Streams (#47)

* Streams Service (WIP)

* Complete Streams Service

streams/handler/list_conversations.go

@@ -0,0 +1,31 @@
+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"
+)
+
+// List all the conversations for a group
+func (s *Streams) ListConversations(ctx context.Context, req *pb.ListConversationsRequest, rsp *pb.ListConversationsResponse) error {
+	// validate the request
+	if len(req.GroupId) == 0 {
+		return ErrMissingGroupID
+	}
+
+	// query the database
+	var convs []Conversation
+	if err := s.DB.Where(&Conversation{GroupID: req.GroupId}).Find(&convs).Error; err != nil {
+		logger.Errorf("Error reading conversation: %v", err)
+		return errors.InternalServerError("DATABASE_ERROR", "Error connecting to database")
+	}
+
+	// serialize the response
+	rsp.Conversations = make([]*pb.Conversation, len(convs))
+	for i, c := range convs {
+		rsp.Conversations[i] = c.Serialize()
+	}
+	return nil
+}