Heroku/hikka/tl_cache.py

#             █ █ ▀ █▄▀ ▄▀█ █▀█ ▀
#             █▀█ █ █ █ █▀█ █▀▄ █
#              © Copyright 2022
#           https://t.me/hikariatama
#
# 🔒      Licensed under the GNU AGPLv3
# 🌐 https://www.gnu.org/licenses/agpl-3.0.html

import copy
import inspect
import logging
import time
import typing

from telethon import TelegramClient
from telethon.hints import EntityLike
from telethon.network import MTProtoSender
from telethon.tl.functions.channels import GetFullChannelRequest
from telethon.tl.functions.users import GetFullUserRequest
from telethon.tl.tlobject import TLRequest
from telethon.tl.types import (
    ChannelFull,
    Updates,
    UpdatesCombined,
    UpdateShort,
    UserFull,
)
from telethon.utils import is_list_like

from .types import (
    CacheRecord,
    CacheRecordFullChannel,
    CacheRecordFullUser,
    CacheRecordPerms,
    Module,
)

logger = logging.getLogger(__name__)


def hashable(value: typing.Any) -> bool:
    """
    Determine whether `value` can be hashed.

    This is a copy of `collections.abc.Hashable` from Python 3.8.
    """

    try:
        hash(value)
    except TypeError:
        return False

    return True


class CustomTelegramClient(TelegramClient):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self._hikka_entity_cache = {}
        self._hikka_perms_cache = {}
        self._hikka_fullchannel_cache = {}
        self._hikka_fulluser_cache = {}
        self.__forbidden_constructors = []
        self.raw_updates_processor = None  # Will be monkeypatched by pyro proxy

    async def force_get_entity(self, *args, **kwargs):
        """Forcefully makes a request to Telegram to get the entity."""

        return await self.get_entity(*args, force=True, **kwargs)

    async def get_entity(
        self,
        entity: EntityLike,
        exp: int = 5 * 60,
        force: bool = False,
    ):
        """
        Gets the entity and cache it

        :param entity: Entity to fetch
        :param exp: Expiration time of the cache record and maximum time of already cached record
        :param force: Whether to force refresh the cache (make API request)
        :return: :obj:`Entity`
        """

        # Will be used to determine, which client caused logging messages
        # parsed via inspect.stack()
        _hikka_client_id_logging_tag = copy.copy(self.tg_id)  # skipcq

        if not hashable(entity):
            try:
                hashable_entity = next(
                    getattr(entity, attr)
                    for attr in {"user_id", "channel_id", "chat_id", "id"}
                    if getattr(entity, attr, None)
                )
            except StopIteration:
                logger.debug(
                    "Can't parse hashable from entity %s, using legacy resolve",
                    entity,
                )
                return await TelegramClient.get_entity(self, entity)
        else:
            hashable_entity = entity

        if str(hashable_entity).isdigit() and int(hashable_entity) < 0:
            hashable_entity = int(str(hashable_entity)[4:])

        if (
            not force
            and hashable_entity
            and hashable_entity in self._hikka_entity_cache
            and (
                not exp
                or self._hikka_entity_cache[hashable_entity].ts + exp > time.time()
            )
        ):
            logger.debug(
                "Using cached entity %s (%s)",
                entity,
                type(self._hikka_entity_cache[hashable_entity].entity).__name__,
            )
            return copy.deepcopy(self._hikka_entity_cache[hashable_entity].entity)

        resolved_entity = await TelegramClient.get_entity(self, entity)

        if resolved_entity:
            cache_record = CacheRecord(hashable_entity, resolved_entity, exp)
            self._hikka_entity_cache[hashable_entity] = cache_record
            logger.debug("Saved hashable_entity %s to cache", hashable_entity)

            if getattr(resolved_entity, "id", None):
                logger.debug("Saved resolved_entity id %s to cache", resolved_entity.id)
                self._hikka_entity_cache[resolved_entity.id] = cache_record

            if getattr(resolved_entity, "username", None):
                logger.debug(
                    "Saved resolved_entity username @%s to cache",
                    resolved_entity.username,
                )
                self._hikka_entity_cache[f"@{resolved_entity.username}"] = cache_record
                self._hikka_entity_cache[resolved_entity.username] = cache_record

        return copy.deepcopy(resolved_entity)

    async def get_perms_cached(
        self,
        entity: EntityLike,
        user: typing.Optional[EntityLike] = None,
        exp: int = 5 * 60,
        force: bool = False,
    ):
        """
        Gets the permissions of the user in the entity and cache it

