Milestone #160 Opt 3b. Adds device class as a third context axis on top
of the #1531 time-of-day/weekday affinity: on the radio path, a candidate
is boosted when its artist concentrates in the current (daypart × weekday
× device) cell. Client-sent (client_id is opaque; no UA stored), so it's
captured going forward and applies to radio only (daily mixes are
cron-built with no device → stay device-agnostic).
Server:
- Migration 0048: play_events.device_class text NULL (no CHECK; normalized
in Go — one whitelist entry per new client class, not a migration).
- events.go: eventRequest.device_class + normalizeDeviceClass (whitelist →
mobile/web/…, else "other", empty → NULL); threaded through both
RecordPlayStartedWithSource and RecordOfflinePlay into InsertPlayEvent.
- ListArtistContextPlayCountsForUser gains a current-device param; the cell
FILTER adds AND ($2='' OR device_class=$2) — '' reproduces the #1531
time-only behaviour exactly (used by mixes). SessionVector.DeviceClass
carries it; the radio handler derives the current device from the user's
latest play (GetLatestPlayDeviceClassForUser) — request-free proxy.
- No new tuning knob: device narrows the existing ContextAffinityScore
(reuses context_time_weight).
Clients:
- web: play_started sends device_class 'web'.
- android: play_started + offline replay send 'mobile' (EventsWire +
PlayOfflinePayload + MutationReplayer + PlayEventsReporter).
Test: LoadContextAffinity device-narrowing integration test (mobile vs web
artist separation; device-agnostic parity).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Two carry-overs from M3 verification, bundled with the search-input
fix already on dev (b7a59a9).
1. Genre splitting in BuildSessionVector
The library has many tracks whose genre tag is a denormalized
multi-genre string ("Indie Pop; Pop; Alternative Pop"). Reading them
as one opaque tag means a single-genre "Pop" track and a multi-genre
track listing Pop both fail to share the Pop key, so the tags axis
in similarity scoring (weight 0.7!) returned 0 in nearly all cases
on real libraries. Result: contextual scoring couldn't differentiate.
Add splitGenres() that splits on ; and , and trims whitespace;
strings without a delimiter come back as a single-element slice
(so the existing single-genre cases keep working unchanged).
Concatenated-without-separator output ("ElectronicComplextroGlitch
Hop") stays opaque — that needs a genre dictionary, out of scope.
2. Play-radio button on TrackRow
playRadio() was only wired to the click handler on /search and
/search/tracks, leaving /library/liked, album pages, and search
results' inner clicks with no way to start a radio. Adds a small
radio button to TrackRow (between LikeButton and the +queue button).
Click → playRadio(track.id), with stopPropagation so the row's own
activate handler doesn't also fire.
Tests:
- 3 new sessionvector tests: TestSplitGenres, multi-genre semicolon
split, no-separator stays opaque. Existing single-genre tests pass
unchanged.
- 1 new TrackRow test: radio button calls playRadio with track id and
does NOT trigger row play.
Verified locally: go -short -race ./... clean, golangci-lint clean,
svelte-check 0/0, 175 vitest tests (was 174), web build succeeds.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Pure aggregation per spec §6: Seed flag (true when prior < 3),
deduplicated Artists ordered by first appearance, Tags bag-of-counts
from tracks.genre (empty genres skipped), RecentTrackIDs preserving
input order. JSON round-trip verified.
bvandeusen