##############################################################################
#
# Copyright (c) 2005 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""zope.security support for the configuration handlers
"""
from zope.interface import providedBy
from zope.proxy import ProxyBase
from zope.proxy import getProxiedObject

from zope.component._compat import ZOPE_SECURITY_NOT_AVAILABLE_EX

try:
    from zope.security.adapter import LocatingTrustedAdapterFactory
    from zope.security.adapter import LocatingUntrustedAdapterFactory
    from zope.security.adapter import TrustedAdapterFactory
    from zope.security.checker import Checker
    from zope.security.checker import CheckerPublic
    from zope.security.checker import InterfaceChecker
    from zope.security.proxy import Proxy
except ZOPE_SECURITY_NOT_AVAILABLE_EX: # pragma: no cover
    def _no_security(*args, **kw):
        raise TypeError(
            "security proxied components are not "
            "supported because zope.security is not available")

    LocatingTrustedAdapterFactory = _no_security
    LocatingUntrustedAdapterFactory = _no_security
    TrustedAdapterFactory = _no_security
    Checker = _no_security
    CheckerPublic = _no_security
    InterfaceChecker = _no_security


PublicPermission = 'zope.Public'

class PermissionProxy(ProxyBase):

    __slots__ = ('__Security_checker__', )

    def __providedBy__(self):
        return providedBy(getProxiedObject(self))
    __providedBy__ = property(__providedBy__)

def _checker(_context, permission, allowed_interface, allowed_attributes):
    if (not allowed_attributes) and (not allowed_interface):
        allowed_attributes = ["__call__"]

    if permission == PublicPermission:
        permission = CheckerPublic

    require = {}
    if allowed_attributes:
        for name in allowed_attributes:
            require[name] = permission
    if allowed_interface:
        for i in allowed_interface:
            for name in i.names(all=True):
                require[name] = permission

    checker = Checker(require)
    return checker

def proxify(ob, checker=None, provides=None, permission=None):
    """Try to get the object proxied with the `checker`, but not too soon

    We really don't want to proxy the object unless we need to.
    """

    if checker is None:
        if provides is None or permission is None:
            raise ValueError('Required arguments: '
                             'checker or both provides and permissions')
        if permission == PublicPermission:
            permission = CheckerPublic
        checker = InterfaceChecker(provides, permission)
    ob = PermissionProxy(ob)
    ob.__Security_checker__ = checker
    return ob

def protectedFactory(original_factory, provides, permission):
    if permission == PublicPermission:
        permission = CheckerPublic
    checker = InterfaceChecker(provides, permission)
    # This has to be named 'factory', aparently, so as not to confuse apidoc :(
    def factory(*args):
        ob = original_factory(*args)
        try:
            ob.__Security_checker__ = checker
        except AttributeError:
            ob = Proxy(ob, checker)
        return ob
    factory.factory = original_factory
    return factory

def securityAdapterFactory(factory, permission, locate, trusted):
    if permission == PublicPermission:
        permission = CheckerPublic
    if locate or (permission is not None and permission is not CheckerPublic):
        if trusted:
            return LocatingTrustedAdapterFactory(factory)
        else:
            return LocatingUntrustedAdapterFactory(factory)
    elif trusted:
        return TrustedAdapterFactory(factory)
    else:
        return factory