import os

import uuid

from django.core.urlresolvers import reverse

from django.db import models

from django.db.models import Q

from django.utils.translation import ugettext_lazy as _

from django.contrib.auth.models import User

import reversion

from markitup.fields import MarkupField

    end = models.DateTimeField(null=True, blank=True)

    closed = models.NullBooleanField()

    published = models.NullBooleanField()

    @classmethod

    def available(cls):

        return cls._default_manager.filter(

            Q(closed=False) | Q(closed=None),

        )

    def is_available(self):

        if self.closed:

            return False

            return False

            return False

        return True

    def __unicode__(self):

        return self.section.name

        help_text=_("Anything else you'd like the program committee to know when making their "

                    "selection: your past experience, etc. This is not made public. Edit using "

                    "<a href='http://daringfireball.net/projects/markdown/basics' "

                    "target='_blank'>Markdown</a>.")

    )

    submitted = models.DateTimeField(

        editable=False,

    )

    speaker = models.ForeignKey("speakers.Speaker", related_name="proposals")

    additional_speakers = models.ManyToManyField("speakers.Speaker", through="AdditionalSpeaker",

                                                 blank=True)

    cancelled = models.BooleanField(default=False)

class SupportingDocument(models.Model):

    proposal = models.ForeignKey(ProposalBase, related_name="supporting_documents")

    uploaded_by = models.ForeignKey(User)

    file = models.FileField(upload_to=uuid_filename)

    description = models.CharField(max_length=140)

    def download_url(self):

        return reverse("proposal_document_download",