feat: implement update handler for banned users

This will prevent them from using the bot.

Author: devcarron

blackjackbot/__init__.py

@@ -1,8 +1,13 @@
 # -*- coding: utf-8 -*-
+from telegram import Update
 from telegram.ext import CommandHandler, CallbackQueryHandler, MessageHandler, Filters
-from blackjackbot.errors import error_handler
 
 from blackjackbot.commands import game, admin, settings, util
+from blackjackbot.errors import error_handler
+from util import BannedUserHandler, banned_user_callback
+
+# Banned users
+banned_user_handler = BannedUserHandler(callback=banned_user_callback, type=Update)
 
 # User commands
 start_command_handler = CommandHandler("start", game.start_cmd)
@@ -29,9 +34,11 @@
 newgame_callback_handler = CallbackQueryHandler(game.newgame_callback, pattern=r"^newgame$")
 language_callback_handler = CallbackQueryHandler(settings.language_callback, pattern=r"^lang_([a-z]{2}(?:-[a-z]{2})?)$")
 
-handlers = [start_command_handler, stop_command_handler, join_callback_handler, hit_callback_handler, stand_callback_handler, start_callback_handler,
-            language_command_handler, stats_command_handler, newgame_callback_handler, reload_lang_command_handler, language_callback_handler,
-            users_command_handler, comment_command_handler, comment_text_command_handler, answer_command_handler, ban_command_handler,
+handlers = [banned_user_handler,
+            start_command_handler, stop_command_handler, join_callback_handler, hit_callback_handler,
+            stand_callback_handler, start_callback_handler, language_command_handler, stats_command_handler,
+            newgame_callback_handler, reload_lang_command_handler, language_callback_handler, users_command_handler,
+            comment_command_handler, comment_text_command_handler, answer_command_handler, ban_command_handler,
             unban_command_handler, bans_command_handler]
 
 __all__ = ['handlers', 'error_handler']

util/__init__.py

@@ -1,4 +1,6 @@
 # -*- coding: utf-8 -*-
+from .bannedusercallback import banned_user_callback
+from .banneduserhandler import BannedUserHandler
 from .cache import Cache
 
-__all__ = ['Cache']
+__all__ = ["Cache", "BannedUserHandler", "banned_user_callback"]

util/bannedusercallback.py

@@ -0,0 +1,10 @@
+# -*- coding: utf-8 -*-
+
+def banned_user_callback(update, context):
+    """Gets called by the dispatcher when it's found that the user sending the update was banned from using the bot"""
+    banned_text = "You have been banned from using this bot!"
+    
+    if update.callback_query:
+        update.callback_query.answer(banned_text)
+    else:
+        update.effective_message.reply_text(banned_text)

util/banneduserhandler.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+from telegram.ext import TypeHandler
+
+import database
+
+
+class BannedUserHandler(TypeHandler):
+
+    def check_update(self, update):
+        db = database.Database()
+        if db.is_user_banned(update.effective_user.id):
+            return True
+        return False