v0.2 Preview: Construction Plan.

backend/engagement/models.py

@@ -0,0 +1,24 @@
+from django.conf import settings
+from django.db import models
+
+
+class DailyCheckIn(models.Model):
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="checkins")
+    date = models.DateField()
+    streak = models.PositiveIntegerField(default=1)
+    reward = models.JSONField(default=dict)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(fields=("user", "date"), name="unique_user_daily_checkin")
+        ]
+
+
+class Notification(models.Model):
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="notifications")
+    category = models.CharField(max_length=40)
+    title = models.CharField(max_length=120)
+    body = models.TextField()
+    is_read = models.BooleanField(default=False)
+    created_at = models.DateTimeField(auto_now_add=True)