feat: add equipment management with QR codes and transfers

Stage 5 (Inventory) implementation:
- Add EquipmentTransferLog model for tracking equipment movements
- Add EquipmentViewSet actions:
  - transfer: move equipment between departments/users
  - write_off: decommission equipment
  - add_maintenance: record maintenance activities
  - qr_code: generate QR code for equipment
  - transfer_history: view equipment transfer history
- Use existing QRCodeGenerator and InventoryNumberGenerator services
- Fix EquipmentStatus constants usage (IN_USE, RETIRED)
- Add 14 new tests for inventory functionality

Test results: 66/66 PASSED
- 20/20 Model tests
- 12/12 API tests
- 9/9 Workflow tests
- 11/11 Budget tests
- 14/14 Inventory tests (NEW)

backend/procurement/migrations/0002_equipmenttransferlog.py

@@ -0,0 +1,39 @@
+# Generated by Django 5.2.4 on 2025-12-09 07:33
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('employees', '0034_alter_employee_telegram'),
+        ('procurement', '0001_initial'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='EquipmentTransferLog',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('from_location', models.CharField(blank=True, max_length=255, verbose_name='Откуда')),
+                ('to_location', models.CharField(blank=True, max_length=255, verbose_name='Куда')),
+                ('transfer_type', models.CharField(choices=[('assignment', 'Назначение ответственного'), ('transfer', 'Перемещение'), ('return', 'Возврат')], default='transfer', max_length=20, verbose_name='Тип передачи')),
+                ('reason', models.TextField(blank=True, verbose_name='Причина/комментарий')),
+                ('created_at', models.DateTimeField(auto_now_add=True, verbose_name='Дата передачи')),
+                ('created_by', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='transfers_created', to=settings.AUTH_USER_MODEL, verbose_name='Кто оформил')),
+                ('equipment', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='transfer_logs', to='procurement.equipment', verbose_name='Оборудование')),
+                ('from_department', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='transfers_out', to='employees.department', verbose_name='Из отдела')),
+                ('from_person', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='equipment_given', to=settings.AUTH_USER_MODEL, verbose_name='От кого')),
+                ('to_department', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='transfers_in', to='employees.department', verbose_name='В отдел')),
+                ('to_person', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='equipment_received', to=settings.AUTH_USER_MODEL, verbose_name='Кому')),
+            ],
+            options={
+                'verbose_name': 'Лог передачи',
+                'verbose_name_plural': 'Логи передач',
+                'ordering': ['-created_at'],
+            },
+        ),
+    ]

backend/procurement/models.py

@@ -480,6 +480,95 @@ class MaintenanceRecord(models.Model):
         )
 
 
+class EquipmentTransferLog(models.Model):
+    """Лог передачи/перемещения оборудования."""
+    
+    TRANSFER_TYPES = [
+        ('assignment', 'Назначение ответственного'),
+        ('transfer', 'Перемещение'),
+        ('return', 'Возврат'),
+    ]
+    
+    equipment = models.ForeignKey(
+        Equipment,
+        on_delete=models.CASCADE,
+        related_name='transfer_logs',
+        verbose_name='Оборудование'
+    )
+    from_department = models.ForeignKey(
+        Department,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name='transfers_out',
+        verbose_name='Из отдела'
+    )
+    to_department = models.ForeignKey(
+        Department,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name='transfers_in',
+        verbose_name='В отдел'
+    )
+    from_person = models.ForeignKey(
+        User,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name='equipment_given',
+        verbose_name='От кого'
+    )
+    to_person = models.ForeignKey(
+        User,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name='equipment_received',
+        verbose_name='Кому'
+    )
+    from_location = models.CharField(
+        'Откуда',
+        max_length=255,
+        blank=True
+    )
+    to_location = models.CharField(
+        'Куда',
+        max_length=255,
+        blank=True
+    )
+    transfer_type = models.CharField(
+        'Тип передачи',
+        max_length=20,
+        choices=TRANSFER_TYPES,
+        default='transfer'
+    )
+    reason = models.TextField(
+        'Причина/комментарий',
+        blank=True
+    )
+    created_at = models.DateTimeField('Дата передачи', auto_now_add=True)
+    created_by = models.ForeignKey(
+        User,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name='transfers_created',
+        verbose_name='Кто оформил'
+    )
+    
+    class Meta:
+        verbose_name = 'Лог передачи'
+        verbose_name_plural = 'Логи передач'
+        ordering = ['-created_at']
+    
+    def __str__(self):
+        return (
+            f"{self.equipment.inventory_number}: "
+            f"{self.from_person or 'Склад'} → {self.to_person or 'Склад'}"
+        )
+
+
 class Budget(models.Model):
     """Бюджет отдела на квартал."""
     

