# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.

from __future__ import absolute_import, division, print_function

import abc
import ipaddress
import warnings
from email.utils import parseaddr

import six
from six.moves import urllib_parse

from cryptography import utils
from cryptography.x509.name import Name
from cryptography.x509.oid import ObjectIdentifier


_GENERAL_NAMES = {
    0: "otherName",
    1: "rfc822Name",
    2: "dNSName",
    3: "x400Address",
    4: "directoryName",
    5: "ediPartyName",
    6: "uniformResourceIdentifier",
    7: "iPAddress",
    8: "registeredID",
}


def _lazy_import_idna():
    # Import idna lazily becase it allocates a decent amount of memory, and
    # we're only using it in deprecated paths.
    try:
        import idna
        return idna
    except ImportError:
        raise ImportError(
            "idna is not installed, but a deprecated feature that requires it"
            " was used. See: https://cryptography.io/en/latest/faq/#importe"
            "rror-idna-is-not-installed"
        )


class UnsupportedGeneralNameType(Exception):
    def __init__(self, msg, type):
        super(UnsupportedGeneralNameType, self).__init__(msg)
        self.type = type


@six.add_metaclass(abc.ABCMeta)
class GeneralName(object):
    @abc.abstractproperty
    def value(self):
        """
        Return the value of the object
        """


@utils.register_interface(GeneralName)
class RFC822Name(object):
    def __init__(self, value):
        if isinstance(value, six.text_type):
            try:
                value.encode("ascii")
            except UnicodeEncodeError:
                value = self._idna_encode(value)
                warnings.warn(
                    "RFC822Name values should be passed as an A-label string. "
                    "This means unicode characters should be encoded via "
                    "idna. Support for passing unicode strings (aka U-label) "
                    "will be removed in a future version.",
                    utils.DeprecatedIn21,
                    stacklevel=2,
                )
        else:
            raise TypeError("value must be string")

        name, address = parseaddr(value)
        if name or not address:
            # parseaddr has found a name (e.g. Name <email>) or the entire
            # value is an empty string.
            raise ValueError("Invalid rfc822name value")

        self._value = value

    value = utils.read_only_property("_value")

    @classmethod
    def _init_without_validation(cls, value):
        instance = cls.__new__(cls)
        instance._value = value
        return instance

    def _idna_encode(self, value):
        idna = _lazy_import_idna()
        _, address = parseaddr(value)
        parts = address.split(u"@")
        return parts[0] + "@" + idna.encode(parts[1]).decode("ascii")

    def __repr__(self):
        return "<RFC822Name(value={0!r})>".format(self.value)

    def __eq__(self, other):
        if not isinstance(other, RFC822Name):
            return NotImplemented

        return self.value == other.value

    def __ne__(self, other):
        return not self == other

    def __hash__(self):
        return hash(self.value)


def _idna_encode(value):
    idna = _lazy_import_idna()
    # Retain prefixes '*.' for common/alt names and '.' for name constraints
    for prefix in ['*.', '.']:
        if value.startswith(prefix):
            value = value[len(prefix):]
            return prefix + idna.encode(value).decode("ascii")
    return idna.encode(value).decode("ascii")


@utils.register_interface(GeneralName)
class DNSName(object):
    def __init__(self, value):
        if isinstance(value, six.text_type):
            try:
                value.encode("ascii")
            except UnicodeEncodeError:
                value = _idna_encode(value)
                warnings.warn(
                    "DNSName values should be passed as an A-label string. "
                    "This means unicode characters should be encoded via "
                    "idna. Support for passing unicode strings (aka U-label) "
                    "will be removed in a future version.",
                    utils.DeprecatedIn21,
                    stacklevel=2,
                )
        else:
            raise TypeError("value must be string")

        self._value = value

    value = utils.read_only_property("_value")

    @classmethod
    def _init_without_validation(cls, value):
        instance = cls.__new__(cls)
        instance._value = value
        return instance

    def __repr__(self):
        return "<DNSName(value={0!r})>".format(self.value)

    def __eq__(self, other):
        if not isinstance(other, DNSName):
            return NotImplemented

        return self.value == other.value

    def __ne__(self, other):
        return not self == other

    def __hash__(self):
        return hash(self.value)


