Booking lifecycle notifications and status updates

backend/apps/notifications/models.py

@@ -0,0 +1,64 @@
+from django.conf import settings
+from django.db import models
+
+from apps.bookings.models import Booking
+
+
+class NotificationChannel(models.TextChoices):
+    SMS = "sms", "SMS"
+    WHATSAPP = "whatsapp", "WhatsApp"
+
+
+class NotificationEvent(models.TextChoices):
+    BOOKING_CREATED = "booking_created", "Booking Created"
+    BOOKING_CONFIRMED = "booking_confirmed", "Booking Confirmed"
+    BOOKING_CANCELLED = "booking_cancelled", "Booking Cancelled"
+
+
+class NotificationStatus(models.TextChoices):
+    PENDING = "pending", "Pending"
+    SENT = "sent", "Sent"
+    FAILED = "failed", "Failed"
+    SKIPPED = "skipped", "Skipped"
+
+
+class Notification(models.Model):
+    booking = models.ForeignKey(
+        Booking,
+        on_delete=models.CASCADE,
+        related_name="notifications",
+        null=True,
+        blank=True,
+    )
+    recipient = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.SET_NULL,
+        related_name="notifications",
+        null=True,
+        blank=True,
+    )
+    phone_number = models.CharField(max_length=20, blank=True)
+    channel = models.CharField(max_length=20, choices=NotificationChannel.choices)
+    event = models.CharField(max_length=50, choices=NotificationEvent.choices)
+    status = models.CharField(
+        max_length=20,
+        choices=NotificationStatus.choices,
+        default=NotificationStatus.PENDING,
+    )
+    provider = models.CharField(max_length=50, blank=True)
+    message = models.TextField(blank=True)
+    provider_payload = models.JSONField(default=dict, blank=True)
+    error_message = models.TextField(blank=True)
+    sent_at = models.DateTimeField(null=True, blank=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(
+                fields=["booking", "recipient", "event", "channel"],
+                name="uniq_notification_booking_event",
+            )
+        ]
+
+    def __str__(self) -> str:
+        return f"{self.event} to {self.phone_number or self.recipient_id}"