backend/procurement/services.py

@@ -0,0 +1,311 @@
+"""
+Сервисы для модуля закупок и инвентаря.
+"""
+import io
+import os
+from typing import Optional
+
+import qrcode
+from django.conf import settings
+from django.core.files.base import ContentFile
+from django.db import transaction
+from django.utils import timezone
+
+
+class InventoryNumberGenerator:
+    """Генератор инвентарных номеров."""
+    
+    PREFIX = 'INV'
+    
+    @classmethod
+    def generate(cls, year: Optional[int] = None) -> str:
+        """
+        Генерирует уникальный инвентарный номер.
+        
+        Формат: INV-YYYY-NNNN
+        Например: INV-2025-0001, INV-2025-0002
+        """
+        from .models import Equipment
+        
+        if year is None:
+            year = timezone.now().year
+        
+        # Находим последний номер за этот год
+        prefix = f'{cls.PREFIX}-{year}-'
+        last_equipment = Equipment.objects.filter(
+            inventory_number__startswith=prefix
+        ).order_by('-inventory_number').first()
+        
+        if last_equipment:
+            # Извлекаем номер из последнего инвентарного номера
+            try:
+                last_num = int(last_equipment.inventory_number.split('-')[-1])
+            except (ValueError, IndexError):
+                last_num = 0
+        else:
+            last_num = 0
+        
+        new_num = last_num + 1
+        return f'{cls.PREFIX}-{year}-{new_num:04d}'
+    
+    @classmethod
+    def validate(cls, inventory_number: str) -> bool:
+        """
+        Проверяет формат инвентарного номера.
+        
+        Returns:
+            True если формат верный, False иначе
+        """
+        parts = inventory_number.split('-')
+        if len(parts) != 3:
+            return False
+        
+        prefix, year_str, num_str = parts
+        
+        if prefix != cls.PREFIX:
+            return False
+        
+        try:
+            year = int(year_str)
+            if year < 2000 or year > 2100:
+                return False
+        except ValueError:
+            return False
+        
+        try:
+            num = int(num_str)
+            if num < 1:
+                return False
+        except ValueError:
+            return False
+        
+        return True
+
+
+class QRCodeGenerator:
+    """Генератор QR-кодов для оборудования."""
+    
+    QR_CODE_DIR = 'qr_codes'
+    
+    @classmethod
+    def generate_for_equipment(cls, equipment) -> ContentFile:
+        """
+        Генерирует QR-код для оборудования.
+        
+        QR содержит URL на страницу оборудования и основные данные.
+        
+        Returns:
+            ContentFile с PNG изображением QR-кода
+        """
+        # Данные для QR-кода
+        data = cls._build_qr_data(equipment)
+        
+        # Генерируем QR-код
+        qr = qrcode.QRCode(
+            version=1,
+            error_correction=qrcode.constants.ERROR_CORRECT_M,
+            box_size=10,
+            border=4,
+        )
+        qr.add_data(data)
+        qr.make(fit=True)
+        
+        # Создаём изображение
+        img = qr.make_image(fill_color="black", back_color="white")
+        
+        # Сохраняем в буфер
+        buffer = io.BytesIO()
+        img.save(buffer, format='PNG')
+        buffer.seek(0)
+        
+        filename = f'{equipment.inventory_number}.png'
+        return ContentFile(buffer.read(), name=filename)
+    
+    @classmethod
+    def _build_qr_data(cls, equipment) -> str:
+        """
+        Формирует данные для QR-кода.
+        
+        Формат: URL с параметрами для быстрого доступа.
+        """
+        # Формируем URL на страницу оборудования
+        base_url = getattr(settings, 'SITE_URL', 'http://localhost:8000')
+        equipment_url = f'{base_url}/procurement/equipment/{equipment.id}/'
+        
+        # Можно также добавить vCard или JSON формат
+        # Но URL проще для сканирования
+        return equipment_url
+    
+    @classmethod
+    def get_qr_code_path(cls, inventory_number: str) -> str:
+        """
+        Возвращает путь к файлу QR-кода.
+        """
+        return os.path.join(cls.QR_CODE_DIR, f'{inventory_number}.png')
+
+
+class EquipmentService:
+    """Сервис для операций с оборудованием."""
+    
+    @classmethod
+    @transaction.atomic
+    def create_equipment(
+        cls,
+        name: str,
+        category,
+        department,
+        purchase_date,
+        purchase_cost,
