from __future__ import annotations

import asyncio
import os
import sys
import re
import html
import httpx
import telegram
from loguru import logger as _logger
from typing import Optional, Union, Any, Callable, Final, Sequence, Iterable
from telegram.ext import Application, MessageHandler, filters
from functools import partial, wraps
from itertools import product as _product
from itertools import starmap
from random import Random, SystemRandom
from collections import deque, Counter
from contextvars import ContextVar
from http.cookiejar import CookieJar, DefaultCookiePolicy

parser = re.compile(
    r'^(?P<slash>[\\/]_?\$?)'
    r'(?P<predicate>([^\s\\]|\\.)*((?<=\S)\\)?)'
    r'(\s+(?P<complement>.+))?$'
)
ouenParser = re.compile(
    r'^('
    r'\\+ .* /+'
    r'|'
    r'＼+ .* ／+'
    r'|'
    r'(\\.*/\s*){2,}'
    r'|'
    r'(＼.*／\s*){2,}'
    r'|'
    r'\\{2,}/{2,}'
    r'|'
    r'＼{2,}／{2,}'
    r')$'
)
pinParser = re.compile(
    r'^[\\/]_?pin$'
)
randomStickerParser = re.compile(
    r'^([\\/]_?){2,}$'
)

convertEscapes = partial(re.compile(r'\\(\s)').sub, r'\1')
htmlEscape = lambda s: s.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
mentionParser = re.compile(r'@([a-zA-Z]\w{4,})')

product = lambda a, b: tuple(map('，'.join, _product(a, b)))

PUNCTUATION_TAIL = (
    '.,?!;:~('
    '。，？！；：～（'
)

try:
    random = SystemRandom()
except NotImplementedError:
    random = Random()
    _logger.warning('SystemRandom is not available, using Random instead')

# env
TOKENS = re.compile(r'[^a-zA-Z\-_\d:]+').split(os.environ.get('TOKEN', ''))
if not TOKENS:
    raise ValueError('no any valid token found')

PROXY = os.environ.get('PROXY')
# Set proxy and disallow cookies
HTTPX_CLIENT = httpx.AsyncClient(http2=True, proxy=PROXY, cookies=CookieJar(DefaultCookiePolicy(allowed_domains=())))

_logger.remove()
_logger.add(
    sys.stderr,
    format="<green>{time:YYYY-MM-DD HH:mm:ss.SSS}</green>"
           "|<level>{level:^8}</level>"
           "|<cyan>{extra[username]:^15}</cyan>"
           "|<level>{message}</level>",
    level="DEBUG",
)
logger_var: ContextVar[_logger] = ContextVar("logger_var", default=_logger)


class RandomizerMeta(type):
    def __init__(cls, name, bases, namespace):
        super().__init__(name, bases, namespace)
        cls._counter = Counter()


class Randomizer(metaclass=RandomizerMeta):
    def __class_getitem__(cls, item: str) -> Any:
        collection = getattr(cls, item)
        if cls._counter[item] % len(collection) == 0:
            random.shuffle(collection)
        cls._counter[item] += 1
        collection.rotate()
        return collection[-1]


class Vegetable(Randomizer):
    permission_denied = deque(
        product(
            {'我太菜了', '我好菜', '我好菜啊', '我菜死了'},
            {'pin 不了这条消息', '学不会怎么 pin 这条消息', '连 pin 都不被允许'}
        )
        +
        product(
            {'我学不会怎么 pin 这条消息', '这么简单的消息我都 pin 不了', '好想 pin 这条消息啊，但我做不到'},
            {'需要浇浇', '怎么会有我这么菜的 bot', '我只能混吃等死', '我怎么会菜成这样'}
        )
        +
        product(
            {'这可要我怎么 pin 呀', '怎么才能 pin 这条消息呀', 'pin 不动呀，这可怎么办'},
            {'拿大头针钉上吗', '找把锤子敲到柱子上吗', '触及知识盲区了都'}
        )
    )
    reject = deque(
        product(
            {'我累了', '我好懒，又懒又菜', '我的 bot 生只要像这样躺着混日子就已经很幸福了'},
            {'根本不想 pin 这条消息', '才不要 pin 这条消息', '还是另请高明吧', '一点 pin 的动力都没有'}
        )
    )


