core/homeassistant/components/nest/camera.py

330 lines
12 KiB
Python

"""Support for Google Nest SDM Cameras."""
from __future__ import annotations
from abc import ABC
import asyncio
from collections.abc import Awaitable, Callable
import datetime
import functools
import logging
from pathlib import Path
from google_nest_sdm.camera_traits import (
CameraLiveStreamTrait,
RtspStream,
StreamingProtocol,
WebRtcStream,
)
from google_nest_sdm.device import Device
from google_nest_sdm.exceptions import ApiException
from webrtc_models import RTCIceCandidateInit
from homeassistant.components.camera import (
Camera,
CameraEntityFeature,
WebRTCAnswer,
WebRTCClientConfiguration,
WebRTCSendMessage,
)
from homeassistant.components.stream import CONF_EXTRA_PART_WAIT_TIME
from homeassistant.core import HomeAssistant, callback
from homeassistant.exceptions import HomeAssistantError
from homeassistant.helpers.entity_platform import AddEntitiesCallback
from homeassistant.helpers.event import async_track_point_in_utc_time
from homeassistant.util.dt import utcnow
from .device_info import NestDeviceInfo
from .types import NestConfigEntry
_LOGGER = logging.getLogger(__name__)
PLACEHOLDER = Path(__file__).parent / "placeholder.png"
# Used to schedule an alarm to refresh the stream before expiration
STREAM_EXPIRATION_BUFFER = datetime.timedelta(seconds=30)
# Refresh streams with a bounded interval and backoff on failure
MIN_REFRESH_BACKOFF_INTERVAL = datetime.timedelta(minutes=1)
MAX_REFRESH_BACKOFF_INTERVAL = datetime.timedelta(minutes=10)
BACKOFF_MULTIPLIER = 1.5
async def async_setup_entry(
hass: HomeAssistant, entry: NestConfigEntry, async_add_entities: AddEntitiesCallback
) -> None:
"""Set up the cameras."""
entities: list[NestCameraBaseEntity] = []
for device in entry.runtime_data.device_manager.devices.values():
if (live_stream := device.traits.get(CameraLiveStreamTrait.NAME)) is None:
continue
if StreamingProtocol.WEB_RTC in live_stream.supported_protocols:
entities.append(NestWebRTCEntity(device))
elif StreamingProtocol.RTSP in live_stream.supported_protocols:
entities.append(NestRTSPEntity(device))
async_add_entities(entities)
class StreamRefresh:
"""Class that will refresh an expiring stream.
This class will schedule an alarm for the next expiration time of a stream.
When the alarm fires, it runs the provided `refresh_cb` to extend the
lifetime of the stream and return a new expiration time.
A simple backoff will be applied when the refresh callback fails.
"""
def __init__(
self,
hass: HomeAssistant,
expires_at: datetime.datetime,
refresh_cb: Callable[[], Awaitable[datetime.datetime | None]],
) -> None:
"""Initialize StreamRefresh."""
self._hass = hass
self._unsub: Callable[[], None] | None = None
self._min_refresh_interval = MIN_REFRESH_BACKOFF_INTERVAL
self._refresh_cb = refresh_cb
self._schedule_stream_refresh(expires_at - STREAM_EXPIRATION_BUFFER)
def unsub(self) -> None:
"""Invalidates the stream."""
if self._unsub:
self._unsub()
async def _handle_refresh(self, _: datetime.datetime) -> None:
"""Alarm that fires to check if the stream should be refreshed."""
self._unsub = None
try:
expires_at = await self._refresh_cb()
except ApiException as err:
_LOGGER.debug("Failed to refresh stream: %s", err)
# Increase backoff until the max backoff interval is reached
self._min_refresh_interval = min(
self._min_refresh_interval * BACKOFF_MULTIPLIER,
MAX_REFRESH_BACKOFF_INTERVAL,
)
refresh_time = utcnow() + self._min_refresh_interval
else:
if expires_at is None:
return
self._min_refresh_interval = MIN_REFRESH_BACKOFF_INTERVAL # Reset backoff
# Defend against invalid stream expiration time in the past
refresh_time = max(
expires_at - STREAM_EXPIRATION_BUFFER,
utcnow() + self._min_refresh_interval,
)
self._schedule_stream_refresh(refresh_time)
def _schedule_stream_refresh(self, refresh_time: datetime.datetime) -> None:
"""Schedules an alarm to refresh any streams before expiration."""
