"""
A guild configuration setting available for editing via bot commands.
"""
from datetime import timedelta
from typing import Any, Optional, Type, TypeVar, Literal

from discord import Interaction, Permissions
from discord.app_commands import Range, Transform
from discord.app_commands.commands import Command, Group, CommandCallback
from discord.ext.commands import Bot

from config import CONFIG
from rocketbot.storage import Storage
from rocketbot.utils import bot_log, TimeDeltaTransformer

# def _fix_command(command: Command) -> None:
# 	"""
# 	HACK: Fixes bug in discord.py 2.3.2 where it's requiring the user to
# 	supply the context argument. This removes that argument from the list.
# 	"""
# 	params = command.params
# 	del params['context']
# 	command.params = params

BaseCog = TypeVar('BaseCog', bound='rocketbot.cogs.BaseCog')

class CogSetting:
	permissions: Permissions = Permissions(Permissions.manage_messages.flag)

	"""
	Describes a configuration setting for a guild that can be edited by the
	mods of those guilds. BaseCog can generate "get" and "set" commands (or
	"enable" and "disable" commands for boolean values) automatically, reducing
	the boilerplate of generating commands manually. Offers simple validation rules.
	"""
	def __init__(self,
			name: str,
			datatype: Optional[Type],
			brief: Optional[str] = None,
			description: Optional[str] = None,
			usage: Optional[str] = None,
			min_value: Optional[Any] = None,
			max_value: Optional[Any] = None,
			enum_values: Optional[set[Any]] = None):
		"""
		Parameters
		----------
		name: str
			Setting identifier. Must follow variable naming conventions.
		datatype: Optional[Type]
		    Datatype of the setting. E.g. int, float, str
		brief: Optional[str]
			Description of the setting, starting with lower case.
			Will be inserted into phrases like "Sets <brief>" and
			"Gets <brief".
		description: Optional[str]
		  	Long-form description. Min, max, and enum values will be
		    appended to the end, so does not need to include these.
		usage: Optional[str]
		    Description of the value argument in a set command, e.g. "<maxcount:int>"
		min_value: Optional[Any]
		    Smallest allowable value. Must be of the same datatype as
		    the value. None for no minimum.
		max_value: Optional[Any]
		    Largest allowable value. None for no maximum.
		enum_values: Optional[set[Any]]
		  	Set of allowed values. None if unconstrained.
		"""
		self.name: str = name
		self.datatype: Type = datatype
		self.brief: Optional[str] = brief
		self.description: str = description or ''  # Can't be None
		self.usage: Optional[str] = usage
		self.min_value: Optional[Any] = min_value
		self.max_value: Optional[Any] = max_value
		self.enum_values: Optional[set[Any]] = enum_values
		if self.enum_values or self.min_value is not None or self.max_value is not None:
			self.description += '\n'
		if self.enum_values:
			allowed_values = '`' + ('`, `'.join(enum_values)) + '`'
			self.description += f'\nAllowed values: {allowed_values}'
		if self.min_value is not None:
			self.description += f'\nMin value: {self.min_value}'
		if self.max_value is not None:
			self.description += f'\nMax value: {self.max_value}'
		if self.usage is None:
			self.usage = f'<{self.name}>'

	def validate_value(self, new_value: Any) -> None:
		"""
		Checks if a value is legal for this setting. Raises a ValueError if not.
		"""
		if self.min_value is not None and new_value < self.min_value:
			raise ValueError(f'`{self.name}` must be >= {self.min_value}')
		if self.max_value is not None and new_value > self.max_value:
			raise ValueError(f'`{self.name}` must be <= {self.max_value}')
		if self.enum_values is not None and new_value not in self.enum_values:
			allowed_values = '`' + ('`, `'.join(self.enum_values)) + '`'
			raise ValueError(f'`{self.name}` must be one of {allowed_values}')

	def set_up(self, cog: BaseCog, bot: Bot) -> None:
		"""
		Sets up getter and setter commands for this setting. This should
		usually only be called by BaseCog.
		"""
		if self.name in ('enabled', 'is_enabled'):
			self.__enable_group.add_command(self.__make_enable_command(cog))
			self.__disable_group.add_command(self.__make_disable_command(cog))
		else:
			self.__get_group.add_command(self.__make_getter_command(cog))
			self.__set_group.add_command(self.__make_setter_command(cog))

