Rework radar system

python_app/models/collection_identity.py

@@ -0,0 +1,35 @@
+"""Acquisition identity shared unchanged by every pipeline stage."""
+
+from __future__ import annotations
+
+from collections.abc import Iterable, Mapping, Sequence
+from typing import Protocol, TypeVar
+
+
+class CollectionIdentity(Protocol):
+    @property
+    def collection_id(self) -> int: ...
+
+    @property
+    def capture_start_ns(self) -> int: ...
+
+
+TCollection = TypeVar("TCollection", bound=CollectionIdentity)
+
+
+def collection_key(collection: CollectionIdentity) -> tuple[int, int]:
+    return collection.collection_id, collection.capture_start_ns
+
+
+def index_collections(collections: Iterable[TCollection]) -> dict[tuple[int, int], TCollection]:
+    return {collection_key(collection): collection for collection in collections}
+
+
+def history_collection_removed(
+    collection: CollectionIdentity, clear_before_ns: int, removed: Sequence[Mapping[str, int]],
+) -> bool:
+    """Apply a capture-time cutoff and exact acquisition deletions to late results."""
+    return (bool(clear_before_ns) and collection.capture_start_ns <= clear_before_ns) or any(
+        collection_key(collection) == (target["collection_id"], target["capture_start_ns"])
+        for target in removed
+    )