default_agent.py

"""Standard conversation implementation for Home Assistant."""

from __future__ import annotations

import asyncio
from collections import OrderedDict
from collections.abc import Awaitable, Callable, Iterable
from dataclasses import dataclass
from enum import Enum, auto
import functools
import logging
from pathlib import Path
import re
import time
from typing import IO, Any, cast

from hassil.expression import Expression, ListReference, Sequence, TextChunk
from hassil.intents import (
    Intents,
    SlotList,
    TextSlotList,
    TextSlotValue,
    WildcardSlotList,
)
from hassil.recognize import (
    MISSING_ENTITY,
    RecognizeResult,
    recognize_all,
    recognize_best,
)
from hassil.string_matcher import UnmatchedRangeEntity, UnmatchedTextEntity
from hassil.trie import Trie
from hassil.util import merge_dict
from home_assistant_intents import ErrorKey, get_intents, get_languages
import yaml

from homeassistant import core
from homeassistant.components.homeassistant.exposed_entities import (
    async_listen_entity_updates,
    async_should_expose,
)
from homeassistant.const import EVENT_STATE_CHANGED, MATCH_ALL
from homeassistant.helpers import (
    area_registry as ar,
    device_registry as dr,
    entity_registry as er,
    floor_registry as fr,
    intent,
    start as ha_start,
    template,
    translation,
)
from homeassistant.helpers.entity_component import EntityComponent
from homeassistant.helpers.event import async_track_state_added_domain
from homeassistant.util.json import JsonObjectType, json_loads_object

from .const import (
    DATA_DEFAULT_ENTITY,
    DEFAULT_EXPOSED_ATTRIBUTES,
    DOMAIN,
    ConversationEntityFeature,
)
from .entity import ConversationEntity
from .models import ConversationInput, ConversationResult
from .trace import ConversationTraceEventType, async_conversation_trace_append

_LOGGER = logging.getLogger(__name__)
_DEFAULT_ERROR_TEXT = "Sorry, I couldn't understand that"
_ENTITY_REGISTRY_UPDATE_FIELDS = ["aliases", "name", "original_name"]

REGEX_TYPE = type(re.compile(""))
TRIGGER_CALLBACK_TYPE = Callable[
    [ConversationInput, RecognizeResult], Awaitable[str | None]
]
METADATA_CUSTOM_SENTENCE = "hass_custom_sentence"
METADATA_CUSTOM_FILE = "hass_custom_file"

ERROR_SENTINEL = object()


def json_load(fp: IO[str]) -> JsonObjectType:
    """Wrap json_loads for get_intents."""
    return json_loads_object(fp.read())


@dataclass(slots=True)
class LanguageIntents:
    """Loaded intents for a language."""

    intents: Intents
    intents_dict: dict[str, Any]
    intent_responses: dict[str, Any]
    error_responses: dict[str, Any]
    language_variant: str | None


@dataclass(slots=True)
class TriggerData:
    """List of sentences and the callback for a trigger."""

    sentences: list[str]
    callback: TRIGGER_CALLBACK_TYPE


@dataclass(slots=True)
class SentenceTriggerResult:
    """Result when matching a sentence trigger in an automation."""

    sentence: str
    sentence_template: str | None
    matched_triggers: dict[int, RecognizeResult]


class IntentMatchingStage(Enum):
    """Stages of intent matching."""

    EXPOSED_ENTITIES_ONLY = auto()
    """Match against exposed entities only."""

    UNEXPOSED_ENTITIES = auto()
    """Match against unexposed entities in Home Assistant."""

    FUZZY = auto()
    """Capture names that are not known to Home Assistant."""


@dataclass(frozen=True)
class IntentCacheKey:
    """Key for IntentCache."""

    text: str
    """User input text."""

    language: str
    """Language of text."""

    device_id: str | None
    """Device id from user input."""


@dataclass(frozen=True)
class IntentCacheValue:
    """Value for IntentCache."""

    result: RecognizeResult | None
    """Result of intent recognition."""

    stage: IntentMatchingStage
    """Stage where result was found."""


class IntentCache:
    """LRU cache for intent recognition results."""

    def __init__(self, capacity: int) -> None:
        """Initialize cache."""
        self.cache: OrderedDict[IntentCacheKey, IntentCacheValue] = OrderedDict()
        self.capacity = capacity

    def get(self, key: IntentCacheKey) -> IntentCacheValue | None:
        """Get value for cache or None."""
        if key not in self.cache:
            return None

        # Move the key to the end to show it was recently used
        self.cache.move_to_end(key)
        return self.cache[key]

    def put(self, key: IntentCacheKey, value: IntentCacheValue) -> None:
        """Put a value in the cache, evicting the least recently used item if necessary."""
        if key in self.cache:
            # Update value and mark as recently used
            self.cache.move_to_end(key)
        elif len(self.cache) >= self.capacity:
            # Evict the oldest item
            self.cache.popitem(last=False)

        self.cache[key] = value

    def clear(self) -> None:
        """Clear the cache."""
        self.cache.clear()


def _get_language_variations(language: str) -> Iterable[str]:
    """Generate language codes with and without region."""
    yield language

    parts = re.split(r"([-_])", language)
    if len(parts) == 3:
        lang, sep, region = parts
        if sep == "_":
            # en_US -> en-US
            yield f"{lang}-{region}"

        # en-US -> en
        yield lang


async def async_setup_default_agent(
    hass: core.HomeAssistant,
    entity_component: EntityComponent[ConversationEntity],
    config_intents: dict[str, Any],
) -> None:
    """Set up entity registry listener for the default agent."""
    entity = DefaultAgent(hass, config_intents)
    await entity_component.async_add_entities([entity])
    hass.data[DATA_DEFAULT_ENTITY] = entity

    @core.callback
    def async_entity_state_listener(
        event: core.Event[core.EventStateChangedData],
    ) -> None:
        """Set expose flag on new entities."""
        async_should_expose(hass, DOMAIN, event.data["entity_id"])

    @core.callback
    def async_hass_started(hass: core.HomeAssistant) -> None:
        """Set expose flag on all entities."""
        for state in hass.states.async_all():
            async_should_expose(hass, DOMAIN, state.entity_id)
        async_track_state_added_domain(hass, MATCH_ALL, async_entity_state_listener)

    ha_start.async_at_started(hass, async_hass_started)


class DefaultAgent(ConversationEntity):
    """Default agent for conversation agent."""

