core/homeassistant/helpers/service.py

"""Service calling related helpers."""
import asyncio
from functools import wraps
import logging
from typing import Callable

import voluptuous as vol

from homeassistant.auth.permissions.const import CAT_ENTITIES, POLICY_CONTROL
from homeassistant.const import (
    ATTR_ENTITY_ID, ENTITY_MATCH_ALL, ATTR_AREA_ID)
import homeassistant.core as ha
from homeassistant.exceptions import (
    HomeAssistantError, TemplateError, Unauthorized, UnknownUser)
from homeassistant.helpers import template, typing
from homeassistant.loader import async_get_integration, bind_hass
from homeassistant.util.yaml import load_yaml
import homeassistant.helpers.config_validation as cv
from homeassistant.util.async_ import run_coroutine_threadsafe
from homeassistant.helpers.typing import HomeAssistantType

CONF_SERVICE = 'service'
CONF_SERVICE_TEMPLATE = 'service_template'
CONF_SERVICE_ENTITY_ID = 'entity_id'
CONF_SERVICE_DATA = 'data'
CONF_SERVICE_DATA_TEMPLATE = 'data_template'

_LOGGER = logging.getLogger(__name__)

SERVICE_DESCRIPTION_CACHE = 'service_description_cache'


@bind_hass
def call_from_config(hass, config, blocking=False, variables=None,
                     validate_config=True):
    """Call a service based on a config hash."""
    run_coroutine_threadsafe(
        async_call_from_config(hass, config, blocking, variables,
                               validate_config), hass.loop).result()


@bind_hass
async def async_call_from_config(hass, config, blocking=False, variables=None,
                                 validate_config=True, context=None):
    """Call a service based on a config hash."""
    if validate_config:
        try:
            config = cv.SERVICE_SCHEMA(config)
        except vol.Invalid as ex:
            _LOGGER.error("Invalid config for calling service: %s", ex)
            return

    if CONF_SERVICE in config:
        domain_service = config[CONF_SERVICE]
    else:
        try:
            config[CONF_SERVICE_TEMPLATE].hass = hass
            domain_service = config[CONF_SERVICE_TEMPLATE].async_render(
                variables)
            domain_service = cv.service(domain_service)
        except TemplateError as ex:
            if blocking:
                raise
            _LOGGER.error('Error rendering service name template: %s', ex)
            return
        except vol.Invalid:
            if blocking:
                raise
            _LOGGER.error('Template rendered invalid service: %s',
                          domain_service)
            return

    domain, service_name = domain_service.split('.', 1)
    service_data = dict(config.get(CONF_SERVICE_DATA, {}))

    if CONF_SERVICE_DATA_TEMPLATE in config:
        try:
            template.attach(hass, config[CONF_SERVICE_DATA_TEMPLATE])
            service_data.update(template.render_complex(
                config[CONF_SERVICE_DATA_TEMPLATE], variables))
        except TemplateError as ex:
            _LOGGER.error('Error rendering data template: %s', ex)
            return

    if CONF_SERVICE_ENTITY_ID in config:
        service_data[ATTR_ENTITY_ID] = config[CONF_SERVICE_ENTITY_ID]

    await hass.services.async_call(
        domain, service_name, service_data, blocking=blocking, context=context)


@bind_hass
def extract_entity_ids(hass, service_call, expand_group=True):
    """Extract a list of entity ids from a service call.

    Will convert group entity ids to the entity ids it represents.
    """
    return run_coroutine_threadsafe(
        async_extract_entity_ids(hass, service_call, expand_group), hass.loop
    ).result()


@bind_hass
async def async_extract_entity_ids(hass, service_call, expand_group=True):
    """Extract a list of entity ids from a service call.

    Will convert group entity ids to the entity ids it represents.

    Async friendly.
    """
    entity_ids = service_call.data.get(ATTR_ENTITY_ID)
    area_ids = service_call.data.get(ATTR_AREA_ID)

    if not entity_ids and not area_ids:
        return []

    extracted = set()

    if entity_ids:
        # Entity ID attr can be a list or a string
        if isinstance(entity_ids, str):
            entity_ids = [entity_ids]

        if expand_group:
            entity_ids = \
                hass.components.group.expand_entity_ids(entity_ids)

        extracted.update(entity_ids)

    if area_ids:
        if isinstance(area_ids, str):
            area_ids = [area_ids]

        dev_reg, ent_reg = await asyncio.gather(
            hass.helpers.device_registry.async_get_registry(),
            hass.helpers.entity_registry.async_get_registry(),
        )
        devices = [
            device
            for area_id in area_ids
            for device in
            hass.helpers.device_registry.async_entries_for_area(
                dev_reg, area_id)
        ]
        extracted.update(
            entry.entity_id
            for device in devices
            for entry in
            hass.helpers.entity_registry.async_entries_for_device(
                ent_reg, device.id)
        )

    return extracted


async def _load_services_file(hass: HomeAssistantType, domain: str):
    """Load services file for an integration."""
    integration = await async_get_integration(hass, domain)
    try:
        return await hass.async_add_executor_job(
            load_yaml, str(integration.file_path / 'services.yaml'))
    except FileNotFoundError:
        _LOGGER.warning("Unable to find services.yaml for the %s integration",
                        domain)
        return {}
    except HomeAssistantError:
        _LOGGER.warning("Unable to parse services.yaml for the %s integration",
                        domain)
        return {}


@bind_hass
async def async_get_all_descriptions(hass):
    """Return descriptions (i.e. user documentation) for all service calls."""
    descriptions_cache = hass.data.setdefault(SERVICE_DESCRIPTION_CACHE, {})
    format_cache_key = '{}.{}'.format
    services = hass.services.async_services()

    # See if there are new services not seen before.
    # Any service that we saw before already has an entry in description_cache.
    missing = set()
    for domain in services:
        for service in services[domain]:
            if format_cache_key(domain, service) not in descriptions_cache:
                missing.add(domain)
                break

    # Files we loaded for missing descriptions
    loaded = {}

    if missing:
        contents = await asyncio.gather(*[
            _load_services_file(hass, domain) for domain in missing
        ])

        for domain, content in zip(missing, contents):
            loaded[domain] = content

    # Build response
    descriptions = {}
    for domain in services:
        descriptions[domain] = {}

        for service in services[domain]:
            cache_key = format_cache_key(domain, service)
            description = descriptions_cache.get(cache_key)

            # Cache missing descriptions
            if description is None:
                domain_yaml = loaded[domain]
                yaml_description = domain_yaml.get(service, {})

                if not yaml_description:
                    _LOGGER.warning("Missing service description for %s/%s",
                                    domain, service)

                description = descriptions_cache[cache_key] = {
                    'description': yaml_description.get('description', ''),
                    'fields': yaml_description.get('fields', {})
                }

            descriptions[domain][service] = description

    return descriptions


@bind_hass
async def entity_service_call(hass, platforms, func, call, service_name='',
                              required_features=None):
    """Handle an entity service call.

    Calls all platforms simultaneously.
    """
    if call.context.user_id:
        user = await hass.auth.async_get_user(call.context.user_id)
        if user is None:
            raise UnknownUser(context=call.context)
        entity_perms = user.permissions.check_entity
    else:
        entity_perms = None

    # Are we trying to target all entities
    if ATTR_ENTITY_ID in call.data:
        target_all_entities = call.data[ATTR_ENTITY_ID] == ENTITY_MATCH_ALL
    else:
        # Remove the service_name parameter along with this warning
        _LOGGER.warning(
            'Not passing an entity ID to a service to target all '
            'entities is deprecated. Update your call to %s to be '
            'instead: entity_id: %s', service_name, ENTITY_MATCH_ALL)
        target_all_entities = True

    if not target_all_entities:
        # A set of entities we're trying to target.
        entity_ids = await async_extract_entity_ids(hass, call, True)

    # If the service function is a string, we'll pass it the service call data
    if isinstance(func, str):
        data = {key: val for key, val in call.data.items()
                if key != ATTR_ENTITY_ID}
    # If the service function is not a string, we pass the service call
    else:
        data = call

    # Check the permissions

    # A list with for each platform in platforms a list of entities to call
    # the service on.
    platforms_entities = []

    if entity_perms is None:
        for platform in platforms:
            if target_all_entities:
                platforms_entities.append(list(platform.entities.values()))
            else:
                platforms_entities.append([
                    entity for entity in platform.entities.values()
                    if entity.entity_id in entity_ids
                ])

    elif target_all_entities:
        # If we target all entities, we will select all entities the user
        # is allowed to control.
        for platform in platforms:
            platforms_entities.append([
                entity for entity in platform.entities.values()
                if entity_perms(entity.entity_id, POLICY_CONTROL)])

    else:
        for platform in platforms:
            platform_entities = []
            for entity in platform.entities.values():
                if entity.entity_id not in entity_ids:
                    continue

                if not entity_perms(entity.entity_id, POLICY_CONTROL):
                    raise Unauthorized(
                        context=call.context,
                        entity_id=entity.entity_id,
                        permission=POLICY_CONTROL
                    )

                platform_entities.append(entity)

            platforms_entities.append(platform_entities)

    tasks = [
        _handle_service_platform_call(func, data, entities, call.context,
                                      required_features)
        for platform, entities in zip(platforms, platforms_entities)
    ]

    if tasks:
        done, pending = await asyncio.wait(tasks)
        assert not pending
        for future in done:
            future.result()  # pop exception if have


async def _handle_service_platform_call(func, data, entities, context,
                                        required_features):
    """Handle a function call."""
    tasks = []

    for entity in entities:
        if not entity.available:
            continue

        # Skip entities that don't have the required feature.
        if required_features is not None \
                and not entity.supported_features & required_features:
            continue

        entity.async_set_context(context)

        if isinstance(func, str):
            await getattr(entity, func)(**data)
        else:
            await func(entity, data)

        if entity.should_poll:
            tasks.append(entity.async_update_ha_state(True))

    if tasks:
        done, pending = await asyncio.wait(tasks)
        assert not pending
        for future in done:
            future.result()  # pop exception if have


@bind_hass
@ha.callback
def async_register_admin_service(
        hass: typing.HomeAssistantType, domain: str,
        service: str, service_func: Callable,
        schema: vol.Schema = vol.Schema({}, extra=vol.PREVENT_EXTRA)) -> None:
    """Register a service that requires admin access."""
    @wraps(service_func)
    async def admin_handler(call):
        if call.context.user_id:
            user = await hass.auth.async_get_user(call.context.user_id)
            if user is None:
                raise UnknownUser(context=call.context)
            if not user.is_admin:
                raise Unauthorized(context=call.context)

        await hass.async_add_job(service_func, call)

    hass.services.async_register(
        domain, service, admin_handler, schema
    )


@bind_hass
@ha.callback
def verify_domain_control(hass: HomeAssistantType, domain: str) -> Callable:
    """Ensure permission to access any entity under domain in service call."""
    def decorator(service_handler: Callable) -> Callable:
        """Decorate."""
        if not asyncio.iscoroutinefunction(service_handler):
            raise HomeAssistantError(
                'Can only decorate async functions.')

        async def check_permissions(call):
            """Check user permission and raise before call if unauthorized."""
            if not call.context.user_id:
                return await service_handler(call)

            user = await hass.auth.async_get_user(call.context.user_id)
            if user is None:
                raise UnknownUser(
                    context=call.context,
                    permission=POLICY_CONTROL,
                    user_id=call.context.user_id)

            reg = await hass.helpers.entity_registry.async_get_registry()
            entities = [
                entity.entity_id for entity in reg.entities.values()
                if entity.platform == domain
            ]

            for entity_id in entities:
                if user.permissions.check_entity(entity_id, POLICY_CONTROL):
                    return await service_handler(call)

            raise Unauthorized(
                context=call.context,
                permission=POLICY_CONTROL,
                user_id=call.context.user_id,
                perm_category=CAT_ENTITIES
            )

        return check_permissions

    return decorator