class AuthUser(object):

    """

    Represents a Kallithea user, including various authentication and

    authorization information. Typically used to store the current user,

    but is also used as a generic user information data structure in

    parts of the code, e.g. user management.

    Constructed from user ID, API key or cookie dict, it looks

    up the matching database `User` and copies all attributes to itself,

    adding various non-persistent data. If lookup fails but anonymous

    access to Kallithea is enabled, the default user is loaded instead.

    `AuthUser` does not by itself authenticate users and the constructor

    sets the `is_authenticated` field to False, except when falling back

    to the default anonymous user (if enabled). It's up to other parts

    of the code to check e.g. if a supplied password is correct, and if

    so, set `is_authenticated` to True.

    However, `AuthUser` does refuse to load a user that is not `active`.

    """

    def __init__(self, user_id=None, api_key=None,

            is_external_auth=False):

        self.is_authenticated = False

        self.is_external_auth = is_external_auth

        user_model = UserModel()

        self.anonymous_user = User.get_default_user(cache=True)

        is_user_loaded = False

        # lookup by userid

        # try go get user by API key

        else:

            log.debug('No data in %s that could been used to log in' % self)

        # If user cannot be found, try falling back to anonymous.

        if not is_user_loaded:

            is_user_loaded =  user_model.fill_data(self, self.anonymous_user)

        # The anonymous user is always "logged in".

        if self.user_id == self.anonymous_user.user_id:

            self.is_authenticated = True

        if not self.username:

            self.username = 'None'

        log.debug('Auth User is now %s' % self)

    def __get_perms(self, user, explicit=True, algo='higherwin', cache=False):

        """

        Fills user permission attribute with permissions taken from database

        works for permissions given for repositories, and for permissions that

        are granted to groups

        :param user: `AuthUser` instance

        :param explicit: In case there are permissions both for user and a group

            that user is part of, explicit flag will define if user will

            explicitly override permissions from group, if it's False it will

            make decision based on the algo

        :param algo: algorithm to decide what permission should be choose if

            it's multiple defined, eg user in two different groups. It also

            decides if explicit flag is turned off how to specify the permission

            for case when user is in a group + have defined separate permission

        """

        user_id = user.user_id

        user_is_admin = user.is_admin

        user_inherit_default_permissions = user.inherit_default_permissions

        log.debug('Getting PERMISSION tree')

        compute = conditional_cache('short_term', 'cache_desc',

                                    condition=cache, func=_cached_perms_data)

        return compute(user_id, user_is_admin,