feat: add ShowManager to annotate a show with its max (last) timeslot

program/models.py

@@ -23,7 +23,7 @@ from versatileimagefield.fields import PPOIField, VersatileImageField
 
 from django.contrib.auth.models import User
 from django.db import models
-from django.db.models import Q
+from django.db.models import Max, Q
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 from steering.settings import THUMBNAIL_SIZES
@@ -204,6 +204,13 @@ class HostLink(Link):
     host = models.ForeignKey(Host, on_delete=models.CASCADE, related_name="links")
 
 
+class ShowManager(models.Manager):
+    def with_max_timeslot_start(self):
+        return (
+            super().get_queryset().annotate(max_timeslot_start=Max("schedules__timeslots__start"))
+        )
+
+
 class Show(models.Model):
     category = models.ManyToManyField(Category, blank=True, related_name="shows")
     cba_series_id = models.IntegerField(blank=True, null=True)
@@ -240,6 +247,8 @@ class Show(models.Model):
     updated_at = models.DateTimeField(auto_now=True, blank=True, null=True)
     updated_by = models.CharField(blank=True, default="", max_length=150)
 
+    objects = ShowManager()
+
     class Meta:
         ordering = ("slug",)