Preview service name when adding a new service

This commit adds a new page, which appears after a user enters the name for
their new service. It shows how the service name will appear in emails and
text messages.

This means that the new service is not created until after they have confirmed
that the name is appropriate in context.

This has also involved:
- visual changes to the ‘email template’ pattern, which wasn’t very refined
  before
- removing a bunch of words from the enter service name page, because most users
  don’t read them, and we reckon that showing a preview is a better way of
  getting them to understand what is meant by service name

Still to do:
- validating the the generated email address for a service is unique (on the
  API) side
- having the API return the generated email address, rather than determining it
  in the admin app

tests/app/main/views/test_add_service.py

@@ -17,13 +17,14 @@ def test_get_should_render_add_service_template(app_,
             assert 'Add a new service' in response.get_data(as_text=True)
 
 
-def test_should_add_service_and_redirect_to_next_page(app_,
-                                                      mock_login,
-                                                      mock_create_service,
-                                                      mock_get_services,
-                                                      api_user_active,
-                                                      mock_get_user,
-                                                      mock_get_user_by_email):
+def test_should_add_service_and_redirect_to_next_page(
+    app_,
+    mock_login,
+    mock_get_services,
+    api_user_active,
+    mock_get_user,
+    mock_get_user_by_email
+):
     with app_.test_request_context():
         with app_.test_client() as client:
             client.login(api_user_active)
@@ -31,6 +32,46 @@ def test_should_add_service_and_redirect_to_next_page(app_,
                 url_for('main.add_service'),
                 data={'name': 'testing the post'})
             assert response.status_code == 302
+            assert response.location == url_for('main.add_from_address', _external=True)
+
+
+def test_should_confirm_add_service(
+    app_,
+    mock_login,
+    mock_get_services,
+    api_user_active,
+    mock_get_user,
+    mock_get_user_by_email
+):
+    with app_.test_request_context():
+        with app_.test_client() as client:
+            client.login(api_user_active)
+            with client.session_transaction() as session:
+                session['service_name'] = 'Renew Your Pet Passport'
+            response = client.get(url_for('main.add_from_address'))
+            assert response.status_code == 200
+            assert 'Preview your service name' in response.get_data(as_text=True)
+            assert 'Renew Your Pet Passport' in response.get_data(as_text=True)
+            assert 'renew.your.pet.passport@notifications.service.gov.uk' in response.get_data(as_text=True)
+
+
+def test_should_add_service_after_confirmation(
+    app_,
+    mock_login,
+    mock_create_service,
+    mock_get_services,
+    api_user_active,
+    mock_get_user,
+    mock_get_user_by_email
+):
+    with app_.test_request_context():
+        with app_.test_client() as client:
+            client.login(api_user_active)
+            with client.session_transaction() as session:
+                print('session: {}'.format(session))
+                session['service_name'] = 'Renew Your Pet Passport'
+            response = client.post(url_for('main.add_from_address'))
+            assert response.status_code == 302
             assert response.location == url_for('main.service_dashboard', service_id=101, _external=True)
             assert mock_create_service.called
             assert mock_get_services.called