Allow countries in last line of addresses

For services that have permission to send international letters we
should not reject letters that are addressed to another country. We
should still reject letters that are badly-addressed.

tests/app/v2/notifications/test_post_letter_notifications.py

@@ -18,7 +18,8 @@ from app.models import (
     NOTIFICATION_SENDING,
     NOTIFICATION_DELIVERED,
     NOTIFICATION_PENDING_VIRUS_CHECK,
-    SMS_TYPE
+    SMS_TYPE,
+    INTERNATIONAL_LETTERS,
 )
 from app.schema_validation import validate
 from app.v2.errors import RateLimitError
@@ -144,8 +145,49 @@ def test_post_letter_notification_formats_postcode(
     assert notification.personalisation["postcode"] == '  Sw1  1aa   '
 
 
-def test_post_letter_notification_throws_error_for_bad_postcode(
+def test_post_letter_notification_stores_country(
     client, notify_db_session, mocker
+):
+    service = create_service(service_permissions=[LETTER_TYPE, INTERNATIONAL_LETTERS])
+    template = create_template(service, template_type="letter")
+    mocker.patch('app.celery.tasks.letters_pdf_tasks.create_letters_pdf.apply_async')
+    data = {
+        'template_id': str(template.id),
+        'personalisation': {
+            'address_line_1': 'Kaiser Wilhelm II',
+            'address_line_2': 'Kronprinzenpalais',
+            'address_line_5': '   deutschland   ',
+        }
+    }
+
+    resp_json = letter_request(client, data, service_id=service.id)
+
+    assert validate(resp_json, post_letter_response) == resp_json
+    notification = Notification.query.one()
+    # In the personalisation we store what the client gives us
+    assert notification.personalisation["address_line_1"] == 'Kaiser Wilhelm II'
+    assert notification.personalisation["address_line_2"] == 'Kronprinzenpalais'
+    assert notification.personalisation["address_line_5"] == '   deutschland   '
+    # In the to field we store the whole address with the canonical country
+    assert notification.to == (
+        'Kaiser Wilhelm II\n'
+        'Kronprinzenpalais\n'
+        'Germany'
+    )
+
+
+@pytest.mark.parametrize('permissions, expected_error', (
+    (
+        [LETTER_TYPE],
+        'Must be a real UK postcode',
+    ),
+    (
+        [LETTER_TYPE, INTERNATIONAL_LETTERS],
+        'Last line of address must be a real UK postcode or another country',
+    ),
+))
+def test_post_letter_notification_throws_error_for_bad_postcode(
+    client, notify_db_session, mocker, permissions, expected_error
 ):
     service = create_service(service_permissions=[LETTER_TYPE])
     template = create_template(service, template_type="letter", postage="first")