Recover interrupted certificate replacement

dns_sync/adapters.py

@@ -252,3 +252,35 @@ class PlanAction:
 class EndpointPlan:
     endpoint_id: str
     actions: tuple[PlanAction, ...]
+    retirements: tuple[RetireRequest, ...] = ()
+
+    def __post_init__(self) -> None:
+        retirements = tuple(self.retirements)
+
+        if any(
+            not isinstance(retirement, RetireRequest)
+            for retirement in retirements
+        ):
+            raise ValueError(
+                "EndpointPlan retirements must be "
+                "RetireRequest instances"
+            )
+
+        identities = [
+            (
+                retirement.object.object_type,
+                retirement.object.local_key,
+            )
+            for retirement in retirements
+        ]
+
+        if len(set(identities)) != len(identities):
+            raise ValueError(
+                "EndpointPlan retirements cannot contain duplicates"
+            )
+
+        object.__setattr__(
+            self,
+            "retirements",
+            retirements,
+        )