class PermsFunction(object):

    """Base function for other check functions"""

    def __init__(self, *perms):

        self.required_perms = set(perms)

        self.user_perms = None

        self.repo_name = None

        self.group_name = None

    def __nonzero__(self):

        """ Defend against accidentally forgetting to call the object

            and instead evaluating it directly in a boolean context,

            which could have security implications.

        """

        raise AssertionError(self.__class__.__name__ + ' is not a bool and must be called!')

    def __call__(self, check_location='unspecified location'):

        user = request.user

        assert user

        assert isinstance(user, AuthUser), user

        cls_name = self.__class__.__name__

        check_scope = self._scope()

        log.debug('checking cls:%s %s usr:%s %s @ %s', cls_name,

                  self.required_perms, user, check_scope,

                  check_location)

        self.user_perms = user.permissions

        result = self.check_permissions()

        result_text = 'granted' if result else 'denied'

        log.debug('Permission to %s %s for user: %s @ %s',

            check_scope, result_text, user, check_location)

        return result

    def check_permissions(self):

        """Dummy function for overriding"""

        raise Exception('You have to write this function in child class')

    def _scope(self):

        return '(unknown scope)'

class HasPermissionAny(PermsFunction):

    def check_permissions(self):

        if self.required_perms.intersection(self.user_perms.get('global')):

            return True

        return False

class HasRepoPermissionAny(PermsFunction):

    def __call__(self, repo_name=None, check_location=''):

        self.repo_name = repo_name

        return super(HasRepoPermissionAny, self).__call__(check_location)

    def check_permissions(self):

        if not self.repo_name:

            self.repo_name = get_repo_slug(request)

        try:

            self._user_perms = set(

                [self.user_perms['repositories'][self.repo_name]]

            )

        except KeyError:

            return False

        if self.required_perms.intersection(self._user_perms):

            return True

        return False

    def _scope(self):

        return 'repo:%s' % self.repo_name

class HasRepoGroupPermissionAny(PermsFunction):

    def __call__(self, group_name=None, check_location=''):

        self.group_name = group_name

        return super(HasRepoGroupPermissionAny, self).__call__(check_location)

    def check_permissions(self):

        try:

            self._user_perms = set(

                [self.user_perms['repositories_groups'][self.group_name]]

            )

        except KeyError:

            return False

        if self.required_perms.intersection(self._user_perms):

            return True

        return False

    def _scope(self):

        return 'repogroup:%s' % self.group_name

class HasUserGroupPermissionAny(PermsFunction):

    def __call__(self, user_group_name=None, check_location=''):

        self.user_group_name = user_group_name

        return super(HasUserGroupPermissionAny, self).__call__(check_location)