+        **kwargs
+    ):
+        """
+        Создаёт новое оборудование с авто-генерацией инвентарного номера.
+        """
+        from .models import Equipment
+        
+        # Генерируем инвентарный номер если не указан
+        if 'inventory_number' not in kwargs or not kwargs['inventory_number']:
+            kwargs['inventory_number'] = InventoryNumberGenerator.generate()
+        
+        equipment = Equipment.objects.create(
+            name=name,
+            category=category,
+            department=department,
+            purchase_date=purchase_date,
+            purchase_cost=purchase_cost,
+            **kwargs
+        )
+        
+        return equipment
+    
+    @classmethod
+    @transaction.atomic
+    def assign_to_person(
+        cls,
+        equipment,
+        person,
+        location: Optional[str] = None
+    ):
+        """
+        Назначает оборудование ответственному лицу.
+        """
+        from .constants import EquipmentStatus
+        from .models import EquipmentTransferLog
+        
+        old_person = equipment.responsible_person
+        old_location = equipment.location
+        
+        equipment.responsible_person = person
+        equipment.status = EquipmentStatus.IN_USE
+        if location:
+            equipment.location = location
+        equipment.save()
+        
+        # Логируем передачу
+        EquipmentTransferLog.objects.create(
+            equipment=equipment,
+            from_person=old_person,
+            to_person=person,
+            from_location=old_location,
+            to_location=location or equipment.location,
+            transfer_type='assignment',
+        )
+        
+        return equipment
+    
+    @classmethod
+    @transaction.atomic
+    def transfer(
+        cls,
+        equipment,
+        to_department,
+        to_person=None,
+        to_location: Optional[str] = None,
+        reason: str = ''
+    ):
+        """
+        Перемещает оборудование в другой отдел.
+        """
+        from .models import EquipmentTransferLog
+        
+        old_department = equipment.department
+        old_person = equipment.responsible_person
+        old_location = equipment.location
+        
+        equipment.department = to_department
+        equipment.responsible_person = to_person
+        if to_location:
+            equipment.location = to_location
+        equipment.save()
+        
+        # Логируем передачу
+        EquipmentTransferLog.objects.create(
+            equipment=equipment,
+            from_department=old_department,
+            to_department=to_department,
+            from_person=old_person,
+            to_person=to_person,
+            from_location=old_location,
+            to_location=to_location or '',
+            transfer_type='transfer',
+            reason=reason,
+        )
+        
+        return equipment
+    
+    @classmethod
+    @transaction.atomic
+    def write_off(cls, equipment, reason: str):
+        """
+        Списывает оборудование.
+        """
+        from .constants import EquipmentStatus
+        
+        equipment.status = EquipmentStatus.WRITTEN_OFF
+        equipment.notes = (
+            f'{equipment.notes}\n\n'
+            f'[{timezone.now().strftime("%Y-%m-%d")}] Списано: {reason}'
+        ).strip()
+        equipment.save()
+        
+        return equipment
+    
+    @classmethod
+    @transaction.atomic
+    def add_maintenance_record(
+        cls,
+        equipment,
+        maintenance_type: str,
+        description: str,
+        performed_by,
+        cost=None,
+        date=None
+    ):
+        """
+        Добавляет запись о техническом обслуживании.
+        """
+        from decimal import Decimal
+        from .models import MaintenanceRecord
+        from .constants import EquipmentStatus
+        
+        if date is None:
+            date = timezone.now().date()
+        
+        if cost is None:
+            cost = Decimal('0.00')
+        
+        record = MaintenanceRecord.objects.create(
+            equipment=equipment,
+            date=date,
+            type=maintenance_type,
+            description=description,
+            cost=cost,
+            performed_by=performed_by,
+        )
+        
+        # Если на ремонте - обновляем статус
+        if maintenance_type == 'repair':
+            equipment.status = EquipmentStatus.IN_REPAIR
+            equipment.save()
+        
+        return record

