public string ProcessMessage(ChatMessage message)
        {
            if (message == null)
            {
                return(string.Empty);
            }

            chatsService.CreateChat(message.Chat);
            chatsService.CreateUser(message.Author);
            chatsService.AddUserToChat(message.Chat.Id, message.Author.Id);

            var commandType = MessageParser.GetCommandTypeFromMessage(message);

            if (commandType == CommandType.NotCommand)
            {
                return(string.Empty);
            }

            var command = CreateCommand(commandType, message);

            return(command.Execute());
        }