class Stickers(Randomizer):
    _cnstr = partial(telegram.Sticker,
                     width=512,
                     height=512,
                     is_animated=False,
                     is_video=False,
                     type=telegram.Sticker.REGULAR)

    stickers = deque(
        starmap(
            _cnstr,
            (
                ('CAACAgUAAxkBAAInuWOcpUaH6eiL7vc9bIw6GedK-DNzAALNAQAC3x9yGXsiKdzwYgnWLAQ', 'AgADzQEAAt8fchk'),
                ('CAACAgUAAxkBAAInu2OcpakDQaHnVWVo_80AAVgE7EcujAAC2gEAAt8fchkAAbkxR5lrlfUsBA', 'AgAD2gEAAt8fchk'),
                ('CAACAgUAAxkBAAInvWOcpcUcJDWODiIxUoSTs840QJaFAALbAQAC3x9yGcc6smv9nZmELAQ', 'AgAD2wEAAt8fchk'),
                ('CAACAgUAAxkBAAKNaWOcn1dZP5Ooe5wX8JrCKkK2qXGzAALnAQAC3x9yGfJozMIlJl_kLAQ', 'AgAD5wEAAt8fchk'),
                ('CAACAgUAAxkBAAInt2Ocor-N-gnaJTGR-RtyopIgI0l5AALrAQAC3x9yGWlN_RGM1AESLAQ', 'AgAD6wEAAt8fchk'),
                ('CAACAgUAAxkBAAInv2Ocph3PT5XiCArmoehOYzCn1sJRAALyAQAC3x9yGSLk1aHaA09kLAQ', 'AgAD8gEAAt8fchk'),
                ('CAACAgUAAxkBAAInwWOcplEELbRuIBkuy3Yyv6YCScxdAAISAgAC3x9yGaW3ftfZrg8eLAQ', 'AgADEgIAAt8fchk'),
                ('CAACAgUAAxkBAAInw2Ocpm8VgaPVTUhDPTGHWjnDjzsDAAIbAgAC3x9yGWCDLF4OLhaMLAQ', 'AgADGwIAAt8fchk'),
            )
        )
    )

    def __new__(cls) -> telegram.Sticker:
        return cls.__class_getitem__('stickers')


def log(func: Callable = None, verbose: bool = True):
    if func is None:
        return partial(log, verbose=verbose)

    @wraps(func)
    async def wrapper(update: telegram.Update, ctx: telegram.ext.CallbackContext):
        logger = logger_var.get()
        logger.debug(str(update.to_dict()))
        return await func(update, ctx, logger)

    return wrapper


class User:
    def __init__(self, uid: Optional[int] = None, username: Optional[str] = None, name: Optional[str] = None):
        if not (uid and name) and not username:
            raise ValueError('invalid user')
        self.name = name
        self.uid = uid
        self.username = username

    async def __get_user_by_username(self):
        r = await HTTPX_CLIENT.get(f'https://t.me/{self.username}')
        og_t = re.search(r'(?<=<meta property="og:title" content=").*(?=")', r.text, re.IGNORECASE).group(0)
        name = html.unescape(og_t) if og_t else None
        page_title = re.search(r'(?<=<title>).*(?=</title>)', r.text, re.IGNORECASE).group(0)
        if page_title == og_t:  # user does not exist
            self.name = None
        elif name:
            self.name = name

    async def mention(self, mention_self: bool = False, pure: bool = False) -> str:
        if not self.name and self.username:
            await self.__get_user_by_username()
        if not self.name:
            return f'@{self.username}'

        mention_deep_link = (f'tg://resolve?domain={self.username}'
                             if (self.username and (not self.uid or self.uid < 0))
                             else f'tg://user?id={self.uid}')
        name = self.name if not mention_self else "自己"
        name = htmlEscape(name)
        return f'<a href="{mention_deep_link}">{name}</a>' if not pure else name

    def __eq__(self, other):
        return (
                type(self) == type(other)
                and (
                        (self.uid and other.uid and self.uid == other.uid)
                        or (self.username and other.username and self.username == other.username)
                )
        )