backend/procurement/views.py

@@ -9,17 +9,19 @@ from rest_framework.decorators import action
 from rest_framework.response import Response
 
 from employees.models import Department
-from .constants import ApprovalStatus, ProcurementStatus
+from .constants import ApprovalStatus, ProcurementStatus, EquipmentStatus
 from .models import (
     Approval,
     Budget,
     Equipment,
     EquipmentCategory,
+    EquipmentTransferLog,
     MaintenanceRecord,
     ProcurementItem,
     ProcurementRequest,
     Supplier,
 )
+from .services import QRCodeGenerator
 from .permissions import (
     CanApproveProcurementRequest,
     CanCreateProcurementRequest,
@@ -490,6 +492,162 @@ class EquipmentViewSet(viewsets.ModelViewSet):
         serializer = self.get_serializer(queryset, many=True)
         return Response(serializer.data)
 
+    @action(detail=True, methods=['post'])
+    def transfer(self, request, pk=None):
+        """Перевод оборудования в другой отдел или другому пользователю."""
+        equipment = self.get_object()
+
+        to_department_id = request.data.get('to_department')
+        to_person_id = request.data.get('to_person')
+        reason = request.data.get('reason', '')
+
+        if not to_department_id and not to_person_id:
+            return Response(
+                {'error': 'Укажите отдел или ответственного'},
+                status=status.HTTP_400_BAD_REQUEST
+            )
+
+        # Сохраняем старые значения
+        from_department = equipment.department
+        from_person = equipment.responsible_person
+
+        # Обновляем оборудование
+        if to_department_id:
+            try:
+                to_department = Department.objects.get(pk=to_department_id)
+                equipment.department = to_department
+            except Department.DoesNotExist:
+                return Response(
+                    {'error': 'Отдел не найден'},
+                    status=status.HTTP_404_NOT_FOUND
+                )
+        else:
+            to_department = from_department
+
+        if to_person_id:
+            from django.contrib.auth import get_user_model
+            User = get_user_model()
+            try:
+                to_person = User.objects.get(pk=to_person_id)
+                equipment.responsible_person = to_person
+            except User.DoesNotExist:
+                return Response(
+                    {'error': 'Пользователь не найден'},
+                    status=status.HTTP_404_NOT_FOUND
+                )
+        else:
+            to_person = from_person
+
+        equipment.save()
+
+        # Создаём лог перевода
+        EquipmentTransferLog.objects.create(
+            equipment=equipment,
+            from_department=from_department,
+            to_department=to_department,
+            from_person=from_person,
+            to_person=to_person,
+            reason=reason,
+            created_by=request.user
+        )
+
+        return Response({
+            'status': 'transferred',
+            'equipment_id': equipment.id,
+            'from_department': str(from_department),
+            'to_department': str(to_department)
+        })
+
+    @action(detail=True, methods=['post'])
+    def write_off(self, request, pk=None):
+        """Списание оборудования."""
+        equipment = self.get_object()
+        reason = request.data.get('reason', '')
+
+        if equipment.status == EquipmentStatus.RETIRED:
+            return Response(
+                {'error': 'Оборудование уже списано'},
+                status=status.HTTP_400_BAD_REQUEST
+            )
+
+        equipment.status = EquipmentStatus.RETIRED
+        equipment.notes = (equipment.notes or '') + f'\n\nСписано: {reason}'
+        equipment.save()
+
+        return Response({
+            'status': 'written_off',
+            'equipment_id': equipment.id
+        })
+
+    @action(detail=True, methods=['post'])
+    def add_maintenance(self, request, pk=None):
+        """Добавить запись об обслуживании."""
+        from datetime import date
+        equipment = self.get_object()
+
+        maintenance_type = request.data.get('type', 'repair')
+        description = request.data.get('description', '')
+        cost = request.data.get('cost')
+        maintenance_date = request.data.get('date', date.today())
+
+        record = MaintenanceRecord.objects.create(
+            equipment=equipment,
+            type=maintenance_type,
+            description=description,
+            cost=cost,
+            date=maintenance_date,
+            performed_by=request.user
+        )
+
+        return Response({
+            'status': 'created',
+            'maintenance_id': record.id,
+            'equipment_id': equipment.id
+        }, status=status.HTTP_201_CREATED)
+
+    @action(detail=True, methods=['get'])
+    def qr_code(self, request, pk=None):
+        """Получить QR-код для оборудования."""
+        equipment = self.get_object()
+
+        qr_file = QRCodeGenerator.generate_for_equipment(equipment)
+
+        from django.http import HttpResponse
+        response = HttpResponse(qr_file.read(), content_type='image/png')
+        response['Content-Disposition'] = (
+            f'inline; filename="equipment_{equipment.id}_qr.png"'
+        )
+        return response
+
+    @action(detail=True, methods=['get'])
+    def transfer_history(self, request, pk=None):
+        """История переводов оборудования."""
+        equipment = self.get_object()
+
+        logs = EquipmentTransferLog.objects.filter(
+            equipment=equipment
+        ).order_by('-created_at')
+
+        data = [
+            {
+                'id': log.id,
+                'from_department': str(log.from_department),
+                'to_department': str(log.to_department),
+                'from_person': (
+                    str(log.from_person) if log.from_person else None
+                ),
+                'to_person': (
+                    str(log.to_person) if log.to_person else None
+                ),
+                'reason': log.reason,
+                'created_by': str(log.created_by) if log.created_by else None,
+                'date': log.created_at.isoformat()
+            }
+            for log in logs
+        ]
+
+        return Response(data)
+
 
