Use Nabu Casa url if no https url set (#26682)

* Use Nabu Casa url if no https url set

* Update test_home_assistant_cast.py

tests/components/cast/test_home_assistant_cast.py

@@ -1,5 +1,5 @@
 """Test Home Assistant Cast."""
-from unittest.mock import Mock
+from unittest.mock import Mock, patch
 from homeassistant.components.cast import home_assistant_cast
 
 from tests.common import MockConfigEntry, async_mock_signal
@@ -26,3 +26,25 @@ async def test_service_show_view(hass):
     assert controller.supporting_app_id == "B12CE3CA"
     assert entity_id == "media_player.kitchen"
     assert view_path == "mock_path"
+
+
+async def test_use_cloud_url(hass):
+    """Test that we fall back to cloud url."""
+    hass.config.api = Mock(base_url="http://example.com")
+    await home_assistant_cast.async_setup_ha_cast(hass, MockConfigEntry())
+    calls = async_mock_signal(hass, home_assistant_cast.SIGNAL_HASS_CAST_SHOW_VIEW)
+
+    with patch(
+        "homeassistant.components.cloud.async_remote_ui_url",
+        return_value="https://something.nabu.acas",
+    ):
+        await hass.services.async_call(
+            "cast",
+            "show_lovelace_view",
+            {"entity_id": "media_player.kitchen", "view_path": "mock_path"},
+            blocking=True,
+        )
+
+    assert len(calls) == 1
+    controller = calls[0][0]
+    assert controller.hass_url == "https://something.nabu.acas"