#!/usr/bin/env python3
import os

from datetime import datetime
from typing import Tuple, List
from argparse import ArgumentParser
from home.config import config
from home.database import SimpleState
from home.api import WebAPIClient

f"""
This script is supposed to be run by cron every 5 minutes or so.
It looks for new lines in log file and sends them to remote server.

OpenWRT must have remote logging enabled (UDP; IP of host this script is launched on; port 514)

/etc/rsyslog.conf contains following (assuming 192.168.1.1 is the router IP):

$ModLoad imudp  
$UDPServerRun 514  
:fromhost-ip, isequal, "192.168.1.1" /var/log/openwrt.log  
& ~

Also comment out the following line: 
$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
 
"""


def parse_line(line: str) -> Tuple[int, str]:
    space_pos = line.index(' ')

    date = line[:space_pos]
    rest = line[space_pos+1:]

    return (
        int(datetime.strptime(date, "%Y-%m-%dT%H:%M:%S%z").timestamp()),
        rest
    )


if __name__ == '__main__':
    parser = ArgumentParser()
    parser.add_argument('--file', type=str, required=True,
                        help='openwrt log file')
    parser.add_argument('--access-point', type=int, required=True,
                        help='access point number')

    arg = config.load('openwrt_logger', parser=parser)

    state = SimpleState(file=config['simple_state']['file'],
                        default={'seek': 0, 'size': 0})

    fsize = os.path.getsize(arg.file)
    if fsize < state['size']:
        state['seek'] = 0

    with open(arg.file, 'r') as f:
        if state['seek']:
            # jump to the latest read position
            f.seek(state['seek'])

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

        # save new position
        state['seek'] = f.tell()
        state['size'] = fsize

        lines: List[Tuple[int, str]] = []

        if content != '':
            for line in content.strip().split('\n'):
                if not line:
                    continue

                try:
                    lines.append(parse_line(line))
                except ValueError:
                    lines.append((0, line))

            api = WebAPIClient()
            api.log_openwrt(lines, arg.access_point)