unified gateway interface

api/pkg/messaging/consumer/consumer.go

@@ -0,0 +1,66 @@
+package consumer
+
+import (
+	"context"
+
+	messaging "github.com/tech/sendico/pkg/messaging"
+	mb "github.com/tech/sendico/pkg/messaging/broker"
+	me "github.com/tech/sendico/pkg/messaging/envelope"
+	"github.com/tech/sendico/pkg/mlogger"
+	"github.com/tech/sendico/pkg/model"
+	"go.uber.org/zap"
+)
+
+type ChannelConsumer struct {
+	logger mlogger.Logger
+	broker mb.Broker
+	event  model.NotificationEvent
+	ch     <-chan me.Envelope
+	ctx    context.Context
+	cancel context.CancelFunc
+}
+
+func (c *ChannelConsumer) ConsumeMessages(handleFunc messaging.MessageHandlerT) error {
+	c.logger.Info("Message consumer is ready")
+	for {
+		select {
+		case msg := <-c.ch:
+			if msg == nil { // nil message indicates the channel was closed
+				c.logger.Info("Consumer shutting down")
+				return nil
+			}
+			if err := handleFunc(c.ctx, msg); err != nil {
+				c.logger.Warn("Error processing message", zap.Error(err))
+			}
+		case <-c.ctx.Done():
+			c.logger.Info("Context done, shutting down")
+			return c.ctx.Err()
+		}
+	}
+}
+
+func (c *ChannelConsumer) Close() {
+	c.logger.Info("Shutting down...")
+	c.cancel()
+	if err := c.broker.Unsubscribe(c.event, c.ch); err != nil {
+		c.logger.Warn("Failed to unsubscribe", zap.Error(err))
+	}
+}
+
+func NewConsumer(logger mlogger.Logger, broker mb.Broker, event model.NotificationEvent) (*ChannelConsumer, error) {
+	ctx, cancel := context.WithCancel(context.Background())
+	ch, err := broker.Subscribe(event)
+	if err != nil {
+		logger.Warn("Failed to create channel consumer", zap.Error(err), zap.String("topic", event.ToString()))
+		cancel()
+		return nil, err
+	}
+	return &ChannelConsumer{
+		logger: logger.Named("consumer").Named(event.ToString()),
+		broker: broker,
+		event:  event,
+		ch:     ch,
+		ctx:    ctx,
+		cancel: cancel,
+	}, nil
+}