refactor: graceful shutdown for server (#482)

backend/internal/job/scheduler.go

@@ -0,0 +1,64 @@
+package job
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"github.com/go-co-op/gocron/v2"
+	"github.com/google/uuid"
+)
+
+type Scheduler struct {
+	scheduler gocron.Scheduler
+}
+
+func NewScheduler() (*Scheduler, error) {
+	scheduler, err := gocron.NewScheduler()
+	if err != nil {
+		return nil, fmt.Errorf("failed to create a new scheduler: %w", err)
+	}
+
+	return &Scheduler{
+		scheduler: scheduler,
+	}, nil
+}
+
+// Run the scheduler.
+// This function blocks until the context is canceled.
+func (s *Scheduler) Run(ctx context.Context) {
+	log.Println("Starting job scheduler")
+	s.scheduler.Start()
+
+	// Block until context is canceled
+	<-ctx.Done()
+
+	err := s.scheduler.Shutdown()
+	if err != nil {
+		log.Printf("[WARN] Error shutting down job scheduler: %v", err)
+	} else {
+		log.Println("Job scheduler shut down")
+	}
+}
+
+func (s *Scheduler) registerJob(ctx context.Context, name string, interval string, job func(ctx context.Context) error) error {
+	_, err := s.scheduler.NewJob(
+		gocron.CronJob(interval, false),
+		gocron.NewTask(job),
+		gocron.WithContext(ctx),
+		gocron.WithEventListeners(
+			gocron.AfterJobRuns(func(jobID uuid.UUID, jobName string) {
+				log.Printf("Job %q run successfully", name)
+			}),
+			gocron.AfterJobRunsWithError(func(jobID uuid.UUID, jobName string, err error) {
+				log.Printf("Job %q failed with error: %v", name, err)
+			}),
+		),
+	)
+
+	if err != nil {
+		return fmt.Errorf("failed to register job %q: %w", name, err)
+	}
+
+	return nil
+}