Complete click.

bot.py

@@ -4,7 +4,7 @@
 import logging
 import config
 import sqlite3
-from telegram.ext import Updater, MessageHandler, Filters
+from telegram.ext import Updater, MessageHandler, CallbackQueryHandler, Filters
 from telegram import InlineKeyboardButton, InlineKeyboardMarkup
 
 logging.basicConfig(format='%(asctime)s - %(name)s - %(levelname)s - \
@@ -37,6 +37,40 @@ def add_vote(db, callback_id, user=None):
     db.commit()
 
 
+def delete_vote(db, callback_id, user):
+    user_id = user.id
+    query = "DELETE FROM poll WHERE callback=? AND user_id=?"
+    cursor.execute(query, (callback_id, user_id))
+    db.commit()
+
+
+def check_vote(db, callback_id, user):
+    user_id = user.id
+    cursor = db.cursor()
+    query = ("SELECT * FROM poll WHERE callback=? AND user_id=?")
+    cursor.execute(query, (callback_id, user_id))
+    if cursor.fetchone():
+        return True
+    else:
+        return False
+
+
+def update_message(bot, db, callback_id):
+    cursor = db.cursor()
+    query = "SELECT message_id FROM message_ids WHERE callback = ?"
+    cursor.execute(query, (callback_id,))
+    message_id = cursor.fetchone()[0]
+    query = "SELECT count(user_id) FROM poll WHERE callback = ?"
+    cursor.execute(query, (callback_id,))
+    count = cursor.fetchone()[0]
+    keyboard = InlineKeyboardMarkup([[InlineKeyboardButton(
+                                    text=f"❤️   {count}",
+                                    callback_data=callback_id)]])
+    bot.edit_message_reply_markup(chat_id=config.channel_id,
+                                  message_id=message_id,
+                                  reply_markup=keyboard)
+
+
 def post(bot, update, db):
     chat_id = update.message.chat_id
     if chat_id in config.allowed_users:
@@ -52,6 +86,17 @@ def post(bot, update, db):
         bot.send_message(chat_id=chat_id, text="Not Authorized")
 
 
+def click(bot, update, db):
+    user = update.callback_query.from_user
+    callback_id = update.callback_query.data
+    if not check_vote(db, callback_id, user):
+        add_vote(db, callback_id, user)
+    else:
+        delete_vote(db, callback_id, user)
+    update_message(bot, db, callback_id)
+    bot.answer_callback_query(update.callback_query.id)
+
+
 updater = Updater(token=config.api_key)
 dispatcher = updater.dispatcher
 
@@ -60,4 +105,5 @@ cursor = db.cursor()
 
 dispatcher.add_handler(MessageHandler(Filters.photo, lambda x, y: post(x,
                                       y, db)))
+dispatcher.add_handler(CallbackQueryHandler(lambda x, y: click(x, y, db)))
 updater.start_polling()