#filters.py

#filters.py

from django.db import models
from django.utils.encoding import smart_unicode, iri_to_uri
from django.contrib.admin.util import get_model_from_relation, \
    reverse_field_path, get_limit_choices_to_from_path

from django.contrib.admin.filterspecs import RelatedFilterSpec

from models import Category


class CategoryFilterSpec(RelatedFilterSpec):
    def __init__(self, f, request, params, model, model_admin,
                 field_path=None):
        super(CategoryFilterSpec, self).__init__(
            f, request, params, model, model_admin, field_path=field_path)

        other_model = get_model_from_relation(f)
        if isinstance(f, (models.ManyToManyField,
                          models.related.RelatedObject)):
            # no direct field on this model, get name from other model
            self.lookup_title = other_model._meta.verbose_name
        else:
            self.lookup_title = f.verbose_name # use field name
        rel_name = other_model._meta.pk.name
        self.lookup_kwarg = '%s__%s__in' % (self.field_path, rel_name)
        self.lookup_kwarg_isnull = '%s__isnull' % (self.field_path)
        self.lookup_val = request.GET.get(self.lookup_kwarg, None)
        self.lookup_val_isnull = request.GET.get(
                                      self.lookup_kwarg_isnull, None)
        lookup_choices = f.get_choices(include_blank=False)
        self.lookup_choices = []
        for pk_val, val in lookup_choices:
            c = Category.objects.get(pk = pk_val)

            if c.parent == None:
                q = str(pk_val)+','
                for p in Category.objects.filter(parent=pk_val):
                    q = q+str(p.pk)+','
                q = q[:-1]
                self.lookup_choices.append((q, val))
            else:
                self.lookup_choices.append((pk_val, val))