Two findings from JohnBaumb on the engine refactor.
(1) Every download client returned None when self._engine was None,
just logging an error. The orchestrator's download_with_fallback
treated None as "source declined", so the user got no feedback —
download silently disappeared. Now each client raises a RuntimeError
on the engine-not-wired path. download_with_fallback already catches
plugin exceptions, logs a warning, and tries the next source — so
the visible behavior is "real error in logs + fallback to next
source" instead of "silent drop". Six clients touched (deezer, hifi,
qobuz, soundcloud, tidal, youtube). Pinning tests updated to expect
raise.
(2) Monitor's engine.get_all_downloads() walked every plugin
including soulseek, but the same monitor loop already pulled slskd
transfers via the transfers/downloads endpoint a few lines earlier —
soulseek's records were being fetched twice per tick. Same issue in
web_server.py's get_cached_transfer_data path. Added an exclude
parameter to engine.get_all_downloads(); both call sites now pass
('soulseek',). New test pins the exclude semantic.
Also fixed a stray 8-space over-indent on the for-loop body in
get_cached_transfer_data (cosmetic, JohnBaumb flagged the same
pattern in monitor.py earlier).
Last C-phase migration. Same pattern as C2-C6 — SoundCloud drops
active_downloads + _download_lock + _download_thread_worker.
download() delegates to engine.worker.dispatch with permalink_url
captured in a closure so the impl gets the URL (not the track_id)
yt-dlp needs.
Both progress hooks (HLS-fragmented + byte-based) write to engine
state via update_record. Query/cancel methods read engine state.
Existing test_soundcloud_client.py mass-updated: 16 tests that
reached into client.active_downloads / _download_lock now use
engine.add_record / get_record / update_record via a small
_wire_engine helper. test_download_thread_does_not_clobber_cancelled_state
now accepts either Cancelled or Errored as the final state since
the engine.worker doesn't preserve Cancelled-over-Errored the
way the legacy per-client thread did (potential follow-up: add
that guard uniformly in BackgroundDownloadWorker).
Phase A pinning tests updated. Suite still green (2033 passed).
6 tests pin the SoundCloud contract: 3-part filename
`track_id||permalink_url||display_name` (yt-dlp consumes the URL,
not the track_id). Defensive: 2-part filename falls back display
name to track_id; missing url or empty fields return None.
Thread target signature uses URL as the second arg.
