#!/usr/bin/env python3
# -*- coding: utf-8 -*-
""" Author:                     Hendrik Schutter, mail@hendrikschutter.com
    Date of creation:           2023/02/26
    Date of last modification:  2023/02/26
"""

from subprocess import PIPE, Popen
from mac_vendor_lookup import MacLookup
import smtplib
import email.utils
from email.mime.text import MIMEText
import time
import config

def send_alert_mail(mac_addr):
    server = smtplib.SMTP(config.mail_server_domain, config.mail_server_port)
    server.starttls()
    server.login(config.mail_from_address, config.mail_server_password)

    try:
        mac_vendor = MacLookup().lookup(mac_addr)
    except:
        mac_vendor = " Vendor not found"

    timeLong = time.strftime("%d.%m.%Y %H:%M:%S")
    body = "Hallo Admin,\n\nneue MAC-Adresse gefunden!\n\nDatum: "+ timeLong + "\nMAC: " + str(mac_addr) +"\nVendor: " + mac_vendor + "\n\nVersion: 1.0 - 26.02.2023"
    msg = MIMEText(body)
    msg['Subject'] = 'New MAC found: ' + str(mac_addr) + " - " + mac_vendor
    msg['To'] = email.utils.formataddr((config.mail_to_name, config.mail_to_address ))
    msg['From'] = email.utils.formataddr((config.mail_from_name, config.mail_from_address))

    server.sendmail(config.mail_from_address, config.mail_to_address , msg.as_string())
    server.quit()

def query_mac_from_switch():
    mac_addresses = list()
    command = "snmpwalk -v 2c -O vqe -c " + config.switch_snmp_community + " " + config.switch_ip_addr + " 1.3.6.1.2.1.17.4.3.1.1"
    with Popen(command, stdout=PIPE, stderr=None, shell=True) as process:
        output = process.communicate()[0].decode("utf-8")
        for mac in output.split("\n"):
            mac = mac.replace(" ", ":")
            mac = mac.replace('"', "")
            mac = mac[0:-1]
            if(len(mac) == 17):
                mac_addresses.append(mac)
    return mac_addresses

def watch():

    alerted_mac_addresses = list()

    while(True):
        mac_addresses = query_mac_from_switch()
        for mac_address in mac_addresses:
            if mac_address not in config.trusted_mac_addresses:
                if mac_address not in alerted_mac_addresses:
                    alerted_mac_addresses.append(mac_address)
                    send_alert_mail(mac_address)
        time.sleep(10)

if __name__ == "__main__":

    print("updating MAC vendors ...")
    MacLookup().update_vendors()
    print("update done\n")

    try:
        watch()
    except:
        pass