Добавлена поддержка документов списания в админке и сигналах

- Зарегистрированы модели WriteOffDocument и WriteOffDocumentItem в админке
- Настроен inline для позиций документа в админке
- Добавлены цветовые индикаторы статусов документа
- Настроены фильтры, поиск и сортировка для удобной работы
- Добавлен сигнал release_reservation_on_writeoff_item_delete
- Автоматическое освобождение резервов при удалении позиций через админку
- Защита от утечки резервов при прямом удалении через ORM

myproject/inventory/admin.py

@@ -7,7 +7,7 @@ from decimal import Decimal
 from inventory.models import (
     Warehouse, StockBatch, Incoming, IncomingBatch, Sale, WriteOff, Transfer,
     Inventory, InventoryLine, Reservation, Stock, StockMovement,
-    SaleBatchAllocation, Showcase
+    SaleBatchAllocation, Showcase, WriteOffDocument, WriteOffDocumentItem
 )
 
 
@@ -356,3 +356,61 @@ class StockMovementAdmin(admin.ModelAdmin):
     search_fields = ('product__name', 'order__order_number')
     date_hierarchy = 'created_at'
     readonly_fields = ('created_at',)
+
+
+# ===== WRITEOFF DOCUMENT (документы списания) =====
+class WriteOffDocumentItemInline(admin.TabularInline):
+    model = WriteOffDocumentItem
+    extra = 0
+    fields = ('product', 'quantity', 'reason', 'notes', 'reservation')
+    readonly_fields = ('reservation',)
+    raw_id_fields = ('product',)
+
+
+@admin.register(WriteOffDocument)
+class WriteOffDocumentAdmin(admin.ModelAdmin):
+    list_display = ('document_number', 'warehouse', 'status_display', 'date', 'items_count', 'total_quantity_display', 'created_by', 'created_at')
+    list_filter = ('status', 'warehouse', 'date', 'created_at')
+    search_fields = ('document_number', 'warehouse__name')
+    date_hierarchy = 'date'
+    readonly_fields = ('document_number', 'created_at', 'updated_at', 'confirmed_at', 'confirmed_by')
+    inlines = [WriteOffDocumentItemInline]
+
+    fieldsets = (
+        ('Документ', {
+            'fields': ('document_number', 'warehouse', 'status', 'date', 'notes')
+        }),
+        ('Аудит', {
+            'fields': ('created_by', 'created_at', 'confirmed_by', 'confirmed_at', 'updated_at'),
+            'classes': ('collapse',)
+        }),
+    )
+
+    def status_display(self, obj):
+        colors = {
+            'draft': '#ff9900',
+            'confirmed': '#008000',
+            'cancelled': '#ff0000',
+        }
+        return format_html(
+            '<span style="color: {}; font-weight: bold;">{}</span>',
+            colors.get(obj.status, '#000000'),
+            obj.get_status_display()
+        )
+    status_display.short_description = 'Статус'
+
+    def items_count(self, obj):
+        return obj.items.count()
+    items_count.short_description = 'Позиций'
+
+    def total_quantity_display(self, obj):
+        return f"{obj.total_quantity} шт"
+    total_quantity_display.short_description = 'Всего'
+
+
+@admin.register(WriteOffDocumentItem)
+class WriteOffDocumentItemAdmin(admin.ModelAdmin):
+    list_display = ('document', 'product', 'quantity', 'reason', 'created_at')
+    list_filter = ('reason', 'document__status', 'created_at')
+    search_fields = ('product__name', 'document__document_number')
+    raw_id_fields = ('product', 'document', 'reservation')

myproject/inventory/signals.py

@@ -11,7 +11,7 @@ from django.utils import timezone
 from decimal import Decimal
 
 from orders.models import Order, OrderItem
-from inventory.models import Reservation, Warehouse, Incoming, StockBatch, Sale, SaleBatchAllocation, Inventory, WriteOff, Stock
+from inventory.models import Reservation, Warehouse, Incoming, StockBatch, Sale, SaleBatchAllocation, Inventory, WriteOff, Stock, WriteOffDocumentItem
 from inventory.services import SaleProcessor
 from inventory.services.batch_manager import StockBatchManager
 from inventory.services.inventory_processor import InventoryProcessor
@@ -1357,3 +1357,19 @@ def update_kit_prices_on_product_change(sender, instance, created, **kwargs):
                 f"после изменения цены товара {instance.sku}: {e}",
                 exc_info=True
             )
+
+
+# ==================== WRITEOFF DOCUMENT SIGNALS ====================
+
+@receiver(pre_delete, sender=WriteOffDocumentItem)
+def release_reservation_on_writeoff_item_delete(sender, instance, **kwargs):
+    """
+    Сигнал: При удалении позиции документа списания освобождаем связанный резерв.
+
+    Это fallback для случаев удаления напрямую через ORM/Admin,
+    минуя WriteOffDocumentService.remove_item().
+    """
+    if instance.reservation and instance.reservation.status == 'reserved':
+        instance.reservation.status = 'released'
+        instance.reservation.released_at = timezone.now()
+        instance.reservation.save(update_fields=['status', 'released_at'])