fix: regenerate SN archive with task-specific DOCX headers

Invalidate cached monthly service-task ZIP archives so exports are rebuilt with the latest task/work-order/vehicle header data. Keep stale detection for work-order archives and add regression tests for per-task header isolation and stale cache replacement.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/modules/fleet/tests/test_work_order_images_endpoint.py

@@ -1,4 +1,5 @@
 from django.contrib.auth import get_user_model
+from django.core.files.base import ContentFile
 from django.core.files.uploadedfile import SimpleUploadedFile
 from django.test import TestCase
 from django.urls import reverse
@@ -352,6 +353,58 @@ class WorkOrderImagesEndpointTests(TestCase):
         self.assertNotIn('MT250226', header_xml)
         self.assertNotIn('LTM-1350', header_xml)
 
+    def test_monthly_service_tasks_archive_uses_task_specific_headers_for_each_docx(self):
+        vehicle_two = Vehicle.objects.create(
+            asset_type='crane',
+            registration_number='WO-IMG-002',
+            make='Tadano',
+            model='ATF 90',
+            crane_serial_number='SN-999',
+            superstructure_working_hours=444,
+            chassis_working_hours=555,
+            current_mileage=66677,
+        )
+        work_order_two = WorkOrder.objects.create(
+            vehicle=vehicle_two,
+            creator=self.user,
+            display_code='MT160726',
+            purpose='kontrola',
+        )
+        Task.objects.create(
+            title='Drugi zadatak',
+            assigned_to=self.user,
+            vehicle=vehicle_two,
+            work_order=work_order_two,
+            scheduled_date=date(2033, 12, 26),
+            service_report_note='Napomena drugog taska',
+        )
+
+        response = self.client.get('/api/fleet/reports/monthly-service-tasks-archive/?year=2033&month=12')
+        self.assertEqual(response.status_code, 200, response.content)
+
+        archive = zipfile.ZipFile(BytesIO(response.content))
+        first_docx = 'MT150726.SN-Test_servisni_zadatak.docx'
+        second_docx = 'MT160726.SN-Drugi_zadatak.docx'
+        self.assertIn(first_docx, archive.namelist())
+        self.assertIn(second_docx, archive.namelist())
+
+        first_header = zipfile.ZipFile(BytesIO(archive.read(first_docx))).read('word/header1.xml').decode('utf-8', errors='ignore')
+        second_header = zipfile.ZipFile(BytesIO(archive.read(second_docx))).read('word/header1.xml').decode('utf-8', errors='ignore')
+
+        self.assertIn('Liebherr LTM 1090', first_header)
+        self.assertIn('MT150726', first_header)
+        self.assertNotIn('Tadano ATF 90', first_header)
+        self.assertNotIn('MT160726', first_header)
+
+        self.assertIn('Tadano ATF 90', second_header)
+        self.assertIn('SN-999', second_header)
+        self.assertIn('444', second_header)
+        self.assertIn('555', second_header)
+        self.assertIn('66677', second_header)
+        self.assertIn('MT160726', second_header)
+        self.assertNotIn('Liebherr LTM 1090', second_header)
+        self.assertNotIn('MT150726', second_header)
+
     def test_monthly_work_orders_archive_contains_work_orders_and_invoices_folder(self):
         WorkOrderInvoice.objects.create(
             work_order=self.work_order,
@@ -402,6 +455,36 @@ class WorkOrderImagesEndpointTests(TestCase):
         self.assertTrue(notifications.filter(metadata__entity_type='fleet_archive', metadata__stage='requested').exists())
         self.assertTrue(notifications.filter(metadata__entity_type='fleet_archive', metadata__stage='completed').exists())
 
