Add local navigation API

internal/store/counts.go

@@ -0,0 +1,50 @@
+package store
+
+import "database/sql"
+
+// SessionDatasetCounts holds row counts for session-scoped datasets.
+type SessionDatasetCounts struct {
+	Drivers      int
+	Results      int
+	StartingGrid int
+	Stints       int
+	PitStops     int
+	Positions    int
+	RaceControl  int
+	Weather      int
+	Laps         int
+}
+
+// CountSessionDatasets returns row counts for ingested session datasets.
+func (s *Store) CountSessionDatasets(sessionKey int) (SessionDatasetCounts, error) {
+	var c SessionDatasetCounts
+	err := s.db.QueryRow(`
+		SELECT
+			(SELECT COUNT(*) FROM session_drivers WHERE session_key = ?),
+			(SELECT COUNT(*) FROM session_results WHERE session_key = ?),
+			(SELECT COUNT(*) FROM starting_grid WHERE session_key = ?),
+			(SELECT COUNT(*) FROM stints WHERE session_key = ?),
+			(SELECT COUNT(*) FROM pit_stops WHERE session_key = ?),
+			(SELECT COUNT(*) FROM positions WHERE session_key = ?),
+			(SELECT COUNT(*) FROM race_control WHERE session_key = ?),
+			(SELECT COUNT(*) FROM weather WHERE session_key = ?),
+			(SELECT COUNT(*) FROM laps WHERE session_key = ?)
+	`,
+		sessionKey, sessionKey, sessionKey, sessionKey, sessionKey,
+		sessionKey, sessionKey, sessionKey, sessionKey,
+	).Scan(
+		&c.Drivers,
+		&c.Results,
+		&c.StartingGrid,
+		&c.Stints,
+		&c.PitStops,
+		&c.Positions,
+		&c.RaceControl,
+		&c.Weather,
+		&c.Laps,
+	)
+	if err == sql.ErrNoRows {
+		return SessionDatasetCounts{}, nil
+	}
+	return c, err
+}

internal/store/meetings.go

@@ -100,6 +100,30 @@ func (s *Store) GetMeeting(meetingKey int) (Meeting, error) {
 	return m, nil
 }
 
+// ListYears returns distinct meeting years ordered newest first.
+func (s *Store) ListYears() ([]int, error) {
+	rows, err := s.db.Query(`
+		SELECT DISTINCT year
+		FROM meetings
+		WHERE year > 0
+		ORDER BY year DESC
+	`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var years []int
+	for rows.Next() {
+		var year int
+		if err := rows.Scan(&year); err != nil {
+			return nil, err
+		}
+		years = append(years, year)
+	}
+	return years, rows.Err()
+}
+
 // ListMeetingsByYear returns meetings for a season ordered by start date.
 func (s *Store) ListMeetingsByYear(year int) ([]Meeting, error) {
 	rows, err := s.db.Query(`

internal/store/store_test.go

@@ -319,6 +319,25 @@ func TestMeetingSessionDriverUpsertsAreIdempotent(t *testing.T) {
 		t.Fatalf("ListSessionsByMeeting() len = %d, want 1", len(sessions))
 	}
 
+	years, err := s.ListYears()
+	if err != nil {
+		t.Fatalf("ListYears() error = %v", err)
+	}
+	if len(years) != 1 || years[0] != 2025 {
+		t.Fatalf("ListYears() = %v, want [2025]", years)
+	}
+
+	counts, err := s.CountSessionDatasets(session.SessionKey)
+	if err != nil {
+		t.Fatalf("CountSessionDatasets() error = %v", err)
+	}
+	if counts.Drivers != 1 {
+		t.Fatalf("CountSessionDatasets().Drivers = %d, want 1", counts.Drivers)
+	}
+	if counts.Results != 0 {
+		t.Fatalf("CountSessionDatasets().Results = %d, want 0", counts.Results)
+	}
+
 	sessionDrivers, err := s.ListSessionDrivers(session.SessionKey)
 	if err != nil {
 		t.Fatalf("ListSessionDrivers() error = %v", err)