import grok
from hurry.file.interfaces import IFileRetrieval
from zope.authentication.interfaces import IAuthentication
from zope.component import getUtilitiesFor
from zope.component.interfaces import ObjectEvent
from zope.pluggableauth import PluggableAuthentication
from waeup.sirp.authentication import setup_authentication
from waeup.sirp.datacenter import DataCenter
from waeup.sirp.students.container import StudentsContainer
from waeup.sirp.imagestorage import ImageStorageFileRetrieval, ImageStorage
from waeup.sirp.interfaces import (
    IUniversity, IWAeUPSIRPPluggable, IObjectUpgradeEvent, )
from waeup.sirp.users import UserContainer
from waeup.sirp.utils.logger import Logger
from waeup.sirp.utils.helpers import attrs_to_fields

class University(grok.Application, grok.Container, Logger):
    """A university.
    """
    grok.implements(IUniversity)

    # Setup authentication for this app. Note: this is only
    # initialized, when a new instance of this app is created.
    grok.local_utility(
        PluggableAuthentication, provides = IAuthentication,
        setup = setup_authentication,)

    grok.local_utility(
        ImageStorageFileRetrieval, provides = IFileRetrieval)

    def __init__(self, *args, **kw):
        super(University, self).__init__(*args, **kw)
        self.setup()
        return

    def setup(self):
        """Setup some hard-wired components.

        Create local datacenter, containers for users, students and
        the like.
        """
        self['users'] = UserContainer()
        self['datacenter'] = DataCenter()
        self['images'] = ImageStorage()
        self['students'] = StudentsContainer()
        self._createPlugins()

    def _createPlugins(self):
        """Create instances of all plugins defined somewhere.
        """
        for name, plugin in getUtilitiesFor(IWAeUPSIRPPluggable):
            plugin.setup(self, name, self.logger)
        return

    def updatePlugins(self):
        """Lookup all plugins and call their `update()` method.
        """
        name = getattr(self, '__name__', '<Unnamed>')
        self.logger.info('Fire upgrade event for site %s' % name)
        grok.notify(ObjectUpgradeEvent(self))
        self.logger.info('Done.')
        self.logger.info('Now upgrading any plugins.')
        for name, plugin in getUtilitiesFor(IWAeUPSIRPPluggable):
            plugin.update(self, name, self.logger)
        self.logger.info('Plugin update finished.')
        return
attrs_to_fields(University)

class ObjectUpgradeEvent(ObjectEvent):
    """An event fired, when datacenter storage moves.
    """
    grok.implements(IObjectUpgradeEvent)

@grok.subscribe(University, grok.IObjectAddedEvent)
def handle_university_added(app, event):
    app.logger.info('University `%s` added.' % getattr(app, '__name__', None))
    return