'''
Created on Apr 5, 2011

@author: leifj
'''

from django.db import models
from django.db.models.fields import CharField, URLField, DateTimeField, IntegerField
from django.contrib.auth.models import Group
from django.db.models.fields.related import OneToOneField
from django.dispatch.dispatcher import Signal
from django_co_connector.settings import CO_ATTRIBUTES
import logging

class GroupConnector(models.Model):
    attribute = CharField(max_length=1024)
    value = CharField(max_length=1024)
    activity_url = URLField(blank=True,null=True)
    membership_url = URLField(blank=True,null=True)
    ttl = IntegerField(blank=True,null=True)
    group = OneToOneField(Group,related_name='connector')
    modify_time = DateTimeField(auto_now=True)
    create_time = DateTimeField(auto_now_add=True)
    
    def __unicode__(self):
        return "%s=%s for %s" % (self.attribute,self.value,self.group.name)
    
    class Meta:
        unique_together = ('attribute','value')
    
    def fetch_updates(self):
        return ([],[])
    
    def fetch_all(self):
        return []
    
    def fetch_meta(self):
        return {}
    
    def update(self):
        # pull JSON to get display and ttl (?)
        (added,removed) = self.fetch_updates()
        for user in added:
            if not self.group in user.groups:
                add_member.send(sender=self.group,user=user)
                user.groups.append(self.group)
        for user in removed:
            if self.group in user.groups:     
                remove_member.send(sender=self.group,user=user)
                user.groups.remove(self.group)
    
add_member = Signal(providing_args=['user'])
remove_member = Signal(providing_args=['user'])

def co_import_from_request(request):
    for attribute in CO_ATTRIBUTES:
        logging.debug(attribute)
        values = request.META.get(attribute)                 
        if values and values != "(null)":
            logging.debug("%s: %s" % (attribute,values))
            co_import_av(request.user,attribute,values.split(';'))

def co_import_av(user,attribute,values):
    for value in values:
        gco = GroupConnector.objects.filter(attribute=attribute,value=value)
        if not gco:
            group,created = Group.objects.get_or_create(name=value)
            gco = GroupConnector.objects.create(attribute=attribute,value=value,group=group)
            
            meta = gco.fetch_meta()
            changed = False
            for attr in ('name','ttl','activity_url','membership_url'):
                if meta.has_key(attr):
                    setattr(gco,attr,meta.get(attr))
                    changed = True
            
            #members = gco.fetch_all()
            #for user in members:
            #    if not gco.group in user.groups:
            #        add_member.send(sender=gco.group,user=user)
            #        user.groups.apppend(gco.group)
            #        user.save()
            
            if changed:
                gco.save()
                gco.group.save()
    
    for gco in GroupConnector.objects.filter(attribute=attribute):
        if not gco.value in values:
            if gco.group in user.groups.all():
                remove_member.send(sender=gco.group,user=user)
                user.groups.remove(gco.group)
                user.save()
        else:
            if not gco.group in user.groups.all():
                add_member.send(sender=gco.group,user=user)
                user.groups.apppend(gco.group)
                user.save()