_LOGGER.debug("Scheduling stream refresh for %s", refresh_time)
self._unsub = async_track_point_in_utc_time(
self._hass,
self._handle_refresh,
refresh_time,
)
class NestCameraBaseEntity(Camera, ABC):
"""Devices that support cameras."""
_attr_has_entity_name = True
_attr_name = None
_attr_is_streaming = True
_attr_supported_features = CameraEntityFeature.STREAM
def __init__(self, device: Device) -> None:
"""Initialize the camera."""
super().__init__()
self._device = device
nest_device_info = NestDeviceInfo(device)
self._attr_device_info = nest_device_info.device_info
self._attr_brand = nest_device_info.device_brand
self._attr_model = nest_device_info.device_model
self.stream_options[CONF_EXTRA_PART_WAIT_TIME] = 3
# The API "name" field is a unique device identifier.
self._attr_unique_id = f"{self._device.name}-camera"
async def async_added_to_hass(self) -> None:
"""Run when entity is added to register update signal handler."""
self.async_on_remove(
self._device.add_update_listener(self.async_write_ha_state)
)
class NestRTSPEntity(NestCameraBaseEntity):
"""Nest cameras that use RTSP."""
_rtsp_stream: RtspStream | None = None
_rtsp_live_stream_trait: CameraLiveStreamTrait
def __init__(self, device: Device) -> None:
"""Initialize the camera."""
super().__init__(device)
self._create_stream_url_lock = asyncio.Lock()
self._rtsp_live_stream_trait = device.traits[CameraLiveStreamTrait.NAME]
self._refresh_unsub: Callable[[], None] | None = None
@property
def use_stream_for_stills(self) -> bool:
"""Always use the RTSP stream to generate snapshots."""
return True
@property
def available(self) -> bool:
"""Return True if entity is available."""
# Cameras are marked unavailable on stream errors in #54659 however nest
# streams have a high error rate (#60353). Given nest streams are so flaky,
# marking the stream unavailable has other side effects like not showing
# the camera image which sometimes are still able to work. Until the
# streams are fixed, just leave the streams as available.
return True
async def stream_source(self) -> str | None:
"""Return the source of the stream."""
async with self._create_stream_url_lock:
if not self._rtsp_stream:
_LOGGER.debug("Fetching stream url")
try:
self._rtsp_stream = (
await self._rtsp_live_stream_trait.generate_rtsp_stream()
)
except ApiException as err:
raise HomeAssistantError(f"Nest API error: {err}") from err
refresh = StreamRefresh(
self.hass,
self._rtsp_stream.expires_at,
self._async_refresh_stream,
)
self._refresh_unsub = refresh.unsub
assert self._rtsp_stream
if self._rtsp_stream.expires_at < utcnow():
_LOGGER.warning("Stream already expired")
return self._rtsp_stream.rtsp_stream_url
async def _async_refresh_stream(self) -> datetime.datetime | None:
"""Refresh stream to extend expiration time."""
if not self._rtsp_stream:
return None
_LOGGER.debug("Extending RTSP stream")
try:
self._rtsp_stream = await self._rtsp_stream.extend_rtsp_stream()
except ApiException as err:
_LOGGER.debug("Failed to extend stream: %s", err)
# Next attempt to catch a url will get a new one
self._rtsp_stream = None
if self.stream:
await self.stream.stop()
self.stream = None
return None
# Update the stream worker with the latest valid url
if self.stream:
self.stream.update_source(self._rtsp_stream.rtsp_stream_url)
return self._rtsp_stream.expires_at
async def async_will_remove_from_hass(self) -> None:
"""Invalidates the RTSP token when unloaded."""