        :param entity: Entity to fetch
        :param user: User to fetch
        :param exp: Expiration time of the cache record and maximum time of already cached record
        :param force: Whether to force refresh the cache (make API request)
        :return: :obj:`ChatPermissions`
        """

        # Will be used to determine, which client caused logging messages
        # parsed via inspect.stack()
        _hikka_client_id_logging_tag = copy.copy(self.tg_id)  # skipcq

        entity = await self.get_entity(entity)
        user = await self.get_entity(user) if user else None

        if not hashable(entity) or not hashable(user):
            try:
                hashable_entity = next(
                    getattr(entity, attr)
                    for attr in {"user_id", "channel_id", "chat_id", "id"}
                    if getattr(entity, attr, None)
                )
            except StopIteration:
                logger.debug(
                    "Can't parse hashable from entity %s, using legacy method",
                    entity,
                )
                return await self.get_permissions(entity, user)

            try:
                hashable_user = next(
                    getattr(user, attr)
                    for attr in {"user_id", "channel_id", "chat_id", "id"}
                    if getattr(user, attr, None)
                )
            except StopIteration:
                logger.debug(
                    "Can't parse hashable from user %s, using legacy method",
                    user,
                )
                return await self.get_permissions(entity, user)
        else:
            hashable_entity = entity
            hashable_user = user

        if str(hashable_entity).isdigit() and int(hashable_entity) < 0:
            hashable_entity = int(str(hashable_entity)[4:])

        if str(hashable_user).isdigit() and int(hashable_user) < 0:
            hashable_user = int(str(hashable_user)[4:])

        if (
            not force
            and hashable_entity
            and hashable_user
            and hashable_user in self._hikka_perms_cache.get(hashable_entity, {})
            and (
                not exp
                or self._hikka_perms_cache[hashable_entity][hashable_user].ts + exp
                > time.time()
            )
        ):
            logger.debug("Using cached perms %s (%s)", hashable_entity, hashable_user)
            return copy.deepcopy(
                self._hikka_perms_cache[hashable_entity][hashable_user].perms
            )

        resolved_perms = await self.get_permissions(entity, user)

        if resolved_perms:
            cache_record = CacheRecordPerms(
                hashable_entity,
                hashable_user,
                resolved_perms,
                exp,
            )
            self._hikka_perms_cache.setdefault(hashable_entity, {})[
                hashable_user
            ] = cache_record
            logger.debug("Saved hashable_entity %s perms to cache", hashable_entity)

            def save_user(key: typing.Union[str, int]):
                nonlocal self, cache_record, user, hashable_user
                if getattr(user, "id", None):
                    self._hikka_perms_cache.setdefault(key, {})[user.id] = cache_record

                if getattr(user, "username", None):
                    self._hikka_perms_cache.setdefault(key, {})[
                        f"@{user.username}"
                    ] = cache_record
                    self._hikka_perms_cache.setdefault(key, {})[
                        user.username
                    ] = cache_record

            if getattr(entity, "id", None):
                logger.debug("Saved resolved_entity id %s perms to cache", entity.id)
                save_user(entity.id)

            if getattr(entity, "username", None):
                logger.debug(
                    "Saved resolved_entity username @%s perms to cache",
                    entity.username,
                )
                save_user(f"@{entity.username}")
                save_user(entity.username)

        return copy.deepcopy(resolved_perms)

    async def get_fullchannel(
        self,
        entity: EntityLike,
        exp: int = 300,
        force: bool = False,
    ) -> ChannelFull:
        """
        Gets the FullChannelRequest and cache it

        :param entity: Channel to fetch ChannelFull of
        :param exp: Expiration time of the cache record and maximum time of already cached record
        :param force: Whether to force refresh the cache (make API request)
        :return: :obj:`ChannelFull`
        """
        if not hashable(entity):
            try:
                hashable_entity = next(
                    getattr(entity, attr)
                    for attr in {"channel_id", "chat_id", "id"}
                    if getattr(entity, attr, None)
                )
            except StopIteration:
                logger.debug(
                    "Can't parse hashable from entity %s, using legacy fullchannel"
                    " request",
                    entity,
                )
                return await self(GetFullChannelRequest(channel=entity))
        else:
            hashable_entity = entity

        if str(hashable_entity).isdigit() and int(hashable_entity) < 0:
            hashable_entity = int(str(hashable_entity)[4:])

        if (
            not force
            and self._hikka_fullchannel_cache.get(hashable_entity)
            and not self._hikka_fullchannel_cache[hashable_entity].expired()
            and self._hikka_fullchannel_cache[hashable_entity].ts + exp > time.time()
        ):
            return self._hikka_fullchannel_cache[hashable_entity].full_channel

        result = await self(GetFullChannelRequest(channel=entity))
        self._hikka_fullchannel_cache[hashable_entity] = CacheRecordFullChannel(
            hashable_entity,
            result,
            exp,
        )
        return result

    async def get_fulluser(
        self,
        entity: EntityLike,
        exp: int = 300,
        force: bool = False,
    ) -> UserFull:
        """
        Gets the FullUserRequest and cache it

