session updates. mostly

backend/playlist/models/session.py

@@ -10,7 +10,7 @@ class Session(models.Model):
 
     @property
     def is_open(self):
-        return datetime.now() < self.opens
+        return (datetime.now() < self.opens) and self.voting_open
 
     opens = models.DateTimeField(null=True, default=None)
     session_id = models.UUIDField(default=uuid.uuid4, editable=False)

backend/playlist/models/vote.py

@@ -5,7 +5,7 @@ from .session import Session
 
 class Vote(models.Model):
     class Meta:
-        unique_together = ["user", "track"]
+        unique_together = ["user", "track", "session"]
     track = models.ForeignKey('Track', on_delete=models.CASCADE)
     user = models.ForeignKey(User, on_delete=models.CASCADE)
     points = models.IntegerField(validators=[MinValueValidator(1), MaxValueValidator(5)])