don't save ticket state in multiple locations

core/tickets/models.py

@@ -2,6 +2,8 @@ from django.db import models
 from django_softdelete.models import SoftDeleteModel
 
 from inventory.models import Event
+from django.db.models.signals import post_save
+from django.dispatch import receiver
 
 STATE_CHOICES = (
     ('pending_new', 'New'),
@@ -24,11 +26,23 @@ STATE_CHOICES = (
 class IssueThread(SoftDeleteModel):
     id = models.AutoField(primary_key=True)
     name = models.CharField(max_length=255)
-    state = models.CharField('state', choices=STATE_CHOICES, max_length=32, default='pending_new')
     assigned_to = models.CharField(max_length=255, null=True)
     last_activity = models.DateTimeField(auto_now=True)
     manually_created = models.BooleanField(default=False)
 
+    @property
+    def state(self):
+        try:
+            return self.state_changes.order_by('-timestamp').first().state
+        except AttributeError:
+            return 'none'
+
+    @state.setter
+    def state(self, value):
+        if self.state == value:
+            return
+        self.state_changes.create(state=value)
+
     class Meta:
         permissions = [
             ('send_mail', 'Can send mail'),
@@ -36,6 +50,12 @@ class IssueThread(SoftDeleteModel):
         ]
 
 
+@receiver(post_save, sender=IssueThread)
+def create_issue_thread(sender, instance, created, **kwargs):
+    if created:
+        StateChange.objects.create(issue_thread=instance, state='pending_new')
+
+
 class Comment(models.Model):
     id = models.AutoField(primary_key=True)
     issue_thread = models.ForeignKey(IssueThread, on_delete=models.CASCADE, related_name='comments')
@@ -46,5 +66,5 @@ class Comment(models.Model):
 class StateChange(models.Model):
     id = models.AutoField(primary_key=True)
     issue_thread = models.ForeignKey(IssueThread, on_delete=models.CASCADE, related_name='state_changes')
-    state = models.CharField(max_length=255)
+    state = models.CharField(max_length=255, choices=STATE_CHOICES, default='pending_new')
     timestamp = models.DateTimeField(auto_now_add=True)