from django import forms
from django.contrib.auth.models import Group, User

from .fields import KFetPermissionsField


class GroupForm(forms.ModelForm):
    permissions = KFetPermissionsField()

    def clean_name(self):
        name = self.cleaned_data['name']
        return 'K-Fêt %s' % name

    def clean_permissions(self):
        kfet_perms = self.cleaned_data['permissions']
        # TODO: With Django >=1.11, the QuerySet method 'difference' can be
        # used.
        # other_groups = self.instance.permissions.difference(
        #     self.fields['permissions'].queryset
        # )
        if self.instance.pk is None:
            return kfet_perms
        other_perms = self.instance.permissions.exclude(
            pk__in=[p.pk for p in self.fields['permissions'].queryset],
        )
        return list(kfet_perms) + list(other_perms)

    class Meta:
        model = Group
        fields = ['name', 'permissions']


class UserGroupForm(forms.ModelForm):
    groups = forms.ModelMultipleChoiceField(
            Group.objects.filter(name__icontains='K-Fêt'),
            label='Statut équipe',
            required=False)

    def clean_groups(self):
        kfet_groups = self.cleaned_data.get('groups')
        if self.instance.pk is None:
            return kfet_groups
        other_groups = self.instance.groups.exclude(name__icontains='K-Fêt')
        return list(kfet_groups) + list(other_groups)

    class Meta:
        model = User
        fields = ['groups']