class ProposalSection(models.Model):

    """

    configuration of proposal submissions for a specific Section.

    a section is available for proposals iff:

      * it is after start (if there is one) and

      * it is before end (if there is one) and

      * closed is NULL or False

    """

    section = models.OneToOneField(Section)

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

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

    closed = models.NullBooleanField()

    published = models.NullBooleanField()

    @classmethod

    def available(cls):

        now = datetime.datetime.now()

            Q(end__gt=now) | Q(end=None),

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

        )

    def is_available(self):

        if self.closed:

            return False

        if self.end and self.end < now:

            return False

        return True

    def __unicode__(self):

        return self.section.name

class ProposalKind(models.Model):

    """

    e.g. talk vs panel vs tutorial vs poster

    Note that if you have different deadlines, reviewers, etc. you'll want

    to distinguish the section as well as the kind.

    """

    section = models.ForeignKey(Section, related_name="proposal_kinds")

    name = models.CharField(_("Name"), max_length=100)

    slug = models.SlugField()

    def __unicode__(self):

        return self.name

class ProposalBase(models.Model):

    objects = InheritanceManager()

    kind = models.ForeignKey(ProposalKind)

    title = models.CharField(max_length=100)

    description = models.TextField(

        _("Brief Description"),

        max_length=400,  # @@@ need to enforce 400 in UI

    )

    abstract = MarkupField(

        _("Detailed Abstract"),

    )

    additional_notes = MarkupField(

        blank=True,

    )

    submitted = models.DateTimeField(

        default=datetime.datetime.now,

        editable=False,

    )

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

    cancelled = models.BooleanField(default=False)

    def can_edit(self):

        return True

    @property

    def section(self):

        return self.kind.section

    @property

    def speaker_email(self):

        return self.speaker.email

    @property

    def number(self):

        return str(self.pk).zfill(3)

    def speakers(self):

        yield self.speaker

            yield speaker

    def notification_email_context(self):

        return {

            "title": self.title,

class AdditionalSpeaker(models.Model):

    SPEAKING_STATUS_PENDING = 1

    SPEAKING_STATUS_ACCEPTED = 2

    SPEAKING_STATUS_DECLINED = 3

    SPEAKING_STATUS = [

        (SPEAKING_STATUS_PENDING, _("Pending")),

        (SPEAKING_STATUS_ACCEPTED, _("Accepted")),

        (SPEAKING_STATUS_DECLINED, _("Declined")),

    ]

    speaker = models.ForeignKey("speakers.Speaker")

    proposalbase = models.ForeignKey(ProposalBase)

    status = models.IntegerField(choices=SPEAKING_STATUS, default=SPEAKING_STATUS_PENDING)

    class Meta:

        db_table = "proposals_proposalbase_additional_speakers"

        unique_together = ("speaker", "proposalbase")

class SupportingDocument(models.Model):

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

    uploaded_by = models.ForeignKey(User)

    created_at = models.DateTimeField(default=datetime.datetime.now)

    file = models.FileField(upload_to=uuid_filename)

    description = models.CharField(max_length=140)

    def download_url(self):