлена колонка "Объединение" в список скидок с иконками - Добавлен фильтр по режиму объединения скидок - Добавлена валидация: только одна exclusive скидка на заказ - Удалены дублирующие поля из Order и OrderItem: - applied_discount, applied_promo_code, discount_amount - Скидки теперь хранятся только в DiscountApplication - Добавлены свойства для обратной совместимости Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-11 13:46:02 +03:00
parent cd758a0645
commit c070e42cab
9 changed files with 192 additions and 112 deletions
--- a/myproject/discounts/services/applier.py
+++ b/myproject/discounts/services/applier.py
@@ -34,8 +34,7 @@ class DiscountApplier:
        from discounts.services.calculator import DiscountCalculator

        # Удаляем предыдущую скидку на заказ
-        if order.applied_promo_code:
-            DiscountApplier._remove_order_discount_only(order)
+        DiscountApplier._remove_order_discount_only(order)

        # Рассчитываем скидку
        result = DiscountCalculator.calculate_order_discount(order, promo_code)
@@ -50,21 +49,7 @@ class DiscountApplier:
        discounts_data = result['discounts']
        total_amount = result['total_amount']

-        # Применяем первую скидку в applied_discount (для обратной совместимости с Order)
-        if discounts_data:
-            first_discount = discounts_data[0]['discount']
-            order.applied_discount = first_discount
-            order.applied_promo_code = promo.code
-            order.discount_amount = total_amount
-            order.save(update_fields=['applied_discount', 'applied_promo_code', 'discount_amount'])
-
-        # Пересчитываем total_amount
-        order.calculate_total()
-
-        # Регистрируем использование промокода
-        promo.record_usage(order.customer)
-
-        # Создаем записи о применении для каждой скидки
+        # Создаем записи о применении для каждой скидки в DiscountApplication
        for disc_data in discounts_data:
            discount = disc_data['discount']
            amount = disc_data['amount']
@@ -85,6 +70,12 @@ class DiscountApplier:
            discount.current_usage_count += 1
            discount.save(update_fields=['current_usage_count'])

+        # Пересчитываем total_amount (использует DiscountApplication)
+        order.calculate_total()
+
+        # Регистрируем использование промокода
+        promo.record_usage(order.customer)
+
        return {
            'success': True,
            'discounts': discounts_data,
@@ -124,12 +115,6 @@ class DiscountApplier:
        if order_result['discounts'] and not order_result['error']:
            total_order_amount = order_result['total_amount']

-            # Сохраняем первую скидку в applied_discount (для совместимости)
-            first_discount_data = order_result['discounts'][0]
-            order.applied_discount = first_discount_data['discount']
-            order.discount_amount = total_order_amount
-            order.save(update_fields=['applied_discount', 'discount_amount'])
-
            # Создаем записи о применении для всех скидок
            for disc_data in order_result['discounts']:
                discount = disc_data['discount']
@@ -167,12 +152,6 @@ class DiscountApplier:
            if item_result['discounts']:
                total_item_amount = item_result['total_amount']

-                # Сохраняем первую скидку в applied_discount (для совместимости)
-                first_discount_data = item_result['discounts'][0]
-                item.applied_discount = first_discount_data['discount']
-                item.discount_amount = total_item_amount
-                item.save(update_fields=['applied_discount', 'discount_amount'])
-
                # Создаем записи о применении для всех скидок
                base_amount = item.price * item.quantity
                for disc_data in item_result['discounts']:
@@ -186,7 +165,7 @@ class DiscountApplier:
                        target='order_item',
                        base_amount=base_amount,
                        discount_amount=amount,
-                        final_amount=item.get_total_price(),
+                        final_amount=base_amount - amount,
                        customer=order.customer,
                        applied_by=user
                    )
@@ -216,14 +195,6 @@ class DiscountApplier:
        Args:
            order: Order
        """
-        DiscountApplier._remove_order_discount_only(order)
-
-        # Удаляем скидки с позиций
-        order.items.update(
-            applied_discount=None,
-            discount_amount=Decimal('0')
-        )
-
        # Удаляем записи о применении
        from discounts.models import DiscountApplication
        DiscountApplication.objects.filter(order=order).delete()
@@ -265,14 +236,6 @@ class DiscountApplier:
        # Рассчитываем сумму
        discount_amount = discount.calculate_discount_amount(Decimal(order.subtotal))

