Files
minstrel/internal/recommendation/candidates.go
T
bvandeusen 5b79aa1047 feat(recommendation): LoadCandidates computes per-candidate ContextualMatchScore
Adds a 6th argument (currentVector SessionVector) to LoadCandidates,
bulk-fetches the user's active contextual_likes in one query, and sets
ContextualMatchScore on each candidate's ScoringInputs via max-similarity
over that candidate's like vectors. Adds helper + 6 integration tests
covering no-likes, single match, multi-like max, soft-delete filtering,
seed-like filtering, and seed-current short-circuit. Adds contextual_likes
to the TRUNCATE list in testPool to prevent cross-test leakage.

internal/api/radio.go is intentionally left broken (Task 6 fixes it).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-27 20:41:55 -04:00

84 lines
2.2 KiB
Go

package recommendation
import (
"context"
"encoding/json"
"time"
"github.com/jackc/pgx/v5/pgtype"
"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
)
// LoadCandidates fetches the candidate pool for radio scoring. Combines
// the existing track+stats query with a one-shot bulk fetch of the user's
// active contextual_likes, mapping each candidate to its max similarity
// against currentVector. Pass currentVector with Seed=true to short-circuit
// the contextual term to 0 (cold-start path).
func LoadCandidates(
ctx context.Context,
q *dbq.Queries,
userID, seedID pgtype.UUID,
recentlyPlayedHours int,
currentVector SessionVector,
) ([]Candidate, error) {
rows, err := q.LoadRadioCandidates(ctx, dbq.LoadRadioCandidatesParams{
UserID: userID,
ID: seedID,
Column3: float64(recentlyPlayedHours),
})
if err != nil {
return nil, err
}
likes, err := loadContextualLikesByTrack(ctx, q, userID)
if err != nil {
return nil, err
}
out := make([]Candidate, 0, len(rows))
for _, r := range rows {
var lpt *time.Time
if r.LastPlayedAt.Valid {
t := r.LastPlayedAt.Time
lpt = &t
}
ctxScore := ContextualMatchScore(currentVector, likes[r.Track.ID], DefaultSimilarityWeights)
out = append(out, Candidate{
Track: r.Track,
Inputs: ScoringInputs{
IsGeneralLiked: r.IsLiked,
LastPlayedAt: lpt,
PlayCount: int(r.PlayCount),
SkipCount: int(r.SkipCount),
ContextualMatchScore: ctxScore,
},
})
}
return out, nil
}
// loadContextualLikesByTrack fetches the user's active contextual_likes in
// one query and groups them by track_id. Rows whose session_vector fails
// to unmarshal are skipped with no error (don't poison scoring over one
// bad row); the SQL query already filters NULL vectors.
func loadContextualLikesByTrack(
ctx context.Context,
q *dbq.Queries,
userID pgtype.UUID,
) (map[pgtype.UUID][]SessionVector, error) {
rows, err := q.ListActiveContextualLikesForUser(ctx, userID)
if err != nil {
return nil, err
}
out := make(map[pgtype.UUID][]SessionVector, len(rows))
for _, r := range rows {
var v SessionVector
if err := json.Unmarshal(r.SessionVector, &v); err != nil {
continue
}
out[r.TrackID] = append(out[r.TrackID], v)
}
return out, nil
}