feat(library): delete archived prompts from the archived shelf (#492)

The archived shelf's bar offers Delete… after Restore. Its review is the
permanent delete only (no Archive choice: the prompts are archived
already), with #482's grid, safety backup, review digests, records hold
and epoch fence. A prompt used as another prompt's negative stays
archived; one restored since the shelf was read is kept and counted.

The preview and delete routes take an optional shelf ('active' or
'archived'). The held write classifies the same shelf, so the permanent
delete is backed up; on this shelf the write archives and rewrites
nothing and counts every reviewed id it did not delete as changed.

py/api/library_delete.py

@@ -49,6 +49,8 @@ _SELECTION_KEYS = frozenset({"prompt_ids", "expected_epoch"})
 _DELETE_KEYS = frozenset({"archive_ids", "delete_ids", "expected_epoch", "backup"})
 # #482: Delete permanently, with its digests; both or neither (a #443 body).
 _PAIRED_KEYS = frozenset({"delete_paired_ids", "paired_digests"})
+# #492: the shelf the Delete… runs on, optional on its own (default "active").
+_SHELF_KEYS = frozenset({"shelf"})
 STORAGE_CHANGED = "Prompt storage was restored; refresh the library"
 
 
@@ -66,8 +68,8 @@ def _storage_changed(exc):
     return _failure(409, exc.code, STORAGE_CHANGED, library_epoch=exc.epoch)
 
 
-async def _body(request, keys, optional=frozenset()):
-    """The JSON object with exactly ``keys`` (plus all or none of ``optional``)."""
+async def _body(request, keys, *groups):
+    """The JSON object with exactly ``keys``, plus all or none of each group."""
     try:
         data = await request.json()
     except ValueError:
@@ -75,11 +77,24 @@ async def _body(request, keys, optional=frozenset()):
     if not isinstance(data, dict):
         raise ValueError("Expected a JSON object")
     extra = set(data) - keys
-    if not keys <= set(data) or (extra and extra != optional):
+    partial = False
+    for group in groups:
+        if extra & group:
+            partial = partial or not group <= extra
+            extra -= group
+    if not keys <= set(data) or extra or partial:
         raise ValueError("Request must contain exactly " + ", ".join(sorted(keys)))
     return data
 
 
+def _shelf(data):
+    """#492: the shelf a Delete… was reviewed on."""
+    shelf = data.get("shelf", "active")
+    if shelf not in ("active", "archived"):
+        raise ValueError("shelf must be active or archived")
+    return shelf
+
+
 def _paired_delete(data, archive_ids):
     """#482: the reviewed archive ids to delete with their pairs -> digest."""
     if "delete_paired_ids" not in data:
@@ -119,8 +134,9 @@ class LibraryDeleteRoutesMixin:
 
     async def preview_library_delete(self, request):
         try:
-            data = await _body(request, _SELECTION_KEYS)
+            data = await _body(request, _SELECTION_KEYS, _SHELF_KEYS)
             ids = parse_bulk_prompt_ids(data["prompt_ids"])
+            shelf = _shelf(data)
         except ValueError as exc:
             return _invalid(str(exc))
         db = self.db
@@ -131,6 +147,7 @@ class LibraryDeleteRoutesMixin:
                     db.classify_library_delete,
                     ids,
                     expected_epoch=data["expected_epoch"],
+                    shelf=shelf,
                 )
                 disk = None
                 if (review["delete"] or review["deletable"]) and policy == "on":
@@ -165,6 +182,7 @@ class LibraryDeleteRoutesMixin:
                 "archive": review["archive"],
                 "protected": review["protected"],
                 "already_archived": len(review["already_archived"]),
+                "not_archived": len(review["not_archived"]),
                 "not_found": len(review["not_found"]),
                 "image_links": review["image_links"],
                 # #482: the archive ids Delete permanently may delete with pairs.
@@ -181,7 +199,8 @@ class LibraryDeleteRoutesMixin:
 
     async def delete_library_prompts(self, request):
         try:
-            data = await _body(request, _DELETE_KEYS, _PAIRED_KEYS)
+            data = await _body(request, _DELETE_KEYS, _PAIRED_KEYS, _SHELF_KEYS)
+            shelf = _shelf(data)
             archive_ids = _reviewed_ids(data["archive_ids"], "archive_ids")
             delete_ids = _reviewed_ids(data["delete_ids"], "delete_ids")
             if not archive_ids and not delete_ids:
@@ -203,7 +222,7 @@ class LibraryDeleteRoutesMixin:
                 PROMPT_DELETE_JOB_KIND, DELETE_TITLE, admission="records"
             ) as job:
                 response = await self._held_library_delete(
-                    self.db, data, archive_ids, delete_ids, paired
+                    self.db, data, archive_ids, delete_ids, paired, shelf
                 )
                 if response.status >= 400:
                     job.finish("failed")
@@ -211,7 +230,9 @@ class LibraryDeleteRoutesMixin:
         except JobBusy as busy:
             return busy_response(busy)
 
-    async def _held_library_delete(self, db, data, archive_ids, delete_ids, paired):
+    async def _held_library_delete(
+        self, db, data, archive_ids, delete_ids, paired, shelf="active"
+    ):
         epoch = data["expected_epoch"]
         promised = data["backup"] == "on" or self._safety_backup_policy() == "on"
         backup = None
@@ -222,6 +243,8 @@ class LibraryDeleteRoutesMixin:
                     db.classify_library_delete,
                     [*delete_ids, *paired],
                     expected_epoch=epoch,
+                    # #492: the same shelf, or archived ids would skip the backup.
+                    shelf=shelf,
                 )
                 candidates = review["fingerprints"]
                 # #482: a permanent delete of a prompt in a saved pair is backed up too.
@@ -248,6 +271,7 @@ class LibraryDeleteRoutesMixin:
                 expected_epoch=epoch,
                 candidates=candidates if candidates is not None else {},
                 delete_paired=paired,
+                shelf=shelf,
             )
         except LibraryCommandError as exc:
             return _storage_changed(exc)