Update interfaces so they all inherit from Device (#893)

Brings consistency to the api across Smart and Iot so the interfaces can be used for their specialist methods as well as the device methods (e.g. turn_on/off).

kasa/bulb.py

@@ -7,6 +7,8 @@ from typing import NamedTuple, Optional
 
 from pydantic.v1 import BaseModel
 
+from .device import Device
+
 
 class ColorTempRange(NamedTuple):
     """Color temperature range."""
@@ -40,7 +42,7 @@ class BulbPreset(BaseModel):
     mode: Optional[int]  # noqa: UP007
 
 
-class Bulb(ABC):
+class Bulb(Device, ABC):
     """Base class for TP-Link Bulb."""
 
     def _raise_for_invalid_brightness(self, value):

kasa/device.py

@@ -245,6 +245,11 @@ class Device(ABC):
         """Return  True if the device is dimmable."""
         return False
 
+    @property
+    def is_fan(self) -> bool:
+        """Return True if the device is a fan."""
+        return self.device_type == DeviceType.Fan
+
     @property
     def is_variable_color_temp(self) -> bool:
         """Return True if the device supports color temperature."""

kasa/fan.py

@@ -4,15 +4,12 @@ from __future__ import annotations
 
 from abc import ABC, abstractmethod
 
+from .device import Device
 
-class Fan(ABC):
+
+class Fan(Device, ABC):
     """Interface for a Fan."""
 
-    @property
-    @abstractmethod
-    def is_fan(self) -> bool:
-        """Return True if the device is a fan."""
-
     @property
     @abstractmethod
     def fan_speed_level(self) -> int:

kasa/smart/smartdevice.py

@@ -46,7 +46,9 @@ AVAILABLE_BULB_EFFECTS = {
 }
 
 
-class SmartDevice(Device, Bulb, Fan):
+# Device must go last as the other interfaces also inherit Device
+# and python needs a consistent method resolution order.
+class SmartDevice(Bulb, Fan, Device):
     """Base class to represent a SMART protocol based device."""
 
     def __init__(