    _attr_name = "Home Assistant"
    _attr_supported_features = ConversationEntityFeature.CONTROL

    def __init__(
        self, hass: core.HomeAssistant, config_intents: dict[str, Any]
    ) -> None:
        """Initialize the default agent."""
        self.hass = hass
        self._lang_intents: dict[str, LanguageIntents | object] = {}

        # intent -> [sentences]
        self._config_intents: dict[str, Any] = config_intents
        self._slot_lists: dict[str, SlotList] | None = None

        # Used to filter slot lists before intent matching
        self._exposed_names_trie: Trie | None = None
        self._unexposed_names_trie: Trie | None = None

        # Sentences that will trigger a callback (skipping intent recognition)
        self.trigger_sentences: list[TriggerData] = []
        self._trigger_intents: Intents | None = None
        self._unsub_clear_slot_list: list[Callable[[], None]] | None = None
        self._load_intents_lock = asyncio.Lock()

        # LRU cache to avoid unnecessary intent matching
        self._intent_cache = IntentCache(capacity=128)

    @property
    def supported_languages(self) -> list[str]:
        """Return a list of supported languages."""
        return get_languages()

    @core.callback
    def _filter_entity_registry_changes(
        self, event_data: er.EventEntityRegistryUpdatedData
    ) -> bool:
        """Filter entity registry changed events."""
        return event_data["action"] == "update" and any(
            field in event_data["changes"] for field in _ENTITY_REGISTRY_UPDATE_FIELDS
        )

    @core.callback
    def _filter_state_changes(self, event_data: core.EventStateChangedData) -> bool:
        """Filter state changed events."""
        return not event_data["old_state"] or not event_data["new_state"]

    @core.callback
    def _listen_clear_slot_list(self) -> None:
        """Listen for changes that can invalidate slot list."""
        assert self._unsub_clear_slot_list is None

        self._unsub_clear_slot_list = [
            self.hass.bus.async_listen(
                ar.EVENT_AREA_REGISTRY_UPDATED,
                self._async_clear_slot_list,
            ),
            self.hass.bus.async_listen(
                fr.EVENT_FLOOR_REGISTRY_UPDATED,
                self._async_clear_slot_list,
            ),
            self.hass.bus.async_listen(
                er.EVENT_ENTITY_REGISTRY_UPDATED,
                self._async_clear_slot_list,
                event_filter=self._filter_entity_registry_changes,
            ),
            self.hass.bus.async_listen(
                EVENT_STATE_CHANGED,
                self._async_clear_slot_list,
                event_filter=self._filter_state_changes,
            ),
            async_listen_entity_updates(self.hass, DOMAIN, self._async_clear_slot_list),
        ]

    async def async_recognize_intent(
        self, user_input: ConversationInput, strict_intents_only: bool = False
    ) -> RecognizeResult | None:
        """Recognize intent from user input."""
        language = user_input.language or self.hass.config.language
        lang_intents = await self.async_get_or_load_intents(language)

        if lang_intents is None:
            # No intents loaded
            _LOGGER.warning("No intents were loaded for language: %s", language)
            return None

        slot_lists = self._make_slot_lists()
        intent_context = self._make_intent_context(user_input)

        if self._exposed_names_trie is not None:
            # Filter by input string
            text_lower = user_input.text.strip().lower()
            slot_lists["name"] = TextSlotList(
                name="name",
                values=[
                    result[2] for result in self._exposed_names_trie.find(text_lower)
                ],
            )

        start = time.monotonic()

        result = await self.hass.async_add_executor_job(
            self._recognize,
            user_input,
            lang_intents,
            slot_lists,
            intent_context,
            language,
            strict_intents_only,
        )

        _LOGGER.debug(
            "Recognize done in %.2f seconds",
            time.monotonic() - start,
        )

        return result

    async def async_process(self, user_input: ConversationInput) -> ConversationResult:
        """Process a sentence."""

        # Check if a trigger matched
        if trigger_result := await self.async_recognize_sentence_trigger(user_input):
            # Process callbacks and get response
            response_text = await self._handle_trigger_result(
                trigger_result, user_input
            )

            # Convert to conversation result
            response = intent.IntentResponse(
                language=user_input.language or self.hass.config.language
            )
            response.response_type = intent.IntentResponseType.ACTION_DONE
            response.async_set_speech(response_text)

            return ConversationResult(response=response)

        # Match intents
        intent_result = await self.async_recognize_intent(user_input)
        return await self._async_process_intent_result(intent_result, user_input)

    async def _async_process_intent_result(
        self,
        result: RecognizeResult | None,
        user_input: ConversationInput,
    ) -> ConversationResult:
        """Process user input with intents."""
        language = user_input.language or self.hass.config.language
        conversation_id = None  # Not supported

        # Intent match or failure
        lang_intents = await self.async_get_or_load_intents(language)

        if result is None:
            # Intent was not recognized
            _LOGGER.debug("No intent was matched for '%s'", user_input.text)
            return _make_error_result(
                language,
                intent.IntentResponseErrorCode.NO_INTENT_MATCH,
                self._get_error_text(ErrorKey.NO_INTENT, lang_intents),
                conversation_id,
            )

        if result.unmatched_entities:
            # Intent was recognized, but not entity/area names, etc.
            _LOGGER.debug(
                "Recognized intent '%s' for template '%s' but had unmatched: %s",
                result.intent.name,
                (
                    result.intent_sentence.text
                    if result.intent_sentence is not None
                    else ""
                ),
                result.unmatched_entities_list,
            )
            error_response_type, error_response_args = _get_unmatched_response(result)
            return _make_error_result(
                language,
                intent.IntentResponseErrorCode.NO_VALID_TARGETS,
                self._get_error_text(
                    error_response_type, lang_intents, **error_response_args
                ),
                conversation_id,
            )

