fix: recover orphaned authored operations (#319)

src/idempotency.py

@@ -78,7 +78,7 @@ class IdempotencyLedger:
                     (now - self.ttl_seconds,),
                 )
                 row = connection.execute(
-                    "SELECT fingerprint, status, response_json FROM idempotency_operations "
+                    "SELECT fingerprint, status, response_json, created_at FROM idempotency_operations "
                     "WHERE key = ?",
                     (key,),
                 ).fetchone()
@@ -87,9 +87,13 @@ class IdempotencyLedger:
                         return Reservation("conflict")
                     if row[1] == "completed":
                         return Reservation("completed", json.loads(row[2]))
+                    if row[3] <= now - self.ttl_seconds:
+                        return Reservation("uncertain")
                     return Reservation("pending")
                 count = connection.execute(
-                    "SELECT COUNT(*) FROM idempotency_operations"
+                    "SELECT COUNT(*) FROM idempotency_operations "
+                    "WHERE status = 'completed' OR created_at > ?",
+                    (now - self.ttl_seconds,),
                 ).fetchone()[0]
                 if count >= self.max_entries:
                     completed = connection.execute(

src/main.py

@@ -314,9 +314,22 @@ async def _run_idempotent_authored_action(
             detail="Authored action queue is busy; please retry",
             headers={"Retry-After": "1"},
         )
-
     existing = _authored_action_operations.get(idempotency_key)
-    if reservation.state == "pending":
+    if reservation.state == "uncertain" and (
+        existing is None or existing[0] != fingerprint
+    ):
+        operation.close()
+        raise HTTPException(
+            status_code=422,
+            detail={
+                "code": "delivery_uncertain",
+                "message": (
+                    "Delivery could not be confirmed. Verify it was not posted before retrying."
+                ),
+            },
+        )
+
+    if reservation.state in {"pending", "uncertain"}:
         operation.close()
         if existing is None or existing[0] != fingerprint:
             raise HTTPException(