main.py

import logging
import os

from telegram.ext import Updater, CommandHandler

import pypdf2

logging.basicConfig(format='%(asctime)s - %(name)s - %(levelname)s - %(message)s', level=logging.INFO)
logger = logging.getLogger(__name__)

def start(update, context):
    update.message.reply_text("Hello! I'm a bot that can edit PDF files. Send me a PDF file and a command to get started.")

def edit_pdf(update, context):
    # Get the file_id of the PDF that the user sent
    file_id = update.message.document.file_id
    file = context.bot.get_file(file_id)
    file.download('file.pdf')
    
    # Open the PDF using the PyPDF2 library
    with open('file.pdf', 'rb') as f:
        pdf = pypdf2.PdfFileReader(f)
    
    # Edit the PDF as desired using the PyPDF2 library
    # For example, you could add a watermark to all pages of the PDF
    watermark = pypdf2.PdfFileReader(open('watermark.pdf', 'rb'))
    for page in range(pdf.getNumPages()):
        pdf.getPage(page).mergePage(watermark.getPage(0))
    
    # Save the edited PDF to a new file
    with open('edited_file.pdf', 'wb') as f:
        pdf.write(f)
    
    # Send the edited PDF back to the user
    with open('edited_file.pdf', 'rb') as f:
        context.bot.send_document(chat_id=update.effective_chat.id, document=f)
    
    # Delete the temporary files
    os.remove('file.pdf')
    os.remove('edited_file.pdf')

def main():
    # Set up the Updater and add the command handlers
    updater = Updater("TOKEN", use_context=True)
    dp = updater.dispatcher
    dp.add_handler(CommandHandler("start", start))
    dp.add_handler(CommandHandler("edit", edit_pdf))
    
    # Start the bot
    updater.start_polling()
    updater.idle()

if __name__ == '__main__':
    main()