from __future__ import absolute_import

from django import forms
from django.utils.translation import ugettext_lazy as _

from .models import DocumentCheckout
from .exceptions import DocumentAlreadyCheckedOut
from .widgets import SplitTimeDeltaField


class DocumentCheckoutForm(forms.ModelForm):
    expiration_datetime = SplitTimeDeltaField()

    class Meta:
        model = DocumentCheckout
        exclude = ('checkout_datetime', 'user_content_type', 'user_object_id')

        widgets = {
            'document': forms.widgets.HiddenInput(),
        }     

    def clean_document(self):
        document = self.cleaned_data['document']
        if document.is_checked_out():
            raise DocumentAlreadyCheckedOut
        return document