Add generic interface for accessing device features (#741)

This adds a generic interface for all device classes to introspect available device features,
that is necessary to make it easier to support a wide variety of supported devices with different set of features.
This will allow constructing generic interfaces (e.g., in homeassistant) that fetch and change these features without hard-coding the API calls.

`Device.features()` now returns a mapping of `<identifier, Feature>` where the `Feature` contains all necessary information (like the name, the icon, a way to get and change the setting) to present and change the defined feature through its interface.

kasa/__init__.py

@@ -33,6 +33,7 @@
     TimeoutException,
     UnsupportedDeviceException,
 )
+from kasa.feature import Feature, FeatureType
 from kasa.iot.iotbulb import BulbPreset, TurnOnBehavior, TurnOnBehaviors
 from kasa.iotprotocol import (
     IotProtocol,
@@ -54,6 +55,8 @@
     "TurnOnBehaviors",
     "TurnOnBehavior",
     "DeviceType",
+    "Feature",
+    "FeatureType",
     "EmeterStatus",
     "Device",
     "Bulb",

kasa/cli.py

@@ -102,6 +102,7 @@ def __call__(self, *args, **kwargs):
             asyncio.get_event_loop().run_until_complete(self.main(*args, **kwargs))
         except Exception as ex:
             echo(f"Got error: {ex!r}")
+            raise
 
 
 def json_formatter_cb(result, **kwargs):
@@ -578,6 +579,10 @@ async def state(ctx, dev: Device):
         else:
             echo(f"\t{info_name}: {info_data}")
 
+    echo("\n\t[bold]== Features == [/bold]")
+    for id_, feature in dev.features.items():
+        echo(f"\t{feature.name} ({id_}): {feature.value}")
+
     if dev.has_emeter:
         echo("\n\t[bold]== Current State ==[/bold]")
         emeter_status = dev.emeter_realtime
@@ -594,8 +599,6 @@ async def state(ctx, dev: Device):
         echo("\n\t[bold]== Verbose information ==[/bold]")
         echo(f"\tCredentials hash:  {dev.credentials_hash}")
         echo(f"\tDevice ID:         {dev.device_id}")
-        for feature in dev.features:
-            echo(f"\tFeature:           {feature}")
         echo()
         _echo_discovery_info(dev._discovery_info)
     return dev.internal_state
@@ -1115,5 +1118,37 @@ async def shell(dev: Device):
         loop.stop()
 
 
+@cli.command(name="feature")
+@click.argument("name", required=False)
+@click.argument("value", required=False)
+@pass_dev
+async def feature(dev, name: str, value):
+    """Access and modify features.
+
+    If no *name* is given, lists available features and their values.
+    If only *name* is given, the value of named feature is returned.
+    If both *name* and *value* are set, the described setting is changed.
+    """
+    if not name:
+        echo("[bold]== Features ==[/bold]")
+        for name, feat in dev.features.items():
+            echo(f"{feat.name} ({name}): {feat.value}")
+        return
+
+    if name not in dev.features:
+        echo(f"No feature by name {name}")
+        return
+
+    feat = dev.features[name]
+
+    if value is None:
+        echo(f"{feat.name} ({name}): {feat.value}")
+        return feat.value
+
+    echo(f"Setting {name} to {value}")
+    value = ast.literal_eval(value)
+    return await dev.features[name].set_value(value)
+
+
 if __name__ == "__main__":
     cli()

kasa/device.py

@@ -3,13 +3,14 @@
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
 from datetime import datetime
-from typing import Any, Dict, List, Optional, Sequence, Set, Union
+from typing import Any, Dict, List, Optional, Sequence, Union
 
 from .credentials import Credentials
 from .device_type import DeviceType
 from .deviceconfig import DeviceConfig
 from .emeterstatus import EmeterStatus
 from .exceptions import SmartDeviceException
+from .feature import Feature
 from .iotprotocol import IotProtocol
 from .protocol import BaseProtocol
 from .xortransport import XorTransport
@@ -69,6 +70,7 @@ def __init__(
         self._discovery_info: Optional[Dict[str, Any]] = None
 
         self.modules: Dict[str, Any] = {}
+        self._features: Dict[str, Feature] = {}
 
     @staticmethod
     async def connect(
@@ -296,9 +298,16 @@ def state_information(self) -> Dict[str, Any]:
         """Return the key state information."""
 
