Telethon/telethon/tl/entity_database.py

from threading import Lock

import re

from .. import utils
from ..tl import TLObject
from ..tl.types import (
    User, Chat, Channel, PeerUser, PeerChat, PeerChannel,
    InputPeerUser, InputPeerChat, InputPeerChannel
)


class EntityDatabase:
    def __init__(self, input_list=None, enabled=True, enabled_full=True):
        """Creates a new entity database with an initial load of "Input"
           entities, if any.

           If 'enabled', input entities will be saved. The whole entity
           will be saved if both 'enabled' and 'enabled_full' are True.
        """
        self.enabled = enabled
        self.enabled_full = enabled_full

        self._lock = Lock()
        self._entities = {}  # marked_id: user|chat|channel

        if input_list:
            self._input_entities = {k: v for k, v in input_list}
        else:
            self._input_entities = {}  # marked_id: hash

        # TODO Allow disabling some extra mappings
        self._username_id = {}  # username: marked_id
        self._phone_id = {}  # phone: marked_id

    def process(self, tlobject):
        """Processes all the found entities on the given TLObject,
           unless .enabled is False.

           Returns True if new input entities were added.
        """
        if not self.enabled:
            return False

        # Save all input entities we know of
        if not isinstance(tlobject, TLObject) and hasattr(tlobject, '__iter__'):
            # This may be a list of users already for instance
            return self.expand(tlobject)

        entities = []
        if hasattr(tlobject, 'chats') and hasattr(tlobject.chats, '__iter__'):
            entities.extend(tlobject.chats)
        if hasattr(tlobject, 'users') and hasattr(tlobject.users, '__iter__'):
            entities.extend(tlobject.users)

        return self.expand(entities)

    def expand(self, entities):
        """Adds new input entities to the local database unconditionally.
           Unknown types will be ignored.
        """
        if not entities or not self.enabled:
            return False

        new = []  # Array of entities (User, Chat, or Channel)
        new_input = {}  # Dictionary of {entity_marked_id: access_hash}
        for e in entities:
            if not isinstance(e, TLObject):
                continue

            try:
                p = utils.get_input_peer(e, allow_self=False)
                new_input[utils.get_peer_id(p, add_mark=True)] = \
                    getattr(p, 'access_hash', 0)  # chats won't have hash

                if self.enabled_full:
                    if isinstance(e, User) \
                            or isinstance(e, Chat) \
                            or isinstance(e, Channel):
                        new.append(e)
            except ValueError:
                pass

        with self._lock:
            before = len(self._input_entities)
            self._input_entities.update(new_input)
            for e in new:
                self._add_full_entity(e)
            return len(self._input_entities) != before

    def _add_full_entity(self, entity):
        """Adds a "full" entity (User, Chat or Channel, not "Input*"),
           despite the value of self.enabled and self.enabled_full.

           Not to be confused with UserFull, ChatFull, or ChannelFull,
           "full" means simply not "Input*".
        """
        marked_id = utils.get_peer_id(
            utils.get_input_peer(entity, allow_self=False), add_mark=True
        )
        try:
            old_entity = self._entities[marked_id]
            old_entity.__dict__.update(entity.__dict__)  # Keep old references

            # Update must delete old username and phone
            username = getattr(old_entity, 'username', None)
            if username:
                del self._username_id[username.lower()]

            phone = getattr(old_entity, 'phone', None)
            if phone:
                del self._phone_id[phone]
        except KeyError:
            # Add new entity
            self._entities[marked_id] = entity

        # Always update username or phone if any
        username = getattr(entity, 'username', None)
        if username:
            self._username_id[username.lower()] = marked_id

        phone = getattr(entity, 'phone', None)
        if phone:
            self._username_id[phone] = marked_id

    def _parse_key(self, key):
        """Parses the given string, integer or TLObject key into a
           marked user ID ready for use on self._entities. Raises
           ValueError if it cannot be parsed.
        """
        if isinstance(key, str):
            phone = EntityDatabase.parse_phone(key)
            try:
                if phone:
                    return self._phone_id[phone]
                else:
                    return self._username_id[key.lstrip('@').lower()]
            except KeyError as e:
                raise ValueError() from e

        if isinstance(key, int):
            return key  # normal IDs are assumed users

        if isinstance(key, TLObject):
            return utils.get_peer_id(key, add_mark=True)

        raise ValueError()

    def __getitem__(self, key):
        """Accepts a digit only string as phone number,
           otherwise it's treated as an username.

           If an integer is given, it's treated as the ID of the desired User.
           The ID given won't try to be guessed as the ID of a chat or channel,
           as there may be an user with that ID, and it would be unreliable.

           If a Peer is given (PeerUser, PeerChat, PeerChannel),
           its specific entity is retrieved as User, Chat or Channel.
           Note that megagroups are channels with .megagroup = True.
        """
        try:
            return self._entities[self._parse_key(key)]
        except (ValueError, KeyError) as e:
            raise KeyError(key) from e

    def __delitem__(self, key):
        try:
            old = self._entities.pop(self._parse_key(key))
            # Try removing the username and phone (if pop didn't fail),
            # since the entity may have no username or phone, just ignore
            # errors. It should be there if we popped the entity correctly.
            try:
                del self._username_id[getattr(old, 'username', None)]
            except KeyError:
                pass

            try:
                del self._phone_id[getattr(old, 'phone', None)]
            except KeyError:
                pass

        except (ValueError, KeyError) as e:
            raise KeyError(key) from e

    @staticmethod
    def parse_phone(phone):
        """Parses the given phone, or returns None if it's invalid"""
        if isinstance(phone, int):
            return str(phone)
        else:
            phone = re.sub(r'[+()\s-]', '', str(phone))
            if phone.isdigit():
                return phone

    def get_input_entity(self, peer):
        try:
            i = utils.get_peer_id(peer, add_mark=True)
            h = self._input_entities[i]  # we store the IDs marked
            i, k = utils.resolve_id(i)  # removes the mark and returns kind

            if k == PeerUser:
                return InputPeerUser(i, h)
            elif k == PeerChat:
                return InputPeerChat(i)
            elif k == PeerChannel:
                return InputPeerChannel(i, h)

        except ValueError as e:
            raise KeyError(peer) from e
        raise KeyError(peer)

    def get_input_list(self):
        return list(self._input_entities.items())

    def clear(self, target=None):
        if target is None:
            self._entities.clear()
        else:
            del self[target]