Only undo last voted

playlist/models/profile.py

@@ -1,5 +1,6 @@
 from django.db import models
 from django.contrib.auth.models import User
+from .track import Track
 from django.db.models.signals import post_save
 from django.dispatch import receiver
 
@@ -14,6 +15,7 @@ class Background(models.Model):
 class Profile(models.Model):
     user = models.OneToOneField(User, on_delete=models.CASCADE)
     background = models.ForeignKey(Background, null=True, on_delete=models.SET_NULL)
+    last_voted = models.ForeignKey(Track, null=True, on_delete=models.SET_NULL)
 
 @receiver(post_save, sender=User)
 def create_user_profile(sender, instance, created, **kwargs):