#  Copyright 2019  Dom Sekotill <dom.sekotill@kodo.org.uk>
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

"""
Helpers for network configuration
"""

from enum import Enum, auto


_registry = {}


def register(variable, cls=None):
	"""
	Register a class as the type for a config option's values

	Can be used as a decorator if 'cls' is not provided:

		@register('my_option')
		class MyType:
			...
	"""
	if cls is not None:
		_registry[variable] = cls
		return None

	def decorator(cls):
		_registry[variable] = cls
		return cls

	return decorator


def get_type(variable):
	"""Get a type-converter for a given configuration variable"""
	return _registry.get(variable, UnknownType)


class _UnknownTypeMeta(type):
	def __instancecheck__(cls, instance):
		return isinstance(instance, (str, int))


# pylint: disable=too-few-public-methods
class UnknownType(metaclass=_UnknownTypeMeta):
	"""A pseudo type for unknown variables which forces non-ints into strings"""

	def __new__(cls, from_instance):
		if not isinstance(from_instance, (str, int)):
			return str(from_instance)
		return from_instance


class ConfigEnum(Enum):
	"""Base enum class for configuration enums used with the SET_NETWORK command"""

	def __str__(self):
		return self.value

	@staticmethod
	def _generate_next_value_(name, *_):
		return name.replace("_", "-")


@register("key_mgmt")
class KeyManagementValue(ConfigEnum):
	"""Enums for the 'key_mgmt' network setting"""

	WPA_PSK = auto()
	WPA_EAP = auto()
	IEEE8021X = auto()
	NONE = auto()
	WPA_NONE = auto()
	FT_PSK = auto()
	FT_EAP = auto()
	FT_EAP_SHA384 = auto()
	WPA_PSK_SHA256 = auto()
	WPA_EAP_SHA256 = auto()
	SAE = auto()
	FT_SAE = auto()
	WPA_EAP_SUITE_B = auto()
	WPA_EAP_SUITE_B_192 = auto()
	OSEN = auto()
	FILS_SHA256 = auto()
	FILS_SHA384 = auto()
	FT_FILS_SHA256 = auto()
	FT_FILS_SHA384 = auto()
	OWE = auto()
	DPP = auto()


register("priority", int)
register("psk", str)
register("ssid", str)