"""
Cog for handling most ungrouped commands and basic behaviors.
"""
import re
from datetime import datetime, timedelta, timezone
from typing import Optional, Union

from discord import Interaction, Message, User, Permissions, AppCommandType
from discord.app_commands import Command, Group, command, default_permissions, guild_only, Transform, Choice, \
	autocomplete
from discord.errors import DiscordException
from discord.ext.commands import Cog

from config import CONFIG
from rocketbot.bot import Rocketbot
from rocketbot.cogs.basecog import BaseCog, BotMessage
from rocketbot.utils import describe_timedelta, TimeDeltaTransformer, dump_stacktrace, MOD_PERMISSIONS
from rocketbot.storage import ConfigKey, Storage

class GeneralCog(BaseCog, name='General'):
	"""
	Cog for handling high-level bot functionality and commands. Should be the
	first cog added to the bot.
	"""

	shared: Optional['GeneralCog'] = None

	def __init__(self, bot: Rocketbot):
		super().__init__(
			bot,
			config_prefix=None,
			short_description='',
		)
		self.is_connected = False
		self.is_first_connect = True
		self.last_disconnect_time: Optional[datetime] = None
		self.noteworthy_disconnect_duration = timedelta(seconds=5)
		GeneralCog.shared = self

	@Cog.listener()
	async def on_connect(self):
		"""Event handler"""
		if self.is_first_connect:
			self.log(None, 'Connected')
			self.is_first_connect = False
		else:
			disconnect_duration = datetime.now(
				timezone.utc) - self.last_disconnect_time if self.last_disconnect_time else None
			if disconnect_duration is not None and disconnect_duration > self.noteworthy_disconnect_duration:
				self.log(None, f'Reconnected after {disconnect_duration.total_seconds()} seconds')
		self.is_connected = True

	@Cog.listener()
	async def on_disconnect(self):
		"""Event handler"""
		self.last_disconnect_time = datetime.now(timezone.utc)
		# self.log(None, 'Disconnected')

	@Cog.listener()
	async def on_resumed(self):
		"""Event handler"""
		disconnect_duration = datetime.now(timezone.utc) - self.last_disconnect_time if self.last_disconnect_time else None
		if disconnect_duration is not None and disconnect_duration > self.noteworthy_disconnect_duration:
			self.log(None, f'Session resumed after {disconnect_duration.total_seconds()} seconds')

	@command(
		description='Posts a test warning',
		extras={
			'long_description': 'Tests whether a warning channel is configured for this ' + \
				'guild by posting a test warning. If a mod mention is ' + \
				'configured, that user/role will be tagged in the test warning.',
		},
	)
	@guild_only()
	@default_permissions(ban_members=True)
	async def test_warn(self, interaction: Interaction):
		"""Command handler"""
		if Storage.get_config_value(interaction.guild, ConfigKey.WARNING_CHANNEL_ID) is None:
			await interaction.response.send_message(
				f'{CONFIG["warning_emoji"]} No warning channel set!',
				ephemeral=True,
			)
		else:
			bm = BotMessage(
				interaction.guild,
				f'Test warning message (requested by {interaction.user.name})',
				type=BotMessage.TYPE_MOD_WARNING)
			await self.post_message(bm)
			await interaction.response.send_message(
				'Warning issued',
				ephemeral=True,
			)

	@command(
		description='Greets the user',
		extras={
			'long_description': 'Replies to the command message. Useful to ensure the ' + \
				'bot is working properly.',
		},
	)
	async def hello(self, interaction: Interaction):
		"""Command handler"""
		await interaction.response.send_message(
			f'Hey, {interaction.user.name}!',
		 	ephemeral=True,
		)

	@command(
		description='Shuts down the bot',
		extras={
			'long_description': 'Causes the bot script to terminate. Only usable by a ' + \
				'user with server admin permissions.',
		},
	)
	@guild_only()
	@default_permissions(administrator=True)
	async def shutdown(self, interaction: Interaction):
		"""Command handler"""
		await interaction.response.send_message('👋', ephemeral=True)
		await self.bot.close()

	@command(
		description='Mass deletes messages',
		extras={
			'long_description': 'Deletes recent messages by the given user. The user ' +
				'can be either an @ mention or a numeric user ID. The age is ' +
				'a duration, such as "30s", "5m", "1h30m". Only the most ' +
				'recent 100 messages in each channel are searched.',
			'usage': '<user:id|mention> <age:timespan>',
		},
	)
	@guild_only()
	@default_permissions(manage_messages=True)
	async def delete_messages(self, interaction: Interaction, user: User, age: Transform[timedelta, TimeDeltaTransformer]) -> None:
		"""Command handler"""
		member_id = user.id
		cutoff: datetime = datetime.now(timezone.utc) - age
		def predicate(message: Message) -> bool:
			return str(message.author.id) == member_id and message.created_at >= cutoff
		deleted_messages = []
		for channel in interaction.guild.text_channels:
			try:
				deleted_messages += await channel.purge(limit=100, check=predicate)
			except DiscordException:
				# XXX: Sloppily glossing over access errors instead of checking access
				pass
		await interaction.response.send_message(
			f'{CONFIG["success_emoji"]} Deleted {len(deleted_messages)} ' + \
			f'messages by {user.mention}> from the past {describe_timedelta(age)}.',
			ephemeral=True,
		)