update_coordinator.py

"""Helpers to help coordinate updates."""

from __future__ import annotations

from abc import abstractmethod
import asyncio
from collections.abc import Awaitable, Callable, Coroutine, Generator
from datetime import datetime, timedelta
import logging
from random import randint
from time import monotonic
from typing import Any, Generic, Protocol
import urllib.error

import aiohttp
from propcache import cached_property
import requests
from typing_extensions import TypeVar

from homeassistant import config_entries
from homeassistant.const import EVENT_HOMEASSISTANT_STOP
from homeassistant.core import CALLBACK_TYPE, Event, HomeAssistant, callback
from homeassistant.exceptions import (
    ConfigEntryAuthFailed,
    ConfigEntryError,
    ConfigEntryNotReady,
)
from homeassistant.util.dt import utcnow

from . import entity, event
from .debounce import Debouncer
from .frame import report_usage
from .typing import UNDEFINED, UndefinedType

REQUEST_REFRESH_DEFAULT_COOLDOWN = 10
REQUEST_REFRESH_DEFAULT_IMMEDIATE = True

_DataT = TypeVar("_DataT", default=dict[str, Any])
_DataUpdateCoordinatorT = TypeVar(
    "_DataUpdateCoordinatorT",
    bound="DataUpdateCoordinator[Any]",
    default="DataUpdateCoordinator[dict[str, Any]]",
)


class UpdateFailed(Exception):
    """Raised when an update has failed."""


class BaseDataUpdateCoordinatorProtocol(Protocol):
    """Base protocol type for DataUpdateCoordinator."""

    @callback
    def async_add_listener(
        self, update_callback: CALLBACK_TYPE, context: Any = None
    ) -> Callable[[], None]:
        """Listen for data updates."""


class DataUpdateCoordinator(BaseDataUpdateCoordinatorProtocol, Generic[_DataT]):
    """Class to manage fetching data from single endpoint.

    Setting :attr:`always_update` to ``False`` will cause coordinator to only
    callback listeners when data has changed. This requires that the data
    implements ``__eq__`` or uses a python object that already does.
    """

    def __init__(
        self,
        hass: HomeAssistant,
        logger: logging.Logger,
        *,
        config_entry: config_entries.ConfigEntry | None | UndefinedType = UNDEFINED,
        name: str,
        update_interval: timedelta | None = None,
        update_method: Callable[[], Awaitable[_DataT]] | None = None,
        setup_method: Callable[[], Awaitable[None]] | None = None,
        request_refresh_debouncer: Debouncer[Coroutine[Any, Any, None]] | None = None,
        always_update: bool = True,
    ) -> None:
        """Initialize global data updater."""
        self.hass = hass
        self.logger = logger
        self.name = name
        self.update_method = update_method
        self.setup_method = setup_method
        self._update_interval_seconds: float | None = None
        self.update_interval = update_interval
        self._shutdown_requested = False
        if config_entry is UNDEFINED:
            self.config_entry = config_entries.current_entry.get()
            # This should be deprecated once all core integrations are updated
            # to pass in the config entry explicitly.
        else:
            self.config_entry = config_entry
        self.always_update = always_update

        # It's None before the first successful update.
        # Components should call async_config_entry_first_refresh
        # to make sure the first update was successful.
        # Set type to just T to remove annoying checks that data is not None
        # when it was already checked during setup.
        self.data: _DataT = None  # type: ignore[assignment]

        # Pick a random microsecond in range 0.05..0.50 to stagger the refreshes
        # and avoid a thundering herd.
        self._microsecond = (
            randint(event.RANDOM_MICROSECOND_MIN, event.RANDOM_MICROSECOND_MAX) / 10**6
        )

        self._listeners: dict[CALLBACK_TYPE, tuple[CALLBACK_TYPE, object | None]] = {}
        self._unsub_refresh: CALLBACK_TYPE | None = None
        self._unsub_shutdown: CALLBACK_TYPE | None = None
        self._request_refresh_task: asyncio.TimerHandle | None = None
        self.last_update_success = True
        self.last_exception: Exception | None = None

        if request_refresh_debouncer is None:
            request_refresh_debouncer = Debouncer(
                hass,
                logger,
                cooldown=REQUEST_REFRESH_DEFAULT_COOLDOWN,
                immediate=REQUEST_REFRESH_DEFAULT_IMMEDIATE,
                function=self.async_refresh,
            )
        else:
            request_refresh_debouncer.function = self.async_refresh

        self._debounced_refresh = request_refresh_debouncer

        if self.config_entry:
            self.config_entry.async_on_unload(self.async_shutdown)

    async def async_register_shutdown(self) -> None:
        """Register shutdown on HomeAssistant stop.

