/// <summary>
/// Handler for message sending.
/// Persists message in database and then sends it through the hub to listeners
/// </summary>
/// <param name="message"></param>
public async Task SendMessage(MessageViewModel message)
{
var createRequest = _mapper.Map <MessageViewModel, CreateChatMessageRequest>(message);
await _mediator.Send(createRequest);
var sender = AllConnectedParticipants.FirstOrDefault(x => x.Key == message.FromId);
if (sender.Value != null)
{
// get fresh presigned url for display
message.DownloadUrl = await _s3AccessService.RenewPresignedUrl(message.DownloadUrl, message.S3Filename);
// send message
await Clients.User(message.ToId).SendAsync("messageReceived", sender.Value.Participant, message);
}
}