        # Will never happen because result will be None when no intents are
        # loaded in async_recognize.
        assert lang_intents is not None

        # Slot values to pass to the intent
        slots: dict[str, Any] = {
            entity.name: {
                "value": entity.value,
                "text": entity.text or entity.value,
            }
            for entity in result.entities_list
        }
        device_area = self._get_device_area(user_input.device_id)
        if device_area:
            slots["preferred_area_id"] = {"value": device_area.id}
        async_conversation_trace_append(
            ConversationTraceEventType.TOOL_CALL,
            {
                "intent_name": result.intent.name,
                "slots": {
                    entity.name: entity.value or entity.text
                    for entity in result.entities_list
                },
            },
        )

        try:
            intent_response = await intent.async_handle(
                self.hass,
                DOMAIN,
                result.intent.name,
                slots,
                user_input.text,
                user_input.context,
                language,
                assistant=DOMAIN,
                device_id=user_input.device_id,
                conversation_agent_id=user_input.agent_id,
            )
        except intent.MatchFailedError as match_error:
            # Intent was valid, but no entities matched the constraints.
            error_response_type, error_response_args = _get_match_error_response(
                self.hass, match_error
            )
            return _make_error_result(
                language,
                intent.IntentResponseErrorCode.NO_VALID_TARGETS,
                self._get_error_text(
                    error_response_type, lang_intents, **error_response_args
                ),
                conversation_id,
            )
        except intent.IntentHandleError as err:
            # Intent was valid and entities matched constraints, but an error
            # occurred during handling.
            _LOGGER.exception("Intent handling error")
            return _make_error_result(
                language,
                intent.IntentResponseErrorCode.FAILED_TO_HANDLE,
                self._get_error_text(
                    err.response_key or ErrorKey.HANDLE_ERROR, lang_intents
                ),
                conversation_id,
            )
        except intent.IntentUnexpectedError:
            _LOGGER.exception("Unexpected intent error")
            return _make_error_result(
                language,
                intent.IntentResponseErrorCode.UNKNOWN,
                self._get_error_text(ErrorKey.HANDLE_ERROR, lang_intents),
                conversation_id,
            )

        if (
            (not intent_response.speech)
            and (intent_response.intent is not None)
            and (response_key := result.response)
        ):
            # Use response template, if available
            response_template_str = lang_intents.intent_responses.get(
                result.intent.name, {}
            ).get(response_key)
            if response_template_str:
                response_template = template.Template(response_template_str, self.hass)
                speech = await self._build_speech(
                    language, response_template, intent_response, result
                )
                intent_response.async_set_speech(speech)

        return ConversationResult(
            response=intent_response, conversation_id=conversation_id
        )

    def _recognize(
        self,
        user_input: ConversationInput,
        lang_intents: LanguageIntents,
        slot_lists: dict[str, SlotList],
        intent_context: dict[str, Any] | None,
        language: str,
        strict_intents_only: bool,
    ) -> RecognizeResult | None:
        """Search intents for a match to user input."""
        skip_exposed_match = False

        # Try cache first
        cache_key = IntentCacheKey(
            text=user_input.text, language=language, device_id=user_input.device_id
        )
        cache_value = self._intent_cache.get(cache_key)
        if cache_value is not None:
            if (cache_value.result is not None) and (
                cache_value.stage == IntentMatchingStage.EXPOSED_ENTITIES_ONLY
            ):
                _LOGGER.debug("Got cached result for exposed entities")
                return cache_value.result

            # Continue with matching, but we know we won't succeed for exposed
            # entities only.
            skip_exposed_match = True

        if not skip_exposed_match:
            start_time = time.monotonic()
            strict_result = self._recognize_strict(
                user_input, lang_intents, slot_lists, intent_context, language
            )
            _LOGGER.debug(
                "Checked exposed entities in %s second(s)",
                time.monotonic() - start_time,
            )

            # Update cache
            self._intent_cache.put(
                cache_key,
                IntentCacheValue(
                    result=strict_result,
                    stage=IntentMatchingStage.EXPOSED_ENTITIES_ONLY,
                ),
            )

            if strict_result is not None:
                # Successful strict match with exposed entities
                return strict_result

        if strict_intents_only:
            # Don't try matching against all entities or doing a fuzzy match
            return None

        # Try again with all entities (including unexposed)
        skip_unexposed_entities_match = False
        if cache_value is not None:
            if (cache_value.result is not None) and (
                cache_value.stage == IntentMatchingStage.UNEXPOSED_ENTITIES
            ):
                _LOGGER.debug("Got cached result for all entities")
                return cache_value.result

            # Continue with matching, but we know we won't succeed for all
            # entities.
            skip_unexposed_entities_match = True

        if not skip_unexposed_entities_match:
            unexposed_entities_slot_lists = {
                **slot_lists,
                "name": self._get_unexposed_entity_names(user_input.text),
            }

            start_time = time.monotonic()
            strict_result = self._recognize_strict(
                user_input,
                lang_intents,
                unexposed_entities_slot_lists,
                intent_context,
                language,
            )

            _LOGGER.debug(
                "Checked all entities in %s second(s)", time.monotonic() - start_time
            )

            # Update cache
            self._intent_cache.put(
                cache_key,
                IntentCacheValue(
                    result=strict_result, stage=IntentMatchingStage.UNEXPOSED_ENTITIES
                ),
            )

            if strict_result is not None:
                # Not a successful match, but useful for an error message.
                # This should fail the intent handling phase (async_match_targets).
                return strict_result

