#!/usr/bin/env python3

from csv import DictReader
from datetime import datetime, timezone
from os import scandir
from os.path import join


def parse():
    NOW = datetime.now()
    active_leases = {}
    for file in scandir("/var/lib/kea/"):
        with open(file.path) as f:
            for row in DictReader(f):
                expires = datetime.fromtimestamp(int(row["expire"]))

                if expires >= NOW:
                    if (
                        row["address"] not in active_leases
                        or active_leases[row["address"]]["expires_dt"] < expires
                    ):
                        row["expires_dt"] = expires
                        active_leases[row["address"]] = row
    return active_leases.values()


def print_table(leases):
    print(""" address         | MAC               | expires | hostname
-----------------+-------------------+---------+----------""")
    for lease in sorted(leases, key=lambda r: r["address"]):
        print(
            f' {lease["address"]:<15} | {lease["hwaddr"].lower()} |  {lease["expires_dt"]:%H:%M}  | {lease["hostname"]}'
        )


if __name__ == "__main__":
    print_table(parse())