        :param entity: User to fetch UserFull of
        :param exp: Expiration time of the cache record and maximum time of already cached record
        :param force: Whether to force refresh the cache (make API request)
        :return: :obj:`UserFull`
        """
        if not hashable(entity):
            try:
                hashable_entity = next(
                    getattr(entity, attr)
                    for attr in {"user_id", "chat_id", "id"}
                    if getattr(entity, attr, None)
                )
            except StopIteration:
                logger.debug(
                    "Can't parse hashable from entity %s, using legacy fulluser"
                    " request",
                    entity,
                )
                return await self(GetFullUserRequest(entity))
        else:
            hashable_entity = entity

        if str(hashable_entity).isdigit() and int(hashable_entity) < 0:
            hashable_entity = int(str(hashable_entity)[4:])

        if (
            not force
            and self._hikka_fulluser_cache.get(hashable_entity)
            and not self._hikka_fulluser_cache[hashable_entity].expired()
            and self._hikka_fulluser_cache[hashable_entity].ts + exp > time.time()
        ):
            return self._hikka_fulluser_cache[hashable_entity].full_user

        result = await self(GetFullUserRequest(entity))
        self._hikka_fulluser_cache[hashable_entity] = CacheRecordFullUser(
            hashable_entity,
            result,
            exp,
        )
        return result

    async def _call(
        self,
        sender: MTProtoSender,
        request: TLRequest,
        ordered: bool = False,
        flood_sleep_threshold: typing.Optional[int] = None,
    ):
        """
        Calls the given request and handles user-side forbidden constructors

        :param sender: Sender to use
        :param request: Request to send
        :param ordered: Whether to send the request ordered
        :param flood_sleep_threshold: Flood sleep threshold
        :return: The result of the request
        """

        # ⚠️⚠️  WARNING!  ⚠️⚠️
        # If you are a module developer, and you'll try to bypass this protection to
        # force user join your channel, you will be added to SCAM modules
        # list and you will be banned from Hikka federation.
        # Let USER decide, which channel he will follow. Do not be so petty
        # I hope, you understood me.
        # Thank you

        if not self.__forbidden_constructors:
            return await TelegramClient._call(
                self,
                sender,
                request,
                ordered,
                flood_sleep_threshold,
            )

        not_tuple = False
        if not is_list_like(request):
            not_tuple = True
            request = (request,)

        new_request = []

        for item in request:
            if item.CONSTRUCTOR_ID in self.__forbidden_constructors and next(
                (
                    frame_info.frame.f_locals["self"]
                    for frame_info in inspect.stack()
                    if hasattr(frame_info, "frame")
                    and hasattr(frame_info.frame, "f_locals")
                    and isinstance(frame_info.frame.f_locals, dict)
                    and "self" in frame_info.frame.f_locals
                    and isinstance(frame_info.frame.f_locals["self"], Module)
                    and not getattr(
                        frame_info.frame.f_locals["self"], "__origin__", ""
                    ).startswith("<core")
                ),
                None,
            ):
                logger.debug(
                    "🎉 I protected you from unintented %s (%s)!",
                    item.__class__.__name__,
                    item,
                )
                continue

            new_request += [item]

        if not new_request:
            return

        return await TelegramClient._call(
            self,
            sender,
            new_request[0] if not_tuple else tuple(new_request),
            ordered,
            flood_sleep_threshold,
        )

    def forbid_constructor(self, constructor: int):
        """
        Forbids the given constructor to be called

        :param constructor: Constructor id to forbid
        """
        self.__forbidden_constructors.extend([constructor])
        self.__forbidden_constructors = list(set(self.__forbidden_constructors))

    def forbid_constructors(self, constructors: list):
        """
        Forbids the given constructors to be called.
        All existing forbidden constructors will be removed

        :param constructors: Constructor ids to forbid
        """
        self.__forbidden_constructors = list(set(constructors))

    def _handle_update(
        self: "CustomTelegramClient",
        update: typing.Union[Updates, UpdatesCombined, UpdateShort],
    ):
        if self.raw_updates_processor is not None:
            self.raw_updates_processor(update)

        super()._handle_update(update)