-        # Применяем к заказу
-        order.applied_discount = discount
-        order.discount_amount = discount_amount
-        order.save(update_fields=['applied_discount', 'discount_amount'])
-
-        # Пересчитываем total_amount
-        order.calculate_total()
-
        # Создаем запись о применении
        DiscountApplication.objects.create(
            order=order,
@@ -289,6 +252,9 @@ class DiscountApplier:
        discount.current_usage_count += 1
        discount.save(update_fields=['current_usage_count'])

+        # Пересчитываем total_amount
+        order.calculate_total()
+
        return {
            'success': True,
            'discount_amount': discount_amount
@@ -307,7 +273,5 @@ class DiscountApplier:
        # Удаляем записи о применении скидок к заказу
        DiscountApplication.objects.filter(order=order, target='order').delete()

-        order.applied_discount = None
-        order.applied_promo_code = None
-        order.discount_amount = Decimal('0')
-        order.save(update_fields=['applied_discount', 'applied_promo_code', 'discount_amount'])
+        # Пересчитываем (order.discount_amount теперь свойство, берущее из DiscountApplication)
+        order.calculate_total()
--- a/myproject/discounts/templates/discounts/discount_form.html
+++ b/myproject/discounts/templates/discounts/discount_form.html
@@ -101,6 +101,22 @@
                        </div>
                    </div>

+                    <div class="mb-3">
+                        <label for="id_combine_mode" class="form-label">Режим объединения с другими скидками</label>
+                        <select class="form-select" id="id_combine_mode" name="combine_mode">
+                            <option value="max_only" {% if form.combine_mode.value == 'max_only' or not form.combine_mode.value %}selected{% endif %}>
+                                🏆 Только максимум (применяется лучшая скидка)
+                            </option>
+                            <option value="stack" {% if form.combine_mode.value == 'stack' %}selected{% endif %}>
+                                📚 Складывать (суммировать с другими)
+                            </option>
+                            <option value="exclusive" {% if form.combine_mode.value == 'exclusive' %}selected{% endif %}>
+                                🚫 Исключающая (отменяет остальные скидки)
+                            </option>
+                        </select>
+                        <div class="form-text">Как эта скидка взаимодействует с другими активными скидками</div>
+                    </div>
+
                    <!-- Ограничения -->
                    <h5 class="mb-3 mt-4">Ограничения</h5>
                    <div class="row mb-3">
--- a/myproject/discounts/templates/discounts/discount_list.html
+++ b/myproject/discounts/templates/discounts/discount_list.html
@@ -60,6 +60,15 @@
                    <option value="inactive" {% if current_filters.is_active == 'inactive' %}selected{% endif %}>Неактивные</option>
                </select>
            </div>
+            <div class="col-md-2">
+                <label class="form-label">Объединение</label>
+                <select name="combine_mode" class="form-select">
+                    <option value="">Все</option>
+                    <option value="stack" {% if current_filters.combine_mode == 'stack' %}selected{% endif %}>Складывать</option>
+                    <option value="max_only" {% if current_filters.combine_mode == 'max_only' %}selected{% endif %}>Максимум</option>
+                    <option value="exclusive" {% if current_filters.combine_mode == 'exclusive' %}selected{% endif %}>Исключающая</option>
+                </select>
+            </div>
            <div class="col-md-3 d-flex align-items-end">
                <button type="submit" class="btn btn-primary me-2">
                    <i class="bi bi-funnel"></i> Применить
@@ -84,6 +93,7 @@
                        <th>Значение</th>
                        <th>Область</th>
                        <th>Авто</th>
+                        <th>Объединение</th>
                        <th>Статус</th>
                        <th>Промокоды</th>
                        <th>Использований</th>
@@ -129,6 +139,15 @@
                            <i class="bi bi-dash-circle text-muted"></i>
                            {% endif %}
                        </td>
+                        <td>
+                            {% if discount.combine_mode == 'stack' %}
+                            <span class="badge bg-secondary" title="Складывать (суммировать)">📚 Склад.</span>
+                            {% elif discount.combine_mode == 'max_only' %}
+                            <span class="badge bg-info" title="Только максимум">🏆 Макс.</span>
+                            {% elif discount.combine_mode == 'exclusive' %}
+                            <span class="badge bg-danger" title="Исключающая (отменяет остальные)">🚫 Исключ.</span>
+                            {% endif %}
+                        </td>
                        <td>
                            {% if discount.is_active %}
                            <span class="badge bg-success">Активна</span>
@@ -180,10 +199,10 @@
            <ul class="pagination justify-content-center">
                {% if page_obj.has_previous %}
                <li class="page-item">
-                    <a class="page-link" href="?page=1{% if current_filters.search %}&search={{ current_filters.search }}{% endif %}{% if current_filters.type %}&type={{ current_filters.type }}{% endif %}{% if current_filters.scope %}&scope={{ current_filters.scope }}{% endif %}{% if current_filters.is_active %}&is_active={{ current_filters.is_active }}{% endif %}">&laquo;</a>
+                    <a class="page-link" href="?page=1{% if current_filters.search %}&search={{ current_filters.search }}{% endif %}{% if current_filters.type %}&type={{ current_filters.type }}{% endif %}{% if current_filters.scope %}&scope={{ current_filters.scope }}{% endif %}{% if current_filters.is_active %}&is_active={{ current_filters.is_active }}{% endif %}{% if current_filters.combine_mode %}&combine_mode={{ current_filters.combine_mode }}{% endif %}">&laquo;</a>
                </li>
                <li class="page-item">
-                    <a class="page-link" href="?page={{ page_obj.previous_page_number }}{% if current_filters.search %}&search={{ current_filters.search }}{% endif %}{% if current_filters.type %}&type={{ current_filters.type }}{% endif %}{% if current_filters.scope %}&scope={{ current_filters.scope }}{% endif %}{% if current_filters.is_active %}&is_active={{ current_filters.is_active }}{% endif %}">&lsaquo;</a>
+                    <a class="page-link" href="?page={{ page_obj.previous_page_number }}{% if current_filters.search %}&search={{ current_filters.search }}{% endif %}{% if current_filters.type %}&type={{ current_filters.type }}{% endif %}{% if current_filters.scope %}&scope={{ current_filters.scope }}{% endif %}{% if current_filters.is_active %}&is_active={{ current_filters.is_active }}{% endif %}{% if current_filters.combine_mode %}&combine_mode={{ current_filters.combine_mode }}{% endif %}">&lsaquo;</a>
                </li>
                {% endif %}