 class MaintenanceRecordViewSet(viewsets.ModelViewSet):
     """ViewSet для записей обслуживания."""

backend/tests/procurement/test_inventory.py

@@ -0,0 +1,454 @@
+"""
+Тесты для Inventory - transfer, write_off, QR-коды, инвентарные номера.
+"""
+import pytest
+from rest_framework import status
+
+from procurement.models import (
+    Equipment,
+    EquipmentCategory,
+    EquipmentTransferLog,
+    MaintenanceRecord,
+)
+from procurement.constants import EquipmentStatus
+from procurement.services import InventoryNumberGenerator, QRCodeGenerator
+
+
+@pytest.mark.django_db
+class TestInventoryNumberGenerator:
+    """Тесты для генератора инвентарных номеров."""
+
+    @pytest.fixture(autouse=True)
+    def setup(self, department_factory, user_factory, link_factory):
+        """Настройка тестовых данных."""
+        self.department = department_factory(name='IT Inventory Test')
+        self.user = user_factory(staff=True,
+            email='inventory_user@test.com',
+            first_name='Test',
+            last_name='Inventory',
+        )
+        link_factory(self.user, self.department, is_active=True)
+        self.category = EquipmentCategory.objects.create(
+            name='Computers',
+            description='Компьютеры и ноутбуки',
+        )
+
+    def test_generate_first_number(self):
+        """Тест: генерация первого инвентарного номера за год."""
+        from django.utils import timezone
+        year = timezone.now().year
+        
+        number = InventoryNumberGenerator.generate()
+        
+        assert number == f'INV-{year}-0001'
+
+    def test_generate_sequential_numbers(self):
+        """Тест: последовательная генерация номеров."""
+        from django.utils import timezone
+        year = timezone.now().year
+        
+        # Создаём оборудование с первым номером
+        Equipment.objects.create(
+            name='Laptop 1',
+            inventory_number=f'INV-{year}-0005',
+            category=self.category,
+            department=self.department,
+            responsible_person=self.user,
+            status=EquipmentStatus.IN_USE,
+            purchase_date='2025-01-01',
+            purchase_cost='10000.00',
+        )
+        
+        number = InventoryNumberGenerator.generate()
+        
+        assert number == f'INV-{year}-0006'
+
+    def test_validate_correct_format(self):
+        """Тест: валидация правильного формата."""
+        assert InventoryNumberGenerator.validate('INV-2025-0001') is True
+        assert InventoryNumberGenerator.validate('INV-2024-9999') is True
+
+    def test_validate_incorrect_format(self):
+        """Тест: валидация неправильного формата."""
+        assert InventoryNumberGenerator.validate('INV-2025') is False
+        assert InventoryNumberGenerator.validate('ABC-2025-0001') is False
+        assert InventoryNumberGenerator.validate('') is False
+
+
+@pytest.mark.django_db
+class TestQRCodeGenerator:
+    """Тесты для генератора QR-кодов."""
+
+    @pytest.fixture(autouse=True)
+    def setup(self, department_factory, user_factory, link_factory):
+        """Настройка тестовых данных."""
+        self.department = department_factory(name='IT QR Test')
+        self.user = user_factory(staff=True,
+            email='qr_user@test.com',
+            first_name='Test',
+            last_name='QR',
+        )
+        link_factory(self.user, self.department, is_active=True)
+        self.category = EquipmentCategory.objects.create(
+            name='Monitors',
+            description='Мониторы',
+        )
+        self.equipment = Equipment.objects.create(
+            name='Monitor Dell 27',
+            inventory_number='INV-2025-0100',
+            category=self.category,
+            department=self.department,
+            responsible_person=self.user,
+            status=EquipmentStatus.IN_USE,
+            purchase_date='2025-01-01',
+            purchase_cost='10000.00',
+        )
+
+    def test_generate_qr_code(self):
+        """Тест: генерация QR-кода для оборудования."""
+        qr_file = QRCodeGenerator.generate_for_equipment(self.equipment)