        # Try again with missing entities enabled
        skip_fuzzy_match = False
        if cache_value is not None:
            if (cache_value.result is not None) and (
                cache_value.stage == IntentMatchingStage.FUZZY
            ):
                _LOGGER.debug("Got cached result for fuzzy match")
                return cache_value.result

            # We know we won't succeed for fuzzy matching.
            skip_fuzzy_match = True

        maybe_result: RecognizeResult | None = None
        if not skip_fuzzy_match:
            start_time = time.monotonic()
            best_num_matched_entities = 0
            best_num_unmatched_entities = 0
            best_num_unmatched_ranges = 0
            for result in recognize_all(
                user_input.text,
                lang_intents.intents,
                slot_lists=slot_lists,
                intent_context=intent_context,
                allow_unmatched_entities=True,
            ):
                if result.text_chunks_matched < 1:
                    # Skip results that don't match any literal text
                    continue

                # Don't count missing entities that couldn't be filled from context
                num_matched_entities = 0
                for matched_entity in result.entities_list:
                    if matched_entity.name not in result.unmatched_entities:
                        num_matched_entities += 1

                num_unmatched_entities = 0
                num_unmatched_ranges = 0
                for unmatched_entity in result.unmatched_entities_list:
                    if isinstance(unmatched_entity, UnmatchedTextEntity):
                        if unmatched_entity.text != MISSING_ENTITY:
                            num_unmatched_entities += 1
                    elif isinstance(unmatched_entity, UnmatchedRangeEntity):
                        num_unmatched_ranges += 1
                        num_unmatched_entities += 1
                    else:
                        num_unmatched_entities += 1

                if (
                    (maybe_result is None)  # first result
                    or (num_matched_entities > best_num_matched_entities)
                    or (
                        # Fewer unmatched entities
                        (num_matched_entities == best_num_matched_entities)
                        and (num_unmatched_entities < best_num_unmatched_entities)
                    )
                    or (
                        # Prefer unmatched ranges
                        (num_matched_entities == best_num_matched_entities)
                        and (num_unmatched_entities == best_num_unmatched_entities)
                        and (num_unmatched_ranges > best_num_unmatched_ranges)
                    )
                    or (
                        # More literal text matched
                        (num_matched_entities == best_num_matched_entities)
                        and (num_unmatched_entities == best_num_unmatched_entities)
                        and (num_unmatched_ranges == best_num_unmatched_ranges)
                        and (
                            result.text_chunks_matched
                            > maybe_result.text_chunks_matched
                        )
                    )
                    or (
                        # Prefer match failures with entities
                        (result.text_chunks_matched == maybe_result.text_chunks_matched)
                        and (num_unmatched_entities == best_num_unmatched_entities)
                        and (num_unmatched_ranges == best_num_unmatched_ranges)
                        and (
                            ("name" in result.entities)
                            or ("name" in result.unmatched_entities)
                        )
                    )
                ):
                    maybe_result = result
                    best_num_matched_entities = num_matched_entities
                    best_num_unmatched_entities = num_unmatched_entities
                    best_num_unmatched_ranges = num_unmatched_ranges

            # Update cache
            self._intent_cache.put(
                cache_key,
                IntentCacheValue(result=maybe_result, stage=IntentMatchingStage.FUZZY),
            )

            _LOGGER.debug(
                "Did fuzzy match in %s second(s)", time.monotonic() - start_time
            )

        return maybe_result

    def _get_unexposed_entity_names(self, text: str) -> TextSlotList:
        """Get filtered slot list with unexposed entity names in Home Assistant."""
        if self._unexposed_names_trie is None:
            # Build trie
            self._unexposed_names_trie = Trie()
            for name_tuple in self._get_entity_name_tuples(exposed=False):
                self._unexposed_names_trie.insert(
                    name_tuple[0].lower(),
                    TextSlotValue.from_tuple(name_tuple, allow_template=False),
                )

        # Build filtered slot list
        text_lower = text.strip().lower()
        return TextSlotList(
            name="name",
            values=[
                result[2] for result in self._unexposed_names_trie.find(text_lower)
            ],
        )

    def _get_entity_name_tuples(
        self, exposed: bool
    ) -> Iterable[tuple[str, str, dict[str, Any]]]:
        """Yield (input name, output name, context) tuples for entities."""
        entity_registry = er.async_get(self.hass)

        for state in self.hass.states.async_all():
            entity_exposed = async_should_expose(self.hass, DOMAIN, state.entity_id)
            if exposed and (not entity_exposed):
                # Required exposed, entity is not
                continue

            if (not exposed) and entity_exposed:
                # Required not exposed, entity is
                continue

            # Checked against "requires_context" and "excludes_context" in hassil
            context = {"domain": state.domain}
            if state.attributes:
                # Include some attributes
                for attr in DEFAULT_EXPOSED_ATTRIBUTES:
                    if attr not in state.attributes:
                        continue
                    context[attr] = state.attributes[attr]

            if (
                entity := entity_registry.async_get(state.entity_id)
            ) and entity.aliases:
                for alias in entity.aliases:
                    alias = alias.strip()
                    if not alias:
                        continue

                    yield (alias, alias, context)

            # Default name
            yield (state.name, state.name, context)

    def _recognize_strict(
        self,
        user_input: ConversationInput,
        lang_intents: LanguageIntents,
        slot_lists: dict[str, SlotList],
        intent_context: dict[str, Any] | None,
        language: str,
    ) -> RecognizeResult | None:
        """Search intents for a strict match to user input."""
        return recognize_best(
            user_input.text,
            lang_intents.intents,
            slot_lists=slot_lists,
            intent_context=intent_context,
            language=language,
            best_metadata_key=METADATA_CUSTOM_SENTENCE,
            best_slot_name="name",
        )

    async def _build_speech(
        self,
        language: str,
        response_template: template.Template,
        intent_response: intent.IntentResponse,
        recognize_result: RecognizeResult,
    ) -> str:
        # Make copies of the states here so we can add translated names for responses.
        matched = [
            state_copy
            for state in intent_response.matched_states
            if (state_copy := core.State.from_dict(state.as_dict()))
        ]
        unmatched = [
            state_copy
            for state in intent_response.unmatched_states
            if (state_copy := core.State.from_dict(state.as_dict()))
        ]
        all_states = matched + unmatched
        domains = {state.domain for state in all_states}
        translations = await translation.async_get_translations(
            self.hass, language, "entity_component", domains
        )

