from zope.interface import implements

from twisted.cred import portal, checkers, credentials
 
from nevow import inevow, rend, tags, guard, loaders
 
class MyPage(rend.Page):
    addSlash = True
    docFactory = loaders.stan(
    tags.html[
        tags.head[tags.title["Hi Boy"]],
        tags.body[
            tags.invisible(render=tags.directive("isLogged"))[
                tags.div(pattern="False")[
                    tags.form(action=guard.LOGIN_AVATAR, method='post')[
                        tags.table[
                            tags.tr[
                                tags.td[ "Username:" ],
                                tags.td[ tags.input(type='text',name='username') ],
                            ],
                            tags.tr[
                                tags.td[ "Password:" ],
                                tags.td[ tags.input(type='password',name='password') ],
                            ]
                        ],
                        tags.input(type='submit'),
                        tags.p,
                    ]
                ],
                tags.invisible(pattern="True")[
                    tags.h3["Hi bro"],
                    tags.invisible(render=tags.directive("sessionId")),
                    tags.br,
                    tags.a(href=guard.LOGOUT_AVATAR)["Logout"]
                ]
            ]
        ]
    ])
 
    def __init__(self, avatarId=None):
        rend.Page.__init__(self)
        self.avatarId=avatarId
 
    def render_isLogged(self, context, data):
        q = inevow.IQ(context)
        true_pattern = q.onePattern('True')
        false_pattern = q.onePattern('False')
        if self.avatarId: return true_pattern or context.tag().clear()
        else: return false_pattern or context.tag().clear()
 
    def render_sessionId(self, context, data):
        sess = inevow.ISession(context)
        return context.tag[sess.uid]
 
    def logout(self):
        print "Bye"
 
### Authentication
def noLogout():
    return None
 
 
class MyRealm:
    """A simple implementor of cred's IRealm.
       For web, this gives us the LoggedIn page.
    """
    implements(portal.IRealm)
 
    def requestAvatar(self, avatarId, mind, *interfaces):
        for iface in interfaces:
            if iface is inevow.IResource:
                # do web stuff
                if avatarId is checkers.ANONYMOUS:
                    resc = MyPage()
                    resc.realm = self
                    return (inevow.IResource, resc, noLogout)
                else:
                    resc = MyPage(avatarId)
                    resc.realm = self
                    return (inevow.IResource, resc, resc.logout)
 
        raise NotImplementedError("Can't support that interface.")
 
 
### Application setup

def createResource():
    realm = MyRealm()
    porta = portal.Portal(realm)

    myChecker = checkers.InMemoryUsernamePasswordDatabaseDontUse()
    myChecker.addUser("user","password")
    myChecker.addUser("fred", "flintstone")
    porta.registerChecker(checkers.AllowAnonymousAccess(), credentials.IAnonymous)
    porta.registerChecker(myChecker)
    res = guard.SessionWrapper(porta)
    
    return res