await super().async_will_remove_from_hass()
if self._refresh_unsub is not None:
self._refresh_unsub()
if self._rtsp_stream:
try:
await self._rtsp_stream.stop_stream()
except ApiException as err:
_LOGGER.debug("Error stopping stream: %s", err)
self._rtsp_stream = None
class NestWebRTCEntity(NestCameraBaseEntity):
"""Nest cameras that use WebRTC."""
def __init__(self, device: Device) -> None:
"""Initialize the camera."""
super().__init__(device)
self._webrtc_sessions: dict[str, WebRtcStream] = {}
self._refresh_unsub: dict[str, Callable[[], None]] = {}
async def _async_refresh_stream(self, session_id: str) -> datetime.datetime | None:
"""Refresh stream to extend expiration time."""
if not (webrtc_stream := self._webrtc_sessions.get(session_id)):
return None
_LOGGER.debug("Extending WebRTC stream %s", webrtc_stream.media_session_id)
webrtc_stream = await webrtc_stream.extend_stream()
if session_id in self._webrtc_sessions:
self._webrtc_sessions[session_id] = webrtc_stream
return webrtc_stream.expires_at
return None
async def async_camera_image(
self, width: int | None = None, height: int | None = None
) -> bytes | None:
"""Return a placeholder image for WebRTC cameras that don't support snapshots."""
return await self.hass.async_add_executor_job(self.placeholder_image)
@classmethod
@functools.cache
def placeholder_image(cls) -> bytes:
"""Return placeholder image to use when no stream is available."""
return PLACEHOLDER.read_bytes()
async def async_handle_async_webrtc_offer(
self, offer_sdp: str, session_id: str, send_message: WebRTCSendMessage
) -> None:
"""Return the source of the stream."""
trait: CameraLiveStreamTrait = self._device.traits[CameraLiveStreamTrait.NAME]
try:
stream = await trait.generate_web_rtc_stream(offer_sdp)
except ApiException as err:
raise HomeAssistantError(f"Nest API error: {err}") from err
_LOGGER.debug(
"Started WebRTC session %s, %s", session_id, stream.media_session_id
)
self._webrtc_sessions[session_id] = stream
send_message(WebRTCAnswer(stream.answer_sdp))
refresh = StreamRefresh(
self.hass,
stream.expires_at,
functools.partial(self._async_refresh_stream, session_id),
)
self._refresh_unsub[session_id] = refresh.unsub
async def async_on_webrtc_candidate(
self, session_id: str, candidate: RTCIceCandidateInit
) -> None:
"""Ignore WebRTC candidates for Nest cloud based cameras."""
return
@callback
def close_webrtc_session(self, session_id: str) -> None:
"""Close a WebRTC session."""
if (stream := self._webrtc_sessions.pop(session_id, None)) is not None:
_LOGGER.debug(
"Closing WebRTC session %s, %s", session_id, stream.media_session_id
)
unsub = self._refresh_unsub.pop(session_id)
unsub()
async def stop_stream() -> None:
try:
await stream.stop_stream()
except ApiException as err:
_LOGGER.debug("Error stopping stream: %s", err)
self.hass.async_create_task(stop_stream())
super().close_webrtc_session(session_id)
@callback
def _async_get_webrtc_client_configuration(self) -> WebRTCClientConfiguration:
"""Return the WebRTC client configuration adjustable per integration."""
return WebRTCClientConfiguration(data_channel="dataSendChannel")
async def async_will_remove_from_hass(self) -> None:
"""Invalidates the RTSP token when unloaded."""
await super().async_will_remove_from_hass()
for session_id in list(self._webrtc_sessions.keys()):
self.close_webrtc_session(session_id)