Handle all entity types on isinstance checks

Only the uses of `isinstance` against `InputPeer*` types were
reviewed. Notably, `utils` is exempt on this because it needs
to deal with everything on a case-by-case basis.

Since the addition of `*FromMessage` peers, any manual `isinstance`
checks to determine the type were prone to breaking or being
forgotten to be updated, so a common `helpers._entity_type()`
method was made to share this logic.

Since the conversion to `Peer` would be too expensive, a simpler
check against the name is made, which should be fast and cheap.

telethon/client/chats.py

@@ -108,8 +108,8 @@ class _ParticipantsIter(RequestIter):
                 filter = filter()
 
         entity = await self.client.get_input_entity(entity)
-        if search and (filter
-                       or not isinstance(entity, types.InputPeerChannel)):
+        ty = helpers._entity_type(entity)
+        if search and (filter or ty != helpers._EntityType.CHANNEL):
             # We need to 'search' ourselves unless we have a PeerChannel
             search = search.casefold()
 
@@ -123,7 +123,7 @@ class _ParticipantsIter(RequestIter):
         # Only used for channels, but we should always set the attribute
         self.requests = []
 
-        if isinstance(entity, types.InputPeerChannel):
+        if ty == helpers._EntityType.CHANNEL:
             self.total = (await self.client(
                 functions.channels.GetFullChannelRequest(entity)
             )).full_chat.participants_count
@@ -149,7 +149,7 @@ class _ParticipantsIter(RequestIter):
                     hash=0
                 ))
 
-        elif isinstance(entity, types.InputPeerChat):
+        elif ty == helpers._EntityType.CHAT:
             full = await self.client(
                 functions.messages.GetFullChatRequest(entity.chat_id))
             if not isinstance(
@@ -281,7 +281,8 @@ class _ProfilePhotoIter(RequestIter):
             self, entity, offset, max_id
     ):
         entity = await self.client.get_input_entity(entity)
-        if isinstance(entity, (types.InputPeerUser, types.InputPeerSelf)):
+        ty = helpers._entity_type(entity)
+        if ty == helpers._EntityType.USER:
             self.request = functions.photos.GetUserPhotosRequest(
                 entity,
                 offset=offset,
@@ -864,7 +865,8 @@ class ChatMethods:
         """
         entity = await self.get_input_entity(entity)
         user = await self.get_input_entity(user)
-        if not isinstance(user, (types.InputPeerUser, types.InputPeerSelf)):
+        ty = helpers._entity_type(user)
+        if ty != helpers._EntityType.USER:
             raise ValueError('You must pass a user entity')
 
         perm_names = (
@@ -872,7 +874,8 @@ class ChatMethods:
             'ban_users', 'invite_users', 'pin_messages', 'add_admins'
         )
 
-        if isinstance(entity, types.InputPeerChannel):
+        ty = helpers._entity_type(entity)
+        if ty == helpers._EntityType.CHANNEL:
             # If we try to set these permissions in a megagroup, we
             # would get a RIGHT_FORBIDDEN. However, it makes sense
             # that an admin can post messages, so we want to avoid the error
@@ -894,7 +897,7 @@ class ChatMethods:
                 for name in perm_names
             }), rank=title or ''))
 
-        elif isinstance(entity, types.InputPeerChat):
+        elif ty == helpers._EntityType.CHAT:
             # If the user passed any permission in a small
             # group chat, they must be a full admin to have it.
             if is_admin is None:
@@ -1015,7 +1018,8 @@ class ChatMethods:
                 await client.edit_permissions(chat, user)
         """
         entity = await self.get_input_entity(entity)
-        if not isinstance(entity, types.InputPeerChannel):
+        ty = helpers._entity_type(entity)
+        if ty != helpers._EntityType.CHANNEL:
             raise ValueError('You must pass either a channel or a supergroup')
 
         rights = types.ChatBannedRights(
@@ -1040,12 +1044,13 @@ class ChatMethods:
             ))
 
         user = await self.get_input_entity(user)
+        ty = helpers._entity_type(user)
+        if ty != helpers._EntityType.USER:
+            raise ValueError('You must pass a user entity')
+
         if isinstance(user, types.InputPeerSelf):
             raise ValueError('You cannot restrict yourself')
 
-        if not isinstance(user, types.InputPeerUser):
-            raise ValueError('You must pass a user entity')
-
         return await self(functions.channels.EditBannedRequest(
             channel=entity,
             user_id=user,
@@ -1086,12 +1091,13 @@ class ChatMethods:
         """
         entity = await self.get_input_entity(entity)
         user = await self.get_input_entity(user)
-        if not isinstance(user, (types.InputPeerUser, types.InputPeerSelf)):
+        if helpers._entity_type(user) != helpers._EntityType.USER:
             raise ValueError('You must pass a user entity')
 
