GH-120: [Go][Service] separate metadata handling functions for entity creation and update

nexoan/crud-api/cmd/server/service.go

@@ -36,7 +36,7 @@ func (s *Server) CreateEntity(ctx context.Context, req *pb.Entity) (*pb.Entity,
 	// Always save the entity in MongoDB, even if it has no metadata
 	// The HandleMetadata function will only process it if it has metadata
 	// FIXME: https://github.com/LDFLK/nexoan/issues/120
-	err := s.mongoRepo.HandleMetadata(ctx, req.Id, req)
+	err := s.mongoRepo.HandleMetadataCreation(ctx, req.Id, req)
 	if err != nil {
 		log.Printf("[server.CreateEntity] Error saving metadata in MongoDB: %v", err)
 		return nil, err
@@ -241,7 +241,7 @@ func (s *Server) UpdateEntity(ctx context.Context, req *pb.UpdateEntityRequest)
 	var metadata map[string]*anypb.Any
 
 	// Pass the ID and metadata to HandleMetadata
-	err := s.mongoRepo.HandleMetadata(ctx, updateEntityID, updateEntity)
+	err := s.mongoRepo.HandleMetadataUpdate(ctx, updateEntityID, updateEntity)
 	if err != nil {
 		// Log error and continue with empty metadata
 		log.Printf("[server.UpdateEntity] Error updating metadata for entity %s: %v", updateEntityID, err)

nexoan/crud-api/db/repository/mongo/metadata_handler.go

@@ -12,39 +12,49 @@ import (
 	"go.mongodb.org/mongo-driver/mongo"
 )
 
-// Add this function to handle metadata operations
-func (repo *MongoRepository) HandleMetadata(ctx context.Context, entityId string, entity *pb.Entity) error {
-	// Skip operations if no metadata is provided
+// CreateMetadata creates a new entity with metadata if it doesn't exist.
+func (repo *MongoRepository) HandleMetadataCreation(ctx context.Context, entityId string, entity *pb.Entity) error {
 	if entity == nil || entity.GetMetadata() == nil || len(entity.GetMetadata()) == 0 {
 		return nil
 	}
 
-	// Check if entity exists
 	existingEntity, err := repo.ReadEntity(ctx, entityId)
 	if err != nil && err != mongo.ErrNoDocuments {
 		return err
 	}
+	if existingEntity != nil {
+		return mongo.ErrNoDocuments
+	}
+
+	newEntity := &pb.Entity{
+		Id:            entityId,
+		Metadata:      entity.GetMetadata(),
+		Kind:          entity.Kind,
+		Created:       entity.Created,
+		Terminated:    entity.Terminated,
+		Name:          entity.Name,
+		Attributes:    entity.Attributes,
+		Relationships: entity.Relationships,
+	}
+	_, err = repo.CreateEntity(ctx, newEntity)
+	return err
+}
+
+// UpdateMetadata updates metadata for an existing entity.
+func (repo *MongoRepository) HandleMetadataUpdate(ctx context.Context, entityId string, entity *pb.Entity) error {
+	if len(entity.GetMetadata()) == 0 {
+		return nil
+	}
 
+	existingEntity, err := repo.ReadEntity(ctx, entityId)
+	if err != nil {
+		return err
+	}
 	if existingEntity == nil {
-		// Create new entity with all fields including metadata
-		newEntity := &pb.Entity{
-			Id:            entityId,
-			Metadata:      entity.GetMetadata(),
-			Kind:          entity.Kind,
-			Created:       entity.Created,
-			Terminated:    entity.Terminated,
-			Name:          entity.Name,
-			Attributes:    entity.Attributes,
-			Relationships: entity.Relationships,
-		}
-		_, err = repo.CreateEntity(ctx, newEntity)
-	} else {
-		// Update existing entity's metadata
-		// TODO: Should we choose _id for placing our id or should we use id field separately and use that.
-		// Because then it is going to be reading or deleting or whatever by filtering using an attribute not the id of the object.
-		_, err = repo.UpdateEntity(ctx, existingEntity.Id, bson.M{"metadata": entity.GetMetadata()})
+		return mongo.ErrNoDocuments
 	}
 
+	_, err = repo.UpdateEntity(ctx, entityId, bson.M{"metadata": entity.GetMetadata()})
 	return err
 }