restrict subscriptions commands to admin only (#41)

* admin restricting is now usable for other groups and private chats
* restrict subscription commands to admins

bot/commands/subscription.py

@@ -6,6 +6,7 @@
 from telegram.ext import CommandHandler, CallbackContext
 
 from bot.core import BotTelegramCore
+from bot.messages import ADMIN_RESTRICTED
 from utils.utils import build_menu
 from db.subject import Subject
 from db.observer import UserObserver
@@ -19,9 +20,14 @@
 
 
 def subscribe(update: Update, context: CallbackContext):
+    user = update.effective_user
     chat = update.effective_chat
     message = update.effective_message
 
+    if not BotTelegramCore.instance().is_admin(user.id, chat.id):
+        message.reply_text(ADMIN_RESTRICTED)
+        return
+
     try:
         observer = UserObserver.objects.get(chat_id=f"{chat.id}")
     except DoesNotExist:
@@ -49,9 +55,14 @@ def subscribe(update: Update, context: CallbackContext):
 
 
 def unsubscribe(update: Update, context: CallbackContext):
+    user = update.effective_user
     chat = update.effective_chat
     message = update.effective_message
 
+    if not BotTelegramCore.instance().is_admin(user.id, chat.id):
+        message.reply_text(ADMIN_RESTRICTED)
+        return
+
     try:
         observer = UserObserver.objects.get(chat_id=f"{chat.id}")
     except DoesNotExist:
@@ -79,9 +90,14 @@ def unsubscribe(update: Update, context: CallbackContext):
 
 
 def subscriptions(update: Update, context: CallbackContext):
+    user = update.effective_user
     chat = update.effective_chat
     message = update.effective_message
 
+    if not BotTelegramCore.instance().is_admin(user.id, chat.id):
+        message.reply_text(ADMIN_RESTRICTED)
+        return
+
     try:
         observer = UserObserver.objects.get(chat_id=f"{chat.id}")
     except DoesNotExist:

bot/core.py

@@ -3,7 +3,7 @@
 
 from decouple import config
 from telegram.ext import Updater, Handler
-from telegram import Update, ParseMode
+from telegram import Update, ParseMode, TelegramError
 
 
 logging.basicConfig(
@@ -49,20 +49,28 @@ def chat_id(self):
 
     @property
     def chat(self):
-        return self._updater.bot.get_chat(self.chat_id)
+        return self.get_chat(self.chat_id)
+
+    def get_chat(self, chat_id):
+        return self._updater.bot.get_chat(chat_id)
 
     def is_from_official_chat(self, update: Update):
         return self.chat_id == update.message.chat.id
 
-    @property
-    def administrators(self):
+    @staticmethod
+    def get_administrators_ids(chat):
         return [chat_member.user.id for
-                chat_member in self.chat.get_administrators()]
+                chat_member in chat.get_administrators()]
 
     @classmethod
-    def is_admin(cls, user_id):
+    def is_admin(cls, user_id, chat_id=None):
         instance = cls.instance()
-        return user_id in instance.administrators
+        try:
+            chat = instance.get_chat(chat_id)
+        except TelegramError:
+            chat = instance.chat
+        return (chat.type == chat.PRIVATE or
+                user_id in instance.get_administrators_ids(chat))
 
     @classmethod
     def send_message(cls, text, chat_id, parse_mode=None):

bot/messages.py

@@ -4,3 +4,4 @@
        "Read my documentation or create a issue on " \
        "https://github.com/dcr-guys/JackBot/"
 
+ADMIN_RESTRICTED = "This command is restricted to admins only!"