init post-service

services/post-service/internal/kafka/consumers/user.go

@@ -0,0 +1,75 @@
+package consumers
+
+import (
+	"context"
+
+	"github.com/rs/zerolog/log"
+	"github.com/segmentio/kafka-go"
+	"google.golang.org/protobuf/proto"
+
+	"github.com/hexolan/panels/post-service/internal"
+	"github.com/hexolan/panels/post-service/internal/kafka/producer"
+	"github.com/hexolan/panels/post-service/internal/kafka/consumers/userv1"
+)
+
+type UserEventConsumer struct {
+	reader *kafka.Reader
+
+	dbRepo internal.PostDBRepository
+	eventProd producer.PostEventProducer
+}
+
+func NewUserEventConsumer(cfg internal.Config, dbRepo internal.PostDBRepository, eventProd producer.PostEventProducer) UserEventConsumer {
+	return UserEventConsumer{
+		reader: kafka.NewReader(kafka.ReaderConfig{
+			Brokers: cfg.KafkaBrokers,
+			GroupID: "post-service",
+			Topic: "user",
+		}),
+		dbRepo: dbRepo,
+	}
+}
+
+func (ec UserEventConsumer) ProcessEvent(evt *userv1.UserEvent) {
+	if evt.GetData() == nil {
+		log.Error().Str("src", "user-event-consumer").Any("event", evt).Msg("no event data provided")
+		return
+	}
+
+	if evt.Type == "deleted" {
+		postIds, err := ec.dbRepo.DeletePostsByUser(context.Background(), evt.GetData().GetId())
+		if err == nil {
+			for _, postId := range postIds {
+				ec.eventProd.DispatchDeletedEvent(postId)
+			}
+		}
+		log.Debug().Str("src", "user-event-consumer").Any("event", evt).Msg("processed user deleted event")
+	}
+}
+
+func (ec UserEventConsumer) ProcessMessage(msg kafka.Message) {
+	var evt userv1.UserEvent
+	err := proto.Unmarshal(msg.Value, &evt)
+	if err != nil {
+		log.Error().Err(err).Str("src", "user-event-consumer").Msg("failed to unmarshal event")
+		return
+	}
+
+	ec.ProcessEvent(&evt)
+}
+
+func (ec UserEventConsumer) Start() {
+	for {
+		msg, err := ec.reader.FetchMessage(context.Background())
+		if err != nil {
+			log.Error().Err(err).Str("src", "user-event-consumer").Msg("failed to fetch msg from Kafka")
+			break
+		}
+		ec.ProcessMessage(msg)
+	}
+
+	// Attempt to close the reader connection (after experiencing a Kafka error)
+	if err := ec.reader.Close(); err != nil {
+		log.Panic().Err(err).Str("src", "user-event-consumer").Msg("failed to close Kafka reader")
+	}
+}