Add limited template to at field for time triggers (#126584)

* Add limited template to at field for time triggers

* fix mypy

* Fix comments

* fix-tests

---------

Co-authored-by: Erik Montnemery <erik@montnemery.com>

homeassistant/components/homeassistant/triggers/time.py

@@ -3,7 +3,7 @@
 from collections.abc import Callable
 from datetime import datetime, timedelta
 from functools import partial
-from typing import NamedTuple
+from typing import Any, NamedTuple
 
 import voluptuous as vol
 
@@ -26,7 +26,8 @@ from homeassistant.core import (
     State,
     callback,
 )
-from homeassistant.helpers import config_validation as cv
+from homeassistant.exceptions import HomeAssistantError
+from homeassistant.helpers import config_validation as cv, template
 from homeassistant.helpers.event import (
     async_track_point_in_time,
     async_track_state_change_event,
@@ -37,6 +38,7 @@ from homeassistant.helpers.typing import ConfigType
 import homeassistant.util.dt as dt_util
 
 _TIME_TRIGGER_ENTITY = vol.All(str, cv.entity_domain(["input_datetime", "sensor"]))
+_TIME_AT_SCHEMA = vol.Any(cv.time, _TIME_TRIGGER_ENTITY)
 
 _TIME_TRIGGER_ENTITY_WITH_OFFSET = vol.Schema(
     {
@@ -45,16 +47,29 @@ _TIME_TRIGGER_ENTITY_WITH_OFFSET = vol.Schema(
     }
 )
 
+
+def valid_at_template(value: Any) -> template.Template:
+    """Validate either a jinja2 template, valid time, or valid trigger entity."""
+    tpl = cv.template(value)
+
+    if tpl.is_static:
+        _TIME_AT_SCHEMA(value)
+
+    return tpl
+
+
 _TIME_TRIGGER_SCHEMA = vol.Any(
     cv.time,
     _TIME_TRIGGER_ENTITY,
     _TIME_TRIGGER_ENTITY_WITH_OFFSET,
+    valid_at_template,
     msg=(
         "Expected HH:MM, HH:MM:SS, an Entity ID with domain 'input_datetime' or "
-        "'sensor', or a combination of a timestamp sensor entity and an offset."
+        "'sensor', a combination of a timestamp sensor entity and an offset, or Limited Template"
     ),
 )
 
+
 TRIGGER_SCHEMA = cv.TRIGGER_BASE_SCHEMA.extend(
     {
         vol.Required(CONF_PLATFORM): "time",
@@ -78,6 +93,7 @@ async def async_attach_trigger(
 ) -> CALLBACK_TYPE:
     """Listen for state changes based on configuration."""
     trigger_data = trigger_info["trigger_data"]
+    variables = trigger_info["variables"] or {}
     entities: dict[tuple[str, timedelta], CALLBACK_TYPE] = {}
     removes: list[CALLBACK_TYPE] = []
     job = HassJob(action, f"time trigger {trigger_info}")
@@ -202,6 +218,16 @@ async def async_attach_trigger(
     to_track: list[TrackEntity] = []
 
     for at_time in config[CONF_AT]:
+        if isinstance(at_time, template.Template):
+            render = template.render_complex(at_time, variables, limited=True)
+            try:
+                at_time = _TIME_AT_SCHEMA(render)
+            except vol.Invalid as exc:
+                raise HomeAssistantError(
+                    f"Limited Template for 'at' rendered a unexpected value '{render}', expected HH:MM, "
+                    f"HH:MM:SS or Entity ID with domain 'input_datetime' or 'sensor'"
+                ) from exc
+
         if isinstance(at_time, str):
             # entity
             update_entity_trigger(at_time, new_state=hass.states.get(at_time))

tests/components/homeassistant/triggers/test_time.py

@@ -159,7 +159,10 @@ async def test_if_fires_using_at_input_datetime(
 @pytest.mark.parametrize(
     ("conf_at", "trigger_deltas"),
     [
-        (["5:00:00", "6:00:00"], [timedelta(0), timedelta(hours=1)]),
+        (
+            ["5:00:00", "6:00:00", "{{ '7:00:00' }}"],
+            [timedelta(0), timedelta(hours=1), timedelta(hours=2)],
+        ),
         (
             [
                 "5:00:05",
@@ -435,10 +438,14 @@ async def test_untrack_time_change(hass: HomeAssistant) -> None:
     assert len(mock_track_time_change.mock_calls) == 3
 
