feat: prevent automatic intervention re-creation in Observation model using ref check

streetup/observations/models.py

@@ -438,6 +438,28 @@ class Observation(models.Model):
     intervention = models.ForeignKey('interventions.Intervention', on_delete=models.SET_NULL, null=True, blank=True, related_name='observations')
     project = models.ForeignKey('projects.Project', on_delete=models.SET_NULL, null=True, blank=True, related_name='observations', verbose_name=_("Projet lié"))
 
+    def has_existing_intervention(self):
+        """
+        Vérifie si une intervention est déjà liée à cette observation,
+        ou si une intervention a déjà été créée à partir de cette observation (ex. via source_ref).
+        Permet d'éviter de ré-instancier automatiquement une intervention en boucle
+        lorsqu'une intervention existante est annulée et que l'observation repasse au statut 'À traiter'.
+        """
+        if self.intervention_id is not None:
+            return True
+        if not self.pk:
+            return False
+
+        from interventions.models import Intervention
+        possible_refs = [str(self.pk)]
+        if self.code:
+            possible_refs.append(self.code)
+        possible_refs.append(f"OBS{self.pk:05d}")
+
+        return Intervention.objects.filter(
+            models.Q(observations=self) | models.Q(source_ref__in=possible_refs)
+        ).exists()
+
     def save(self, *args, **kwargs):
         is_new = self.pk is None
         old_status = None
@@ -459,7 +481,7 @@ class Observation(models.Model):
         if (self.symptom_id and 
             self.symptom.auto_create_intervention and 
             self.status == 'to_process' and 
-            not self.intervention_id):
+            not self.has_existing_intervention()):
             
             status_changed_to_to_process = (old_status != 'to_process' and self.status == 'to_process')
             symptom_changed_to_auto = (old_symptom_id != self.symptom_id and self.symptom.auto_create_intervention)

streetup/observations/tests.py

@@ -502,3 +502,73 @@ class ObservationPermissionTests(TestCase):
 		self.assertContains(response, "Une intervention liée à cette observation a été annulée")
 		self.assertContains(response, "INT-TEST-CANCEL")
 
+	def test_no_auto_intervention_loop_on_cancellation(self):
+		from contracts.models import Contract, Company
+		from interventions.models import Symptom, Intervention
+		from interventions.views.workflow import attempt_status_update
+		from django.utils import timezone
+
+		company = Company.objects.create(name='Provider Co Loop')
+		contract = Contract.objects.create(
+			contract_number='C-LOOP',
+			company=company,
+			start_date=timezone.now().date(),
+			end_date=timezone.now().date() + timezone.timedelta(days=365)
+		)
+
+		symptom = Symptom.objects.create(
+			name_fr='Symptome Auto Loop Test',
+			name_nl='Symptoom Auto Loop Test',
+			thematic=self.thematic_a,
+			auto_create_intervention=True,
+			contract=contract,
+			provider=company,
+		)
+
+		# 1. Create observation in 'to_process' -> auto-creates intervention
+		obs = Observation.objects.create(
+			description='Loop test observation',
+			latitude=50.5,
+			longitude=4.5,
+			created_by=self.internal_user,
+			thematic=self.thematic_a,
+			symptom=symptom,
+			status='to_process',
+		)
+
+		obs.refresh_from_db()
+		self.assertIsNotNone(obs.intervention)
+		self.assertEqual(obs.status, 'in_progress')
+		first_intervention = obs.intervention
+
+		# 2. Cancel the intervention
+		success, msg, _ = attempt_status_update(
+			request=None,
+			intervention=first_intervention,
+			user=self.admin_user,
+			new_status='canceled',
+			cancellation_type='other',
+			cancellation_reason='Test cancellation reason',
+		)
+		self.assertTrue(success, msg)
+
+		# 3. Observation status is reset to 'to_process'
+		obs.refresh_from_db()
+		self.assertEqual(obs.status, 'to_process')
+
+		# 4. Save observation again (or unlink and save) - MUST NOT create a new intervention
+		obs.save()
+		obs.refresh_from_db()
+		self.assertEqual(obs.status, 'to_process')
+
+		# Unlink intervention and save observation again
+		obs.intervention = None
+		obs.save()
+		obs.refresh_from_db()
+
+		# Total interventions with source_ref equal to obs.code or obs.pk must still be 1
+		possible_refs = [str(obs.pk), obs.code, f"OBS{obs.pk:05d}"]
+		total_interventions = Intervention.objects.filter(source_ref__in=possible_refs).count()
+		self.assertEqual(total_interventions, 1)
+		self.assertEqual(obs.status, 'to_process')
+