#! /usr/bin/python

from os import path
from dateutil import parser
import datetime
import json
import re
import hashlib
import paho.mqtt.publish as publish
from watchfiles import Change, watch
import config


# config stuff
LOG_DIR = config.LOG_DIR
BROKER_HOST = config.BROKER_HOST
BROKER_PORT = config.BROKER_PORT
BROKER_ACCOUNT = config.BROKER_ACCOUNT
BROKER_PASSWORD = config.BROKER_PASSWORD
BROKER_TOPIC = config.BROKER_TOPIC


last_parse = datetime.datetime.now()


def filter_logs(change: Change, path: str) -> bool:
    return path.endswith("access.log")


def parse_nginx_log(log):
    lineformat = re.compile(
        r"""(?P<ipaddress>\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}|(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))) - - \[(?P<dateandtime>\d{2}\/[a-z]{3}\/\d{4}:\d{2}:\d{2}:\d{2} (\+|\-)\d{4})\] ((\"(GET|POST|HEAD|PUT|DELETE) )(?P<url>.+)(http\/(1\.1|2\.0)")) (?P<statuscode>\d{3}) (?P<bytessent>\d+) (?P<refferer>-|"([^"]+)") (["](?P<useragent>[^"]+)["])""",
        re.IGNORECASE,
    )
    visits = ()
    global last_parse

    try:
        logfile = open(log)
    except Exception as e:
        print(f"Error while trying to open the logfile: {e}")

    for line in logfile.readlines():
        data = re.search(lineformat, line)
        if data:
            datadict = data.groupdict()
            ip = datadict["ipaddress"]
            datetimestring = datadict["dateandtime"]
            date = parser.parse(datetimestring, fuzzy=True, ignoretz=True)

            if last_parse > date:
                # if a visitors is from the past (before the script launch or already processed), ignore it
                continue

            if ip in visits:
                # ignore IP adresses that are already seen
                continue

            # add the IP address to a tuple
            visits = (*visits, ip)

    # save the parsing datetime for later
    last_parse = datetime.datetime.now()

    return visits


def to_color(ip_address):
    # converts an IP (or any string) to a color code (hex value)

    hash = hashlib.shake_256(ip_address.encode(), usedforsecurity=False).digest(3)
    # concatenate the 3 hex shit into one ('0x87', '0xc3', '0xd2' to '0x87c3d2')
    # #cursedCode
    # return hex(((hash[0] << 8) | hash[1]) << 8 | hash[2])
    return (int(hash[0]), int(hash[1]), int(hash[2]))


def to_mqtt(payload):
    try:
        publish.single(
            topic=f"{BROKER_TOPIC}/visits",
            payload=json.dumps({"color": payload}),
            qos=0,
            hostname=BROKER_HOST,
            port=BROKER_PORT,
            auth={"username": BROKER_ACCOUNT, "password": BROKER_PASSWORD},
            client_id="bisitariak",
        )
    except Exception as e:
        print(f"Error while trying to publish on the broker: {e}")


### actual script:


for changes in watch(LOG_DIR, watch_filter=filter_logs):
    for log in changes:
        logfile = log[1]
        for ip in parse_nginx_log(logfile):
            color = to_color(ip)
            to_mqtt(color)
            print(f"published color '{color}' for IP '{ip}'")