Implement notifications service with shared messaging and email drivers (#36)

backend/shared/messaging/internal/natscap/adapter.go

@@ -0,0 +1,114 @@
+package natscap
+
+import (
+	"context"
+	"strings"
+
+	"git.sendico.io/tech/sxchnge/shared/messaging/capability"
+	basenats "git.sendico.io/tech/sxchnge/shared/messaging/internal/natsb"
+	"git.sendico.io/tech/sxchnge/shared/messaging/reliable"
+	"github.com/nats-io/nats.go"
+)
+
+type DurableAdapter struct {
+	broker *basenats.NatsBroker
+}
+
+type durableAdminContext interface {
+	AddStream(cfg *nats.StreamConfig, opts ...nats.JSOpt) (*nats.StreamInfo, error)
+	UpdateStream(cfg *nats.StreamConfig, opts ...nats.JSOpt) (*nats.StreamInfo, error)
+	StreamInfo(stream string, opts ...nats.JSOpt) (*nats.StreamInfo, error)
+	AddConsumer(stream string, cfg *nats.ConsumerConfig, opts ...nats.JSOpt) (*nats.ConsumerInfo, error)
+	UpdateConsumer(stream string, cfg *nats.ConsumerConfig, opts ...nats.JSOpt) (*nats.ConsumerInfo, error)
+	ConsumerInfo(stream, consumer string, opts ...nats.JSOpt) (*nats.ConsumerInfo, error)
+}
+
+func NewDurableAdapter(broker *basenats.NatsBroker) *DurableAdapter {
+	if broker == nil || broker.JetStream() == nil {
+		return nil
+	}
+	return &DurableAdapter{broker: broker}
+}
+
+func (a *DurableAdapter) Publish(ctx context.Context, record reliable.Record) error {
+	if err := reliable.ValidatePublicRecord(record); err != nil {
+		return err
+	}
+	normalized, err := reliable.NormalizePublicRecord(record)
+	if err != nil {
+		return err
+	}
+	return a.publishRecord(ctx, normalized)
+}
+
+func (a *DurableAdapter) PublishRuntime(ctx context.Context, record reliable.Record) error {
+	normalized, err := reliable.NormalizeRuntimeRecord(record)
+	if err != nil {
+		return err
+	}
+	return a.publishRecord(ctx, normalized)
+}
+
+func (a *DurableAdapter) publishRecord(ctx context.Context, record reliable.Record) error {
+	js := a.jetStream()
+	if js == nil {
+		return capability.Unavailable("durable transport")
+	}
+	msg := &nats.Msg{
+		Subject: strings.TrimSpace(record.Subject),
+		Data:    append([]byte(nil), record.Payload...),
+		Header:  nats.Header{},
+	}
+	for key, values := range record.Headers {
+		for _, value := range values {
+			msg.Header.Add(key, value)
+		}
+	}
+	if record.MessageID != "" {
+		msg.Header.Set(nats.MsgIdHdr, record.MessageID)
+	}
+	_, err := js.PublishMsg(msg, nats.Context(ctx))
+	return err
+}
+
+func (a *DurableAdapter) OpenConsumer(ctx context.Context, settings reliable.DurableSettings, consumer reliable.DurableConsumerSettings) (reliable.Subscription, error) {
+	js := a.jetStream()
+	if js == nil {
+		return nil, capability.Unavailable("durable transport")
+	}
+	sub, err := js.PullSubscribe(
+		consumer.Subject,
+		consumer.Durable,
+		nats.Bind(settings.Stream.Name, consumer.Durable),
+		nats.Context(ctx),
+	)
+	if err != nil {
+		return nil, err
+	}
+	return &natsSubscription{sub: sub}, nil
+}
+
+func (a *DurableAdapter) EnsureProducerResources(_ context.Context, settings reliable.DurableSettings) error {
+	if a == nil || a.broker == nil {
+		return capability.Unavailable("durable admin")
+	}
+	return ensureDurableStream(a.broker.Logger(), a.jetStream(), settings)
+}
+
+func (a *DurableAdapter) EnsureConsumerResources(_ context.Context, settings reliable.DurableSettings, consumer reliable.DurableConsumerSettings) error {
+	if a == nil || a.broker == nil {
+		return capability.Unavailable("durable admin")
+	}
+	js := a.jetStream()
+	if err := ensureDurableStream(a.broker.Logger(), js, settings); err != nil {
+		return err
+	}
+	return ensureDurableConsumerConfig(a.broker.Logger(), js, settings, consumer)
+}
+
+func (a *DurableAdapter) jetStream() nats.JetStreamContext {
+	if a == nil || a.broker == nil {
+		return nil
+	}
+	return a.broker.JetStream()
+}