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

from discord import Message
from discord.errors import DiscordException
from discord.ext import commands

from config import CONFIG
from rocketbot.bot import Rocketbot
from rocketbot.cogs.basecog import BaseCog, BotMessage
from rocketbot.utils import timedelta_from_str, describe_timedelta, dump_stacktrace
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.
	"""
	def __init__(self, bot: Rocketbot):
		super().__init__(bot, None)
		self.is_connected = False
		self.is_ready = False
		self.is_first_ready = True
		self.is_first_connect = True
		self.last_disconnect_time: Optional[datetime] = None
		self.noteworthy_disconnect_duration = timedelta(seconds=5)

	@commands.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

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

	@commands.Cog.listener()
	async def on_ready(self):
		"""Event handler"""
		self.log(None, 'Bot done initializing')
		self.is_ready = True
		try:
			synced_commands = await self.bot.tree.sync()
			for command in synced_commands:
				self.log(None, f'Synced command: {command.name}')
		except Exception as e:
			dump_stacktrace(e)
		if self.is_first_ready:
			print('----------------------------------------------------------')
			self.is_first_ready = False

	@commands.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')

	@commands.command(
		brief='Posts a test warning',
		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.',
	)
	@commands.has_permissions(ban_members=True)
	@commands.guild_only()
	async def testwarn(self, context):
		"""Command handler"""
		if Storage.get_config_value(context.guild, ConfigKey.WARNING_CHANNEL_ID) is None:
			await context.message.reply(
				f'{CONFIG["warning_emoji"]} No warning channel set!',
				mention_author=False)
		else:
			bm = BotMessage(
				context.guild,
				f'Test warning message (requested by {context.author.name})',
				type=BotMessage.TYPE_MOD_WARNING)
			await self.post_message(bm)

	@commands.command(
		brief='Simple test reply',
		description='Replies to the command message. Useful to ensure the ' + \
			'bot is working properly.',
	)
	async def hello(self, context):
		"""Command handler"""
		await context.message.reply(
			f'Hey, {context.author.name}!',
		 	mention_author=False)

	@commands.command(
		brief='Shuts down the bot',
		description='Causes the bot script to terminate. Only usable by a ' + \
			'user with server admin permissions.',
	)
	@commands.has_permissions(administrator=True)
	@commands.guild_only()
	async def shutdown(self, context: commands.Context):
		"""Command handler"""
		await context.message.add_reaction('👋')
		await self.bot.close()

	@commands.command(
		brief='Mass deletes messages',
		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>'
	)
	@commands.has_permissions(manage_messages=True)
	@commands.guild_only()
	async def deletemessages(self, context, user: str, age: str) -> None:
		"""Command handler"""
		member_id = self.__parse_member_id(user)
		if member_id is None:
			await context.message.reply(
				f'{CONFIG["failure_emoji"]} user must be a mention or numeric user id',
				mention_author=False)
			return
		try:
			age_delta: timedelta = timedelta_from_str(age)
		except ValueError:
			await context.message.reply(
				f'{CONFIG["failure_emoji"]} age must be a timespan, like "30s", "10m", "1h30m"',
				mention_author=False)
			return
		cutoff: datetime = datetime.now(timezone.utc) - age_delta
		def predicate(message: Message) -> bool:
			return str(message.author.id) == member_id and message.created_at >= cutoff
		deleted_messages = []
		for channel in context.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 context.message.reply(
			f'{CONFIG["success_emoji"]} Deleted {len(deleted_messages)} ' + \
			f'messages by <@!{member_id}> from the past {describe_timedelta(age_delta)}.',
			mention_author=False)

	def __parse_member_id(self, arg: str) -> Optional[str]:
		p = re.compile('^<@!?([0-9]+)>$')
		m = p.match(arg)
		if m:
			return m.group(1)
		p = re.compile('^([0-9]+)$')
		m = p.match(arg)
		if m:
			return m.group(1)
		return None