#!/usr/bin/env python3.9

import os # Used exactly once to check for the config file
import shutil # Used exactly once to copy the sample config file
import asyncio
import re
import json
import requests
import io
import traceback

import atoot # Asynchronous Mastodon API wrapper
import scrython # Scryfall API (similar to Gatherer but I prefer Scryfall)

import nest_asyncio  # I cannot even begin to explain why I need this one.
nest_asyncio.apply() # It has something to do with Scrython using asyncio, which means I can't
                     # use it from within my asyncio code. And that's on purpose, I think.
                     # But this patches asyncio to allow that, somehow?
                     # I'm sorry, it's completely beyond me. Look it up.

import face

from debug import *

async def startup():
	log('Starting up...')
	if not os.path.exists('config.py'):
		log('Config file not found, copying', Severity.WARNING)
		shutil.copyfile('config.sample.py', 'config.py')

	import config
	async with atoot.client(config.instance, access_token=config.access_token) as c:
		log('Connected to server!')
		me = await c.verify_account_credentials()
		log('Credentials verified!')

		tasks = []

		tasks.append(asyncio.create_task(listen(c, me)))
		tasks.append(asyncio.create_task(repeat(5 * 60, update_followers, c, me)))

		for t in tasks:
			await t

async def get_cards(card_names):
	async def download_card_image(session, c):
		log(f'Downloading image for {c.name()}...')
		url = c.image_uris(0, 'normal')
		async with session.get(url) as r:
			# BytesIO stores the data in memory as a file-like object.
			# We can turn around and upload it to fedi without ever
			# touching the disk.
			image = io.BytesIO(await r.read())

		log(f'Done downloading image for {c.name()}!')
		return image

	def get_text_representation(c):
		try:
			# Double face cards have to be treated ENTIRELY DIFFERENTLY
			# Instead of card objects we just get a list of two dictionaries.
			# I've decided to try to reuse at much code as possible by jerryrigging
			# my own Face object that can be passed into my card parsing logic
			return '\n\n//\n\n'.join((
				get_text_representation(face.Face(card_face)) for card_face in c.card_faces()
			))
		except:
			pass

		# I genuinely think this is the best way to check whether a card has
		# power/toughness, considering how Scrython is implemented.
		# Can't even check for Creature type because of stuff like Vehicles.
		try:
			c.power()
			has_pt = True
		except KeyError:
			has_pt = False

		ret = c.name() # All cards have a name.

		# Some cards (lands, [[Wheel of Fate]], whatever) don't have mana costs.
		# Add it if it's there.
		if c.mana_cost():
			ret += f' - {c.mana_cost()}'

		# All cards have a type line.
		ret += '\n' + c.type_line()

		# Funnily enough, not all cards have oracle text.
		# It feels like they should, but that's ignoring vanilla creatures.
		if c.oracle_text():
			ret += f'\n\n{c.oracle_text()}'

		# Finally, power/toughness.
		if has_pt:
			ret += f'\n\n{c.power()}/{c.toughness()}'

		return ret

	# Responses list: One entry for each [[card name]] in parent, even if the
	# response is just "No card named 'CARDNAME' was found."
	responses = []
	# Cards list: Only cards that were found successfully
	cards = []

	for name in card_names:
		try:
			c = scrython.cards.Named(fuzzy=name)
			cards.append(c)
			responses.append(f'{c.name()} - {c.scryfall_uri()}')
		except scrython.foundation.ScryfallError:
			responses.append(f'No card named "{name}" was found.')

