Streams (#47)

* Streams Service (WIP)

* Complete Streams Service

streams/handler/read_conversation.go

@@ -0,0 +1,38 @@
+package handler
+
+import (
+	"context"
+
+	"gorm.io/gorm"
+
+	"github.com/micro/micro/v3/service/errors"
+	"github.com/micro/micro/v3/service/logger"
+	pb "github.com/micro/services/streams/proto"
+)
+
+// Read a conversation using its ID, can filter using group ID if provided
+func (s *Streams) ReadConversation(ctx context.Context, req *pb.ReadConversationRequest, rsp *pb.ReadConversationResponse) error {
+	// validate the request
+	if len(req.Id) == 0 {
+		return ErrMissingID
+	}
+
+	// construct the query
+	q := Conversation{ID: req.Id}
+	if req.GroupId != nil {
+		q.GroupID = req.GroupId.Value
+	}
+
+	// execute the query
+	var conv Conversation
+	if err := s.DB.Where(&q).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")
+	}
+
+	// serialize the response
+	rsp.Conversation = conv.Serialize()
+	return nil
+}