feat: update conditionals.py to use resolve_requested_version and DocumentVersion

- Replace resolve_effective_document_by_pk stub with direct get_object_or_404
  + resolve_requested_version calls in all five conditional functions
- Switch from .modified (shim) to .added (DocumentVersion native field)
- Switch thumbnail cache key to use version.id instead of document id
- Re-add get_root_document/get_latest_version_for_root stubs to versioning.py
  (bulk_edit.py still needs them; Task 10 will remove them)
- Update TestVersionAwareFilters tests to reflect simplified filter behavior
  (no more FieldError fallback; filters query content directly)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/documents/conditionals.py

@@ -4,6 +4,7 @@ from typing import Any
 
 from django.conf import settings
 from django.core.cache import cache
+from django.shortcuts import get_object_or_404
 
 from documents.caching import CACHE_5_MINUTES
 from documents.caching import CACHE_50_MINUTES
@@ -13,7 +14,7 @@ from documents.caching import CLASSIFIER_VERSION_KEY
 from documents.caching import get_thumbnail_modified_key
 from documents.classifier import DocumentClassifier
 from documents.models import Document
-from documents.versioning import resolve_effective_document_by_pk
+from documents.versioning import resolve_requested_version
 
 
 def suggestions_etag(request, pk: int) -> str | None:
@@ -73,48 +74,53 @@ def metadata_etag(request, pk: int) -> str | None:
     Metadata is extracted from the original file, so use its checksum as the
     ETag
     """
-    doc = resolve_effective_document_by_pk(pk, request).document
-    if doc is None:
+    doc = get_object_or_404(Document, pk=pk)
+    resolution = resolve_requested_version(doc, request)
+    version = resolution.version
+    if version is None:
         return None
-    return doc.checksum
+    return version.checksum
 
 
 def metadata_last_modified(request, pk: int) -> datetime | None:
     """
-    Metadata is extracted from the original file, so use its modified.  Strictly speaking, this is
-    not the modification of the original file, but of the database object, but might as well
-    error on the side of more cautious
+    Metadata is extracted from the original file, so use its added time.
     """
-    doc = resolve_effective_document_by_pk(pk, request).document
-    if doc is None:
+    doc = get_object_or_404(Document, pk=pk)
+    resolution = resolve_requested_version(doc, request)
+    version = resolution.version
+    if version is None:
         return None
-    return doc.modified
+    return version.added
 
 
 def preview_etag(request, pk: int) -> str | None:
     """
     ETag for the document preview, using the original or archive checksum, depending on the request
     """
-    doc = resolve_effective_document_by_pk(pk, request).document
-    if doc is None:
+    doc = get_object_or_404(Document, pk=pk)
+    resolution = resolve_requested_version(doc, request)
+    version = resolution.version
+    if version is None:
         return None
     use_original = (
         hasattr(request, "query_params")
         and "original" in request.query_params
         and request.query_params["original"] == "true"
     )
-    return doc.checksum if use_original else doc.archive_checksum
+    return version.checksum if use_original else version.archive_checksum
 
 
 def preview_last_modified(request, pk: int) -> datetime | None:
     """
-    Uses the documents modified time to set the Last-Modified header.  Not strictly
-    speaking correct, but close enough and quick
+    Uses the version added time to set the Last-Modified header.
     """
-    doc = resolve_effective_document_by_pk(pk, request).document
-    if doc is None:
+    doc = get_object_or_404(Document, pk=pk)
+    resolution = resolve_requested_version(doc, request)
+    version = resolution.version
+    if version is None:
         return None
-    return doc.modified
+    return version.added
 
 
 def thumbnail_last_modified(request: Any, pk: int) -> datetime | None:
@@ -123,22 +129,22 @@ def thumbnail_last_modified(request: Any, pk: int) -> datetime | None:
     Cache should be (slightly?) faster than filesystem
     """
     try:
-        doc = resolve_effective_document_by_pk(pk, request).document
-        if doc is None:
+        doc = get_object_or_404(Document, pk=pk)
+        resolution = resolve_requested_version(doc, request)
+        version = resolution.version
+        if version is None:
             return None
-        if not doc.thumbnail_path.exists():
+        if not version.thumbnail_path.exists():
             return None
-        # Use the effective document id for cache key
-        doc_key = get_thumbnail_modified_key(doc.id)
+        doc_key = get_thumbnail_modified_key(version.id)
 
         cache_hit = cache.get(doc_key)
         if cache_hit is not None:
             cache.touch(doc_key, CACHE_50_MINUTES)
             return cache_hit
 
