from struct import pack

# A pattern to match the timestamp format that the tai64nlocal program
# produces. It appears in both dnscache and tinydns lines, after
# they've been piped through tai64nlocal, of course.
timestamp_pat = r'[\d-]+ [\d:\.]+'

# A dictionary mapping query type identifiers, in decimal, to their
# friendly names for tinydns. Reference:
#
#   https://en.wikipedia.org/wiki/List_of_DNS_record_types
#
# Note that mapping here is non-exhaustive, and that tinydns will
# log responses for record types that it does not know about.
query_type = {
      1: "a",
      2: "ns",
      5: "cname",
      6: "soa",
     12: "ptr",
     13: "hinfo",
     15: "mx",
     16: "txt",
     17: "rp",
     24: "sig",
     25: "key",
     28: "aaaa",
     33: "srv",
     35: "naptr",
     38: "a6",
     48: "dnskey",
     52: "tlsa",
     65: "https",
    252: "axfr",
    255: "any",
    257: "caa"
}

def convert_ip(ip : str) -> str:
    r"""
    Convert a hex string representing an IP address to
    human-readable form.

    Parameters
    ----------

    ip : str
        The hexadecimal representation of either an IPv4 or an IPv6
        address.

    Returns
    -------

    The usual decimal dotted-quad representation is returned for an
    IPv4 address. IPv6 addresses are returned almost as-is, but with
    colons inserted in the appropriate places, between every four
    characters.

    Examples
    --------

        >>> convert_ip("7f000001")
        '127.0.0.1'
        >>> convert_ip("00000000000000000000ffff7f000001")
        '0000:0000:0000:0000:0000:ffff:7f00:0001'
    """
    if len(ip) == 8:
        # IPv4, eg. "7f000001" -> "7f 00 00 01" -> "127.0.0.1"
        return ".".join(map(str, pack(">L", int(ip, 16))))
    elif len(ip) == 32:
        # IPv6 is actually simpler -- it's just a string-slicing operation.
        return ":".join([ip[(4*i) : (4*i+4)] for i in range(8)])