Big changes

server/internal/store/analytics.go

@@ -2,12 +2,51 @@ package store
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"time"
 
 	"github.com/jackc/pgx/v5"
 )
 
+// BrowsingCandidates returns library items the user actively focused or selected,
+// strongest first. Impressions are intentionally excluded: merely scrolling past a row
+// is not evidence of taste.
+func (s *Store) BrowsingCandidates(
+	ctx context.Context,
+	userID string,
+	since time.Time,
+	limit int,
+) ([]json.RawMessage, error) {
+	rows, err := s.pool.Query(ctx, `
+		SELECT li.payload
+		FROM row_events re
+		JOIN library_items li ON li.id = re.item_id
+		WHERE re.emby_user_id = $1
+		  AND re.occurred_at >= $2
+		  AND re.event IN ('focus', 'select')
+		GROUP BY li.id, li.payload
+		ORDER BY
+			count(*) FILTER (WHERE re.event = 'select') * 20 +
+			count(*) FILTER (WHERE re.event = 'focus') * 2 +
+			coalesce(sum(re.dwell_ms), 0) / 10000 DESC,
+			max(re.occurred_at) DESC
+		LIMIT $3`, userID, since, limit)
+	if err != nil {
+		return nil, fmt.Errorf("store: browsing candidates: %w", err)
+	}
+	defer rows.Close()
+	out := []json.RawMessage{}
+	for rows.Next() {
+		var payload []byte
+		if err := rows.Scan(&payload); err != nil {
+			return nil, err
+		}
+		out = append(out, json.RawMessage(payload))
+	}
+	return out, rows.Err()
+}
+
 // RowEvent is one reported interaction with a home-screen row.
 type RowEvent struct {
 	OccurredAt time.Time