 
+@pytest.mark.parametrize(
+    ("at_sensor"), ["sensor.next_alarm", "{{ 'sensor.next_alarm' }}"]
+)
 async def test_if_fires_using_at_sensor(
     hass: HomeAssistant,
     freezer: FrozenDateTimeFactory,
     service_calls: list[ServiceCall],
+    at_sensor: str,
 ) -> None:
     """Test for firing at sensor time."""
     now = dt_util.now()
@@ -461,7 +468,7 @@ async def test_if_fires_using_at_sensor(
         automation.DOMAIN,
         {
             automation.DOMAIN: {
-                "trigger": {"platform": "time", "at": "sensor.next_alarm"},
+                "trigger": {"platform": "time", "at": at_sensor},
                 "action": {
                     "service": "test.automation",
                     "data_template": {"some": some_data},
@@ -626,6 +633,9 @@ async def test_if_fires_using_at_sensor_with_offset(
         {"platform": "time", "at": "input_datetime.bla"},
         {"platform": "time", "at": "sensor.bla"},
         {"platform": "time", "at": "12:34"},
+        {"platform": "time", "at": "{{ '12:34' }}"},
+        {"platform": "time", "at": "{{ 'input_datetime.bla' }}"},
+        {"platform": "time", "at": "{{ 'sensor.bla' }}"},
         {"platform": "time", "at": {"entity_id": "sensor.bla", "offset": "-00:01"}},
         {
             "platform": "time",
@@ -724,3 +734,70 @@ async def test_datetime_in_past_on_load(
         service_calls[2].data["some"]
         == f"time-{future.day}-{future.hour}-input_datetime.my_trigger"
     )
+
+
+@pytest.mark.parametrize(
+    "trigger",
+    [
+        {"platform": "time", "at": "{{ 'hello world' }}"},
+        {"platform": "time", "at": "{{ 74 }}"},
+        {"platform": "time", "at": "{{ true }}"},
+        {"platform": "time", "at": "{{ 7.5465 }}"},
+    ],
+)
+async def test_if_at_template_renders_bad_value(
+    hass: HomeAssistant,
+    caplog: pytest.LogCaptureFixture,
+    trigger: dict[str, str],
+) -> None:
+    """Test for invalid templates."""
+    assert await async_setup_component(
+        hass,
+        automation.DOMAIN,
+        {
+            automation.DOMAIN: {
+                "trigger": trigger,
+                "action": {
+                    "service": "test.automation",
+                },
+            }
+        },
+    )
+
+    await hass.async_block_till_done()
+
+    assert (
+        "expected HH:MM, HH:MM:SS or Entity ID with domain 'input_datetime' or 'sensor'"
+        in caplog.text
+    )
+
+
+@pytest.mark.parametrize(
+    "trigger",
+    [
+        {"platform": "time", "at": "{{ now().strftime('%H:%M') }}"},
+        {"platform": "time", "at": "{{ states('sensor.blah') | int(0) }}"},
+    ],
+)
+async def test_if_at_template_limited_template(
+    hass: HomeAssistant,
+    caplog: pytest.LogCaptureFixture,
+    trigger: dict[str, str],
+) -> None:
+    """Test for invalid templates."""
+    assert await async_setup_component(
+        hass,
+        automation.DOMAIN,
+        {
+            automation.DOMAIN: {
+                "trigger": trigger,
+                "action": {
+                    "service": "test.automation",
+                },
+            }
+        },
+    )
+
+    await hass.async_block_till_done()
+
+    assert "is not supported in limited templates" in caplog.text