Allow broadcasts to be cancelled

Currently this is a `get` request from the dashboard. Once we have a page
for viewing an individual broadcast it should probably show there
instead and be a `get`/confirm/`post` loop like for deleting a template.

app/main/views/broadcast.py

@@ -124,3 +124,17 @@ def preview_broadcast_message(service_id, broadcast_message_id):
         'views/broadcast/preview-message.html',
         broadcast_message=broadcast_message,
     )
+
+
+@main.route('/services/<uuid:service_id>/broadcast/<uuid:broadcast_message_id>/cancel')
+@user_has_permissions('send_messages')
+@service_has_permission('broadcast')
+def cancel_broadcast_message(service_id, broadcast_message_id):
+    BroadcastMessage.from_id(
+        broadcast_message_id,
+        service_id=current_service.id,
+    ).cancel_broadcast()
+    return redirect(url_for(
+        '.broadcast_dashboard',
+        service_id=current_service.id,
+    ))

app/models/broadcast_message.py

@@ -125,6 +125,13 @@ class BroadcastMessage(JSONModel):
             service_id=self.service_id,
         )
 
+    def cancel_broadcast(self):
+        broadcast_message_api_client.update_broadcast_message_status(
+            'cancelled',
+            broadcast_message_id=self.id,
+            service_id=self.service_id,
+        )
+
 
 class BroadcastMessages(ModelList):
 

app/navigation.py

@@ -358,6 +358,7 @@ class HeaderNavigation(Navigation):
         'choose_broadcast_area',
         'remove_broadcast_area',
         'preview_broadcast_message',
+        'cancel_broadcast_message',
     }
 
     # header HTML now comes from GOVUK Frontend so requires a boolean, not an attribute
@@ -413,6 +414,7 @@ class MainNavigation(Navigation):
             'choose_broadcast_area',
             'remove_broadcast_area',
             'preview_broadcast_message',
+            'cancel_broadcast_message',
         },
         'uploads': {
             'upload_contact_list',
@@ -1001,6 +1003,7 @@ class CaseworkNavigation(Navigation):
         'choose_broadcast_area',
         'remove_broadcast_area',
         'preview_broadcast_message',
+        'cancel_broadcast_message',
     }
 
 
@@ -1318,4 +1321,5 @@ class OrgNavigation(Navigation):
         'choose_broadcast_area',
         'remove_broadcast_area',
         'preview_broadcast_message',
+        'cancel_broadcast_message',
     }

app/templates/views/broadcast/dashboard.html

@@ -24,15 +24,20 @@
         </div>
       {% endcall %}
       {% call field(align='right') %}
-        <p class="govuk-body govuk-!-margin-top-6 govuk-!-margin-bottom-0">
-          {% if item.status == 'broadcasting' %}
+        {% if item.status == 'broadcasting' %}
+          <p class="govuk-body letter-recipient-summary">
             Live until {{ item.finishes_at|format_datetime_relative }}
-          {% elif item.status == 'cancelled' %}
+            <a href="{{ url_for('.cancel_broadcast_message', service_id=current_service.id, broadcast_message_id=item.id) }}" class="destructive-link destructive-link--no-visited-state">Stop broadcasting</a>
+          </p>
+        {% elif item.status == 'cancelled' %}
+          <p class="govuk-body govuk-!-margin-top-6 govuk-!-margin-bottom-0">
             Stopped {{ item.cancelled_at|format_datetime_relative }}
-          {% else %}
+          </p>
+        {% else %}
+          <p class="govuk-body govuk-!-margin-top-6 govuk-!-margin-bottom-0">
             Finished {{ item.finishes_at|format_datetime_relative }}
-          {% endif %}
-        </p>
+          </p>
+        {% endif %}
       {% endcall %}
     {% endcall %}
   </div>

tests/app/main/views/test_broadcast.py

@@ -78,7 +78,7 @@ def test_broadcast_dashboard(
     assert [
         normalize_spaces(row.text) for row in page.select('table')[0].select('tbody tr')
     ] == [
-        'Example template To England and Scotland Live until tomorrow at 2:20am',
+        'Example template To England and Scotland Live until tomorrow at 2:20am Stop broadcasting',
     ]
     assert [
         normalize_spaces(row.text) for row in page.select('table')[1].select('tbody tr')
@@ -275,3 +275,28 @@ def test_start_broadcasting(
         service_id=SERVICE_ONE_ID,
         broadcast_message_id=fake_uuid,
     )
+
+
+def test_cancel_broadcast(
+    client_request,
+    service_one,
+    mock_get_draft_broadcast_message,
+    mock_update_broadcast_message_status,
+    fake_uuid,
+):
+    service_one['permissions'] += ['broadcast']
+    client_request.get(
+        '.cancel_broadcast_message',
+        service_id=SERVICE_ONE_ID,
+        broadcast_message_id=fake_uuid,
+        _expected_redirect=url_for(
+            '.broadcast_dashboard',
+            service_id=SERVICE_ONE_ID,
+            _external=True,
+        ),
+    ),
+    mock_update_broadcast_message_status.assert_called_once_with(
+        'cancelled',
+        service_id=SERVICE_ONE_ID,
+        broadcast_message_id=fake_uuid,
+    )