fix(weekly-reports): dupe on report timestamp instead of batch (#76031)

- It has been observed that a portion of our duplicate weekly emails
come from the schedule celery task being killed and restarted, which
will cause duplicates for any orgs that were queued in the first batch.
- this also generates a new batch_id, which causes our de-duplication
logic to not work, as batch_id is included in the redis key that we use.
- [x] This PR modifies our logic so that the dupe checker instead uses
the timestamp for which the weekly report is generated on. this should
be a safe way to ensure no duplicates occur across batches.
- [x] Updates the test.

src/sentry/tasks/summaries/weekly_reports.py

@@ -5,7 +5,7 @@
 import uuid
 from collections.abc import Mapping, Sequence
 from dataclasses import dataclass
-from datetime import timedelta
+from datetime import datetime, timedelta
 from functools import partial
 from typing import Any, cast
 
@@ -293,7 +293,7 @@ def _send_to_user(self, user_template_context: Mapping[str, Any]) -> None:
         template_context: Mapping[str, Any] | None = user_template_context.get("context")
         user_id: int | None = user_template_context.get("user_id")
         if template_context and user_id:
-            dupe_check = _DuplicateDeliveryCheck(self, user_id)
+            dupe_check = _DuplicateDeliveryCheck(self, user_id, self.ctx.timestamp)
             if not dupe_check.check_for_duplicate_delivery():
                 self.send_email(template_ctx=template_context, user_id=user_id)
                 dupe_check.record_delivery()
@@ -337,9 +337,13 @@ def send_email(self, template_ctx: Mapping[str, Any], user_id: int) -> None:
 
 
 class _DuplicateDeliveryCheck:
-    def __init__(self, batch: OrganizationReportBatch, user_id: int):
+    def __init__(self, batch: OrganizationReportBatch, user_id: int, timestamp: float):
         self.batch = batch
         self.user_id = user_id
+        # note that if the timestamps between batches cross a UTC day boundary,
+        # this will not work correctly. but we always start reports at midnight UTC,
+        # so that is unlikely to be an issue.
+        self.report_date = datetime.fromtimestamp(timestamp).strftime("%Y-%m-%d")
 
         # Tracks state from `check_for_duplicate_delivery` to `record_delivery`
         self.count: int | None = None
@@ -349,7 +353,11 @@ def _get_redis_cluster(self) -> LocalClient:
 
     @property
     def _redis_name(self) -> str:
-        name_parts = (self.batch.batch_id, self.batch.ctx.organization.id, self.user_id)
+        name_parts = (
+            self.report_date,
+            self.batch.ctx.organization.id,
+            self.user_id,
+        )
         return ":".join(str(part) for part in name_parts)
 
     def _get_log_extras(self) -> dict[str, Any]:
@@ -358,6 +366,7 @@ def _get_log_extras(self) -> dict[str, Any]:
             "organization": self.batch.ctx.organization.id,
             "user_id": self.user_id,
             "has_email_override": bool(self.batch.email_override),
+            "report_date": self.report_date,
         }
 
     def check_for_duplicate_delivery(self) -> bool:

tests/sentry/tasks/test_weekly_reports.py

@@ -1011,24 +1011,26 @@ def test_duplicate_detection(self, mock_send_email, mock_prepare_template_contex
         ctx = OrganizationReportContext(0, 0, self.organization)
         template_context = prepare_template_context(ctx, [self.user.id])
         mock_prepare_template_context.return_value = template_context
-        batch_id = UUID("abe8ba3e-90af-4a98-b925-5f30250ae6a0")
+        batch1_id = UUID("abe8ba3e-90af-4a98-b925-5f30250ae6a0")
+        batch2_id = UUID("abe8ba3e-90af-4a98-b925-5f30250ae6a1")
         self._set_option_value("always")
 
         # First send
-        OrganizationReportBatch(ctx, batch_id).deliver_reports()
+        OrganizationReportBatch(ctx, batch1_id).deliver_reports()
         assert mock_send_email.call_count == 1
         mock_logger.error.assert_not_called()
 
         # Duplicate send
-        OrganizationReportBatch(ctx, batch_id).deliver_reports()
+        OrganizationReportBatch(ctx, batch2_id).deliver_reports()
         assert mock_send_email.call_count == 1
         assert mock_logger.error.call_count == 1
         mock_logger.error.assert_called_once_with(
             "weekly_report.delivery_record.duplicate_detected",
             extra={
-                "batch_id": str(batch_id),
+                "batch_id": str(batch2_id),
                 "organization": self.organization.id,
                 "user_id": self.user.id,
                 "has_email_override": False,
+                "report_date": "1970-01-01",
             },
         )