+    def test_monthly_service_tasks_archive_request_ignores_stale_cached_archive(self):
+        stale = GeneratedFleetArchive.objects.create(
+            requested_by=self.user,
+            archive_type='service_tasks',
+            year=2033,
+            month=12,
+            status='ready',
+            filename='stale-archive.zip',
+            expires_at=timezone.now() + timedelta(days=2),
+        )
+        stale.file.save('stale-archive.zip', ContentFile(b'OLD-ARCHIVE'), save=True)
+        stale_updated_at = timezone.now() - timedelta(days=1)
+        GeneratedFleetArchive.objects.filter(pk=stale.pk).update(updated_at=stale_updated_at)
+        self.task.service_report_note = 'Nova napomena nakon cache-a'
+        self.task.save()
+
+        response = self.client.post(
+            '/api/fleet/reports/monthly-service-tasks-archive-request/',
+            data={'year': 2033, 'month': 12},
+            format='json',
+        )
+        self.assertIn(response.status_code, [200, 202], response.content)
+        payload = response.json()
+        self.assertIn('generated_archive_id', payload)
+        self.assertNotEqual(str(stale.pk), str(payload['generated_archive_id']))
+
+        stale.refresh_from_db()
+        self.assertFalse(stale.is_active)
+        self.assertEqual(stale.status, 'failed')
+
     def test_monthly_work_orders_archive_request_creates_ready_download_with_notification(self):
         WorkOrderInvoice.objects.create(
             work_order=self.work_order,

backend/modules/fleet/views.py

@@ -23,7 +23,7 @@ from django.http import HttpResponse, FileResponse
 from django.urls import reverse
 from django.utils import timezone
 from django.utils.html import escape
-from django.db.models import Q
+from django.db.models import Q, Max
 from django.db import transaction
 from reportlab.lib.pagesizes import A4
 from reportlab.lib import colors
@@ -2959,6 +2959,33 @@ def _get_cached_generated_archive(*, user, archive_type, year, month):
     )
 
 
+def _latest_monthly_archive_source_update(*, user, archive_type, year, month):
+    from modules.task_management.models import Task
+
+    base_tasks = Task.objects.filter(
+        assigned_to=user,
+        is_active=True,
+        scheduled_date__year=year,
+        scheduled_date__month=month,
+        work_order__isnull=False,
+        work_order__is_active=True,
+    )
+    latest_candidates = [
+        base_tasks.aggregate(value=Max('updated_at')).get('value'),
+        base_tasks.aggregate(value=Max('work_order__updated_at')).get('value'),
+        base_tasks.aggregate(value=Max('work_order__vehicle__updated_at')).get('value'),
+        base_tasks.aggregate(value=Max('work_hours_table__updated_at')).get('value'),
+    ]
+    if archive_type == 'work_orders':
+        latest_candidates.append(
+            base_tasks.aggregate(value=Max('work_order__invoices__updated_at')).get('value')
+        )
+    latest_values = [value for value in latest_candidates if value is not None]
+    if not latest_values:
+        return None
+    return max(latest_values)
+
+
 def _request_monthly_archive_generation(*, request, archive_type):
     year, month = _parse_year_month_params(request)
     _cleanup_expired_generated_archive_records()
@@ -2970,6 +2997,24 @@ def _request_monthly_archive_generation(*, request, archive_type):
         month=month,
     )
     if cached:
+        if archive_type == 'service_tasks':
+            cached.is_active = False
+            cached.status = 'failed'
+            cached.error_message = 'ZIP arhiva servisnih taskova se regenerira za najnoviji kontekst.'
+            cached.save(update_fields=['is_active', 'status', 'error_message', 'updated_at'])
+        else:
+            latest_source_update = _latest_monthly_archive_source_update(
+                user=request.user,
+                archive_type=archive_type,
+                year=year,
+                month=month,
+            )
+            if latest_source_update and cached.updated_at and cached.updated_at < latest_source_update:
+                cached.is_active = False
+                cached.status = 'failed'
+                cached.error_message = 'ZIP arhiva zastarjela zbog novijih izmjena izvora.'
+                cached.save(update_fields=['is_active', 'status', 'error_message', 'updated_at'])
+            else:
                 _notify_monthly_archive_request(
                     user=request.user,
                     archive_type=archive_type,