-        if isinstance(entity, types.InputPeerChat):
+        ty = helpers._entity_type(entity)
+        if ty == helpers._EntityType.CHAT:
             await self(functions.messages.DeleteChatUserRequest(entity.chat_id, user))
-        elif isinstance(entity, types.InputPeerChannel):
+        elif ty == helpers._EntityType.CHANNEL:
             if isinstance(user, types.InputPeerSelf):
                 await self(functions.channels.LeaveChannelRequest(entity))
             else:

telethon/client/dialogs.py

@@ -3,7 +3,7 @@ import inspect
 import itertools
 import typing
 
-from .. import utils, hints
+from .. import helpers, utils, hints
 from ..requestiter import RequestIter
 from ..tl import types, functions, custom
 
@@ -436,10 +436,11 @@ class DialogMethods:
                 await client.delete_dialog('username')
         """
         entity = await self.get_input_entity(entity)
-        if isinstance(entity, types.InputPeerChannel):
+        ty = helpers._entity_type(entity)
+        if ty == helpers._EntityType.CHANNEL:
             return await self(functions.channels.LeaveChannelRequest(entity))
 
-        if isinstance(entity, types.InputPeerChat):
+        if ty == helpers._EntityType.CHAT:
             result = await self(functions.messages.DeleteChatUserRequest(
                 entity.chat_id, types.InputUserSelf()))
         else:

telethon/client/downloads.py

@@ -257,7 +257,8 @@ class DownloadMethods:
             # See issue #500, Android app fails as of v4.6.0 (1155).
             # The fix seems to be using the full channel chat photo.
             ie = await self.get_input_entity(entity)
-            if isinstance(ie, types.InputPeerChannel):
+            ty = helpers._entity_type(ie)
+            if ty == helpers._EntityType.CHANNEL:
                 full = await self(functions.channels.GetFullChannelRequest(ie))
                 return await self._download_photo(
                     full.full_chat.chat_photo, file,

telethon/client/messageparse.py

@@ -2,7 +2,7 @@ import itertools
 import re
 import typing
 
-from .. import utils
+from .. import helpers, utils
 from ..tl import types
 
 if typing.TYPE_CHECKING:
@@ -134,7 +134,7 @@ class MessageParseMethods:
                 id_to_message[update.message.id] = update.message
 
             elif (isinstance(update, types.UpdateEditMessage)
-                  and not isinstance(request.peer, types.InputPeerChannel)):
+                  and helpers._entity_type(request.peer) != helpers._EntityType.CHANNEL):
                 if request.id == update.message.id:
                     update.message._finish_init(self, entities, input_chat)
                     return update.message

telethon/client/messages.py

@@ -2,7 +2,7 @@ import inspect
 import itertools
 import typing
 
-from .. import utils, errors, hints
+from .. import helpers, utils, errors, hints
 from ..requestiter import RequestIter
 from ..tl import types, functions
 
@@ -57,8 +57,8 @@ class _MessagesIter(RequestIter):
 
         if from_user:
             from_user = await self.client.get_input_entity(from_user)
-            if not isinstance(from_user, (
-                    types.InputPeerUser, types.InputPeerSelf)):
+            ty = helpers._entity_type(from_user)
+            if ty != helpers._EntityType.USER:
                 from_user = None  # Ignore from_user unless it's a user
 
         if from_user:
@@ -86,8 +86,8 @@ class _MessagesIter(RequestIter):
                 filter = types.InputMessagesFilterEmpty()
 
             # Telegram completely ignores `from_id` in private chats
-            if isinstance(
-                    self.entity, (types.InputPeerUser, types.InputPeerSelf)):
+            ty = helpers._entity_type(self.entity)
+            if ty == helpers._EntityType.USER:
                 # Don't bother sending `from_user` (it's ignored anyway),
                 # but keep `from_id` defined above to check it locally.
                 from_user = None
@@ -246,6 +246,7 @@ class _IDsIter(RequestIter):
         self._ids = list(reversed(ids)) if self.reverse else ids
         self._offset = 0
         self._entity = (await self.client.get_input_entity(entity)) if entity else None
+        self._ty = helpers._EntityType(self._entity) if self._entity else None
 
