refactor: extract shared file-status query logic into utility function

- Created app/utils/file_queries.py with apply_status_filter function
- Updated app/api/files.py to use shared function
- Updated app/views/files.py to use shared function
- Removed unused 'or_' import from app/api/files.py
- Added comprehensive tests in tests/test_file_queries.py
- All tests pass (10 new tests, 14 existing tests verified)

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/views/files.py

@@ -8,6 +8,7 @@ from fastapi import Depends, Query, Request
 from sqlalchemy.orm import Session
 
 from app.config import settings
+from app.utils.file_queries import apply_status_filter
 from app.utils.file_status import get_files_processing_status
 from app.views.base import APIRouter, get_db, logger, require_login, templates
 
@@ -48,36 +49,7 @@ def files_page(
             query = query.filter(FileRecord.mime_type == mime_type)
 
         # Apply status filter (before pagination for correct counts)
-        if status:
-            # Subquery to get file IDs matching the status
-            if status == "pending":
-                # Files with no logs
-                subq = db.query(ProcessingLog.file_id).distinct()
-                query = query.filter(~FileRecord.id.in_(subq))
-            elif status == "processing":
-                # Files with in_progress logs
-                subq = db.query(ProcessingLog.file_id).filter(ProcessingLog.status == "in_progress").distinct()
-                query = query.filter(FileRecord.id.in_(subq))
-            elif status == "failed":
-                # Files with failure logs
-                subq = db.query(ProcessingLog.file_id).filter(ProcessingLog.status == "failure").distinct()
-                query = query.filter(FileRecord.id.in_(subq))
-            elif status == "completed":
-                # Files with success logs but no failures or in_progress
-                success_files = (
-                    db.query(ProcessingLog.file_id).filter(ProcessingLog.status == "success").distinct().subquery()
-                )
-
-                failed_files = (
-                    db.query(ProcessingLog.file_id)
-                    .filter(or_(ProcessingLog.status == "failure", ProcessingLog.status == "in_progress"))
-                    .distinct()
-                    .subquery()
-                )
-
-                query = query.filter(FileRecord.id.in_(db.query(success_files.c.file_id))).filter(
-                    ~FileRecord.id.in_(db.query(failed_files.c.file_id))
-                )
+        query = apply_status_filter(query, db, status)
 
         # Get total count before pagination
         total_items = query.count()