        # Use translated state names
        for state in all_states:
            device_class = state.attributes.get("device_class", "_")
            key = f"component.{state.domain}.entity_component.{device_class}.state.{state.state}"
            state.state = translations.get(key, state.state)

        # Get first matched or unmatched state.
        # This is available in the response template as "state".
        state1: core.State | None = None
        if intent_response.matched_states:
            state1 = matched[0]
        elif intent_response.unmatched_states:
            state1 = unmatched[0]

        # Render response template
        speech_slots = {
            entity_name: entity_value.text or entity_value.value
            for entity_name, entity_value in recognize_result.entities.items()
        }
        speech_slots.update(intent_response.speech_slots)

        speech = response_template.async_render(
            {
                # Slots from intent recognizer and response
                "slots": speech_slots,
                # First matched or unmatched state
                "state": (
                    template.TemplateState(self.hass, state1)
                    if state1 is not None
                    else None
                ),
                "query": {
                    # Entity states that matched the query (e.g, "on")
                    "matched": [
                        template.TemplateState(self.hass, state) for state in matched
                    ],
                    # Entity states that did not match the query
                    "unmatched": [
                        template.TemplateState(self.hass, state) for state in unmatched
                    ],
                },
            }
        )

        # Normalize whitespace
        if speech is not None:
            speech = str(speech)
            speech = " ".join(speech.strip().split())

        return speech

    async def async_reload(self, language: str | None = None) -> None:
        """Clear cached intents for a language."""
        if language is None:
            self._lang_intents.clear()
            _LOGGER.debug("Cleared intents for all languages")
        else:
            self._lang_intents.pop(language, None)
            _LOGGER.debug("Cleared intents for language: %s", language)

        # Intents have changed, so we must clear the cache
        self._intent_cache.clear()

    async def async_prepare(self, language: str | None = None) -> None:
        """Load intents for a language."""
        if language is None:
            language = self.hass.config.language

        lang_intents = await self.async_get_or_load_intents(language)

        # No intents loaded
        if lang_intents is None:
            return

        self._make_slot_lists()

    async def async_get_or_load_intents(self, language: str) -> LanguageIntents | None:
        """Load all intents of a language with lock."""
        if lang_intents := self._lang_intents.get(language):
            return (
                None
                if lang_intents is ERROR_SENTINEL
                else cast(LanguageIntents, lang_intents)
            )

        async with self._load_intents_lock:
            # In case it was loaded now
            if lang_intents := self._lang_intents.get(language):
                return (
                    None
                    if lang_intents is ERROR_SENTINEL
                    else cast(LanguageIntents, lang_intents)
                )

            start = time.monotonic()

            result = await self.hass.async_add_executor_job(
                self._load_intents, language
            )

            if result is None:
                self._lang_intents[language] = ERROR_SENTINEL
            else:
                self._lang_intents[language] = result

            _LOGGER.debug(
                "Full intents load completed for language=%s in %.2f seconds",
                language,
                time.monotonic() - start,
            )

            return result

    def _load_intents(self, language: str) -> LanguageIntents | None:
        """Load all intents for language (run inside executor)."""
        intents_dict: dict[str, Any] = {}
        language_variant: str | None = None
        supported_langs = set(get_languages())

        # Choose a language variant upfront and commit to it for custom
        # sentences, etc.
        all_language_variants = {lang.lower(): lang for lang in supported_langs}

        # en-US, en_US, en, ...
        for maybe_variant in _get_language_variations(language):
            matching_variant = all_language_variants.get(maybe_variant.lower())
            if matching_variant:
                language_variant = matching_variant
                break

        if not language_variant:
            _LOGGER.warning(
                "Unable to find supported language variant for %s", language
            )
            return None

        # Load intents for this language variant
        lang_variant_intents = get_intents(language_variant, json_load=json_load)

        if lang_variant_intents:
            # Merge sentences into existing dictionary
            # Overriding because source dict is empty
            intents_dict = lang_variant_intents

            _LOGGER.debug(
                "Loaded built-in intents for language=%s (%s)",
                language,
                language_variant,
            )

        # Check for custom sentences in <config>/custom_sentences/<language>/
        custom_sentences_dir = Path(
            self.hass.config.path("custom_sentences", language_variant)
        )
        if custom_sentences_dir.is_dir():
            for custom_sentences_path in custom_sentences_dir.rglob("*.yaml"):
                with custom_sentences_path.open(
                    encoding="utf-8"
                ) as custom_sentences_file:
                    # Merge custom sentences
                    if not isinstance(
                        custom_sentences_yaml := yaml.safe_load(custom_sentences_file),
                        dict,
                    ):
                        _LOGGER.warning(
                            "Custom sentences file does not match expected format path=%s",
                            custom_sentences_file.name,
                        )
                        continue

                    # Add metadata so we can identify custom sentences in the debugger
                    custom_intents_dict = custom_sentences_yaml.get("intents", {})
                    for intent_dict in custom_intents_dict.values():
                        intent_data_list = intent_dict.get("data", [])
                        for intent_data in intent_data_list:
                            sentence_metadata = intent_data.get("metadata", {})
                            sentence_metadata[METADATA_CUSTOM_SENTENCE] = True
                            sentence_metadata[METADATA_CUSTOM_FILE] = str(
                                custom_sentences_path.relative_to(
                                    custom_sentences_dir.parent
                                )
                            )
                            intent_data["metadata"] = sentence_metadata

                    merge_dict(intents_dict, custom_sentences_yaml)

