CVAT 1

@rules.predicate
def has_change_permissions(db_user, db_job):
    db_task = db_job.segment.task
    # A job can be annotated by any user if the task's assignee is None.
    has_rights = (db_task.assignee is None and not settings.RESTRICTIONS['reduce_task_visibility']) or is_task_assignee(db_user, db_task)
    if db_job.assignee is not None:
        has_rights |= (db_user == db_job.assignee) and (db_job.status == 'annotation')
    if db_job.reviewer is not None:
        has_rights |= (db_user == db_job.reviewer) and (db_job.status == 'validation')

    return has_rights

rules.add_perm('engine.job.change', has_admin_role | is_job_owner | has_change_permissions)

class TaskChangePermission(BasePermission):
    # pylint: disable=no-self-use
    def has_object_permission(self, request, view, obj):
        return request.user.has_perm('engine.task.change', obj)