def get_user(msg: telegram.Message) -> User:
    user = msg.sender_chat or msg.from_user
    return User(name=user.full_name or user.title, uid=user.id, username=user.username)


def get_reply(msg: telegram.Message) -> Optional[telegram.Message]:
    """
    Telegram creates a false reply to the forum_topic_created service message
    when a topic message is not replying to anything.
    Filter it out.
    """
    rpl = msg.reply_to_message
    if rpl and not rpl.forum_topic_created:
        return rpl
    return None


def get_users(msg: telegram.Message) -> tuple[User, User]:
    msg_from = msg
    msg_rpl = get_reply(msg) or msg_from
    from_user, rpl_user = get_user(msg_from), get_user(msg_rpl)
    return from_user, rpl_user


def parse_command(ctx: telegram.ext.CallbackContext) -> Optional[dict[str, Union[str, bool]]]:
    match = ctx.match
    parsed = match.groupdict()
    predicate = parsed['predicate']
    complement = parsed['complement']
    if not predicate and complement:
        return None  # invalid command

    omit_le = predicate.endswith('\\')
    predicate = predicate[:-1] if omit_le else predicate
    predicate = convertEscapes(predicate)
    predicate = ctx.bot_data['delUsername'](predicate)
    result = {'predicate': htmlEscape(predicate),
              'complement': htmlEscape(complement or ''),
              'slash': parsed['slash'],
              'swap': parsed['slash'] not in ('/', '/$'),
              'omit_le': omit_le}
    return result


def get_tail(tail_char: str) -> str:
    if tail_char in PUNCTUATION_TAIL:
        return ''
    halfwidth_mark = tail_char.isascii()
    return '!' if halfwidth_mark else '！'


async def get_text(user_from: User, user_rpl: User, command: dict):
    is_self_rpl = user_from == user_rpl
    mention_from, mention_rpl = await asyncio.gather(user_from.mention(), user_rpl.mention(mention_self=is_self_rpl))
    slash, predicate, complement, omit_le = \
        command['slash'], command['predicate'], command['complement'], command['omit_le']

    if predicate == '':
        ret = '!' if not command['swap'] else '¡'
    elif predicate == 'me':
        ret = f"{mention_from}{bool(complement) * ' '}{complement}"
        ret += get_tail((complement or user_from.mention(pure=True))[-1])
    elif predicate == 'you':
        ret = f"{mention_rpl}{bool(complement) * ' '}{complement}"
        ret += get_tail((complement or user_rpl.mention(mention_self=is_self_rpl, pure=True))[-1])
    elif complement:
        ret = f"{mention_from} {predicate} {mention_rpl} {complement}"
        ret += get_tail(complement[-1])
    else:
        ret = f"{mention_from} {predicate} "
        ret += '了 ' if not omit_le else ''
        ret += mention_rpl
        ret += get_tail(mention_rpl[-1])
    return ret


@log(verbose=False)
async def reply(update: telegram.Update, ctx: telegram.ext.CallbackContext, logger: _logger = _logger):
    command = parse_command(ctx)
    if not command:
        return

    logger.debug(str(update.to_dict()))
    msg = update.effective_message
    from_user, rpl_user = get_users(msg)

    if from_user == rpl_user:
        mention_match = mentionParser.search(command['predicate'])
        if mention_match:
            mention = mentionParser.search(msg.text).group(1)
            rpl_user = User(username=mention)
            command['predicate'] = command['predicate'][:mention_match.start()]
        else:
            mention_match = mentionParser.search(command['complement'])
            if mention_match:
                mention = mentionParser.search(msg.text).group(1)
                rpl_user = User(username=mention)
                complement = command['complement']
                complement = complement[:mention_match.start()] + complement[mention_match.end():]
                command['complement'] = complement.strip()

    if command['swap'] and (not from_user == rpl_user):
        (from_user, rpl_user) = (rpl_user, from_user)

    text = await get_text(from_user, rpl_user, command)
    logger.info(text)

    await msg.reply_text('\u200e' + text, parse_mode='HTML')