@utils.register_interface(GeneralName)
class UniformResourceIdentifier(object):
    def __init__(self, value):
        if isinstance(value, six.text_type):
            try:
                value.encode("ascii")
            except UnicodeEncodeError:
                value = self._idna_encode(value)
                warnings.warn(
                    "URI values should be passed as an A-label string. "
                    "This means unicode characters should be encoded via "
                    "idna. Support for passing unicode strings (aka U-label) "
                    " will be removed in a future version.",
                    utils.DeprecatedIn21,
                    stacklevel=2,
                )
        else:
            raise TypeError("value must be string")

        self._value = value

    value = utils.read_only_property("_value")

    @classmethod
    def _init_without_validation(cls, value):
        instance = cls.__new__(cls)
        instance._value = value
        return instance

    def _idna_encode(self, value):
        idna = _lazy_import_idna()
        parsed = urllib_parse.urlparse(value)
        if parsed.port:
            netloc = (
                idna.encode(parsed.hostname) +
                ":{0}".format(parsed.port).encode("ascii")
            ).decode("ascii")
        else:
            netloc = idna.encode(parsed.hostname).decode("ascii")

        # Note that building a URL in this fashion means it should be
        # semantically indistinguishable from the original but is not
        # guaranteed to be exactly the same.
        return urllib_parse.urlunparse((
            parsed.scheme,
            netloc,
            parsed.path,
            parsed.params,
            parsed.query,
            parsed.fragment
        ))

    def __repr__(self):
        return "<UniformResourceIdentifier(value={0!r})>".format(self.value)

    def __eq__(self, other):
        if not isinstance(other, UniformResourceIdentifier):
            return NotImplemented

        return self.value == other.value

    def __ne__(self, other):
        return not self == other

    def __hash__(self):
        return hash(self.value)


@utils.register_interface(GeneralName)
class DirectoryName(object):
    def __init__(self, value):
        if not isinstance(value, Name):
            raise TypeError("value must be a Name")

        self._value = value

    value = utils.read_only_property("_value")

    def __repr__(self):
        return "<DirectoryName(value={0})>".format(self.value)

    def __eq__(self, other):
        if not isinstance(other, DirectoryName):
            return NotImplemented

        return self.value == other.value

    def __ne__(self, other):
        return not self == other

    def __hash__(self):
        return hash(self.value)


@utils.register_interface(GeneralName)
class RegisteredID(object):
    def __init__(self, value):
        if not isinstance(value, ObjectIdentifier):
            raise TypeError("value must be an ObjectIdentifier")

        self._value = value

    value = utils.read_only_property("_value")

    def __repr__(self):
        return "<RegisteredID(value={0})>".format(self.value)

    def __eq__(self, other):
        if not isinstance(other, RegisteredID):
            return NotImplemented

        return self.value == other.value

    def __ne__(self, other):
        return not self == other

    def __hash__(self):
        return hash(self.value)


@utils.register_interface(GeneralName)
class IPAddress(object):
    def __init__(self, value):
        if not isinstance(
            value,
            (
                ipaddress.IPv4Address,
                ipaddress.IPv6Address,
                ipaddress.IPv4Network,
                ipaddress.IPv6Network
            )
        ):
            raise TypeError(
                "value must be an instance of ipaddress.IPv4Address, "
                "ipaddress.IPv6Address, ipaddress.IPv4Network, or "
                "ipaddress.IPv6Network"
            )

        self._value = value

    value = utils.read_only_property("_value")

    def __repr__(self):
        return "<IPAddress(value={0})>".format(self.value)

    def __eq__(self, other):
        if not isinstance(other, IPAddress):
            return NotImplemented

        return self.value == other.value

    def __ne__(self, other):
        return not self == other

    def __hash__(self):
        return hash(self.value)


@utils.register_interface(GeneralName)
class OtherName(object):
    def __init__(self, type_id, value):
        if not isinstance(type_id, ObjectIdentifier):
            raise TypeError("type_id must be an ObjectIdentifier")
        if not isinstance(value, bytes):
            raise TypeError("value must be a binary string")

        self._type_id = type_id
        self._value = value

    type_id = utils.read_only_property("_type_id")
    value = utils.read_only_property("_value")

    def __repr__(self):
        return "<OtherName(type_id={0}, value={1!r})>".format(
            self.type_id, self.value)

    def __eq__(self, other):
        if not isinstance(other, OtherName):
            return NotImplemented

        return self.type_id == other.type_id and self.value == other.value

    def __ne__(self, other):
        return not self == other

    def __hash__(self):
        return hash((self.type_id, self.value))