	# Download card images.
	# A status can only have four images on it, so we can't necessarily include
	# every card mentioned in the status.
	# The reason I choose to include /no/ images in that case is that someone
	# linking to more than 4 cards is probably talking about enough different things
	# that it would be weird for the first four they happened to mention to have images.
	# Like if someone's posting a decklist it would be weird for the first four cards to
	# be treated as special like that.
	if 1 <= len(cards) <= 4:
		async with aiohttp.ClientSession() as session:
			images = tuple(zip(
				await asyncio.gather(
					*(download_card_image(session, c) for c in cards)
				),
				(get_text_representation(c) for c in cards)
			))
	else:
		images = None

	return responses, images

async def update_followers(c, me):
	log('Updating followed accounts...')
	accounts_following_me = set(map(lambda a: a['id'], await c.account_followers(me)))
	accounts_i_follow = set(map(lambda a: a['id'], await c.account_following(me)))

	# Accounts that follow me that I don't follow
	to_follow = accounts_following_me - accounts_i_follow

	# Accounts I follow that don't follow me
	to_unfollow = accounts_i_follow - accounts_following_me

	if to_follow:
		# Note that the bot listens for follows and tries to follow 
		# back instantly. This is /usually/ dead code but it's a failsafe
		# in case someone followed while the bot was down or something.
		log(f'{len(to_follow)} accounts to follow:')
		for account in to_follow:
			await c.account_follow(account)
			log(f'Followed {account}')
	else:
		log('No accounts to follow.')

	if to_unfollow:
		log(f'{len(to_unfollow)} accounts to unfollow:')
		for account in to_unfollow:
			await c.account_unfollow(account)
			log(f'Unfollowed {account}')
	else:
		log('No accounts to unfollow.')

async def listen(c, me):
	log('Listening...')
	async with c.streaming('user') as stream:
		async for msg in stream:
			status = json.loads(msg.json()['payload'])
			try:
				# Two events come in for each status on the timeline. I don't know why.
				# One of them has the status nested deeper. Just ignore that one I guess.
				if 'status' in status: continue

				status_id = status['id']
				status_author = '@' + status['account']['acct']
				status_text = status['content']
				status_visibility = status['visibility']
			except:
				try:
					if status['type'] == 'follow':
						id = status['account']['id']
						log(f'Received follow from {id}, following back')
						await c.account_follow(id)
				except:
					log('Event came in that we don\'t know how to handle.', Severity.WARNING)
					log(status, Severity.WARNING)

				continue

			# Reply unlisted or at the same visibility as the parent, whichever is
			# more restrictive
			# I realized after writing this that I don't /think/ it ever matters?
			# I think replies behave the same on public and unlisted. But I'm not 100%
			# sure so it stays.
			reply_visibility = min(('unlisted', status_visibility), key=['direct', 'private', 'unlisted', 'public'].index)

			media_ids = None

			try:
				card_names = re.findall(r'\[\[(.+?)\]\]', status_text)

				# ignore any statuses without cards in them
				if not card_names: continue

				cards, media = await get_cards(card_names)

				reply_text = status_author

				# Just a personal preference thing. If I ask for one card, put the
				# text on the same line as the mention. If I ask for more, start the
				# list a couple of lines down.
				if len(cards) == 1:
					reply_text += ' ' + cards[0]
				else:
					reply_text += '\n\n' + '\n'.join(cards)

				if media:
					media_ids = []
					for image, desc in media:
						media_ids.append((await c.upload_attachment(fileobj=image, params={}, description=desc))['id'])
			except Exception as e:
				# Oops!
				log(traceback.print_exc(), Severity.ERROR)
				reply_text = f'{status_author} Sorry! You broke me somehow. Please let Holly know what you did!'

			log('Sending reply...')
			reply = await c.create_status(status=reply_text, media_ids=media_ids, in_reply_to_id=status_id, visibility=reply_visibility)
			log(f'Reply sent! {reply["uri"]}')

# https://stackoverflow.com/a/55505152/2114129
async def repeat(interval, func, *args, **kwargs):
	"""Run func every interval seconds.

	If func has not finished before *interval*, will run again
	immediately when the previous iteration finished.

	*args and **kwargs are passed as the arguments to func.
	"""
	while True:
		await asyncio.gather(
			func(*args, **kwargs),
			asyncio.sleep(interval),
		)

if __name__ == '__main__':
	asyncio.run(startup())