	def __make_getter_command(self, cog: BaseCog) -> Command:
		setting: CogSetting = self
		setting_name = setting.name
		if cog.config_prefix is not None:
			setting_name = f'{cog.config_prefix}_{setting_name}'
		async def getter(self, interaction: Interaction) -> None:
			print(f"invoking getter for {setting_name}")
			key = f'{self.__class__.__name__}.{setting.name}'
			value = Storage.get_config_value(interaction.guild, key)
			if value is None:
				value = self.get_cog_default(setting.name)
				await interaction.response.send_message(
					f'{CONFIG["info_emoji"]} `{setting_name}` is using default of `{value}`',
					ephemeral=True
				)
			else:
				await interaction.response.send_message(
					f'{CONFIG["info_emoji"]} `{setting_name}` is set to `{value}`',
					ephemeral=True
				)
		setattr(cog.__class__, f'_cmd_get_{setting.name}', getter)
		getter.__qualname__ = f'{self.__class__.__name__}._cmd_get_{setting.name}'
		getter.__self__ = cog
		bot_log(None, cog.__class__, f"Creating /get {setting_name}")
		command = Command(
			name=setting_name,
			description=f'Shows {self.brief}.',
			callback=getter,
			parent=CogSetting.__get_group,
		)
		return command

	def __make_setter_command(self, cog: BaseCog) -> Command:
		setting: CogSetting = self
		setting_name = setting.name
		if cog.config_prefix is not None:
			setting_name = f'{cog.config_prefix}_{setting_name}'
		async def setter_general(self, interaction: Interaction, new_value) -> None:
			print(f"invoking setter for {setting_name} with value {new_value}")
			try:
				setting.validate_value(new_value)
			except ValueError as ve:
				await interaction.response.send_message(
					f'{CONFIG["failure_emoji"]} {ve}',
					ephemeral=True
				)
				return
			key = f'{self.__class__.__name__}.{setting.name}'
			Storage.set_config_value(interaction.guild, key, new_value)
			await interaction.response.send_message(
				f'{CONFIG["success_emoji"]} `{setting_name}` is now set to `{new_value}`',
				ephemeral=True
			)
			await self.on_setting_updated(interaction.guild, setting)
			self.log(interaction.guild, f'{interaction.user.name} set {key} to {new_value}')

		setter: CommandCallback = setter_general
		if self.datatype == int:
			if self.min_value is not None or self.max_value is not None:
				r_min = self.min_value
				r_max = self.max_value
				async def setter_range(self, interaction: Interaction, new_value: Range[int, r_min, r_max]) -> None:
					await self.setter_general(interaction, new_value)
				setter = setter_range
			else:
				async def setter_int(self, interaction: Interaction, new_value: int) -> None:
					await self.setter_general(interaction, new_value)
				setter = setter_int
		elif self.datatype == float:
			async def setter_float(self, interaction: Interaction, new_value: float) -> None:
				await self.setter_general(interaction, new_value)
			setter = setter_float
		elif self.datatype == timedelta:
			async def setter_timedelta(self, interaction: Interaction, new_value: Transform[timedelta, TimeDeltaTransformer]) -> None:
				await self.setter_general(interaction, new_value)
			setter = setter_timedelta
		elif getattr(self.datatype, '__origin__', None) == Literal:
			dt = self.datatype
			async def setter_enum(self, interaction: Interaction, new_value: dt) -> None:
				await self.setter_general(interaction, new_value)
			setter = setter_enum
		elif self.datatype == str:
			if self.enum_values is not None:
				raise ValueError('Type for a setting with enum values should be typing.Literal')
			else:
				async def setter_str(self, interaction: Interaction, new_value: str) -> None:
					await self.setter_general(interaction, new_value)
				setter = setter_str
		elif setting.datatype == bool:
			async def setter_bool(self, interaction: Interaction, new_value: bool) -> None:
				await self.setter_general(interaction, new_value)
			setter = setter_bool
		elif setting.datatype is not None:
			raise ValueError(f'Invalid type {self.datatype}')
		setattr(cog.__class__, f'_cmd_set_{setting.name}', setter)
		setter.__qualname__ = f'{cog.__class__.__name__}._cmd_set_{setting.name}'
		setter.__self__ = cog
		bot_log(None, cog.__class__, f"Creating /set {setting_name} {self.datatype}")
		command = Command(
			name=setting_name,
			description=f'Sets {self.brief}.',
			callback=setter,
			parent=CogSetting.__set_group,
		)
		# HACK: Passing `cog` in init gets ignored and set to `None` so set after.
		# This ensures the callback is passed the cog as `self` argument.
		# command.cog = cog
		# _fix_command(command)
		return command

