feat: add jikan cache cleanup worker

internal/database/jikan_cache_cleanup.go

@@ -0,0 +1,72 @@
+package database
+
+import (
+	"context"
+	"mal/internal/db"
+	"mal/internal/observability"
+	"time"
+
+	"go.uber.org/fx"
+)
+
+const (
+	jikanCacheCleanupInterval = time.Hour
+	jikanCacheCleanupTimeout  = 30 * time.Second
+	jikanCacheCleanupWorker   = "jikan_cache_cleanup"
+)
+
+func RegisterJikanCacheCleanupWorker(lc fx.Lifecycle, queries *db.Queries, metrics *observability.Metrics) {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	lc.Append(fx.Hook{
+		OnStart: func(startCtx context.Context) error {
+			go func() {
+				<-startCtx.Done()
+				cancel()
+			}()
+			go runJikanCacheCleanupWorker(ctx, queries, metrics)
+			return nil
+		},
+		OnStop: func(context.Context) error {
+			cancel()
+			return nil
+		},
+	})
+}
+
+func runJikanCacheCleanupWorker(ctx context.Context, queries *db.Queries, metrics *observability.Metrics) {
+	observability.Info("jikan_cache_cleanup_worker_start", "database", "", nil)
+
+	ticker := time.NewTicker(jikanCacheCleanupInterval)
+	defer ticker.Stop()
+
+	for {
+		cleanupExpiredJikanCache(ctx, queries, metrics)
+
+		select {
+		case <-ticker.C:
+		case <-ctx.Done():
+			observability.Info("jikan_cache_cleanup_worker_stop", "database", "", nil)
+			return
+		}
+	}
+}
+
+func cleanupExpiredJikanCache(ctx context.Context, queries *db.Queries, metrics *observability.Metrics) {
+	cleanupCtx, cancel := context.WithTimeout(ctx, jikanCacheCleanupTimeout)
+	defer cancel()
+
+	err := queries.DeleteExpiredJikanCache(cleanupCtx)
+	metrics.ObserveWorkerTick(jikanCacheCleanupWorker, err)
+	if err != nil {
+		observability.Warn(
+			"jikan_cache_cleanup_failed",
+			"database",
+			"",
+			map[string]any{
+				"worker": jikanCacheCleanupWorker,
+			},
+			err,
+		)
+	}
+}