-        # No cache, get the timestamp and cache the datetime
         last_modified = datetime.fromtimestamp(
-            doc.thumbnail_path.stat().st_mtime,
+            version.thumbnail_path.stat().st_mtime,
             tz=UTC,
         )
         cache.set(doc_key, last_modified, CACHE_50_MINUTES)

src/documents/tests/test_api_document_versions.py

@@ -7,7 +7,6 @@ from auditlog.models import LogEntry  # type: ignore[import-untyped]
 from django.contrib.auth.models import Permission
 from django.contrib.auth.models import User
 from django.contrib.contenttypes.models import ContentType
-from django.core.exceptions import FieldError
 from django.core.files.uploadedfile import SimpleUploadedFile
 from rest_framework import status
 from rest_framework.test import APITestCase
@@ -619,31 +618,21 @@ class TestDocumentVersioningApi(DirectoriesMixin, APITestCase):
 
 
 class TestVersionAwareFilters:
-    def test_title_content_filter_falls_back_to_content(self) -> None:
+    def test_title_content_filter_queries_content_directly(self) -> None:
         queryset = mock.Mock()
-        fallback_queryset = mock.Mock()
-        queryset.filter.side_effect = [FieldError("missing field"), fallback_queryset]
 
-        result = TitleContentFilter().filter(queryset, " latest ")
+        TitleContentFilter().filter(queryset, " latest ")
 
-        assert result is fallback_queryset
-        assert queryset.filter.call_count == 2
+        assert queryset.filter.call_count == 1
 
-    def test_effective_content_filter_falls_back_to_content_lookup(self) -> None:
+    def test_effective_content_filter_queries_content_directly(self) -> None:
         queryset = mock.Mock()
-        fallback_queryset = mock.Mock()
-        queryset.filter.side_effect = [FieldError("missing field"), fallback_queryset]
 
-        result = EffectiveContentFilter(lookup_expr="icontains").filter(
-            queryset,
-            " latest ",
-        )
+        EffectiveContentFilter(lookup_expr="icontains").filter(queryset, " latest ")
 
-        assert result is fallback_queryset
-        first_kwargs = queryset.filter.call_args_list[0].kwargs
-        second_kwargs = queryset.filter.call_args_list[1].kwargs
-        assert first_kwargs == {"effective_content__icontains": "latest"}
-        assert second_kwargs == {"content__icontains": "latest"}
+        assert queryset.filter.call_count == 1
+        kwargs = queryset.filter.call_args_list[0].kwargs
+        assert kwargs == {"content__icontains": "latest"}
 
     def test_effective_content_filter_returns_input_for_empty_values(self) -> None:
         queryset = mock.Mock()

src/documents/versioning.py

@@ -41,6 +41,25 @@ def get_version_by_pk(doc: Document, version_pk: int) -> DocumentVersion | None:
     return DocumentVersion.objects.filter(pk=version_pk, document=doc).first()
 
 
+def get_root_document(doc: Document) -> Document:
+    """Return the root document.
+
+    In the new model, every Document IS the root. This is a compatibility stub
+    used by bulk_edit.py; Task 10 will refactor the callers.
+    """
+    return doc
+
+
+def get_latest_version_for_root(doc: Document) -> Document:
+    """Return the document to use as the version source.
+
+    In the new model, DocumentVersion holds per-version files.  This stub
+    returns the document itself so that bulk_edit callers that have not yet
+    been updated to the new model do not crash. Task 10 will replace this.
+    """
+    return doc
+
+
 def resolve_requested_version(
     doc: Document,
     request: Any,