SendinBlue: implement tracking webhooks

Completes #84

anymail/webhooks/sendinblue.py

@@ -0,0 +1,76 @@
+import json
+from datetime import datetime
+
+from django.utils.timezone import utc
+
+from .base import AnymailBaseWebhookView
+from ..signals import AnymailTrackingEvent, EventType, RejectReason, tracking
+
+
+class SendinBlueTrackingWebhookView(AnymailBaseWebhookView):
+    """Handler for SendinBlue delivery and engagement tracking webhooks"""
+
+    esp_name = "SendinBlue"
+    signal = tracking
+
+    def parse_events(self, request):
+        esp_event = json.loads(request.body.decode('utf-8'))
+        return [self.esp_to_anymail_event(esp_event)]
+
+    # SendinBlue's webhook payload data doesn't seem to be documented anywhere.
+    # There's a list of webhook events at https://apidocs.sendinblue.com/webhooks/#3.
+    event_types = {
+        # Map SendinBlue event type: Anymail normalized (event type, reject reason)
+        "request": (EventType.QUEUED, None),  # received even if message won't be sent (e.g., before "blocked")
+        "delivered": (EventType.DELIVERED, None),
+        "hard_bounce": (EventType.BOUNCED, RejectReason.BOUNCED),
+        "soft_bounce": (EventType.BOUNCED, RejectReason.BOUNCED),
+        "blocked": (EventType.REJECTED, RejectReason.BLOCKED),
+        "spam": (EventType.COMPLAINED, RejectReason.SPAM),
+        "invalid_email": (EventType.BOUNCED, RejectReason.INVALID),
+        "deferred": (EventType.DEFERRED, None),
+        "opened": (EventType.OPENED, None),  # see also unique_opened below
+        "click": (EventType.CLICKED, None),
+        "unsubscribe": (EventType.UNSUBSCRIBED, None),
+        "list_addition": (EventType.SUBSCRIBED, None),  # shouldn't occur for transactional messages
+        "unique_opened": (EventType.OPENED, None),  # you'll *also* receive an "opened"
+    }
+
+    def esp_to_anymail_event(self, esp_event):
+        esp_type = esp_event.get("event")
+        event_type, reject_reason = self.event_types.get(esp_type, (EventType.UNKNOWN, None))
+        recipient = esp_event.get("email")
+
+        try:
+            # SendinBlue supplies "ts", "ts_event" and "date" fields, which seem to be based on the
+            # timezone set in the account preferences (and possibly with inconsistent DST adjustment).
+            # "ts_epoch" is the only field that seems to be consistently UTC; it's in milliseconds
+            timestamp = datetime.fromtimestamp(esp_event["ts_epoch"] / 1000.0, tz=utc)
+        except (KeyError, ValueError):
+            timestamp = None
+
+        try:
+            tags = [esp_event["tag"]]
+        except KeyError:
+            tags = []
+
+        try:
+            metadata = json.loads(esp_event["X-Mailin-custom"])
+        except (KeyError, TypeError):
+            metadata = {}
+
+        return AnymailTrackingEvent(
+            description=None,
+            esp_event=esp_event,
+            event_id=None,  # SendinBlue doesn't provide a unique event id
+            event_type=event_type,
+            message_id=esp_event.get("message-id"),
+            metadata=metadata,
+            mta_response=esp_event.get("reason"),
+            recipient=recipient,
+            reject_reason=reject_reason,
+            tags=tags,
+            timestamp=timestamp,
+            user_agent=None,
+            click_url=esp_event.get("link"),
+        )