Dissociate letter contact blocks before archiving

Otherwise you can’t archive it.

app/dao/service_letter_contact_dao.py

@@ -73,25 +73,21 @@ def archive_letter_contact(service_id, letter_contact_id):
         service_id=service_id
     ).one()
 
-    if _is_template_default(letter_contact_id):
-        raise ArchiveValidationError("You cannot delete the default letter contact block for a template")
     if letter_contact_to_archive.is_default:
         raise ArchiveValidationError("You cannot delete a default letter contact block")
 
+    Template.query.filter_by(
+        service_letter_contact_id=letter_contact_id
+    ).update({
+        'service_letter_contact_id': None
+    })
+
     letter_contact_to_archive.archived = True
 
     db.session.add(letter_contact_to_archive)
     return letter_contact_to_archive
 
 
-def _is_template_default(letter_contact_id):
-    template_defaults = Template.query.filter_by(
-        service_letter_contact_id=letter_contact_id
-    ).all()
-
-    return any(template_defaults)
-
-
 def _get_existing_default(service_id):
     letter_contacts = dao_get_letter_contacts_by_service_id(service_id=service_id)
     if letter_contacts:

tests/app/dao/test_service_letter_contact_dao.py

@@ -209,16 +209,22 @@ def test_archive_letter_contact_does_not_archive_a_service_default_letter_contac
     assert 'You cannot delete a default letter contact block' in str(e.value)
 
 
-def test_archive_letter_contact_does_not_archive_a_template_default_letter_contact(notify_db_session):
+def test_archive_letter_contact_does_dissociates_template_defaults_before_archiving(notify_db_session):
     service = create_service()
     create_letter_contact(service=service, contact_block='Edinburgh, ED1 1AA')
     template_default = create_letter_contact(service=service, contact_block='Aberdeen, AB12 23X', is_default=False)
-    create_template(service=service, template_type='letter', reply_to=template_default.id)
+    associated_template_1 = create_template(service=service, template_type='letter', reply_to=template_default.id)
+    associated_template_2 = create_template(service=service, template_type='letter', reply_to=template_default.id)
+
+    assert associated_template_1.reply_to == template_default.id
+    assert associated_template_2.reply_to == template_default.id
+    assert template_default.archived is False
 
-    with pytest.raises(ArchiveValidationError) as e:
     archive_letter_contact(service.id, template_default.id)
 
-    assert 'You cannot delete the default letter contact block for a template' in str(e.value)
+    assert associated_template_1.reply_to is None
+    assert associated_template_2.reply_to is None
+    assert template_default.archived is True
 
 
 def test_dao_get_letter_contact_by_id(sample_service):

tests/app/service/test_rest.py

@@ -2901,7 +2901,7 @@ def test_delete_service_letter_contact_can_archive_letter_contact(admin_request,
     assert letter_contact.archived is True
 
 
-def test_delete_service_letter_contact_returns_400_if_archiving_template_default(admin_request, notify_db_session):
+def test_delete_service_letter_contact_returns_200_if_archiving_template_default(admin_request, notify_db_session):
     service = create_service()
     create_letter_contact(service=service, contact_block='Edinburgh, ED1 1AA')
     letter_contact = create_letter_contact(service=service, contact_block='Swansea, SN1 3CC', is_default=False)
@@ -2911,12 +2911,9 @@ def test_delete_service_letter_contact_returns_400_if_archiving_template_default
         'service.delete_service_letter_contact',
         service_id=service.id,
         letter_contact_id=letter_contact.id,
-        _expected_status=400
+        _expected_status=200
     )
-    assert response == {
+    assert response['data']['archived'] is True
-        'message': 'You cannot delete the default letter contact block for a template',
-        'result': 'error'}
-    assert letter_contact.archived is False
 
 
 def test_add_service_sms_sender_can_add_multiple_senders(client, notify_db_session):