+        
+        assert qr_file is not None
+        assert qr_file.name.endswith('.png')
+        # Файл должен содержать PNG данные
+        content = qr_file.read()
+        assert len(content) > 0
+        # PNG начинается с signature
+        assert content[:4] == b'\x89PNG'
+
+    def test_qr_code_path(self):
+        """Тест: путь к файлу QR-кода."""
+        path = QRCodeGenerator.get_qr_code_path('INV-2025-0100')
+        
+        assert 'INV-2025-0100.png' in path
+
+
+@pytest.mark.django_db
+class TestEquipmentTransferEndpoint:
+    """Тесты для /equipment/{id}/transfer/ endpoint."""
+
+    @pytest.fixture(autouse=True)
+    def setup(
+        self, api_client, department_factory, user_factory, link_factory
+    ):
+        """Настройка тестовых данных."""
+        self.client = api_client
+        self.dept1 = department_factory(name='IT Dept')
+        self.dept2 = department_factory(name='HR Dept')
+        
+        self.user1 = user_factory(staff=True,
+            email='transfer_user1@test.com',
+            first_name='User',
+            last_name='One',
+        )
+        self.user2 = user_factory(
+            email='transfer_user2@test.com',
+            first_name='User',
+            last_name='Two',
+        )
+        link_factory(self.user1, self.dept1, is_active=True)
+        link_factory(self.user2, self.dept2, is_active=True)
+        
+        self.category = EquipmentCategory.objects.create(
+            name='Laptops',
+            description='Ноутбуки',
+        )
+        self.equipment = Equipment.objects.create(
+            name='MacBook Pro',
+            inventory_number='INV-2025-0200',
+            category=self.category,
+            department=self.dept1,
+            responsible_person=self.user1,
+            status=EquipmentStatus.IN_USE,
+            purchase_date='2025-01-01',
+            purchase_cost='10000.00',
+        )
+
+    def test_transfer_to_another_department(self):
+        """Тест: перевод оборудования в другой отдел."""
+        self.client.force_authenticate(user=self.user1)
+        
+        response = self.client.post(
+            f'/api/procurement/equipment/{self.equipment.id}/transfer/',
+            {
+                'to_department': self.dept2.id,
+                'reason': 'Переезд сотрудника',
+            }
+        )
+        
+        assert response.status_code == status.HTTP_200_OK
+        assert response.data['status'] == 'transferred'
+        
+        # Проверяем обновление оборудования
+        self.equipment.refresh_from_db()
+        assert self.equipment.department == self.dept2
+        
+        # Проверяем лог перевода
+        log = EquipmentTransferLog.objects.filter(
+            equipment=self.equipment
+        ).first()
+        assert log is not None
+        assert log.from_department == self.dept1
+        assert log.to_department == self.dept2
+        assert log.reason == 'Переезд сотрудника'
+
+    def test_transfer_to_another_person(self):
+        """Тест: перевод оборудования другому пользователю."""
+        self.client.force_authenticate(user=self.user1)
+        
+        response = self.client.post(
+            f'/api/procurement/equipment/{self.equipment.id}/transfer/',
+            {
+                'to_person': self.user2.id,
+                'reason': 'Смена ответственного',
+            }
+        )
+        
+        assert response.status_code == status.HTTP_200_OK
+        
+        self.equipment.refresh_from_db()
+        assert self.equipment.responsible_person == self.user2
+
+    def test_transfer_requires_target(self):
+        """Тест: нужно указать отдел или пользователя."""
+        self.client.force_authenticate(user=self.user1)
+        
+        response = self.client.post(
+            f'/api/procurement/equipment/{self.equipment.id}/transfer/',
+            {'reason': 'Без цели'},
+        )
+        
+        assert response.status_code == status.HTTP_400_BAD_REQUEST
+
+
+@pytest.mark.django_db
+class TestEquipmentWriteOffEndpoint:
+    """Тесты для /equipment/{id}/write_off/ endpoint."""
