#!/usr/bin/env python3
"""Asynchronous network monitoring script, reports current state every 5 seconds."""

from ipaddress import (
    IPv4Address as IPAddress,
    IPv4Network as IPNetwork,
    IPv4Interface as IPInterface,
    AddressValueError,
)

from dbus_fast.aio import MessageBus
from dbus_fast import Variant, BusType
import re
import asyncio
from subprocess import PIPE
import functools

MONITOR_IPS = {"ezrinet": IPAddress("10.242.3.1"), "internet": IPAddress("1.1.1.1")}

INTERFACE_IGNORE_PATTERNS = [
    re.compile(r"^vb-"),
    re.compile(r"^vz-"),
    re.compile(r"^virbr[0-9]+"),
    re.compile(r"^lo$"),
]


def timer(interval: float, initial_delay: float = 0):
    """Decorate a function or coroutine to run it on the given interval."""

    def decorator(func):

        async def do_interval():
            try:
                await asyncio.sleep(initial_delay)
                while True:
                    await func()
                    await asyncio.sleep(interval)
            except asyncio.CancelledError:
                return

        def start():
            loop = asyncio.get_running_loop()
            if "_timer_task" in func.__dict__:
                raise Exception("Timer is already running.")
            func.__dict__["_timer_task"] = loop.create_task(do_interval())

        func.__dict__["start"] = start
        return func

    return decorator


async def ping(address: IPAddress) -> tuple[bool, float | None]:
    """Ping a host and return a tuple of [success, ping time]."""
    proc = await asyncio.create_subprocess_exec(
        "ping", "-c1", "-w1", "-n", str(address), stdout=PIPE
    )
    stdout, stderr = await proc.communicate()

    _match = re.search(
        r"icmp_seq=1 ttl=[0-9]+ time=([0-9]+\.?[0-9]*) ms", stdout.decode("utf-8")
    )
    if _match is None:
        return (False, None)
    else:
        return (True, float(_match.group(1)))


@timer(5)
async def ping_checks():
    """Recurring ping checks for configured IP addresses."""