Validate conversation_command in start timer intent (#149915)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Artur Pragacz <49985303+arturpragacz@users.noreply.github.com>

homeassistant/components/intent/timers.py

@@ -30,6 +30,7 @@ _LOGGER = logging.getLogger(__name__)
 TIMER_NOT_FOUND_RESPONSE = "timer_not_found"
 MULTIPLE_TIMERS_MATCHED_RESPONSE = "multiple_timers_matched"
 NO_TIMER_SUPPORT_RESPONSE = "no_timer_support"
+NO_TIMER_COMMAND_RESPONSE = "no_timer_command"
 
 
 @dataclass
@@ -192,6 +193,17 @@ class MultipleTimersMatchedError(intent.IntentHandleError):
         super().__init__("Multiple timers matched", MULTIPLE_TIMERS_MATCHED_RESPONSE)
 
 
+class NoTimerCommandError(intent.IntentHandleError):
+    """Error when a conversation command does not match any intent."""
+
+    def __init__(self, command: str) -> None:
+        """Initialize error."""
+        super().__init__(
+            f"Intent not recognized: {command}",
+            NO_TIMER_COMMAND_RESPONSE,
+        )
+
+
 class TimersNotSupportedError(intent.IntentHandleError):
     """Error when a timer intent is used from a device that isn't registered to handle timer events."""
 
@@ -836,6 +848,12 @@ class StartTimerIntentHandler(intent.IntentHandler):
             # Fail early if this is not a delayed command
             raise TimersNotSupportedError(intent_obj.device_id)
 
+        # Validate conversation command if provided
+        if conversation_command and not await self._validate_conversation_command(
+            intent_obj, conversation_command
+        ):
+            raise NoTimerCommandError(conversation_command)
+
         name: str | None = None
         if "name" in slots:
             name = slots["name"]["value"]
@@ -865,6 +883,48 @@ class StartTimerIntentHandler(intent.IntentHandler):
 
         return intent_obj.create_response()
 
+    async def _validate_conversation_command(
+        self, intent_obj: intent.Intent, conversation_command: str
+    ) -> bool:
+        """Validate that a conversation command can be executed."""
+        from homeassistant.components.conversation import (  # noqa: PLC0415
+            ConversationInput,
+            async_get_agent,
+            default_agent,
+        )
+
+        # Only validate if using the default agent
+        conversation_agent = async_get_agent(
+            intent_obj.hass, intent_obj.conversation_agent_id
+        )
+
+        if conversation_agent is None or not isinstance(
+            conversation_agent, default_agent.DefaultAgent
+        ):
+            return True  # Skip validation
+
+        test_input = ConversationInput(
+            text=conversation_command,
+            context=intent_obj.context,
+            conversation_id=None,
+            device_id=intent_obj.device_id,
+            satellite_id=intent_obj.satellite_id,
+            language=intent_obj.language,
+            agent_id=conversation_agent.entity_id,
+        )
+
+        # check for sentence trigger
+        if (
+            await conversation_agent.async_recognize_sentence_trigger(test_input)
+        ) is not None:
+            return True
+
+        # check for intent
+        if (await conversation_agent.async_recognize_intent(test_input)) is not None:
+            return True
+
+        return False
+
 
 class CancelTimerIntentHandler(intent.IntentHandler):
     """Intent handler for cancelling a timer."""

tests/components/intent/test_timers.py

@@ -1,12 +1,15 @@
 """Tests for intent timers."""
 
 import asyncio
-from unittest.mock import MagicMock, patch
+from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
+from homeassistant.components import conversation
 from homeassistant.components.intent.timers import (
+    TIMER_DATA,
     MultipleTimersMatchedError,
+    NoTimerCommandError,
     TimerEventType,
     TimerInfo,
     TimerManager,
@@ -32,6 +35,8 @@ from tests.common import MockConfigEntry
 @pytest.fixture
 async def init_components(hass: HomeAssistant) -> None:
     """Initialize required components for tests."""
+    assert await async_setup_component(hass, "homeassistant", {})
+    assert await async_setup_component(hass, "conversation", {})
     assert await async_setup_component(hass, "intent", {})
 
