implement trending system initialization and background updates

relay/main.go

@@ -48,6 +48,10 @@ func main() {
 		panic(err)
 	}
 
+	// Initialize trending system to start background calculations
+	fmt.Println("Initializing trending system...")
+	trending.Initialize(db.DB.DB)
+
 	relay.StoreEvent = append(relay.StoreEvent, db.SaveEvent)
 	relay.QueryEvents = append(relay.QueryEvents, db.QueryEvents)
 	relay.DeleteEvent = append(relay.DeleteEvent, db.DeleteEvent)

relay/trending/kinds.go

@@ -3,6 +3,7 @@ package trending
 import (
 	"database/sql"
 	"encoding/json"
+	"fmt"
 	"time"
 
 	"git.highperfocused.tech/highperfocused/lumina-relay/relay/cache"
@@ -20,15 +21,47 @@ type Post struct {
 
 var (
 	trendingCache  = cache.New()
-	cacheDuration = 5 * time.Minute
+	cacheDuration  = 35 * time.Minute // Slightly longer than update interval
+	updateInterval = 30 * time.Minute
 )
 
+// Initialize sets up the background updating of trending calculations
+// This should be called once at application startup
+func Initialize(db *sql.DB) {
+	// Perform initial calculation
+	if _, err := calculateTrendingKind20(db); err != nil {
+		fmt.Printf("Error in initial trending calculation: %v\n", err)
+	}
+
+	// Set up periodic updates
+	go func() {
+		ticker := time.NewTicker(updateInterval)
+		defer ticker.Stop()
+
+		for range ticker.C {
+			if _, err := calculateTrendingKind20(db); err != nil {
+				fmt.Printf("Error updating trending data: %v\n", err)
+			} else {
+				fmt.Printf("Successfully updated trending data at %s\n", time.Now().Format(time.RFC3339))
+			}
+		}
+	}()
+}
+
 // GetTrendingKind20 returns the top 20 trending posts of kind 20 from the last 24 hours
+// It returns cached results that are updated periodically in the background
 func GetTrendingKind20(db *sql.DB) ([]Post, error) {
 	if cached, ok := trendingCache.Get("trending_kind_20"); ok {
 		return cached.([]Post), nil
 	}
 
+	// If cache is empty (which shouldn't happen with background updates),
+	// calculate on demand
+	return calculateTrendingKind20(db)
+}
+
+// calculateTrendingKind20 performs the actual calculation and updates the cache
+func calculateTrendingKind20(db *sql.DB) ([]Post, error) {
 	query := `
 		WITH reactions AS (
 			SELECT