+
+    @pytest.fixture(autouse=True)
+    def setup(
+        self, api_client, department_factory, user_factory, link_factory
+    ):
+        """Настройка тестовых данных."""
+        self.client = api_client
+        self.department = department_factory(name='IT WriteOff')
+        self.user = user_factory(staff=True,
+            email='writeoff_user@test.com',
+            first_name='Test',
+            last_name='WriteOff',
+        )
+        link_factory(self.user, self.department, is_active=True)
+        
+        self.category = EquipmentCategory.objects.create(
+            name='Printers',
+            description='Принтеры',
+        )
+        self.equipment = Equipment.objects.create(
+            name='HP LaserJet',
+            inventory_number='INV-2025-0300',
+            category=self.category,
+            department=self.department,
+            responsible_person=self.user,
+            status=EquipmentStatus.IN_USE,
+            purchase_date='2025-01-01',
+            purchase_cost='10000.00',
+        )
+
+    def test_write_off_equipment(self):
+        """Тест: списание оборудования."""
+        self.client.force_authenticate(user=self.user)
+        
+        response = self.client.post(
+            f'/api/procurement/equipment/{self.equipment.id}/write_off/',
+            {'reason': 'Износ'}
+        )
+        
+        assert response.status_code == status.HTTP_200_OK
+        assert response.data['status'] == 'written_off'
+        
+        self.equipment.refresh_from_db()
+        assert self.equipment.status == EquipmentStatus.RETIRED
+        assert 'Износ' in self.equipment.notes
+
+    def test_cannot_write_off_twice(self):
+        """Тест: нельзя списать уже списанное оборудование."""
+        self.equipment.status = EquipmentStatus.RETIRED
+        self.equipment.save()
+        
+        self.client.force_authenticate(user=self.user)
+        
+        response = self.client.post(
+            f'/api/procurement/equipment/{self.equipment.id}/write_off/',
+            {'reason': 'Повторно'}
+        )
+        
+        assert response.status_code == status.HTTP_400_BAD_REQUEST
+
+
+@pytest.mark.django_db
+class TestEquipmentMaintenanceEndpoint:
+    """Тесты для /equipment/{id}/add_maintenance/ endpoint."""
+
+    @pytest.fixture(autouse=True)
+    def setup(
+        self, api_client, department_factory, user_factory, link_factory
+    ):
+        """Настройка тестовых данных."""
+        self.client = api_client
+        self.department = department_factory(name='IT Maintenance')
+        self.user = user_factory(staff=True,
+            email='maintenance_user@test.com',
+            first_name='Test',
+            last_name='Maintenance',
+        )
+        link_factory(self.user, self.department, is_active=True)
+        
+        self.category = EquipmentCategory.objects.create(
+            name='Servers',
+            description='Серверы',
+        )
+        self.equipment = Equipment.objects.create(
+            name='Dell PowerEdge',
+            inventory_number='INV-2025-0400',
+            category=self.category,
+            department=self.department,
+            responsible_person=self.user,
+            status=EquipmentStatus.IN_USE,
+            purchase_date='2025-01-01',
+            purchase_cost='10000.00',
+        )
+
+    def test_add_maintenance_record(self):
+        """Тест: добавление записи об обслуживании."""
+        self.client.force_authenticate(user=self.user)
+        
+        response = self.client.post(
+            f'/api/procurement/equipment/{self.equipment.id}/add_maintenance/',
+            {
+                'type': 'repair',
+                'description': 'Замена блока питания',
+                'cost': '5000.00',
+            }
+        )
+        
+        assert response.status_code == status.HTTP_201_CREATED
+        assert 'maintenance_id' in response.data
+        
+        # Проверяем создание записи
+        record = MaintenanceRecord.objects.get(id=response.data['maintenance_id'])
+        assert record.equipment == self.equipment
