# Copyright 2014-2015, Tresys Technology, LLC
#
# SPDX-License-Identifier: LGPL-2.1-only
#
import logging
import re
from typing import Iterable

from .descriptors import CriteriaSetDescriptor
from .mixins import MatchName
from .policyrep import TypeAttribute
from .query import PolicyQuery
from .util import match_regex_or_set


class TypeAttributeQuery(MatchName, PolicyQuery):

    """
    Query SELinux policy type attributes.

    Parameter:
    policy            The policy to query.

    Keyword Parameters/Class attributes:
    name                The type name to match.
    name_regex          If true, regular expression matching
                        will be used on the type names.
    types               The type to match.
    types_equal         If true, only attributes with type sets
                        that are equal to the criteria will
                        match.  Otherwise, any intersection
                        will match.
    types_regex         If true, regular expression matching
                        will be used on the type names instead
                        of set logic.
    """

    types = CriteriaSetDescriptor("types_regex", "lookup_type")
    types_equal: bool = False
    types_regex: bool = False

    def __init__(self, policy, **kwargs) -> None:
        super(TypeAttributeQuery, self).__init__(policy, **kwargs)
        self.log = logging.getLogger(__name__)

    def results(self) -> Iterable[TypeAttribute]:
        """Generator which yields all matching types."""
        self.log.info("Generating type attribute results from {0.policy}".format(self))
        self._match_name_debug(self.log)
        self.log.debug("Types: {0.types!r}, regex: {0.types_regex}, "
                       "eq: {0.types_equal}".format(self))

        for attr in self.policy.typeattributes():
            if not self._match_name(attr):
                continue

            if self.types and not match_regex_or_set(
                    set(attr.expand()),
                    self.types,
                    self.types_equal,
                    self.types_regex):
                continue

            yield attr