     @property
-    @abstractmethod
-    def features(self) -> Set[str]:
+    def features(self) -> Dict[str, Feature]:
         """Return the list of supported features."""
+        return self._features
+
+    def _add_feature(self, feature: Feature):
+        """Add a new feature to the device."""
+        desc_name = feature.name.lower().replace(" ", "_")
+        if desc_name in self._features:
+            raise SmartDeviceException("Duplicate feature name %s" % desc_name)
+        self._features[desc_name] = feature
 
     @property
     @abstractmethod

kasa/feature.py

@@ -0,0 +1,50 @@
+"""Generic interface for defining device features."""
+from dataclasses import dataclass
+from enum import Enum, auto
+from typing import TYPE_CHECKING, Any, Callable, Optional, Union
+
+if TYPE_CHECKING:
+    from .device import Device
+
+
+class FeatureType(Enum):
+    """Type to help decide how to present the feature."""
+
+    Sensor = auto()
+    BinarySensor = auto()
+    Switch = auto()
+    Button = auto()
+
+
+@dataclass
+class Feature:
+    """Feature defines a generic interface for device features."""
+
+    #: Device instance required for getting and setting values
+    device: "Device"
+    #: User-friendly short description
+    name: str
+    #: Name of the property that allows accessing the value
+    attribute_getter: Union[str, Callable]
+    #: Name of the method that allows changing the value
+    attribute_setter: Optional[str] = None
+    #: Container storing the data, this overrides 'device' for getters
+    container: Any = None
+    #: Icon suggestion
+    icon: Optional[str] = None
+    #: Type of the feature
+    type: FeatureType = FeatureType.Sensor
+
+    @property
+    def value(self):
+        """Return the current value."""
+        container = self.container if self.container is not None else self.device
+        if isinstance(self.attribute_getter, Callable):
+            return self.attribute_getter(container)
+        return getattr(container, self.attribute_getter)
+
+    async def set_value(self, value):
+        """Set the value."""
+        if self.attribute_setter is None:
+            raise ValueError("Tried to set read-only feature.")
+        return await getattr(self.device, self.attribute_setter)(value)

kasa/iot/iotdevice.py

@@ -22,6 +22,7 @@
 from ..deviceconfig import DeviceConfig
 from ..emeterstatus import EmeterStatus
 from ..exceptions import SmartDeviceException
+from ..feature import Feature
 from ..protocol import BaseProtocol
 from .modules import Emeter, IotModule
 
@@ -184,8 +185,9 @@ def __init__(
         super().__init__(host=host, config=config, protocol=protocol)
 
         self._sys_info: Any = None  # TODO: this is here to avoid changing tests
-        self._features: Set[str] = set()
         self._children: Sequence["IotDevice"] = []
+        self._supported_modules: Optional[Dict[str, IotModule]] = None
+        self._legacy_features: Set[str] = set()
 
     @property
     def children(self) -> Sequence["IotDevice"]:
@@ -260,7 +262,7 @@ async def _query_helper(
 
     @property  # type: ignore
     @requires_update
-    def features(self) -> Set[str]:
+    def features(self) -> Dict[str, Feature]:
         """Return a set of features that the device supports."""
         return self._features
 
@@ -276,7 +278,7 @@ def supported_modules(self) -> List[str]:
     @requires_update
     def has_emeter(self) -> bool:
         """Return True if device has an energy meter."""
-        return "ENE" in self.features
+        return "ENE" in self._legacy_features
 
     async def get_sys_info(self) -> Dict[str, Any]:
         """Retrieve system information."""
@@ -299,9 +301,28 @@ async def update(self, update_children: bool = True):
             self._last_update = response
             self._set_sys_info(response["system"]["get_sysinfo"])
 
+        if not self._features:
+            await self._initialize_features()
+
         await self._modular_update(req)
         self._set_sys_info(self._last_update["system"]["get_sysinfo"])
 