        Should only be used by coordinators that are not linked to a config entry.
        """
        if self.config_entry:
            raise RuntimeError("This should only be used outside of config entries.")

        async def _on_hass_stop(_: Event) -> None:
            """Shutdown coordinator on HomeAssistant stop."""
            await self.async_shutdown()

        self._unsub_shutdown = self.hass.bus.async_listen_once(
            EVENT_HOMEASSISTANT_STOP, _on_hass_stop
        )

    @callback
    def async_add_listener(
        self, update_callback: CALLBACK_TYPE, context: Any = None
    ) -> Callable[[], None]:
        """Listen for data updates."""
        schedule_refresh = not self._listeners

        @callback
        def remove_listener() -> None:
            """Remove update listener."""
            self._listeners.pop(remove_listener)
            if not self._listeners:
                self._unschedule_refresh()

        self._listeners[remove_listener] = (update_callback, context)

        # This is the first listener, set up interval.
        if schedule_refresh:
            self._schedule_refresh()

        return remove_listener

    @callback
    def async_update_listeners(self) -> None:
        """Update all registered listeners."""
        for update_callback, _ in list(self._listeners.values()):
            update_callback()

    async def async_shutdown(self) -> None:
        """Cancel any scheduled call, and ignore new runs."""
        self._shutdown_requested = True
        self._async_unsub_refresh()
        self._async_unsub_shutdown()
        self._debounced_refresh.async_shutdown()

    @callback
    def _unschedule_refresh(self) -> None:
        """Unschedule any pending refresh since there is no longer any listeners."""
        self._async_unsub_refresh()
        self._debounced_refresh.async_cancel()

    def async_contexts(self) -> Generator[Any]:
        """Return all registered contexts."""
        yield from (
            context for _, context in self._listeners.values() if context is not None
        )

    def _async_unsub_refresh(self) -> None:
        """Cancel any scheduled call."""
        if self._unsub_refresh:
            self._unsub_refresh()
            self._unsub_refresh = None

    def _async_unsub_shutdown(self) -> None:
        """Cancel any scheduled call."""
        if self._unsub_shutdown:
            self._unsub_shutdown()
            self._unsub_shutdown = None

    @property
    def update_interval(self) -> timedelta | None:
        """Interval between updates."""
        return self._update_interval

    @update_interval.setter
    def update_interval(self, value: timedelta | None) -> None:
        """Set interval between updates."""
        self._update_interval = value
        self._update_interval_seconds = value.total_seconds() if value else None

    @callback
    def _schedule_refresh(self) -> None:
        """Schedule a refresh."""
        if self._update_interval_seconds is None:
            return

        if self.config_entry and self.config_entry.pref_disable_polling:
            return

        # We do not cancel the debouncer here. If the refresh interval is shorter
        # than the debouncer cooldown, this would cause the debounce to never be called
        self._async_unsub_refresh()

        # We use loop.call_at because DataUpdateCoordinator does
        # not need an exact update interval which also avoids
        # calling dt_util.utcnow() on every update.
        hass = self.hass
        loop = hass.loop

        next_refresh = (
            int(loop.time()) + self._microsecond + self._update_interval_seconds
        )
        self._unsub_refresh = loop.call_at(
            next_refresh, self.__wrap_handle_refresh_interval
        ).cancel

    @callback
    def __wrap_handle_refresh_interval(self) -> None:
        """Handle a refresh interval occurrence."""
        if self.config_entry:
            self.config_entry.async_create_background_task(
                self.hass,
                self._handle_refresh_interval(),
                name=f"{self.name} - {self.config_entry.title} - refresh",
                eager_start=True,
            )
        else:
            self.hass.async_create_background_task(
                self._handle_refresh_interval(),
                name=f"{self.name} - refresh",
                eager_start=True,
            )

    async def _handle_refresh_interval(self, _now: datetime | None = None) -> None:
        """Handle a refresh interval occurrence."""
        self._unsub_refresh = None
        await self._async_refresh(log_failures=True, scheduled=True)

    async def async_request_refresh(self) -> None:
        """Request a refresh.

