Add DAO function and endpoint for archiving letter contact blocks

Added a new DAO function which archives letter contact blocks by
setting archived to True. This raises an ArchiveValidationError if
trying to archive the default letter block for a service or the default
letter contact block for a template.

Added a new endpoint for archiving letter contact blocks.

tests/app/dao/test_service_letter_contact_dao.py

@@ -4,13 +4,15 @@ from sqlalchemy.exc import SQLAlchemyError
 
 from app.dao.service_letter_contact_dao import (
     add_letter_contact_for_service,
+    archive_letter_contact,
     dao_get_letter_contacts_by_service_id,
     dao_get_letter_contact_by_id,
     update_letter_contact
 )
 from app.errors import InvalidRequest
+from app.exceptions import ArchiveValidationError
 from app.models import ServiceLetterContact
-from tests.app.db import create_letter_contact, create_service
+from tests.app.db import create_letter_contact, create_service, create_template
 
 
 def test_dao_get_letter_contacts_by_service_id(notify_db_session):
@@ -170,6 +172,55 @@ def test_update_letter_contact_unset_default_for_only_letter_contact_raises_exce
         )
 
 
+def test_archive_letter_contact(notify_db_session):
+    service = create_service()
+    create_letter_contact(service=service, contact_block='Aberdeen, AB12 23X')
+    letter_contact = create_letter_contact(service=service, contact_block='Edinburgh, ED1 1AA', is_default=False)
+
+    archive_letter_contact(service.id, letter_contact.id)
+
+    assert letter_contact.archived
+    assert letter_contact.updated_at is not None
+
+
+def test_archive_letter_contact_does_not_archive_a_letter_contact_for_a_different_service(
+    notify_db_session,
+    sample_service,
+):
+    service = create_service(service_name="First service")
+    letter_contact = create_letter_contact(
+        service=sample_service,
+        contact_block='Edinburgh, ED1 1AA',
+        is_default=False)
+
+    with pytest.raises(SQLAlchemyError):
+        archive_letter_contact(service.id, letter_contact.id)
+
+    assert not letter_contact.archived
+
+
+def test_archive_letter_contact_does_not_archive_a_service_default_letter_contact(notify_db_session):
+    service = create_service()
+    letter_contact = create_letter_contact(service=service, contact_block='Edinburgh, ED1 1AA')
+
+    with pytest.raises(ArchiveValidationError) as e:
+        archive_letter_contact(service.id, letter_contact.id)
+
+    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):
+    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)
+
+    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)
+
+
 def test_dao_get_letter_contact_by_id(sample_service):
     letter_contact = create_letter_contact(service=sample_service, contact_block='Aberdeen, AB12 23X')
     result = dao_get_letter_contact_by_id(service_id=sample_service.id, letter_contact_id=letter_contact.id)

tests/app/service/test_rest.py

@@ -2733,6 +2733,38 @@ def test_update_service_letter_contact_returns_404_when_invalid_service_id(clien
     assert result['message'] == 'No result found'
 
 
+def test_delete_service_letter_contact_can_archive_letter_contact(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)
+
+    admin_request.post(
+        'service.delete_service_letter_contact',
+        service_id=service.id,
+        letter_contact_id=letter_contact.id,
+    )
+
+    assert letter_contact.archived is True
+
+
+def test_delete_service_letter_contact_returns_400_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)
+    create_template(service=service, template_type='letter', reply_to=letter_contact.id)
+
+    response = admin_request.post(
+        'service.delete_service_letter_contact',
+        service_id=service.id,
+        letter_contact_id=letter_contact.id,
+        _expected_status=400
+    )
+    assert response == {
+        '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):
     service = create_service()
     data = {