Fixhancement: improve ASN handling with PDF operations (#11689)

src/documents/bulk_edit.py

@@ -7,7 +7,6 @@ from pathlib import Path
 from typing import TYPE_CHECKING
 from typing import Literal
 
-from celery import chain
 from celery import chord
 from celery import group
 from celery import shared_task
@@ -38,6 +37,42 @@ if TYPE_CHECKING:
 logger: logging.Logger = logging.getLogger("paperless.bulk_edit")
 
 
+@shared_task(bind=True)
+def restore_archive_serial_numbers_task(
+    self,
+    backup: dict[int, int | None],
+    *args,
+    **kwargs,
+) -> None:
+    restore_archive_serial_numbers(backup)
+
+
+def release_archive_serial_numbers(doc_ids: list[int]) -> dict[int, int | None]:
+    """
+    Clears ASNs on documents that are about to be replaced so new documents
+    can be assigned ASNs without uniqueness collisions. Returns a backup map
+    of doc_id -> previous ASN for potential restoration.
+    """
+    qs = Document.objects.filter(
+        id__in=doc_ids,
+        archive_serial_number__isnull=False,
+    ).only("pk", "archive_serial_number")
+    backup = dict(qs.values_list("pk", "archive_serial_number"))
+    qs.update(archive_serial_number=None)
+    logger.info(f"Released archive serial numbers for documents {list(backup.keys())}")
+    return backup
+
+
+def restore_archive_serial_numbers(backup: dict[int, int | None]) -> None:
+    """
+    Restores ASNs using the provided backup map, intended for
+    rollback when replacement consumption fails.
+    """
+    for doc_id, asn in backup.items():
+        Document.objects.filter(pk=doc_id).update(archive_serial_number=asn)
+    logger.info(f"Restored archive serial numbers for documents {list(backup.keys())}")
+
+
 def set_correspondent(
     doc_ids: list[int],
     correspondent: Correspondent,
@@ -305,10 +340,10 @@ def reprocess(doc_ids: list[int]) -> Literal["OK"]:
 
 def set_permissions(
     doc_ids: list[int],
-    set_permissions,
+    set_permissions: dict,
     *,
-    owner=None,
-    merge=False,
+    owner: User | None = None,
+    merge: bool = False,
 ) -> Literal["OK"]:
     qs = Document.objects.filter(id__in=doc_ids).select_related("owner")
 
@@ -386,6 +421,7 @@ def merge(
 
     merged_pdf = pikepdf.new()
     version: str = merged_pdf.pdf_version
+    handoff_asn: int | None = None
     # use doc_ids to preserve order
     for doc_id in doc_ids:
         doc = qs.get(id=doc_id)
@@ -401,6 +437,8 @@ def merge(
                 version = max(version, pdf.pdf_version)
                 merged_pdf.pages.extend(pdf.pages)
             affected_docs.append(doc.id)
+            if handoff_asn is None and doc.archive_serial_number is not None:
+                handoff_asn = doc.archive_serial_number
         except Exception as e:
             logger.exception(
                 f"Error merging document {doc.id}, it will not be included in the merge: {e}",
@@ -426,6 +464,8 @@ def merge(
                 DocumentMetadataOverrides.from_document(metadata_document)
             )
             overrides.title = metadata_document.title + " (merged)"
+            if metadata_document.archive_serial_number is not None:
+                handoff_asn = metadata_document.archive_serial_number
         else:
             overrides = DocumentMetadataOverrides()
     else:
@@ -433,8 +473,11 @@ def merge(
 
     if user is not None:
         overrides.owner_id = user.id
-    # Avoid copying or detecting ASN from merged PDFs to prevent collision
-    overrides.skip_asn = True
+    if not delete_originals:
+        overrides.skip_asn_if_exists = True
+
+    if delete_originals and handoff_asn is not None:
+        overrides.asn = handoff_asn
 
     logger.info("Adding merged document to the task queue.")
 
@@ -447,12 +490,20 @@ def merge(
     )
 
     if delete_originals:
+        backup = release_archive_serial_numbers(affected_docs)
         logger.info(
             "Queueing removal of original documents after consumption of merged document",
         )
-        chain(consume_task, delete.si(affected_docs)).delay()
-    else:
-        consume_task.delay()
+        try:
+            consume_task.apply_async(
+                link=[delete.si(affected_docs)],
+                link_error=[restore_archive_serial_numbers_task.s(backup)],
+            )
+        except Exception:
+            restore_archive_serial_numbers(backup)
+            raise
+        else:
+            consume_task.delay()
 
     return "OK"
 
@@ -494,6 +545,8 @@ def split(
                 overrides.title = f"{doc.title} (split {idx + 1})"
                 if user is not None:
                     overrides.owner_id = user.id
+                if not delete_originals:
+                    overrides.skip_asn_if_exists = True
                 logger.info(
                     f"Adding split document with pages {split_doc} to the task queue.",
                 )
@@ -508,10 +561,20 @@ def split(
                 )
 
             if delete_originals:
+                backup = release_archive_serial_numbers([doc.id])
                 logger.info(
                     "Queueing removal of original document after consumption of the split documents",
                 )
-                chord(header=consume_tasks, body=delete.si([doc.id])).delay()
+                try:
+                    chord(
+                        header=consume_tasks,
+                        body=delete.si([doc.id]),
+                    ).apply_async(
+                        link_error=[restore_archive_serial_numbers_task.s(backup)],
+                    )
+                except Exception:
+                    restore_archive_serial_numbers(backup)
+                    raise
             else:
                 group(consume_tasks).delay()
 
@@ -551,7 +614,7 @@ def delete_pages(doc_ids: list[int], pages: list[int]) -> Literal["OK"]:
 
 def edit_pdf(
     doc_ids: list[int],
-    operations: list[dict],
+    operations: list[dict[str, int]],
     *,
     delete_original: bool = False,
     update_document: bool = False,
@@ -614,7 +677,10 @@ def edit_pdf(
             )
             if user is not None:
                 overrides.owner_id = user.id
-
+            if not delete_original:
+                overrides.skip_asn_if_exists = True
+            if delete_original and len(pdf_docs) == 1:
+                overrides.asn = doc.archive_serial_number
             for idx, pdf in enumerate(pdf_docs, start=1):
                 filepath: Path = (
                     Path(tempfile.mkdtemp(dir=settings.SCRATCH_DIR))
@@ -633,7 +699,17 @@ def edit_pdf(
                 )
 
             if delete_original:
-                chord(header=consume_tasks, body=delete.si([doc.id])).delay()
+                backup = release_archive_serial_numbers([doc.id])
+                try:
+                    chord(
+                        header=consume_tasks,
+                        body=delete.si([doc.id]),
+                    ).apply_async(
+                        link_error=[restore_archive_serial_numbers_task.s(backup)],
+                    )
+                except Exception:
+                    restore_archive_serial_numbers(backup)
+                    raise
             else:
                 group(consume_tasks).delay()