        Refresh will wait a bit to see if it can batch them.
        """
        await self._debounced_refresh.async_call()

    async def _async_update_data(self) -> _DataT:
        """Fetch the latest data from the source."""
        if self.update_method is None:
            raise NotImplementedError("Update method not implemented")
        return await self.update_method()

    async def async_config_entry_first_refresh(self) -> None:
        """Refresh data for the first time when a config entry is setup.

        Will automatically raise ConfigEntryNotReady if the refresh
        fails. Additionally logging is handled by config entry setup
        to ensure that multiple retries do not cause log spam.
        """
        if self.config_entry is None:
            report_usage(
                "uses `async_config_entry_first_refresh`, which is only supported "
                "for coordinators with a config entry and will stop working in "
                "Home Assistant 2025.11"
            )
        elif (
            self.config_entry.state
            is not config_entries.ConfigEntryState.SETUP_IN_PROGRESS
        ):
            report_usage(
                "uses `async_config_entry_first_refresh`, which is only supported "
                f"when entry state is {config_entries.ConfigEntryState.SETUP_IN_PROGRESS}, "
                f"but it is in state {self.config_entry.state}, "
                "This will stop working in Home Assistant 2025.11",
            )
        if await self.__wrap_async_setup():
            await self._async_refresh(
                log_failures=False, raise_on_auth_failed=True, raise_on_entry_error=True
            )
            if self.last_update_success:
                return
        ex = ConfigEntryNotReady()
        ex.__cause__ = self.last_exception
        raise ex

    async def __wrap_async_setup(self) -> bool:
        """Error handling for _async_setup."""
        try:
            await self._async_setup()
        except (
            TimeoutError,
            requests.exceptions.Timeout,
            aiohttp.ClientError,
            requests.exceptions.RequestException,
            urllib.error.URLError,
            UpdateFailed,
        ) as err:
            self.last_exception = err

        except (ConfigEntryError, ConfigEntryAuthFailed) as err:
            self.last_exception = err
            self.last_update_success = False
            raise

        except Exception as err:  # pylint: disable=broad-except
            self.last_exception = err
            self.logger.exception("Unexpected error fetching %s data", self.name)
        else:
            return True

        self.last_update_success = False
        return False

    async def _async_setup(self) -> None:
        """Set up the coordinator.

        Can be overwritten by integrations to load data or resources
        only once during the first refresh.
        """
        if self.setup_method is None:
            return None
        return await self.setup_method()

    async def async_refresh(self) -> None:
        """Refresh data and log errors."""
        await self._async_refresh(log_failures=True)

    async def _async_refresh(  # noqa: C901
        self,
        log_failures: bool = True,
        raise_on_auth_failed: bool = False,
        scheduled: bool = False,
        raise_on_entry_error: bool = False,
    ) -> None:
        """Refresh data."""
        self._async_unsub_refresh()
        self._debounced_refresh.async_cancel()

        if self._shutdown_requested or scheduled and self.hass.is_stopping:
            return

        if log_timing := self.logger.isEnabledFor(logging.DEBUG):
            start = monotonic()

        auth_failed = False
        previous_update_success = self.last_update_success
        previous_data = self.data

        try:
            self.data = await self._async_update_data()

        except (TimeoutError, requests.exceptions.Timeout) as err:
            self.last_exception = err
            if self.last_update_success:
                if log_failures:
                    self.logger.error("Timeout fetching %s data", self.name)
                self.last_update_success = False

        except (aiohttp.ClientError, requests.exceptions.RequestException) as err:
            self.last_exception = err
            if self.last_update_success:
                if log_failures:
                    self.logger.error("Error requesting %s data: %s", self.name, err)
                self.last_update_success = False

        except urllib.error.URLError as err:
            self.last_exception = err
            if self.last_update_success:
                if log_failures:
                    if err.reason == "timed out":
                        self.logger.error("Timeout fetching %s data", self.name)
                    else:
                        self.logger.error(
                            "Error requesting %s data: %s", self.name, err
                        )
                self.last_update_success = False

        except UpdateFailed as err:
            self.last_exception = err
            if self.last_update_success:
                if log_failures:
                    self.logger.error("Error fetching %s data: %s", self.name, err)
                self.last_update_success = False

        except ConfigEntryError as err:
            self.last_exception = err
            if self.last_update_success:
                if log_failures:
                    self.logger.error(
                        "Config entry setup failed while fetching %s data: %s",
                        self.name,
                        err,
                    )
                self.last_update_success = False
            if raise_on_entry_error:
                raise

