# SPDX-License-Identifier: GPL-3.0-or-later

# Policies for blocking and allowing JS in pages fetched with HTTP.
#
# This file is part of Hydrilla&Haketilo.
#
# Copyright (C) 2022 Wojtek Kosior
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
#
# I, Wojtek Kosior, thereby promise not to sue for violation of this
# file's license. Although I request that you do not make use of this
# code in a proprietary program, I am not going to enforce this in
# court.

"""
.....
"""

import dataclasses as dc
import typing as t

from ...url_patterns import ParsedPattern
from .. import csp
from .. import state
from ..import http_messages
from . import base


class AllowPolicy(base.Policy):
    """...."""
    priority: t.ClassVar[base.PolicyPriority] = base.PolicyPriority._TWO


script_csp_directives = ('script-src', 'script-src-elem', 'script-src-attr')

class BlockPolicy(base.Policy):
    """...."""
    _process_response: t.ClassVar[bool] = True

    priority: t.ClassVar[base.PolicyPriority] = base.PolicyPriority._TWO

    def _csp_to_clear(self, http_info: http_messages.FullHTTPInfo) \
        -> t.Sequence[str]:
        return script_csp_directives

    def _csp_to_add(self, http_info: http_messages.FullHTTPInfo) \
        -> t.Mapping[str, t.Sequence[str]]:
        return dict((d, ["'none'"]) for d in script_csp_directives)


@dc.dataclass(frozen=True)
class RuleAllowPolicy(AllowPolicy):
    """...."""
    pattern: ParsedPattern


@dc.dataclass(frozen=True)
class RuleBlockPolicy(BlockPolicy):
    """...."""
    pattern: ParsedPattern


@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class RulePolicyFactory(base.PolicyFactory):
    """...."""
    pattern: ParsedPattern

    def __lt__(self, other: base.PolicyFactory) -> bool:
        """...."""
        if type(other) is not type(self):
            return super().__lt__(other)

        assert isinstance(other, RulePolicyFactory)

        return self.pattern < other.pattern


@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class RuleBlockPolicyFactory(RulePolicyFactory):
    """...."""
    def make_policy(self, haketilo_state: state.HaketiloState) \
        -> RuleBlockPolicy:
        """...."""
        return RuleBlockPolicy(self.pattern)


@dc.dataclass(frozen=True, unsafe_hash=True) # type: ignore[misc]
class RuleAllowPolicyFactory(RulePolicyFactory):
    """...."""
    def make_policy(self, haketilo_state: state.HaketiloState) \
        -> RuleAllowPolicy:
        """...."""
        return RuleAllowPolicy(self.pattern)