from django.dispatch import Signal

event_created = Signal(providing_args=['event'])
event_updated = Signal(providing_args=['event', 'diff', 'user'])
event_status_updated = Signal(providing_args=['event', 'flag'])
event_registration_closed = Signal(providing_args=['event', 'user'])


def signal_handler_for_event_update(sender, **kwargs):
    event = kwargs.get('event')
    diff = kwargs.get('diff')
    updater = kwargs.get('user')
    event.workflow.send_emails_on_update(diff, updater)


def signal_handler_for_event_status_update(sender, **kwargs):
    event = kwargs.get('event')
    flag = kwargs.get('flag')
    event.workflow.send_emails_on_status_update(flag)


def signal_handler_for_event_registration_closed(sender, **kwargs):
    event = kwargs.get('event')
    updater = kwargs.get('user')
    event.workflow.send_emails_on_registration_closed(updater)