From bd032f066e514e67d578e1cd0fcc91371ff4a3bc Mon Sep 17 00:00:00 2001
From: Arslan 'Ars2014' Sakhapov <mister.saxapoff@yandex.ru>
Date: Thu, 8 Aug 2019 19:12:49 +0500
Subject: [PATCH] Added AdminFilter and example of its usage

---
 aiogram/dispatcher/dispatcher.py       |  7 ++++-
 aiogram/dispatcher/filters/__init__.py |  3 +-
 aiogram/dispatcher/filters/builtin.py  | 40 ++++++++++++++++++++++++++
 examples/admin_filter_example.py       | 28 ++++++++++++++++++
 4 files changed, 76 insertions(+), 2 deletions(-)
 create mode 100644 examples/admin_filter_example.py

diff --git a/aiogram/dispatcher/dispatcher.py b/aiogram/dispatcher/dispatcher.py
index 0da5f621..6e3aacc5 100644
--- a/aiogram/dispatcher/dispatcher.py
+++ b/aiogram/dispatcher/dispatcher.py
@@ -9,7 +9,7 @@ import aiohttp
 from aiohttp.helpers import sentinel
 
 from .filters import Command, ContentTypeFilter, ExceptionsFilter, FiltersFactory, HashTag, Regexp, \
-    RegexpCommandsFilter, StateFilter, Text, IdFilter
+    RegexpCommandsFilter, StateFilter, Text, IdFilter, AdminFilter
 from .handler import Handler
 from .middlewares import MiddlewareManager
 from .storage import BaseStorage, DELTA, DisabledStorage, EXCEEDED_COUNT, FSMContext, \
@@ -119,6 +119,11 @@ class Dispatcher(DataMixin, ContextInstanceMixin):
             self.channel_post_handlers, self.edited_channel_post_handlers,
             self.callback_query_handlers, self.inline_query_handlers
         ])
+        filters_factory.bind(AdminFilter, event_handlers=[
+            self.message_handlers, self.edited_message_handlers,
+            self.channel_post_handlers, self.edited_channel_post_handlers,
+            self.callback_query_handlers, self.inline_query_handlers
+        ])
 
     def __del__(self):
         self.stop_polling()
diff --git a/aiogram/dispatcher/filters/__init__.py b/aiogram/dispatcher/filters/__init__.py
index eb4a5a52..b9174ee6 100644
--- a/aiogram/dispatcher/filters/__init__.py
+++ b/aiogram/dispatcher/filters/__init__.py
@@ -1,5 +1,5 @@
 from .builtin import Command, CommandHelp, CommandPrivacy, CommandSettings, CommandStart, ContentTypeFilter, \
-    ExceptionsFilter, HashTag, Regexp, RegexpCommandsFilter, StateFilter, Text, IdFilter
+    ExceptionsFilter, HashTag, Regexp, RegexpCommandsFilter, StateFilter, Text, IdFilter, AdminFilter
 from .factory import FiltersFactory
 from .filters import AbstractFilter, BoundFilter, Filter, FilterNotPassed, FilterRecord, execute_filter, \
     check_filters, get_filter_spec, get_filters_spec
@@ -24,6 +24,7 @@ __all__ = [
     'StateFilter',
     'Text',
     'IdFilter',
+    'AdminFilter',
     'get_filter_spec',
     'get_filters_spec',
     'execute_filter',
diff --git a/aiogram/dispatcher/filters/builtin.py b/aiogram/dispatcher/filters/builtin.py
index df72b9d0..4401f349 100644
--- a/aiogram/dispatcher/filters/builtin.py
+++ b/aiogram/dispatcher/filters/builtin.py
@@ -562,3 +562,43 @@ class IdFilter(Filter):
             return chat_id in self.chat_id
 
         return False
+
+
+class AdminFilter(Filter):
+    """
+    Checks if user is admin in a chat.
+    If chat_id is not set, the filter will check in the current chat (correct only for messages).
+    chat_id is required for InlineQuery.
+    """
+
+    def __init__(self, admin_chat_id: typing.Optional[int] = None, admin_current_chat: typing.Optional[bool] = False):
+        self.chat_id = admin_chat_id
+        self.check_current_chat = admin_current_chat
+
+    @classmethod
+    def validate(cls, full_config: typing.Dict[str, typing.Any]) -> typing.Optional[typing.Dict[str, typing.Any]]:
+        result = {}
+
+        if "admin_chat_id" in full_config:  # use prefix 'admin' to not conflict with IdFilter
+            result["admin_chat_id"] = full_config.pop("admin_chat_id")
+        if "admin_current_chat" in full_config:  # set True if need to check current chat
+            result["admin_current_chat"] = full_config.pop("admin_current_chat")
+
+        return result
+
+    async def check(self, obj: Union[Message, CallbackQuery, InlineQuery]) -> bool:
+        user_id = obj.from_user.id
+        chat_id = self.chat_id
+
+        if not chat_id or self.check_current_chat:
+            if isinstance(obj, Message):
+                chat_id = obj.chat.id
+            elif isinstance(obj, CallbackQuery):
+                if obj.message:
+                    chat_id = obj.message.chat.id
+            else:
+                raise ValueError("Cannot get current chat in a InlineQuery")
+
+        admins = [member.user.id for member in await obj.bot.get_chat_administrators(chat_id)]
+
+        return user_id in admins
diff --git a/examples/admin_filter_example.py b/examples/admin_filter_example.py
new file mode 100644
index 00000000..052f8efe
--- /dev/null
+++ b/examples/admin_filter_example.py
@@ -0,0 +1,28 @@
+import logging
+
+from aiogram import Bot, Dispatcher, types, executor
+
+API_TOKEN = 'API TOKEN HERE'
+
+logging.basicConfig(level=logging.DEBUG)
+
+bot = Bot(token=API_TOKEN)
+dp = Dispatcher(bot=bot)
+
+chat_id = -1001241113577
+
+
+# checks specified chat
+@dp.message_handler(admin_chat_id=chat_id)
+async def handler(msg: types.Message):
+    await msg.reply(f"You are an admin of the chat '{chat_id}'", reply=False)
+
+
+# checks current chat
+@dp.message_handler(admin_current_chat=True)
+async def handler(msg: types.Message):
+    await msg.reply("You are an admin of the current chat!", reply=False)
+
+
+if __name__ == '__main__':
+    executor.start_polling(dp)