@log
async def repeat(update: telegram.Update, _ctx: telegram.ext.CallbackContext, logger: _logger = _logger):
    chat = update.effective_chat
    msg = update.effective_message
    tid = msg.message_thread_id

    logger.info(msg.text)
    if msg.has_protected_content:
        await msg.copy(chat.id, message_thread_id=tid)
    else:
        await msg.forward(chat.id, message_thread_id=tid)


@log
async def pin(update: telegram.Update, _ctx: telegram.ext.CallbackContext, logger: _logger = _logger):
    msg = update.effective_message
    msg_to_pin = get_reply(msg)
    if not msg_to_pin:
        vegetable = f'{Vegetable["reject"]} (Reply to a message to use the command)'
        await msg.reply_text(vegetable)
        logger.warning(vegetable)
        return

    try:
        await msg_to_pin.unpin()
        await msg_to_pin.pin(disable_notification=True)
        logger.info(f'Pinned {msg_to_pin.text}')
    except telegram.error.BadRequest as e:
        vegetable = f'{Vegetable["permission_denied"]} ({e})'
        await msg_to_pin.reply_text(vegetable)
        logger.warning(vegetable)


@log
async def random_sticker(update: telegram.Update, _ctx: telegram.ext.CallbackContext, logger: _logger = _logger):
    msg = update.effective_message
    sticker = Stickers()
    logger.info(sticker)
    await msg.reply_sticker(sticker)


class App:
    _apps: Final[set["App"]] = set()
    # MessageHandler is stateless and reusable, so we can reuse the same instance for all handlers.
    # Note: this is not always true for other handlers, e.g., ConversationHandler.
    _handlers: Final[Sequence[MessageHandler]] = (
        MessageHandler(
            filters.Regex(ouenParser) & ~filters.UpdateType.EDITED,
            repeat,
            block=False,
        ),
        MessageHandler(
            filters.Regex(randomStickerParser) & ~filters.UpdateType.EDITED,
            random_sticker,
            block=False,
        ),
        MessageHandler(
            filters.Regex(pinParser) & ~filters.UpdateType.EDITED,
            pin,
            block=False,
        ),
        MessageHandler(
            filters.Regex(parser) & ~filters.UpdateType.EDITED,
            reply,
            block=False,
        ),
    )

    def __init__(self, token: str):
        self.token = token
        ab = Application.builder().token(token)
        if PROXY:
            ab = ab.proxy(PROXY).get_updates_proxy(PROXY)
        self.application = ab.build()
        self.application.add_handlers(self._handlers)

    async def start(self):
        app = self.application
        await app.initialize()

        username = f'@{app.bot.username}'
        logger = _logger.bind(username=username)
        logger_var.set(logger)
        app.bot_data['delUsername'] = partial(re.compile(username, re.I).sub, '')

        if app.post_init:
            await app.post_init(app)

        await app.updater.start_polling()
        await app.start()

        logger.info('Started')
        self._apps.add(self)

    async def shutdown(self):
        app = self.application
        logger = logger_var.get()

        await app.updater.stop()
        await app.stop()
        if app.post_stop:
            await app.post_stop(app)

        await app.shutdown()
        if app.post_shutdown:
            await app.post_shutdown(app)

        logger.info('Stopped')
        self._apps.discard(self)

    @classmethod
    async def start_all(cls, tokens: Iterable[str]):
        await asyncio.gather(*(cls(token).start() for token in tokens))

    @classmethod
    async def shutdown_all(cls):
        if cls._apps:
            await asyncio.gather(*(app.shutdown() for app in cls._apps))
        assert not cls._apps, 'Not all apps were stopped'

    @classmethod
    async def run(cls, tokens: Iterable[str]):
        try:
            # Initialize and reuse the HTTPX client for all instances, and shut it down on exit.
            async with HTTPX_CLIENT:
                await cls.start_all(tokens)
                # The Event is never set to finish, so it is equivalent to asyncio.get_running_loop().run_forever().
                await asyncio.Event().wait()
        except (KeyboardInterrupt, SystemExit):
            pass
        finally:
            await cls.shutdown_all()


def main():
    asyncio.run(App.run(TOKENS))


if __name__ == '__main__':
    main()