Fourth sub-PR in the download orchestrator series. Strict 1:1 lift —
zero behavior change. ~407 lines moved out of web_server.py.
What moved:
- _run_post_processing_worker → run_post_processing_worker
The lifted function is intentionally kept as one ~400-line block to
preserve byte-for-byte parity with the original. Refactoring it into
smaller helpers (context lookup, file search loop, transfer-folder
handler, downloads-folder handler) gets its own follow-up PR.
Dependencies: 9 callbacks bundled in `PostProcessDeps` dataclass.
- config_manager, soulseek_client, run_async (live refs)
- docker_resolve_path, extract_filename, make_context_key
(small utilities still in web_server.py — will lift in a future PR
alongside other shared utilities)
- find_completed_file (file search helper, still in web_server.py)
- enhance_file_metadata, wipe_source_tags (web_server wrappers around
core.metadata.enrichment)
- post_process_with_verification (web_server wrapper around
core.imports.pipeline)
- mark_task_completed (wraps runtime_state.mark_task_completed +
session counter)
- on_download_completed (deferred to PR4g batch lifecycle)
Direct imports for already-lifted helpers (no injection needed):
- core.imports.album_naming.resolve_album_group
- core.imports.context.{get_import_clean_title, get_import_clean_album,
get_import_original_search, get_import_context_artist,
get_import_context_album, normalize_import_context}
- core.imports.filename.extract_track_number_from_filename
- core.metadata.enrichment (re-exported as metadata_enrichment)
- core.runtime_state.{download_tasks, tasks_lock,
matched_downloads_context, matched_context_lock}
Behavior parity:
- Same control flow: missing-task short-circuit → cancelled/completed
short-circuit → missing-filename failure → docker path resolution →
context lookup with fuzzy fallback → expected filename generation →
YouTube special-case path resolution → 5-attempt search loop with
Strategy 1 (original filename in download+transfer) and Strategy 2
(expected final filename in transfer) → file-not-found failure →
transfer-folder handler with metadata enhancement → downloads-folder
handler with full post-process verification
- Same retry count (5), sleep duration (5s), per-attempt logging
- Same album_info dict construction with is_album=True for explicit
album downloads
- Same album grouping skip when context.is_album_download is True
- Same wipe_source_tags fallback when enhancement context missing
- Same matched_downloads_context cleanup on success
- Same exception swallowing at processing-error and critical-error
layers, both setting status='failed' + error_message + calling
on_download_completed(b, t, success=False)
- Every logger message text preserved verbatim (so log filters keep
working)
Tests: 16 new under tests/downloads/test_downloads_post_processing.py
covering missing task, cancelled, already-completed, stream_processed,
missing filename + username, file-not-found-after-retries with sleep
mocked, stream-processor-completes-mid-search, transfer-folder with
metadata enhanced + with no context (wipes tags), downloads-folder
with + without context, processing exception, critical outer
exception, YouTube special path, fuzzy context matching.
Full suite: 950 passing (was 934). Ruff clean.