"""

Tagging components for Django's form library.

"""

from django import forms

from django.utils.translation import ugettext as _

from tagging import settings

from tagging.models import Tag

from tagging.utils import parse_tag_input

class TagAdminForm(forms.ModelForm):

    class Meta:

        model = Tag

    def clean_name(self):

        value = self.cleaned_data['name']

        tag_names = parse_tag_input(value)

        if len(tag_names) > 1:

            raise forms.ValidationError(_('Multiple tags were given.'))

        elif len(tag_names[0]) > settings.MAX_TAG_LENGTH:

            raise forms.ValidationError(

                _('A tag may be no more than %s characters long.') %

                    settings.MAX_TAG_LENGTH)

        return value

class TagField(forms.CharField):

    """

    A ``CharField`` which validates that its input is a valid list of

    tag names.

    """

    def clean(self, value):

        value = super(TagField, self).clean(value)

        if value == u'':

            return value

        for tag_name in parse_tag_input(value):

            if len(tag_name) > settings.MAX_TAG_LENGTH:

                raise forms.ValidationError(

                    _('Each tag may be no more than %s characters long.') %

                        settings.MAX_TAG_LENGTH)

        return value