@@ -193,10 +212,10 @@

                {% if page_obj.has_next %}
                <li class="page-item">
-                    <a class="page-link" href="?page={{ page_obj.next_page_number }}{% if current_filters.search %}&search={{ current_filters.search }}{% endif %}{% if current_filters.type %}&type={{ current_filters.type }}{% endif %}{% if current_filters.scope %}&scope={{ current_filters.scope }}{% endif %}{% if current_filters.is_active %}&is_active={{ current_filters.is_active }}{% endif %}">&rsaquo;</a>
+                    <a class="page-link" href="?page={{ page_obj.next_page_number }}{% if current_filters.search %}&search={{ current_filters.search }}{% endif %}{% if current_filters.type %}&type={{ current_filters.type }}{% endif %}{% if current_filters.scope %}&scope={{ current_filters.scope }}{% endif %}{% if current_filters.is_active %}&is_active={{ current_filters.is_active }}{% endif %}{% if current_filters.combine_mode %}&combine_mode={{ current_filters.combine_mode }}{% endif %}">&rsaquo;</a>
                </li>
                <li class="page-item">
-                    <a class="page-link" href="?page={{ page_obj.paginator.num_pages }}{% if current_filters.search %}&search={{ current_filters.search }}{% endif %}{% if current_filters.type %}&type={{ current_filters.type }}{% endif %}{% if current_filters.scope %}&scope={{ current_filters.scope }}{% endif %}{% if current_filters.is_active %}&is_active={{ current_filters.is_active }}{% endif %}">&raquo;</a>
+                    <a class="page-link" href="?page={{ page_obj.paginator.num_pages }}{% if current_filters.search %}&search={{ current_filters.search }}{% endif %}{% if current_filters.type %}&type={{ current_filters.type }}{% endif %}{% if current_filters.scope %}&scope={{ current_filters.scope }}{% endif %}{% if current_filters.is_active %}&is_active={{ current_filters.is_active }}{% endif %}{% if current_filters.combine_mode %}&combine_mode={{ current_filters.combine_mode }}{% endif %}">&raquo;</a>
                </li>
                {% endif %}
            </ul>
--- a/myproject/discounts/views.py
+++ b/myproject/discounts/views.py
@@ -71,6 +71,7 @@ class DiscountListView(DiscountAccessMixin, ListView):
        discount_type = self.request.GET.get('type')
        scope = self.request.GET.get('scope')
        is_active = self.request.GET.get('is_active')
+        combine_mode = self.request.GET.get('combine_mode')
        search = self.request.GET.get('search')