         # 30s flood wait every 300 messages (3 requests of 100 each, 30 of 10, etc.)
         if self.wait_time is None:
@@ -259,7 +260,7 @@ class _IDsIter(RequestIter):
         self._offset += _MAX_CHUNK_SIZE
 
         from_id = None  # By default, no need to validate from_id
-        if isinstance(self._entity, (types.InputChannel, types.InputPeerChannel)):
+        if self._ty == helpers._EntityType.CHANNEL:
             try:
                 r = await self.client(
                     functions.channels.GetMessagesRequest(self._entity, ids))
@@ -1108,7 +1109,7 @@ class MessageMethods:
         )
 
         entity = await self.get_input_entity(entity) if entity else None
-        if isinstance(entity, types.InputPeerChannel):
+        if helpers._entity_type(entity) == helpers._EntityType.CHANNEL:
             return await self([functions.channels.DeleteMessagesRequest(
                          entity, list(c)) for c in utils.chunks(message_ids)])
         else:
@@ -1181,7 +1182,7 @@ class MessageMethods:
                 return True
 
         if max_id is not None:
-            if isinstance(entity, types.InputPeerChannel):
+            if helpers._entity_type(entity) == helpers._EntityType.CHANNEL:
                 return await self(functions.channels.ReadHistoryRequest(
                     utils.get_input_channel(entity), max_id=max_id))
             else:

telethon/client/users.py

@@ -4,7 +4,7 @@ import itertools
 import time
 import typing
 
-from .. import errors, utils, hints
+from .. import errors, helpers, utils, hints
 from ..errors import MultiError, RPCError
 from ..helpers import retry_range
 from ..tl import TLRequest, types, functions
@@ -258,12 +258,20 @@ class UserMethods:
             else:
                 inputs.append(await self.get_input_entity(x))
 
-        users = [x for x in inputs
-                 if isinstance(x, (types.InputPeerUser, types.InputPeerSelf))]
-        chats = [x.chat_id for x in inputs
-                 if isinstance(x, types.InputPeerChat)]
-        channels = [x for x in inputs
-                    if isinstance(x, types.InputPeerChannel)]
+        lists = {
+            helpers._EntityType.USER: [],
+            helpers._EntityType.CHAT: [],
+            helpers._EntityType.CHANNEL: [],
+        }
+        for x in inputs:
+            try:
+                lists[helpers._entity_type(x)].append(x)
+            except TypeError:
+                pass
+
+        users = lists[helpers._EntityType.USER]
+        chats = lists[helpers._EntityType.CHAT]
+        channels = lists[helpers._EntityType.CHANNEL]
         if users:
             # GetUsersRequest has a limit of 200 per call
             tmp = []

telethon/helpers.py

@@ -1,10 +1,17 @@
 """Various helpers not related to the Telegram API itself"""
 import asyncio
+import enum
 import os
 import struct
 from hashlib import sha1
 
 
+class _EntityType(enum.Enum):
+    USER = 0
+    CHAT = 1
+    CHANNEL = 2
+
+
 # region Multiple utilities
 
 
@@ -131,6 +138,41 @@ def _sync_exit(self, *args):
     return loop.run_until_complete(self.__aexit__(*args))
 
 
+def _entity_type(entity):
+    # This could be a `utils` method that just ran a few `isinstance` on
+    # `utils.get_peer(...)`'s result. However, there are *a lot* of auto
+    # casts going on, plenty of calls and temporary short-lived objects.
+    #
+    # So we just check if a string is in the class name.
+    # Still, assert that it's the right type to not return false results.
+    try:
+        if entity.SUBCLASS_OF_ID not in (
+                0x2d45687,  # crc32(b'Peer')
+                0xc91c90b6,  # crc32(b'InputPeer')
+                0xe669bf46,  # crc32(b'InputUser')
+                0x40f202fd,  # crc32(b'InputChannel')
+                0x2da17977,  # crc32(b'User')
+                0xc5af5d94,  # crc32(b'Chat')
+                0x1f4661b9,  # crc32(b'UserFull')
+                0xd49a2697,  # crc32(b'ChatFull')
+        ):
+            raise TypeError('{} does not have any entity type'.format(entity))
+    except AttributeError:
+        raise TypeError('{} is not a TLObject, cannot determine entity type'.format(entity))
+
+    name = entity.__class__.__name__
+    if 'User' in name:
+        return _EntityType.USER
+    elif 'Chat' in name:
+        return _EntityType.CHAT
+    elif 'Channel' in name:
+        return _EntityType.CHANNEL
+    elif 'Self' in name:
+        return _EntityType.USER
+
+    # 'Empty' in name or not found, we don't care, not a valid entity.
+    raise TypeError('{} does not have any entity type'.format(entity))
+
 # endregion
 
