#!/usr/bin/env python3
import requests
import sys
import traceback
import json
import os

from argparse import ArgumentParser


def readstate(file: str) -> dict:
    if not os.path.exists(file):
        default_state = {'seek': 0}
        writestate(file, default_state)
        return default_state

    with open(file, 'r') as f:
        return json.loads(f.read())


def writestate(file: str, state: dict):
    with open(file, 'w') as f:
        f.write(json.dumps(state))


def main():
    # parse arguments
    parser = ArgumentParser()
    parser.add_argument('--log-file',
                        type=str,
                        help='A file to read from')
    parser.add_argument('--state-file',
                        default=('%s/.log-checker.state' % os.getenv('HOME')))
    parser.add_argument('--token',
                        help='Telegram bot token')
    parser.add_argument('--chat-id',
                        type=int,
                        help='Telegram chat id (with bot)')

    args = parser.parse_args()

    # read file
    state = readstate(args.state_file)
    with open(args.log_file, 'r') as f:
        # jump to the latest readed position
        f.seek(state['seek'])

        # read till the end of the file
        content = f.read()

        # save new position
        state['seek'] = f.tell()
        writestate(args.state_file, state)

        # if got something, send it to telegram
        if content != '':
            print('sending: %s' % content)
            r = requests.post('https://api.telegram.org/bot%s/sendMessage' % args.token, data={
                'chat_id': args.chat_id,
                'text': content
            })
            print(r.status_code)
            print(r.text)


if __name__ == '__main__':
    try:
        main()
    except:
        traceback.print_exc()
        sys.exit(1)