listen.py

from argparse import ArgumentParser, RawTextHelpFormatter
from enum import Enum
import sys

from telethon.sync import TelegramClient, events

from print import print, printerr
from parsers import add_api_arg, add_session_arg, add_msg_format_arg
from tg_utils import get_entity, unpack_peer

parser = ArgumentParser(description='Listen to Telegram sources (channels, users, chats) and print them',
                        epilog='Program prints tab-separated lists to identify the peer and message to forward\n' \
                                '  - msg_id: int - id of message to forward\n' \
                                '  - peer_type: (user|chat|channel) - type of a peer\n' \
                                '  - peer_id: int - id of a peer\n' \
                                '  - message text: str - text of the message',
                        formatter_class=RawTextHelpFormatter)
parser.add_argument('sources', nargs='+', help='Sources to listen. Can be usernames, phone numbers, chat names, etc.')
add_msg_format_arg(parser)
add_api_arg(parser)
add_session_arg(parser)
args = parser.parse_args()

with TelegramClient(args.session, args.api.id, args.api.hash) as client:
    try:
        entities = [get_entity(client, source) for source in args.sources]
    except Exception as e:
        printerr(e.args[0])
        sys.exit(1)

    @client.on(events.NewMessage(chats=entities))
    async def handler(event):
        message = event.message
        peer_type, peer_id = unpack_peer(message.peer_id)
        print(message.id, peer_type, peer_id, args.msg_fmt(message.text), sep='\t')

    client.run_until_disconnected()