                _LOGGER.debug(
                    "Loaded custom sentences language=%s (%s), path=%s",
                    language,
                    language_variant,
                    custom_sentences_path,
                )

        # Load sentences from HA config for default language only
        if self._config_intents and (
            self.hass.config.language in (language, language_variant)
        ):
            hass_config_path = self.hass.config.path()
            merge_dict(
                intents_dict,
                {
                    "intents": {
                        intent_name: {
                            "data": [
                                {
                                    "sentences": sentences,
                                    "metadata": {
                                        METADATA_CUSTOM_SENTENCE: True,
                                        METADATA_CUSTOM_FILE: hass_config_path,
                                    },
                                }
                            ]
                        }
                        for intent_name, sentences in self._config_intents.items()
                    }
                },
            )
            _LOGGER.debug(
                "Loaded intents from configuration.yaml",
            )

        if not intents_dict:
            return None

        intents = Intents.from_dict(intents_dict)

        # Load responses
        responses_dict = intents_dict.get("responses", {})
        intent_responses = responses_dict.get("intents", {})
        error_responses = responses_dict.get("errors", {})

        return LanguageIntents(
            intents,
            intents_dict,
            intent_responses,
            error_responses,
            language_variant,
        )

    @core.callback
    def _async_clear_slot_list(self, event: core.Event[Any] | None = None) -> None:
        """Clear slot lists when a registry has changed."""
        # Two subscribers can be scheduled at same time
        _LOGGER.debug("Clearing slot lists")
        if self._unsub_clear_slot_list is None:
            return
        self._slot_lists = None
        self._exposed_names_trie = None
        self._unexposed_names_trie = None
        for unsub in self._unsub_clear_slot_list:
            unsub()
        self._unsub_clear_slot_list = None

        # Slot lists have changed, so we must clear the cache
        self._intent_cache.clear()

    @core.callback
    def _make_slot_lists(self) -> dict[str, SlotList]:
        """Create slot lists with areas and entity names/aliases."""
        if self._slot_lists is not None:
            return self._slot_lists

        start = time.monotonic()

        # Gather entity names, keeping track of exposed names.
        # We try intent recognition with only exposed names first, then all names.
        #
        # NOTE: We do not pass entity ids in here because multiple entities may
        # have the same name. The intent matcher doesn't gather all matching
        # values for a list, just the first. So we will need to match by name no
        # matter what.
        exposed_entity_names = list(self._get_entity_name_tuples(exposed=True))
        _LOGGER.debug("Exposed entities: %s", exposed_entity_names)

        # Expose all areas.
        areas = ar.async_get(self.hass)
        area_names = []
        for area in areas.async_list_areas():
            area_names.append((area.name, area.name))
            if not area.aliases:
                continue

            for alias in area.aliases:
                alias = alias.strip()
                if not alias:
                    continue

                area_names.append((alias, alias))

        # Expose all floors.
        floors = fr.async_get(self.hass)
        floor_names = []
        for floor in floors.async_list_floors():
            floor_names.append((floor.name, floor.name))
            if not floor.aliases:
                continue

            for alias in floor.aliases:
                alias = alias.strip()
                if not alias:
                    continue

                floor_names.append((alias, floor.name))

        # Build trie
        self._exposed_names_trie = Trie()
        name_list = TextSlotList.from_tuples(exposed_entity_names, allow_template=False)
        for name_value in name_list.values:
            assert isinstance(name_value.text_in, TextChunk)
            name_text = name_value.text_in.text.strip().lower()
            self._exposed_names_trie.insert(name_text, name_value)

        self._slot_lists = {
            "area": TextSlotList.from_tuples(area_names, allow_template=False),
            "name": name_list,
            "floor": TextSlotList.from_tuples(floor_names, allow_template=False),
        }

        self._listen_clear_slot_list()

        _LOGGER.debug(
            "Created slot lists in %.2f seconds",
            time.monotonic() - start,
        )

        return self._slot_lists

    def _make_intent_context(
        self, user_input: ConversationInput
    ) -> dict[str, Any] | None:
        """Return intent recognition context for user input."""
        if not user_input.device_id:
            return None

        device_area = self._get_device_area(user_input.device_id)
        if device_area is None:
            return None

        return {"area": {"value": device_area.name, "text": device_area.name}}

    def _get_device_area(self, device_id: str | None) -> ar.AreaEntry | None:
        """Return area object for given device identifier."""
        if device_id is None:
            return None

        devices = dr.async_get(self.hass)
        device = devices.async_get(device_id)
        if (device is None) or (device.area_id is None):
            return None

        areas = ar.async_get(self.hass)

        return areas.async_get_area(device.area_id)

    def _get_error_text(
        self,
        error_key: ErrorKey | str,
        lang_intents: LanguageIntents | None,
        **response_args,
    ) -> str:
        """Get response error text by type."""
        if lang_intents is None:
            return _DEFAULT_ERROR_TEXT

        if isinstance(error_key, ErrorKey):
            response_key = error_key.value
        else:
            response_key = error_key

        response_str = (
            lang_intents.error_responses.get(response_key) or _DEFAULT_ERROR_TEXT
        )
        response_template = template.Template(response_str, self.hass)

        return response_template.async_render(response_args)

    @core.callback
    def register_trigger(
        self,
        sentences: list[str],
        callback: TRIGGER_CALLBACK_TYPE,
    ) -> core.CALLBACK_TYPE:
        """Register a list of sentences that will trigger a callback when recognized."""
        trigger_data = TriggerData(sentences=sentences, callback=callback)
        self.trigger_sentences.append(trigger_data)

        # Force rebuild on next use
        self._trigger_intents = None

        return functools.partial(self._unregister_trigger, trigger_data)