+    async def _initialize_features(self):
+        self._add_feature(
+            Feature(
+                device=self, name="RSSI", attribute_getter="rssi", icon="mdi:signal"
+            )
+        )
+        if "on_time" in self._sys_info:
+            self._add_feature(
+                Feature(
+                    device=self,
+                    name="On since",
+                    attribute_getter="on_since",
+                    icon="mdi:clock",
+                )
+            )
+
     async def _modular_update(self, req: dict) -> None:
         """Execute an update query."""
         if self.has_emeter:
@@ -310,6 +331,18 @@ async def _modular_update(self, req: dict) -> None:
             )
             self.add_module("emeter", Emeter(self, self.emeter_type))
 
+        # TODO: perhaps modules should not have unsupported modules,
+        #  making separate handling for this unnecessary
+        if self._supported_modules is None:
+            supported = {}
+            for module in self.modules.values():
+                if module.is_supported:
+                    supported[module._module] = module
+                for module_feat in module._module_features.values():
+                    self._add_feature(module_feat)
+
+            self._supported_modules = supported
+
         request_list = []
         est_response_size = 1024 if "system" in req else 0
         for module in self.modules.values():
@@ -357,9 +390,7 @@ def _set_sys_info(self, sys_info: Dict[str, Any]) -> None:
         """Set sys_info."""
         self._sys_info = sys_info
         if features := sys_info.get("feature"):
-            self._features = _parse_features(features)
-        else:
-            self._features = set()
+            self._legacy_features = _parse_features(features)
 
     @property  # type: ignore
     @requires_update

kasa/iot/iotplug.py

@@ -4,6 +4,7 @@
 
 from ..device_type import DeviceType
 from ..deviceconfig import DeviceConfig
+from ..feature import Feature, FeatureType
 from ..protocol import BaseProtocol
 from .iotdevice import IotDevice, requires_update
 from .modules import Antitheft, Cloud, Schedule, Time, Usage
@@ -56,6 +57,17 @@ def __init__(
         self.add_module("time", Time(self, "time"))
         self.add_module("cloud", Cloud(self, "cnCloud"))
 
+        self._add_feature(
+            Feature(
+                device=self,
+                name="LED",
+                icon="mdi:led-{state}",
+                attribute_getter="led",
+                attribute_setter="set_led",
+                type=FeatureType.Switch,
+            )
+        )
+
     @property  # type: ignore
     @requires_update
     def is_on(self) -> bool:
@@ -88,5 +100,4 @@ async def set_led(self, state: bool):
     @requires_update
     def state_information(self) -> Dict[str, Any]:
         """Return switch-specific state information."""
-        info = {"LED state": self.led, "On since": self.on_since}
-        return info
+        return {}

kasa/iot/modules/cloud.py

@@ -4,6 +4,7 @@
 except ImportError:
     from pydantic import BaseModel
 
+from ...feature import Feature, FeatureType
 from .module import IotModule
 
 
@@ -25,6 +26,24 @@ class CloudInfo(BaseModel):
 class Cloud(IotModule):
     """Module implementing support for cloud services."""
 
+    def __init__(self, device, module):
+        super().__init__(device, module)
+        self._add_feature(
+            Feature(
+                device=device,
+                container=self,
+                name="Cloud connection",
+                icon="mdi:cloud",
+                attribute_getter="is_connected",
+                type=FeatureType.BinarySensor,
+            )
+        )
+
+    @property
+    def is_connected(self) -> bool:
+        """Return true if device is connected to the cloud."""
+        return self.info.binded
+
     def query(self):
         """Request cloud connectivity info."""
         return self.query_for_command("get_info")

kasa/iot/modules/module.py

@@ -2,9 +2,10 @@
 import collections
 import logging
 from abc import ABC, abstractmethod
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Dict
 
 from ...exceptions import SmartDeviceException
+from ...feature import Feature
 
 if TYPE_CHECKING:
     from kasa.iot import IotDevice
@@ -34,6 +35,14 @@ class IotModule(ABC):
     def __init__(self, device: "IotDevice", module: str):
         self._device = device
         self._module = module
+        self._module_features: Dict[str, Feature] = {}
+
+    def _add_feature(self, feature: Feature):
+        """Add module feature."""
+        feature_name = f"{self._module}_{feature.name}"
+        if feature_name in self._module_features:
+            raise SmartDeviceException("Duplicate name detected %s" % feature_name)
+        self._module_features[feature_name] = feature
 
     @abstractmethod
     def query(self):