AmazonDownloadClient was missing set_engine() and set_shutdown_check().
The download engine auto-wires plugins by calling set_engine(self) at
registration time if the method exists (engine.py:136). Without it,
_engine stayed None forever, causing every download() call to raise
RuntimeError("_engine is not set") — silently failing and marking all
tracks not found.
All other streaming clients (Deezer, Qobuz, Tidal, HiFi, SoundCloud)
expose set_engine(); Amazon now matches the pattern.
Tests added: set_engine wires _engine, set_shutdown_check wires callback,
set_engine unblocks download dispatch (the exact live failure mode).
Follows the exact same standard as Tidal, Qobuz, HiFi, and Deezer.
registry.py — import + register AmazonDownloadClient as 'amazon'.
amazon_download_client.py — read amazon_download.quality / allow_fallback
from config on init; pass quality as preferred_codec to AmazonClient;
_download_sync codec waterfall respects allow_fallback flag.
download_orchestrator.py — reload_settings() updates preferred_codec +
allow_fallback on the live client after a settings save. 'amazon' added
to _streaming_sources so search_and_download_best routes it correctly.
api_call_tracker.py — 'amazon' registered in RATE_LIMITS (120/min),
SERVICE_LABELS, and SERVICE_ORDER so API call monitoring shows Amazon.
web_server.py — 'amazon_download' added to the settings service loop.
'amazon' added to serverless_sources (no slskd probe needed). Streaming
file-finder extended to handle amazon username + ||asin||title encoding
(extension-less fuzzy match, same as Tidal/Qobuz/HiFi). New endpoint:
GET /api/amazon/test-connection → checks T2Tunes proxy status.
webui/index.html — amazon-download-settings-container: quality dropdown
(flac/opus/eac3), allow-fallback checkbox, test-connection button.
webui/static/settings.js — 'Amazon Music' added to HYBRID_SOURCES,
_hybridSourceEnabled, allSources mode list, loadSettings(), saveSettings()
payload, updateDownloadSourceUI() show/hide + auto-test. New
testAmazonConnection() function.
core/amazon_client.py — T2Tunes-backed metadata client following the
DeezerClient/iTunesClient contract. Exposes search_tracks, search_artists,
search_albums, get_track_details, get_album, get_album_tracks, get_artist,
get_artist_albums, get_track_features. T2TunesStreamInfo dataclass captures
the hex decryption key returned by the proxy (CENC/AES-128). Handles the
"stremeable" API typo. 0.5 s rate-limit guard + api_call_tracker.
core/amazon_download_client.py — DownloadSourcePlugin backed by the above
client. Codec waterfall: FLAC → Opus → EAC3. Downloads the encrypted MP4
container, decrypts with ffmpeg -decryption_key, yields the native audio
file (.flac / .opus / .eac3). Not yet wired into the app source registry —
validated in isolation only; see tests/tools/.
tools/t2tunes_probe.py + tools/t2tunes_media_plan.py — standalone CLI tools
used for live API exploration during development.
tests/tools/test_amazon_client.py — 72 unit tests (all mocked).
tests/tools/test_amazon_download_client.py — 52 unit tests (all mocked).
124 tests pass.