    @core.callback
    def _rebuild_trigger_intents(self) -> None:
        """Rebuild the HassIL intents object from the current trigger sentences."""
        intents_dict = {
            "language": self.hass.config.language,
            "intents": {
                # Use trigger data index as a virtual intent name for HassIL.
                # This works because the intents are rebuilt on every
                # register/unregister.
                str(trigger_id): {"data": [{"sentences": trigger_data.sentences}]}
                for trigger_id, trigger_data in enumerate(self.trigger_sentences)
            },
        }

        trigger_intents = Intents.from_dict(intents_dict)

        # Assume slot list references are wildcards
        wildcard_names: set[str] = set()
        for trigger_intent in trigger_intents.intents.values():
            for intent_data in trigger_intent.data:
                for sentence in intent_data.sentences:
                    _collect_list_references(sentence, wildcard_names)

        for wildcard_name in wildcard_names:
            trigger_intents.slot_lists[wildcard_name] = WildcardSlotList(wildcard_name)

        self._trigger_intents = trigger_intents

        _LOGGER.debug("Rebuilt trigger intents: %s", intents_dict)

    @core.callback
    def _unregister_trigger(self, trigger_data: TriggerData) -> None:
        """Unregister a set of trigger sentences."""
        self.trigger_sentences.remove(trigger_data)

        # Force rebuild on next use
        self._trigger_intents = None

    async def async_recognize_sentence_trigger(
        self, user_input: ConversationInput
    ) -> SentenceTriggerResult | None:
        """Try to match sentence against registered trigger sentences.

        Calls the registered callbacks if there's a match and returns a sentence
        trigger result.
        """
        if not self.trigger_sentences:
            # No triggers registered
            return None

        if self._trigger_intents is None:
            # Need to rebuild intents before matching
            self._rebuild_trigger_intents()

        assert self._trigger_intents is not None

        matched_triggers: dict[int, RecognizeResult] = {}
        matched_template: str | None = None
        for result in recognize_all(user_input.text, self._trigger_intents):
            if result.intent_sentence is not None:
                matched_template = result.intent_sentence.text

            trigger_id = int(result.intent.name)
            if trigger_id in matched_triggers:
                # Already matched a sentence from this trigger
                break

            matched_triggers[trigger_id] = result

        if not matched_triggers:
            # Sentence did not match any trigger sentences
            return None

        _LOGGER.debug(
            "'%s' matched %s trigger(s): %s",
            user_input.text,
            len(matched_triggers),
            list(matched_triggers),
        )

        return SentenceTriggerResult(
            user_input.text, matched_template, matched_triggers
        )

    async def _handle_trigger_result(
        self, result: SentenceTriggerResult, user_input: ConversationInput
    ) -> str:
        """Run sentence trigger callbacks and return response text."""

        # Gather callback responses in parallel
        trigger_callbacks = [
            self.trigger_sentences[trigger_id].callback(user_input, trigger_result)
            for trigger_id, trigger_result in result.matched_triggers.items()
        ]

        # Use first non-empty result as response.
        #
        # There may be multiple copies of a trigger running when editing in
        # the UI, so it's critical that we filter out empty responses here.
        response_text = ""
        response_set_by_trigger = False
        for trigger_future in asyncio.as_completed(trigger_callbacks):
            trigger_response = await trigger_future
            if trigger_response is None:
                continue

            response_text = trigger_response
            response_set_by_trigger = True
            break

        if response_set_by_trigger:
            # Response was explicitly set to empty
            response_text = response_text or ""
        elif not response_text:
            # Use translated acknowledgment for pipeline language
            language = user_input.language or self.hass.config.language
            translations = await translation.async_get_translations(
                self.hass, language, DOMAIN, [DOMAIN]
            )
            response_text = translations.get(
                f"component.{DOMAIN}.conversation.agent.done", "Done"
            )

        return response_text

    async def async_handle_sentence_triggers(
        self, user_input: ConversationInput
    ) -> str | None:
        """Try to input sentence against sentence triggers and return response text.

        Returns None if no match occurred.
        """
        if trigger_result := await self.async_recognize_sentence_trigger(user_input):
            return await self._handle_trigger_result(trigger_result, user_input)

        return None

    async def async_handle_intents(
        self,
        user_input: ConversationInput,
    ) -> intent.IntentResponse | None:
        """Try to match sentence against registered intents and return response.

        Only performs strict matching with exposed entities and exact wording.
        Returns None if no match occurred.
        """
        result = await self.async_recognize_intent(user_input, strict_intents_only=True)
        if not isinstance(result, RecognizeResult):
            # No error message on failed match
            return None

        conversation_result = await self._async_process_intent_result(
            result, user_input
        )
        return conversation_result.response


def _make_error_result(
    language: str,
    error_code: intent.IntentResponseErrorCode,
    response_text: str,
    conversation_id: str | None = None,
) -> ConversationResult:
    """Create conversation result with error code and text."""
    response = intent.IntentResponse(language=language)
    response.async_set_error(error_code, response_text)
    return ConversationResult(response, conversation_id)


def _get_unmatched_response(result: RecognizeResult) -> tuple[ErrorKey, dict[str, Any]]:
    """Get key and template arguments for error when there are unmatched intent entities/slots."""

