# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license

# Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
# provided that the above copyright notice and this permission notice
# appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

import dns.rdtypes.mxbase
import struct

class A(dns.rdtypes.mxbase.MXBase):

    """A record for Chaosnet
    @ivar domain: the domain of the address
    @type domain: dns.name.Name object
    @ivar address: the 16-bit address
    @type address: int"""

    __slots__ = ['domain', 'address']

    def __init__(self, rdclass, rdtype, address, domain):
        super(A, self).__init__(rdclass, rdtype, address, domain)
        self.domain = domain
        self.address = address

    def to_text(self, origin=None, relativize=True, **kw):
        domain = self.domain.choose_relativity(origin, relativize)
        return '%s %o' % (domain, self.address)

    @classmethod
    def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
        domain = tok.get_name()
        address = tok.get_uint16(base=8)
        domain = domain.choose_relativity(origin, relativize)
        tok.get_eol()
        return cls(rdclass, rdtype, address, domain)

    def to_wire(self, file, compress=None, origin=None):
        self.domain.to_wire(file, compress, origin)
        pref = struct.pack("!H", self.address)
        file.write(pref)

    def to_digestable(self, origin=None):
        return self.domain.to_digestable(origin) + \
            struct.pack("!H", self.address)

    @classmethod
    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
        (domain, cused) = dns.name.from_wire(wire[: current + rdlen-2],
                                               current)
        current += cused
        (address,) = struct.unpack('!H', wire[current: current + 2])
        if cused+2 != rdlen:
            raise dns.exception.FormError
        if origin is not None:
            domain = domain.relativize(origin)
        return cls(rdclass, rdtype, address, domain)

    def choose_relativity(self, origin=None, relativize=True):
        self.domain = self.domain.choose_relativity(origin, relativize)