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

# Copyright (C) 2001-2017 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
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

import struct

import dns.edns
import dns.immutable
import dns.exception
import dns.rdata


# We don't implement from_text, and that's ok.
# pylint: disable=abstract-method

@dns.immutable.immutable
class OPT(dns.rdata.Rdata):

    """OPT record"""

    __slots__ = ['options']

    def __init__(self, rdclass, rdtype, options):
        """Initialize an OPT rdata.

        *rdclass*, an ``int`` is the rdataclass of the Rdata,
        which is also the payload size.

        *rdtype*, an ``int`` is the rdatatype of the Rdata.

        *options*, a tuple of ``bytes``
        """

        super().__init__(rdclass, rdtype)
        def as_option(option):
            if not isinstance(option, dns.edns.Option):
                raise ValueError('option is not a dns.edns.option')
            return option
        self.options = self._as_tuple(options, as_option)

    def _to_wire(self, file, compress=None, origin=None, canonicalize=False):
        for opt in self.options:
            owire = opt.to_wire()
            file.write(struct.pack("!HH", opt.otype, len(owire)))
            file.write(owire)

    def to_text(self, origin=None, relativize=True, **kw):
        return ' '.join(opt.to_text() for opt in self.options)

    @classmethod
    def from_wire_parser(cls, rdclass, rdtype, parser, origin=None):
        options = []
        while parser.remaining() > 0:
            (otype, olen) = parser.get_struct('!HH')
            with parser.restrict_to(olen):
                opt = dns.edns.option_from_wire_parser(otype, parser)
            options.append(opt)
        return cls(rdclass, rdtype, options)

    @property
    def payload(self):
        "payload size"
        return self.rdclass