	def __make_enable_command(self, cog: BaseCog) -> Command:
		setting: CogSetting = self
		async def enabler(self: BaseCog, interaction: Interaction) -> None:
			print(f"invoking enable for {self.config_prefix}")
			key = f'{self.__class__.__name__}.{setting.name}'
			Storage.set_config_value(interaction.guild, key, True)
			await interaction.response.send_message(
				f'{CONFIG["success_emoji"]} {setting.brief.capitalize()} enabled.',
				ephemeral=True
			)
			await self.on_setting_updated(interaction.guild, setting)
			self.log(interaction.guild, f'{interaction.user.name} enabled {self.__class__.__name__}')
		setattr(cog.__class__, f'_cmd_enable', enabler)
		enabler.__qualname__ = f'{cog.__class__.__name__}._cmd_enable'
		enabler.__self__ = cog
		bot_log(None, cog.__class__, f"Creating /enable {cog.config_prefix}")

		command = Command(
			name=cog.config_prefix,
			description=f'Enables {cog.config_prefix} functionality',
			callback=enabler,
			parent=CogSetting.__enable_group,
		)
		# command.cog = cog
		# _fix_command(command)
		return command

	def __make_disable_command(self, cog: BaseCog) -> Command:
		setting: CogSetting = self
		async def disabler(self: BaseCog, interaction: Interaction) -> None:
			print(f"invoking disable for {self.config_prefix}")
			key = f'{self.__class__.__name__}.{setting.name}'
			Storage.set_config_value(interaction.guild, key, False)
			await interaction.response.send_message(
				f'{CONFIG["success_emoji"]} {setting.brief.capitalize()} disabled.',
				ephemeral=True
			)
			await self.on_setting_updated(interaction.guild, setting)
			self.log(interaction.guild, f'{interaction.user.name} disabled {self.__class__.__name__}')
		setattr(cog.__class__, f'_cmd_disable', disabler)
		disabler.__qualname__ = f'{cog.__class__.__name__}._cmd_disable'
		disabler.__self__ = cog
		bot_log(None, cog.__class__, f"Creating /disable {cog.config_prefix}")

		command = Command(
			name=cog.config_prefix,
			description=f'Disables {cog.config_prefix} functionality',
			callback=disabler,
			parent=CogSetting.__disable_group,
		)
		# command.cog = cog
		# _fix_command(command)
		return command

	__has_set_up_base_commands: bool = False
	__set_group: Group
	__get_group: Group
	__enable_group: Group
	__disable_group: Group

	@classmethod
	def set_up_all(cls, cog: BaseCog, bot: Bot, settings: list['CogSetting']) -> None:
		"""
		Sets up editing commands for a list of CogSettings and adds them to a
		cog. If the cog has a command Group, commands will be added to it.
		Otherwise, they will be added at the top level.
		"""
		cls.__set_up_base_commands(bot)
		if len(settings) == 0:
			return
		bot_log(None, cog.__class__, f"Setting up slash commands for {cog.__class__.__name__}")
		for setting in settings:
			setting.set_up(cog, bot)
		bot_log(None, cog.__class__, f"Done setting up slash commands for {cog.__class__.__name__}")

	@classmethod
	def __set_up_base_commands(cls, bot: Bot) -> None:
		if cls.__has_set_up_base_commands:
			return
		cls.__has_set_up_base_commands = True
		cls.__set_group = Group(
			name='set',
			description='Sets a bot configuration value for this guild',
			default_permissions=cls.permissions
		)
		cls.__get_group = Group(
			name='get',
			description='Shows a configured bot value for this guild',
			default_permissions=cls.permissions
		)
		cls.__enable_group = Group(
			name='enable',
			description='Enables bot functionality for this guild',
			default_permissions=cls.permissions
		)
		cls.__disable_group = Group(
			name='disable',
			description='Disables bot functionality for this guild',
			default_permissions=cls.permissions
		)
		bot.tree.add_command(cls.__set_group)
		bot.tree.add_command(cls.__get_group)
		bot.tree.add_command(cls.__enable_group)
		bot.tree.add_command(cls.__disable_group)