Streams (#47)

* Streams Service (WIP)

* Complete Streams Service

streams/handler/update_conversation.go

@@ -0,0 +1,41 @@
+package handler
+
+import (
+	"context"
+
+	"github.com/micro/micro/v3/service/errors"
+	"github.com/micro/micro/v3/service/logger"
+	pb "github.com/micro/services/streams/proto"
+	"gorm.io/gorm"
+)
+
+// Update a conversations topic
+func (s *Streams) UpdateConversation(ctx context.Context, req *pb.UpdateConversationRequest, rsp *pb.UpdateConversationResponse) error {
+	// validate the request
+	if len(req.Id) == 0 {
+		return ErrMissingID
+	}
+	if len(req.Topic) == 0 {
+		return ErrMissingTopic
+	}
+
+	// lookup the conversation
+	var conv Conversation
+	if err := s.DB.Where(&Conversation{ID: req.Id}).First(&conv).Error; err == gorm.ErrRecordNotFound {
+		return ErrNotFound
+	} else if err != nil {
+		logger.Errorf("Error reading conversation: %v", err)
+		return errors.InternalServerError("DATABASE_ERROR", "Error connecting to database")
+	}
+
+	// update the conversation
+	conv.Topic = req.Topic
+	if err := s.DB.Save(&conv).Error; err != nil {
+		logger.Errorf("Error updating conversation: %v", err)
+		return errors.InternalServerError("DATABASE_ERROR", "Error connecting to database")
+	}
+
+	// serialize the result
+	rsp.Conversation = conv.Serialize()
+	return nil
+}