        if discount_type:
@@ -79,6 +80,8 @@ class DiscountListView(DiscountAccessMixin, ListView):
            queryset = queryset.filter(scope=scope)
        if is_active:
            queryset = queryset.filter(is_active=(is_active == 'active'))
+        if combine_mode:
+            queryset = queryset.filter(combine_mode=combine_mode)
        if search:
            queryset = queryset.filter(
                Q(name__icontains=search) | Q(description__icontains=search)
@@ -92,6 +95,7 @@ class DiscountListView(DiscountAccessMixin, ListView):
            'type': self.request.GET.get('type', ''),
            'scope': self.request.GET.get('scope', ''),
            'is_active': self.request.GET.get('is_active', ''),
+            'combine_mode': self.request.GET.get('combine_mode', ''),
            'search': self.request.GET.get('search', ''),
        }
        context['can_edit'] = self._can_edit()
@@ -110,7 +114,7 @@ class DiscountCreateView(LoginRequiredMixin, RoleRequiredMixin, CreateView):
    template_name = 'discounts/discount_form.html'
    fields = [
        'name', 'description', 'discount_type', 'value', 'scope',
-        'is_auto', 'is_active', 'priority',
+        'is_auto', 'is_active', 'priority', 'combine_mode',
        'start_date', 'end_date',
        'min_order_amount', 'max_usage_count',
        'products', 'categories', 'excluded_products',
@@ -119,6 +123,21 @@ class DiscountCreateView(LoginRequiredMixin, RoleRequiredMixin, CreateView):
    success_url = reverse_lazy('system_settings:discounts:list')

    def form_valid(self, form):
+        # Валидация: нельзя создать больше одной активной exclusive скидки на заказ
+        if form.instance.combine_mode == 'exclusive' and form.instance.scope == 'order' and form.instance.is_active:
+            existing_exclusive = Discount.objects.filter(
+                combine_mode='exclusive',
+                scope='order',
+                is_active=True
+            ).exists()
+
+            if existing_exclusive:
+                form.add_error(
+                    'combine_mode',
+                    'Уже существует активная исключающая скидка на заказ. Может быть только одна.'
+                )
+                return self.form_invalid(form)
+
        form.instance.created_by = self.request.user
        messages.success(self.request, f'Скидка "{form.instance.name}" создана')
        return super().form_valid(form)
@@ -142,7 +161,7 @@ class DiscountUpdateView(LoginRequiredMixin, RoleRequiredMixin, UpdateView):
    template_name = 'discounts/discount_form.html'
    fields = [
        'name', 'description', 'discount_type', 'value', 'scope',
-        'is_auto', 'is_active', 'priority',
+        'is_auto', 'is_active', 'priority', 'combine_mode',
        'start_date', 'end_date',
        'min_order_amount', 'max_usage_count',
        'products', 'categories', 'excluded_products',
@@ -151,6 +170,21 @@ class DiscountUpdateView(LoginRequiredMixin, RoleRequiredMixin, UpdateView):
    success_url = reverse_lazy('system_settings:discounts:list')

    def form_valid(self, form):
+        # Валидация: нельзя создать больше одной активной exclusive скидки на заказ
+        if form.instance.combine_mode == 'exclusive' and form.instance.scope == 'order' and form.instance.is_active:
+            existing_exclusive = Discount.objects.filter(
+                combine_mode='exclusive',
+                scope='order',
+                is_active=True
+            ).exclude(pk=self.object.pk).exists()
+
+            if existing_exclusive:
+                form.add_error(
+                    'combine_mode',
+                    'Уже существует активная исключающая скидка на заказ. Может быть только одна.'
+                )
+                return self.form_invalid(form)
+
        messages.success(self.request, f'Скидка "{form.instance.name}" обновлена')
        return super().form_valid(form)