        except ConfigEntryAuthFailed as err:
            auth_failed = True
            self.last_exception = err
            if self.last_update_success:
                if log_failures:
                    self.logger.error(
                        "Authentication failed while fetching %s data: %s",
                        self.name,
                        err,
                    )
                self.last_update_success = False
            if raise_on_auth_failed:
                raise

            if self.config_entry:
                self.config_entry.async_start_reauth(self.hass)
        except NotImplementedError as err:
            self.last_exception = err
            raise

        except Exception as err:
            self.last_exception = err
            self.last_update_success = False
            self.logger.exception("Unexpected error fetching %s data", self.name)

        else:
            if not self.last_update_success:
                self.last_update_success = True
                self.logger.info("Fetching %s data recovered", self.name)

        finally:
            if log_timing:
                self.logger.debug(
                    "Finished fetching %s data in %.3f seconds (success: %s)",
                    self.name,
                    monotonic() - start,  # pylint: disable=possibly-used-before-assignment
                    self.last_update_success,
                )
            if not auth_failed and self._listeners and not self.hass.is_stopping:
                self._schedule_refresh()

        self._async_refresh_finished()

        if not self.last_update_success and not previous_update_success:
            return

        if (
            self.always_update
            or self.last_update_success != previous_update_success
            or previous_data != self.data
        ):
            self.async_update_listeners()

    @callback
    def _async_refresh_finished(self) -> None:
        """Handle when a refresh has finished.

        Called when refresh is finished before listeners are updated.

        To be overridden by subclasses.
        """

    @callback
    def async_set_update_error(self, err: Exception) -> None:
        """Manually set an error, log the message and notify listeners."""
        self.last_exception = err
        if self.last_update_success:
            self.logger.error("Error requesting %s data: %s", self.name, err)
            self.last_update_success = False
            self.async_update_listeners()

    @callback
    def async_set_updated_data(self, data: _DataT) -> None:
        """Manually update data, notify listeners and reset refresh interval."""
        self._async_unsub_refresh()
        self._debounced_refresh.async_cancel()

        self.data = data
        self.last_update_success = True
        self.logger.debug(
            "Manually updated %s data",
            self.name,
        )

        if self._listeners:
            self._schedule_refresh()

        self.async_update_listeners()


class TimestampDataUpdateCoordinator(DataUpdateCoordinator[_DataT]):
    """DataUpdateCoordinator which keeps track of the last successful update."""

    last_update_success_time: datetime | None = None

    @callback
    def _async_refresh_finished(self) -> None:
        """Handle when a refresh has finished."""
        if self.last_update_success:
            self.last_update_success_time = utcnow()


class BaseCoordinatorEntity[
    _BaseDataUpdateCoordinatorT: BaseDataUpdateCoordinatorProtocol
](entity.Entity):
    """Base class for all Coordinator entities."""

    def __init__(
        self, coordinator: _BaseDataUpdateCoordinatorT, context: Any = None
    ) -> None:
        """Create the entity with a DataUpdateCoordinator."""
        self.coordinator = coordinator
        self.coordinator_context = context

    @cached_property
    def should_poll(self) -> bool:
        """No need to poll. Coordinator notifies entity of updates."""
        return False

    async def async_added_to_hass(self) -> None:
        """When entity is added to hass."""
        await super().async_added_to_hass()
        self.async_on_remove(
            self.coordinator.async_add_listener(
                self._handle_coordinator_update, self.coordinator_context
            )
        )

    @callback
    def _handle_coordinator_update(self) -> None:
        """Handle updated data from the coordinator."""
        self.async_write_ha_state()

    @abstractmethod
    async def async_update(self) -> None:
        """Update the entity.

        Only used by the generic entity update service.
        """


class CoordinatorEntity(BaseCoordinatorEntity[_DataUpdateCoordinatorT]):
    """A class for entities using DataUpdateCoordinator."""

    def __init__(
        self, coordinator: _DataUpdateCoordinatorT, context: Any = None
    ) -> None:
        """Create the entity with a DataUpdateCoordinator.

        Passthrough to BaseCoordinatorEntity.

        Necessary to bind TypeVar to correct scope.
        """
        super().__init__(coordinator, context)

    @property
    def available(self) -> bool:
        """Return if entity is available."""
        return self.coordinator.last_update_success

    async def async_update(self) -> None:
        """Update the entity.

        Only used by the generic entity update service.
        """
        # Ignore manual update requests if the entity is disabled
        if not self.enabled:
            return

        await self.coordinator.async_request_refresh()