From afc69411586d02906f4600a5e11c2d7d6b14ffde Mon Sep 17 00:00:00 2001
From: Chris Busillo <info@shinycomputers.com>
Date: Thu, 14 May 2026 21:23:01 -0400
Subject: [PATCH] Retire landed merge train batches

---
 control_plane/service.py | 50 +++++++++++++++++++++++++++++++++++++++-
 tests/test_service.py    | 32 +++++++++++++++++++++++++
 2 files changed, 81 insertions(+), 1 deletion(-)

diff --git a/control_plane/service.py b/control_plane/service.py
index f7225d5..877298b 100644
--- a/control_plane/service.py
+++ b/control_plane/service.py
@@ -2712,6 +2712,28 @@ def _latest_merge_train_batch_landing_plan_record(
     return latest_record
 
 
+def _latest_completed_merge_train_batch_landing_plan_record(
+    *,
+    record_store: _MergeTrainBatchLandingPlanRecordStore,
+    repository: str,
+    base_branch: str,
+) -> MergeTrainBatchLandingPlanRecord | None:
+    records = record_store.list_merge_train_batch_landing_plan_records(
+        repository=repository,
+        base_branch=base_branch,
+        status="active",
+        limit=25,
+    )
+    latest_record = _latest_merge_train_batch_landing_progress_record(records)
+    if latest_record is None:
+        return None
+    if not latest_record.landing_plan.entries:
+        return None
+    if any(entry.status != "merged" for entry in latest_record.landing_plan.entries):
+        return None
+    return latest_record
+
+
 def _latest_merge_train_stack_collapse_plan_record(
     *,
     record_store: _MergeTrainStackCollapsePlanRecordStore,
@@ -7843,7 +7865,33 @@ def product_action_allowed(
                     repository=controller_request.repository,
                     base_branch=controller_request.base_branch,
                 )
-                if active_landing_record is not None:
+                completed_landing_record = None
+                if active_landing_record is None:
+                    completed_landing_record = (
+                        _latest_completed_merge_train_batch_landing_plan_record(
+                            record_store=landing_store,
+                            repository=controller_request.repository,
+                            base_branch=controller_request.base_branch,
+                        )
+                    )
+                if completed_landing_record is not None:
+                    _validate_merge_train_landing_record_for_controller(
+                        landing_record=completed_landing_record,
+                        policy_key=repository_policy.policy_key,
+                        policy_sha256=policy_record.policy_sha256,
+                    )
+                    result = {
+                        "repository": controller_request.repository,
+                        "base_branch": controller_request.base_branch,
+                        "mode": "dry-run",
+                        "controller_action": "batch_landed",
+                        "merge_train_batch_landing_plan_record_id": completed_landing_record.record_id,
+                        "landing_plan": completed_landing_record.landing_plan.model_dump(
+                            mode="json"
+                        ),
+                    }
+                    driver_result = result
+                elif active_landing_record is not None:
                     _validate_merge_train_landing_record_for_controller(
                         landing_record=active_landing_record,
                         policy_key=repository_policy.policy_key,
diff --git a/tests/test_service.py b/tests/test_service.py
index 5044fb6..2b79d1d 100644
--- a/tests/test_service.py
+++ b/tests/test_service.py
@@ -1847,6 +1847,27 @@ def test_merge_train_controller_advances_unstacked_batch_flow(self) -> None:
                         "mutate": True,
                     },
                 )
+                landing_records_before_retire = FilesystemRecordStore(
+                    state_dir
+                ).list_merge_train_batch_landing_plan_records(
+                    repository="cbusillo/sellyouroutboard", base_branch="main"
+                )
+                retire_status, retire_payload = _invoke_app(
+                    app,
+                    method="POST",
+                    path="/v1/work-graph/merge-train/controller/run-once",
+                    payload={
+                        "schema_version": 1,
+                        "repository": "cbusillo/sellyouroutboard",
+                        "base_branch": "main",
+                        "mutate": True,
+                    },
+                )
+                landing_records_after_retire = FilesystemRecordStore(
+                    state_dir
+                ).list_merge_train_batch_landing_plan_records(
+                    repository="cbusillo/sellyouroutboard", base_branch="main"
+                )
 
         self.assertEqual(plan_status, 202)
         self.assertEqual(plan_payload["result"]["controller_action"], "plan_candidate")
@@ -1861,6 +1882,17 @@ def test_merge_train_controller_advances_unstacked_batch_flow(self) -> None:
         self.assertEqual(land_status, 202)
         self.assertEqual(land_payload["result"]["controller_action"], "land_batch")
         self.assertEqual(land_payload["result"]["landing_plan"]["entries"][0]["status"], "merged")
+        self.assertEqual(retire_status, 202)
+        self.assertEqual(retire_payload["result"]["controller_action"], "batch_landed")
+        self.assertEqual(retire_payload["result"]["mode"], "dry-run")
+        self.assertEqual(
+            retire_payload["result"]["merge_train_batch_landing_plan_record_id"],
+            land_payload["records"]["merge_train_batch_landing_plan_record_id"],
+        )
+        self.assertEqual(
+            tuple(record.record_id for record in landing_records_after_retire),
+            tuple(record.record_id for record in landing_records_before_retire),
+        )
 
     def test_merge_train_controller_stops_after_candidate_failure(self) -> None:
         with (