[hw-6] add notifier service, kafka

loms/internal/infra/messaging/kafka_outbox/dispatcher.go

@@ -0,0 +1,54 @@
+package kafkaoutbox
+
+import (
+	"context"
+	"time"
+
+	"route256/loms/internal/domain/entity"
+	"route256/loms/internal/domain/repository/outbox"
+
+	"github.com/rs/zerolog/log"
+)
+
+type producer interface {
+	SendRaw(ctx context.Context, id entity.ID, value []byte) error
+}
+
+type outboxRepo interface {
+	WithNewEvents(ctx context.Context, limit int, h func(c context.Context, e outbox.Event) error) error
+}
+
+type Dispatcher struct {
+	repo     outboxRepo
+	producer producer
+	limit    int
+	interval time.Duration
+}
+
+func NewDispatcher(repo outboxRepo, producer producer, batch int, pollEvery time.Duration) *Dispatcher {
+	return &Dispatcher{
+		repo:     repo,
+		producer: producer,
+		limit:    batch,
+		interval: pollEvery,
+	}
+}
+
+func (d *Dispatcher) Run(ctx context.Context) {
+	t := time.NewTicker(d.interval)
+	defer t.Stop()
+
+	for {
+		if err := d.repo.WithNewEvents(ctx, d.limit, func(c context.Context, e outbox.Event) error {
+			return d.producer.SendRaw(c, e.OrderID, e.Payload)
+		}); err != nil {
+			log.Error().Err(err).Msg("d.repo.WithNewEvents")
+		}
+
+		select {
+		case <-ctx.Done():
+			return
+		case <-t.C:
+		}
+	}
+}