Device specialization is confusing and unnecessarily complicated

[jaraco]

In the handling of Device.new, there are some convoluted behaviors in resolving the specialized subclasses of BinarySensor (namely Sensor, Occupancy, and Motion):

jaraco.abode/jaraco/abode/devices/base.py

Lines 127 to 180 in 595f714

	@staticmethod
	def resolve_type_unknown(state):
	if state['generic_type'] != 'unknown':
	return
	from .sensor import Sensor
	if Sensor.is_sensor(state):
	state['generic_type'] = 'sensor'
	return
	version = state.get('version', '')
	state['generic_type'] = (
	'occupancy' if version.startswith('MINIPIR') else 'motion'
	)
	@classmethod
	def new(cls, state, client):
	"""Create new device object for the given type."""
	pkg.import_all()
	try:
	type_tag = state['type_tag']
	except KeyError as exc:
	raise jaraco.abode.Exception(ERROR.UNABLE_TO_MAP_DEVICE) from exc
	state['generic_type'] = cls.get_generic_type(type_tag)
	cls.resolve_type_unknown(state)
	sensor = cls.by_type().get(state['generic_type'], lambda *args: None)
	return sensor(state, client)
	@classmethod
	def by_type(cls):
	return {sub_cls.__name__.lower(): sub_cls for sub_cls in iter_subclasses(cls)}
	@classmethod
	def get_generic_type(cls, type_tag):
	lookup = {
	f'device_type.{tag}': sub_cls.__name__.lower()
	for sub_cls in iter_subclasses(cls)
	for tag in sub_cls.tags
	}
	# These device types are all considered 'occupancy' but could apparently
	# also be multi-sensors based on their state.
	unknowns = (
	'room_sensor',
	'temperature_sensor',
	# LM = LIGHT MOTION?
	'lm',
	'pir',
	'povs',
	)
	lookup.update((f'device_type.{unknown}', 'unknown') for unknown in unknowns)
	return lookup.get(type_tag.lower())

In particular, in get_generic_type, the device tags are explicitly managed rather than being associated with a sub_cls and then indicated as "unknown", even though they are known. Then another routine resolve_type_unknown replaces these falsely-unknown types with real types.

This roundabout approach to resolving types is confusing, error-prone, and counter-intuitive, contributing to home-assistant/core#121300 and delaying its resolution.

Let's find a better way.

[jaraco]

Attempting to understand the difference between "Motion" and "Occupancy" sensors as coded in:

jaraco.abode/jaraco/abode/devices/base.py

Lines 140 to 142 in abb2c6a

	state['generic_type'] = (
	'occupancy' if version.startswith('MINIPIR') else 'motion'
	)

I did some searching and found MisterWil/abodepy#10 (comment), which seems to indicate that the origin of these two classes is javascript (presumably from the Abode web UI) that alters the labels based on the reported version.

Moreover, there seems to be no examples of a device that returns a version prefixed with "MINIPIR", so this code path may never be activated.