    # Filter out non-text and missing context entities
    unmatched_text: dict[str, str] = {
        key: entity.text.strip()
        for key, entity in result.unmatched_entities.items()
        if isinstance(entity, UnmatchedTextEntity) and entity.text != MISSING_ENTITY
    }

    if unmatched_area := unmatched_text.get("area"):
        # area only
        return ErrorKey.NO_AREA, {"area": unmatched_area}

    if unmatched_floor := unmatched_text.get("floor"):
        # floor only
        return ErrorKey.NO_FLOOR, {"floor": unmatched_floor}

    # Area may still have matched
    matched_area: str | None = None
    if matched_area_entity := result.entities.get("area"):
        matched_area = matched_area_entity.text.strip()

    matched_floor: str | None = None
    if matched_floor_entity := result.entities.get("floor"):
        matched_floor = matched_floor_entity.text.strip()

    if unmatched_name := unmatched_text.get("name"):
        if matched_area:
            # device in area
            return ErrorKey.NO_ENTITY_IN_AREA, {
                "entity": unmatched_name,
                "area": matched_area,
            }
        if matched_floor:
            # device on floor
            return ErrorKey.NO_ENTITY_IN_FLOOR, {
                "entity": unmatched_name,
                "floor": matched_floor,
            }

        # device only
        return ErrorKey.NO_ENTITY, {"entity": unmatched_name}

    # Default error
    return ErrorKey.NO_INTENT, {}


def _get_match_error_response(
    hass: core.HomeAssistant,
    match_error: intent.MatchFailedError,
) -> tuple[ErrorKey, dict[str, Any]]:
    """Return key and template arguments for error when target matching fails."""

    constraints, result = match_error.constraints, match_error.result
    reason = result.no_match_reason

    if (
        reason
        in (intent.MatchFailedReason.DEVICE_CLASS, intent.MatchFailedReason.DOMAIN)
    ) and constraints.device_classes:
        device_class = next(iter(constraints.device_classes))  # first device class
        if constraints.area_name:
            # device_class in area
            return ErrorKey.NO_DEVICE_CLASS_IN_AREA, {
                "device_class": device_class,
                "area": constraints.area_name,
            }

        # device_class only
        return ErrorKey.NO_DEVICE_CLASS, {"device_class": device_class}

    if (reason == intent.MatchFailedReason.DOMAIN) and constraints.domains:
        domain = next(iter(constraints.domains))  # first domain
        if constraints.area_name:
            # domain in area
            return ErrorKey.NO_DOMAIN_IN_AREA, {
                "domain": domain,
                "area": constraints.area_name,
            }

        if constraints.floor_name:
            # domain in floor
            return ErrorKey.NO_DOMAIN_IN_FLOOR, {
                "domain": domain,
                "floor": constraints.floor_name,
            }

        # domain only
        return ErrorKey.NO_DOMAIN, {"domain": domain}

    if reason == intent.MatchFailedReason.DUPLICATE_NAME:
        if constraints.floor_name:
            # duplicate on floor
            return ErrorKey.DUPLICATE_ENTITIES_IN_FLOOR, {
                "entity": result.no_match_name,
                "floor": constraints.floor_name,
            }

        if constraints.area_name:
            # duplicate on area
            return ErrorKey.DUPLICATE_ENTITIES_IN_AREA, {
                "entity": result.no_match_name,
                "area": constraints.area_name,
            }

        return ErrorKey.DUPLICATE_ENTITIES, {"entity": result.no_match_name}

    if reason == intent.MatchFailedReason.INVALID_AREA:
        # Invalid area name
        return ErrorKey.NO_AREA, {"area": result.no_match_name}

    if reason == intent.MatchFailedReason.INVALID_FLOOR:
        # Invalid floor name
        return ErrorKey.NO_FLOOR, {"floor": result.no_match_name}

    if reason == intent.MatchFailedReason.FEATURE:
        # Feature not supported by entity
        return ErrorKey.FEATURE_NOT_SUPPORTED, {}

    if reason == intent.MatchFailedReason.STATE:
        # Entity is not in correct state
        assert constraints.states
        state = next(iter(constraints.states))
        if constraints.domains:
            # Translate if domain is available
            domain = next(iter(constraints.domains))
            state = translation.async_translate_state(
                hass, state, domain, None, None, None
            )

        return ErrorKey.ENTITY_WRONG_STATE, {"state": state}

    if reason == intent.MatchFailedReason.ASSISTANT:
        # Not exposed
        if constraints.name:
            if constraints.area_name:
                return ErrorKey.NO_ENTITY_IN_AREA_EXPOSED, {
                    "entity": constraints.name,
                    "area": constraints.area_name,
                }
            if constraints.floor_name:
                return ErrorKey.NO_ENTITY_IN_FLOOR_EXPOSED, {
                    "entity": constraints.name,
                    "floor": constraints.floor_name,
                }
            return ErrorKey.NO_ENTITY_EXPOSED, {"entity": constraints.name}

        if constraints.device_classes:
            device_class = next(iter(constraints.device_classes))

            if constraints.area_name:
                return ErrorKey.NO_DEVICE_CLASS_IN_AREA_EXPOSED, {
                    "device_class": device_class,
                    "area": constraints.area_name,
                }
            if constraints.floor_name:
                return ErrorKey.NO_DEVICE_CLASS_IN_FLOOR_EXPOSED, {
                    "device_class": device_class,
                    "floor": constraints.floor_name,
                }
            return ErrorKey.NO_DEVICE_CLASS_EXPOSED, {"device_class": device_class}

        if constraints.domains:
            domain = next(iter(constraints.domains))

            if constraints.area_name:
                return ErrorKey.NO_DOMAIN_IN_AREA_EXPOSED, {
                    "domain": domain,
                    "area": constraints.area_name,
                }
            if constraints.floor_name:
                return ErrorKey.NO_DOMAIN_IN_FLOOR_EXPOSED, {
                    "domain": domain,
                    "floor": constraints.floor_name,
                }
            return ErrorKey.NO_DOMAIN_EXPOSED, {"domain": domain}

    # Default error
    return ErrorKey.NO_INTENT, {}


def _collect_list_references(expression: Expression, list_names: set[str]) -> None:
    """Collect list reference names recursively."""
    if isinstance(expression, Sequence):
        seq: Sequence = expression
        for item in seq.items:
            _collect_list_references(item, list_names)
    elif isinstance(expression, ListReference):
        # {list}
        list_ref: ListReference = expression
        list_names.add(list_ref.slot_name)