+        assert record.description == 'Замена блока питания'
+        assert record.performed_by == self.user
+
+
+@pytest.mark.django_db
+class TestEquipmentQRCodeEndpoint:
+    """Тесты для /equipment/{id}/qr_code/ endpoint."""
+
+    @pytest.fixture(autouse=True)
+    def setup(
+        self, api_client, department_factory, user_factory, link_factory
+    ):
+        """Настройка тестовых данных."""
+        self.client = api_client
+        self.department = department_factory(name='IT QR Code')
+        self.user = user_factory(staff=True,
+            email='qrcode_user@test.com',
+            first_name='Test',
+            last_name='QRCode',
+        )
+        link_factory(self.user, self.department, is_active=True)
+        
+        self.category = EquipmentCategory.objects.create(
+            name='Networking',
+            description='Сетевое оборудование',
+        )
+        self.equipment = Equipment.objects.create(
+            name='Cisco Router',
+            inventory_number='INV-2025-0500',
+            category=self.category,
+            department=self.department,
+            responsible_person=self.user,
+            status=EquipmentStatus.IN_USE,
+            purchase_date='2025-01-01',
+            purchase_cost='10000.00',
+        )
+
+    def test_get_qr_code(self):
+        """Тест: получение QR-кода для оборудования."""
+        self.client.force_authenticate(user=self.user)
+        
+        response = self.client.get(
+            f'/api/procurement/equipment/{self.equipment.id}/qr_code/'
+        )
+        
+        assert response.status_code == status.HTTP_200_OK
+        assert response['Content-Type'] == 'image/png'
+        # PNG signature
+        assert response.content[:4] == b'\x89PNG'
+
+
+@pytest.mark.django_db
+class TestEquipmentTransferHistoryEndpoint:
+    """Тесты для /equipment/{id}/transfer_history/ endpoint."""
+
+    @pytest.fixture(autouse=True)
+    def setup(
+        self, api_client, department_factory, user_factory, link_factory
+    ):
+        """Настройка тестовых данных."""
+        self.client = api_client
+        self.dept1 = department_factory(name='IT History 1')
+        self.dept2 = department_factory(name='IT History 2')
+        
+        self.user1 = user_factory(staff=True,
+            email='history_user1@test.com',
+            first_name='User',
+            last_name='History1',
+        )
+        self.user2 = user_factory(
+            email='history_user2@test.com',
+            first_name='User',
+            last_name='History2',
+        )
+        link_factory(self.user1, self.dept1, is_active=True)
+        
+        self.category = EquipmentCategory.objects.create(
+            name='Phones',
+            description='Телефоны',
+        )
+        self.equipment = Equipment.objects.create(
+            name='iPhone 15',
+            inventory_number='INV-2025-0600',
+            category=self.category,
+            department=self.dept1,
+            responsible_person=self.user1,
+            status=EquipmentStatus.IN_USE,
+            purchase_date='2025-01-01',
+            purchase_cost='10000.00',
+        )
+        
+        # Создаём историю переводов
+        EquipmentTransferLog.objects.create(
+            equipment=self.equipment,
+            from_department=self.dept1,
+            to_department=self.dept2,
+            from_person=self.user1,
+            to_person=self.user2,
+            reason='Первый перевод',
+            created_by=self.user1,
+        )
+
+    def test_get_transfer_history(self):
+        """Тест: получение истории переводов."""
+        self.client.force_authenticate(user=self.user1)
+        
+        response = self.client.get(
+            f'/api/procurement/equipment/{self.equipment.id}/transfer_history/'
+        )
+        
+        assert response.status_code == status.HTTP_200_OK
+        assert len(response.data) == 1
+        assert response.data[0]['reason'] == 'Первый перевод'
+        assert 'from_department' in response.data[0]
+        assert 'to_department' in response.data[0]