 
@@ -1463,6 +1468,106 @@ async def test_start_timer_with_conversation_command(
         assert mock_converse.call_args.args[1] == test_command
 
 
+async def test_start_timer_with_sentence_trigger_validation(
+    hass: HomeAssistant, init_components
+) -> None:
+    """Test starting a timer with a conversation command validates against sentence triggers."""
+    device_id = "test_device"
+    timer_name = "test timer"
+    test_command = "turn on the lights"
+    agent_id = None  # Default agent
+
+    with patch(
+        "homeassistant.components.conversation.async_get_agent"
+    ) as mock_get_agent:
+        mock_agent = MagicMock(spec=conversation.default_agent.DefaultAgent)
+        mock_agent.async_recognize_sentence_trigger = AsyncMock(
+            return_value=MagicMock(),
+        )
+        mock_agent.async_recognize_intent = AsyncMock(return_value=None)
+        mock_get_agent.return_value = mock_agent
+
+        result = await intent.async_handle(
+            hass,
+            "test",
+            intent.INTENT_START_TIMER,
+            {
+                "name": {"value": timer_name},
+                "seconds": {"value": 5},
+                "conversation_command": {"value": test_command},
+            },
+            device_id=device_id,
+            conversation_agent_id=agent_id,
+        )
+
+        assert result.response_type == intent.IntentResponseType.ACTION_DONE
+
+        # Verify the sentence trigger was checked
+        mock_agent.async_recognize_sentence_trigger.assert_called_once()
+
+        # Verify timer was created successfully
+        timer_manager = hass.data[TIMER_DATA]
+        assert len(timer_manager.timers) == 1
+
+
+async def test_start_timer_with_invalid_conversation_command(
+    hass: HomeAssistant, init_components
+) -> None:
+    """Test starting a timer with an invalid conversation command fails validation."""
+    device_id = "test_device"
+    timer_name = "test timer"
+    invalid_command = "invalid command that does not exist"
+    agent_id = None  # Default agent
+
+    with pytest.raises(NoTimerCommandError):
+        await intent.async_handle(
+            hass,
+            "test",
+            intent.INTENT_START_TIMER,
+            {
+                "name": {"value": timer_name},
+                "seconds": {"value": 5},
+                "conversation_command": {"value": invalid_command},
+            },
+            device_id=device_id,
+            conversation_agent_id=agent_id,
+        )
+
+    # Verify no timer was created
+    timer_manager = hass.data[TIMER_DATA]
+    assert len(timer_manager.timers) == 0
+
+
+async def test_start_timer_with_conversation_command_skip_validation(
+    hass: HomeAssistant, init_components
+) -> None:
+    """Test starting a timer with a conversation command skips validation for non-default agents."""
+    device_id = "test_device"
+    timer_name = "test timer"
+    invalid_command = "invalid command that does not exist"
+    agent_id = "conversation.test_llm_agent"
+
+    # This should NOT raise an error because validation is skipped for all non-default agents
+    result = await intent.async_handle(
+        hass,
+        "test",
+        intent.INTENT_START_TIMER,
+        {
+            "name": {"value": timer_name},
+            "seconds": {"value": 5},
+            "conversation_command": {"value": invalid_command},
+        },
+        device_id=device_id,
+        conversation_agent_id=agent_id,
+    )
+
+    assert result.response_type == intent.IntentResponseType.ACTION_DONE
+
+    # Verify timer was created successfully despite invalid command
+    timer_manager = hass.data[TIMER_DATA]
+    assert len(timer_manager.timers) == 1
+
+
 async def test_pause_unpause_timer_disambiguate(
     hass: HomeAssistant, init_components
 ) -> None: