from queue import Queue, Empty
from threading import Thread
from time import time
from traceback import format_exception
from typing import Optional, Any, Collection, Mapping
from sqlalchemy import or_, text
from sqlalchemy.orm import make_transient, Session
from platypush.config import Config
from platypush.context import get_plugin, get_bus
from platypush.entities import (
Entity,
get_plugin_entity_registry,
get_entities_registry,
)
from platypush.message.event.entities import EntityUpdateEvent, EntityDeleteEvent
from platypush.plugins import Plugin, action
[docs]class EntitiesPlugin(Plugin):
"""
This plugin is used to interact with native platform entities (e.g. switches, lights,
sensors etc.) through a consistent interface, regardless of the integration type.
"""
[docs] def __init__(self, **kwargs):
super().__init__(**kwargs)
def _get_session(self, *args, **kwargs) -> Session:
db = get_plugin('db')
assert db
return db.get_session(*args, **kwargs)
[docs] @action
def get(
self,
types: Optional[Collection[str]] = None,
plugins: Optional[Collection[str]] = None,
**filter,
):
"""
Retrieve a list of entities.
:param types: Entity types, as specified by the (lowercase) class name and table name.
Default: all entities.
:param plugins: Filter by plugin IDs (default: all plugins).
:param filter: Filter entities with these criteria (e.g. `name`, `id`,
`state`, `type`, `plugin` etc.)
"""
entity_registry = get_entities_registry()
selected_types = []
all_types = {
e.__tablename__.lower(): e for e in entity_registry # type: ignore
}
if types:
selected_types = {t.lower() for t in types}
entity_types = {t: et for t, et in all_types.items() if t in selected_types}
invalid_types = selected_types.difference(entity_types.keys())
assert not invalid_types, (
f'No such entity types: {invalid_types}. '
f'Supported types: {list(all_types.keys())}'
)
selected_types = entity_types.keys()
enabled_plugins = list(
{
*Config.get_plugins().keys(),
*Config.get_backends().keys(),
}
)
with self._get_session() as session:
query = session.query(Entity).filter(
or_(Entity.plugin.in_(enabled_plugins), Entity.plugin.is_(None))
)
if selected_types:
query = query.filter(Entity.type.in_(selected_types))
if plugins:
query = query.filter(Entity.plugin.in_(plugins))
if filter:
query = query.filter_by(**filter)
return [e.to_json() for e in query.all()]
[docs] @action
def scan(
self,
types: Optional[Collection[str]] = None,
plugins: Optional[Collection[str]] = None,
timeout: Optional[float] = 30.0,
):
"""
(Re-)scan entities and return the updated results.
:param types: Filter by entity types (e.g. `switch`, `light`, `sensor` etc.).
:param plugins: Filter by plugin names (e.g. `switch.tplink` or `light.hue`).
:param timeout: Scan timeout in seconds. Default: 30.
"""
filter = {}
plugin_registry = get_plugin_entity_registry()
if plugins:
filter['plugins'] = plugins
plugin_registry['by_plugin'] = {
plugin: plugin_registry['by_plugin'][plugin]
for plugin in plugins
if plugin in plugin_registry['by_plugin']
}
if types:
filter['types'] = types
filter_entity_types = set(types)
plugin_registry['by_plugin'] = {
plugin_name: entity_types
for plugin_name, entity_types in plugin_registry['by_plugin'].items()
if any(t for t in entity_types if t in filter_entity_types)
}
enabled_plugins = plugin_registry['by_plugin'].keys()
def worker(plugin_name: str, q: Queue):
try:
plugin = get_plugin(plugin_name)
assert plugin, f'No such configured plugin: {plugin_name}'
# Force a plugin scan by calling the `status` action
response = plugin.status()
assert not response.errors, response.errors
q.put((plugin_name, response.output))
except Exception as e:
q.put((plugin_name, e))
q = Queue()
start_time = time()
results = []
workers = [
Thread(target=worker, args=(plugin_name, q))
for plugin_name in enabled_plugins
]
for w in workers:
w.start()
while len(results) < len(workers) and (
not timeout or (time() - start_time < timeout)
):
try:
plugin_name, result = q.get(block=True, timeout=0.5)
if isinstance(result, Exception):
self.logger.warning(
'Could not load results from plugin %s: %s', plugin_name, result
)
self.logger.warning(
''.join(
format_exception(
type(result), value=result, tb=result.__traceback__
)
)
)
else:
results.append(result)
except Empty:
continue
if len(results) < len(workers):
self.logger.warning('Scan timed out for some plugins')
for w in workers:
w.join(timeout=max(0, timeout - (time() - start_time)) if timeout else None)
return self.get(**filter)
[docs] @action
def execute(self, id: Any, action: str, *args, **kwargs):
"""
Execute an action on an entity (for example `on`/`off` on a switch, or `get`
on a sensor).
:param id: Entity ID (i.e. the entity's db primary key, not the plugin's external
or "logical" key)
:param action: Action that should be run. It should be a method implemented
by the entity's class.
:param args: Action's extra positional arguments.
:param kwargs: Action's extra named arguments.
"""
with self._get_session() as session:
entity = session.query(Entity).filter_by(id=id).one_or_none()
assert entity, f'No such entity ID: {id}'
return entity.run(action, *args, **kwargs)
[docs] @action
def delete(self, *entities: int): # type: ignore
"""
Delete a set of entity IDs.
Note: this should only be done if the entity is no longer available or
the associated plugin has been disabled, otherwise the entities will be
re-created by the plugins on the next scan.
:param entities: IDs of the entities to be removed.
:return: The payload of the deleted entities.
"""
with self._get_session(locked=True) as session:
if str(session.connection().engine.url).startswith('sqlite://'):
# SQLite requires foreign_keys to be explicitly enabled
# in order to proper manage cascade deletions
session.execute(text('PRAGMA foreign_keys = ON'))
entities: Collection[Entity] = (
session.query(Entity).filter(Entity.id.in_(entities)).all()
)
for entity in entities:
session.delete(entity)
session.commit()
for entity in entities:
make_transient(entity)
get_bus().post(EntityDeleteEvent(entity))
return entities
[docs] @action
def rename(self, **entities: Mapping[str, str]):
"""
Rename a sequence of entities.
Renaming, as of now, is actually done by setting the ``.meta.name_override``
property of an entity rather than fully renaming the entity (which may be owned
by a plugin that doesn't support renaming, therefore the next entity update may
overwrite the name).
:param entities: Entity `id` -> `new_name` mapping.
"""
return self.set_meta(
**{
entity_id: {'name_override': name}
for entity_id, name in entities.items()
}
)
# vim:sw=4:ts=4:et:
