def deletable(self):

        return self.created_on > datetime.datetime.now() - datetime.timedelta(minutes=5)

class ChangesetStatus(Base, BaseModel):

    __tablename__ = 'changeset_statuses'

    __table_args__ = (

        Index('cs_revision_idx', 'revision'),

        Index('cs_version_idx', 'version'),

        Index('cs_pull_request_id_idx', 'pull_request_id'),

        Index('cs_changeset_comment_id_idx', 'changeset_comment_id'),

        Index('cs_pull_request_id_user_id_version_idx', 'pull_request_id', 'user_id', 'version'),

        Index('cs_repo_id_pull_request_id_idx', 'repo_id', 'pull_request_id'),

        UniqueConstraint('repo_id', 'revision', 'version'),

        _table_args_default_dict,

    )

    STATUS_NOT_REVIEWED = DEFAULT = 'not_reviewed'

    STATUS_APPROVED = 'approved'

    STATUS_REJECTED = 'rejected' # is shown as "Not approved" - TODO: change database content / scheme

    STATUS_UNDER_REVIEW = 'under_review'

    STATUSES = [

        (STATUS_NOT_REVIEWED, _("Not reviewed")),  # (no icon) and default

        (STATUS_REJECTED, _("Not approved")),

    ]

    STATUSES_DICT = dict(STATUSES)

    changeset_status_id = Column(Integer(), unique=True, primary_key=True)

    repo_id = Column(Integer(), ForeignKey('repositories.repo_id'), nullable=False)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=False)

    revision = Column(String(40), nullable=True)

    status = Column(String(128), nullable=False, default=DEFAULT)

    changeset_comment_id = Column(Integer(), ForeignKey('changeset_comments.comment_id'), nullable=False)

    modified_at = Column(DateTime(), nullable=False, default=datetime.datetime.now)

    version = Column(Integer(), nullable=False, default=0)

    pull_request_id = Column(Integer(), ForeignKey('pull_requests.pull_request_id'), nullable=True)

    author = relationship('User')

    repo = relationship('Repository')

    comment = relationship('ChangesetComment')

    pull_request = relationship('PullRequest')

    def __unicode__(self):

        return u"<%s('%s:%s')>" % (

            self.__class__.__name__,

            self.status, self.author

        )