 # region Cryptographic related utils

telethon_generator/data/errors.csv

@@ -149,6 +149,7 @@ MESSAGE_IDS_EMPTY,400,No message ids were provided
 MESSAGE_ID_INVALID,400,"The specified message ID is invalid or you can't do that operation on such message"
 MESSAGE_NOT_MODIFIED,400,Content of the message was not modified
 MESSAGE_TOO_LONG,400,Message was too long. Current maximum length is 4096 UTF-8 characters
+MSG_ID_INVALID,400,The message ID used in the peer was invalid
 MSG_WAIT_FAILED,400,A waiting call returned an error
 MT_SEND_QUEUE_TOO_LONG,500,
 NEED_CHAT_INVALID,500,The provided chat is invalid

telethon_generator/data/methods.csv

@@ -238,7 +238,7 @@ messages.sendEncryptedFile,user,MSG_WAIT_FAILED
 messages.sendEncryptedService,user,DATA_INVALID ENCRYPTION_DECLINED MSG_WAIT_FAILED USER_IS_BLOCKED
 messages.sendInlineBotResult,user,CHAT_SEND_INLINE_FORBIDDEN CHAT_WRITE_FORBIDDEN INLINE_RESULT_EXPIRED PEER_ID_INVALID QUERY_ID_EMPTY SCHEDULE_DATE_TOO_LATE SCHEDULE_TOO_MUCH WEBPAGE_CURL_FAILED WEBPAGE_MEDIA_EMPTY
 messages.sendMedia,both,BOT_PAYMENTS_DISABLED BOT_POLLS_DISABLED CHANNEL_INVALID CHANNEL_PRIVATE CHAT_ADMIN_REQUIRED CHAT_SEND_MEDIA_FORBIDDEN CHAT_WRITE_FORBIDDEN EXTERNAL_URL_INVALID FILE_PARTS_INVALID FILE_PART_LENGTH_INVALID INPUT_USER_DEACTIVATED MEDIA_CAPTION_TOO_LONG MEDIA_EMPTY PAYMENT_PROVIDER_INVALID PEER_ID_INVALID PHOTO_EXT_INVALID PHOTO_INVALID_DIMENSIONS PHOTO_SAVE_FILE_INVALID POLL_OPTION_DUPLICATE RANDOM_ID_DUPLICATE SCHEDULE_DATE_TOO_LATE SCHEDULE_TOO_MUCH STORAGE_CHECK_FAILED Timeout USER_BANNED_IN_CHANNEL USER_IS_BLOCKED USER_IS_BOT VIDEO_CONTENT_TYPE_INVALID WEBPAGE_CURL_FAILED WEBPAGE_MEDIA_EMPTY
-messages.sendMessage,both,AUTH_KEY_DUPLICATED BUTTON_DATA_INVALID BUTTON_TYPE_INVALID BUTTON_URL_INVALID CHANNEL_INVALID CHANNEL_PRIVATE CHAT_ADMIN_REQUIRED CHAT_ID_INVALID CHAT_RESTRICTED CHAT_WRITE_FORBIDDEN ENTITIES_TOO_LONG ENTITY_MENTION_USER_INVALID INPUT_USER_DEACTIVATED MESSAGE_EMPTY MESSAGE_TOO_LONG PEER_ID_INVALID RANDOM_ID_DUPLICATE REPLY_MARKUP_INVALID REPLY_MARKUP_TOO_LONG SCHEDULE_BOT_NOT_ALLOWED SCHEDULE_DATE_TOO_LATE SCHEDULE_TOO_MUCH Timeout USER_BANNED_IN_CHANNEL USER_IS_BLOCKED USER_IS_BOT YOU_BLOCKED_USER
+messages.sendMessage,both,AUTH_KEY_DUPLICATED BUTTON_DATA_INVALID BUTTON_TYPE_INVALID BUTTON_URL_INVALID CHANNEL_INVALID CHANNEL_PRIVATE CHAT_ADMIN_REQUIRED CHAT_ID_INVALID CHAT_RESTRICTED CHAT_WRITE_FORBIDDEN ENTITIES_TOO_LONG ENTITY_MENTION_USER_INVALID INPUT_USER_DEACTIVATED MESSAGE_EMPTY MESSAGE_TOO_LONG MSG_ID_INVALID PEER_ID_INVALID RANDOM_ID_DUPLICATE REPLY_MARKUP_INVALID REPLY_MARKUP_TOO_LONG SCHEDULE_BOT_NOT_ALLOWED SCHEDULE_DATE_TOO_LATE SCHEDULE_TOO_MUCH Timeout USER_BANNED_IN_CHANNEL USER_IS_BLOCKED USER_IS_BOT YOU_BLOCKED_USER
 messages.sendMultiMedia,both,SCHEDULE_DATE_TOO_LATE SCHEDULE_TOO_MUCH
 messages.sendReaction,User,REACTION_INVALID
 messages.sendVote,user,