Source code for camelot.model.authentication

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"""Set of classes to store authentication and permissions
"""

import datetime
import threading

from sqlalchemy.types import Date, Unicode, DateTime
from sqlalchemy.schema import Column
from sqlalchemy import orm

import camelot.types
from camelot.core.orm import Entity, Session
from camelot.core.utils import ugettext_lazy as _
from camelot.admin.entity_admin import EntityAdmin

def end_of_times():
    return datetime.date( year = 2400, month = 12, day = 31 )

_current_authentication_ = threading.local()

def get_current_authentication( _obj = None ):
    """Get the currently logged in :class:'AuthenticationMechanism'"""
    global _current_authentication_
    if not hasattr( _current_authentication_, 'mechanism' ) \
        or not _current_authentication_.mechanism \
        or not orm.object_session( _current_authentication_.mechanism ):
            import getpass
            _current_authentication_.mechanism = AuthenticationMechanism.get_or_create( unicode( getpass.getuser(), encoding='utf-8', errors='ignore' ) )
    return _current_authentication_.mechanism

def clear_current_authentication():
    _current_authentication_.mechanism = None

def update_last_login():
    """Update the last login of the current person to now"""
    authentication = get_current_authentication()
    authentication.last_login = datetime.datetime.now()
    session = orm.object_session( authentication )
    if session:
        session.flush()

class AuthenticationMechanism( Entity ):
    
    __tablename__ = 'authentication_mechanism'
    
    authentication_type = Column( camelot.types.Enumeration( [ (1, 'operating_system'),
                                                               (2, 'database') ] ),
                                  nullable = False, 
                                  index = True , 
                                  default = 'operating_system' )
    username = Column( Unicode( 40 ), nullable = False, index = True, unique = True )
    password = Column( Unicode( 200 ), nullable = True, index = False, default = None )
    from_date = Column( Date(), default = datetime.date.today, nullable = False, index = True )
    thru_date = Column( Date(), default = end_of_times, nullable = False, index = True )
    last_login = Column( DateTime() )

    @classmethod
    def get_or_create( cls, username ):
        session = Session()
        authentication = session.query( cls ).filter_by( username = username ).first()
        if not authentication:
            authentication = cls( username = username )
            session.add( authentication )
            session.flush()
        return authentication

    def __unicode__( self ):
        return self.username
    
    class Admin( EntityAdmin ):
        verbose_name = _('Authentication mechanism')
        list_display = ['authentication_type', 'username', 'from_date', 'thru_date', 'last_login']