import re
ipv4_pattern = re.compile(r"(\d+)\.(\d+)\.(\d+)\.(\d+)", re.ASCII)


def read_ips(f):
    # TODO: make async and more robust. (regex pls)
    # TODO: does readlines() block if the pipe is left open i.e. user input?
    for ip in f.readlines():
        if "#" in ip:
            ip, _, _ = ip.partition("#")
        ip = ip.strip()
        if ip.count(".") != 3:
            continue
        yield ip


def addr_to_int(ip):
    match = ipv4_pattern.fullmatch(ip)
    assert match is not None, row
    segs = list(map(int, match.group(1, 2, 3, 4)))
    assert all(0 <= seg <= 255 for seg in segs), match.group(0)
    numeric = segs[0] << 24 | segs[1] << 16 | segs[2] << 8 | segs[3]
    return numeric


def ipkey(ip_string):
    # this is more lenient than addr_to_int.
    segs = [int(s) for s in ip_string.replace(":", ".").split(".")]
    return sum(256**(3 - i) * seg for i, seg in enumerate(segs))